University of Alberta Librai 0 1620 3416715 3 For Reference NOT TO BE TAKEN FROM THIS ROOM STUDIES ON THE GENUS AGR0PYR0N Prank Herbert Pete Department of Field Crops University of Alberta Edmonton, Alberta, April, 1930. (3x UBBIS aw'diEsrejais STUDIES ON THE GENUS AGROPYRON. CSlS O 2> Frank Herbert Peto Department of Field Crops A THESIS submitted to the University of Alberta in partial fulfilment of the requirements for the degree of MASTER OF SCIENCE. Edmonton, Alberta. April, 1930. c TABLE OF CONTENTS. Page. INTRODUCTION . 1 PART I. DISTRIBUTION AND MORPHOLOGICAL VARIABILITY. Collection and propagation of material . 3 Distribution of the Agropyrons. General distribution . 5 Distribution in Alberta . 6 Morphological variability. Literature review . 9 Observations . 10 Discussion . 14 PART II. CYTGLOGICAL STUDIES. Literature review . . 18 Material . 19 Methods . Pollen-mother-cell preparations . 20 Root-tip preparations . 23 Formulas for reagents . 24 Cytology of species . 26 Discussion Polyploidy . 32 Cytological evidence of natural hybridization. 33 GENERAL CONCLUSIONS . 40 SUMMARY . 42 LITERATURE CITED . 44 . . . . . ...... . . . o T Oi.f:-OHTKI ; . ' ' . : : ' ' - r: . . . . . ' . a n o Tv j o t • v erl $ J. o a c - J: o u o i t & q i (I . . . . . ........... J T oo- " VJ . . . . . . . . . tv-. . o ; , i. .. . J: : ■ :: /. j j • • . ,ol - o . . . . . •. . . oo: j . . . . , . ; . . . Bi . . . .......... . ' . : . . 'V . . :: iv • , . ........... . . , . . . • t: o . . , . . . . . , 3i) JJ-'Tv, ; ...... : j . '• v,o; • .. :' . . . . . . • STOii; -■•r.v.J, . . . . J.J: ..cot o . . ,":V ... ....... . . . ooi; jo 'io ‘ ; cl ;jr:;0 a j is sv; o si o . . . . \^J&i:oIo'Y;X ,t - . . . . . . Y; . ... — . — . . . . :v’' . t • i STUDIES ON THE GENUS AGROPYRON.* INTRODUCTION. Preliminary investigations on the genus Agropyron have revealed many problems of a fundamental nature and the solu¬ tion of these is a matter of considerable importance since the genus contains some of our most valuable native hay and p as tur e gras se s . The taxonomy of the Agropyrons is in a very unsatisfactory condition. Authorities differ widely in their concepts of the species within this genus. This undoubtedly is due to the wide range of variability existing wTithin the so-called species and also to the large number of intergrading types that occur between these species. In some instances the extent of the variability has never been reported and in others some of the intermediate types have been classified as distinct species. These taxonomic difficulties extend to the seeds; analysts and seed merchants are unable to separate the desirable and unde¬ sirable forms with reasonable accuracy. Comparative morpho¬ logy cannot be relied upon entirely to solve these taxDnomic difficulties; additional evidence, provided by ecological, gene- tical and cytologies! studies, appears to be necessary. The in¬ formation made available through the application of all these methods of study will undoubtedly be of great value to the * This is a general project of the Department of Field Crops. The first contribution was made by W. Robinson (26) whose work covered the seasons of 1926-27 . - j-fi : JJ Digitized by the Internet Archive in 2018 with funding from University of Alberta Libraries \ . .x . • V https://archive.org/details/studiesongenusagOOpeto 2. taxonomist and to the plant breeder as well. A knowledge of the distribution of the various species and their adap¬ tability to various types of soil and climate is prerequisite to the selection of types of economic value. Investigations of a genetical nature are needed to explain the wide variabi¬ lity found within the species and also the appearance of intermediate types. Cytological evidence such as chromosome number may assist in providing a definite basis for classifi¬ cation, in addition to indicating the crossability of species with each other, while chromosome behavior at reduction division is of value in detecting hybridity as well as in providing clues to the possible causes of sterility. Certain of these modes of attack have been employed in this investigation in an endeavor to solve some of the taxonomic difficulties and to provide useful information of a fundamental nature to the plant breeder, The writer has had an opportunity during the last two years of making a general study of the distribution and morphological variabi¬ lity of the Agropyrons, in addition to making a more inten¬ sive cytological study of a few species of this genus. ■ ,I£ el i . Lq t ■ . £ ' • ' • ' . iaoacoy iO . ; :ii. t O $ b&L a.;, _ ' " ©T'.. 6 ■ . t . i ■ . . a SBC tul . ' - £s - . . - - ; : jli:- ; 3/2 v -i zl> 1*1-6 ;; ■ ' ai s o a, -r ls. ©-r.r %v to ai no : siv i c . I t . . J . ©i/Io n© • . . a / 5' '.a. . . : : . a. a ... •• • ... / .. . . 3 ■ £ a j.: .a.::- .zes.;- 1- oohloli-OzI^ . . - ' . iBoiaolajirf:;--, Ims nottistiritztb ©a a to ^huts Lbi ones 9T0J :. . . . ■ J ■ . ; : v . . ' £ ... ...) , ;• ..o v Vio 3 £.3 0 £ do 7 ,;o ©via 3. PART I. DISTRIBUTION AND MORPHOLOGICAL VARIABILITY. Collection and propagation of material. A large proportion of the material used in this inves¬ tigation was collected during the summer of 1929. A wide area of Alberta was covered by two automobile trips. The general route of the first was from Edmonton south as far as Medicine Hat via Hanna and Brooks, west through Leth¬ bridge, Raymond and Cardston, and then north through Macleod and Calgary. Later another trip was made west of Edmonton through the Edson district, returning via Greencourt and Rockfort Bridge. Dr. L.E. Kirk of the University of Saskat¬ chewan supplied specimens taken from a wide territory in Saskatchewan. Additional specimens were collected by the writer in southern Manitoba. In collecting, the whole plant was dug up, the roots wrapped in moist cotton batting and placed in fibre cans where they would keep satisfactorily for a couple of weeks. The stems and inflorescence were pressed for herbarial purposes. Complete information as to locality, soil type, and plant associations was recorded. On returning to the university the roots Y/ere planted either in the grass-garden or in the greenhouse. This procedure makes possible a study of the influence of environment on the morphological charac¬ ters of these plants by comparing the plants produced at the university under uniform conditions with herbarium specimens .7, . , 7 . A A.T AAAa A A AAA.: A A, • - -• . : 1 ■ I ' - ■ _ . ?7; ;.:T .r/.x beau A ir a.:A ao a Aa aGa^a: ; a-ob! \ .7 : .• A to ‘xomwjxa a.aA aaitaJj £0X00 I lav : :a; r: a i A 371 A ,3 A c.Xi 0 xJAa C/A, 7' . AA . 3 A, 0 A. A A JMA a . a ■ A " : a A. ■ X : - v.;; r7.ij07dX a aa f aAo . xS bna shtajH b A. &r ‘ oriioAAoX 8 a X ■ . ■ .. - A'- - ■■■ t - .7 .a L. A . X xa i a A ■?.=; 0.2 a a J:xa ‘xsAAcab aaa^J a 77- /a A Xxie : • . X o ' . - - % t ■ - - ■ .. ;ii; 7-. A .Axx , 7_v; • a-aa iaca' a . ... .• ‘ 3 oil ; a - nBWoXo lOO 8' s ... ■ £ . . . £ . - . ' . a o : i: : : 0 - a ; :. a :: A ; . ; 3 n i Ar 0 X riw - .... . A ■ - a .nee- AxXiv .7 a 3-obI cr bn : ; A Asd noAAoo' X aioiM ni XeacBiw : r, Lr . . • .. . - . : SI • • ; ...... .-a n . .. 1 . i . A . a 7 : . ' . Xaaaoooa sow .;i.;a.A. . a. oca .a: Xi-xiu xi i\ : -..-a . . : .A a..AaA 9 XoXibXa aa ... ■ . aAoox a A.;.: ; a‘: .a. .a au .. . 3 A A 3 1. ' ... A, ; , OCX ' 3 A A . 03 Jj -OlA 'i A Alr: lAA A J. AO • . • ■ A. A. , A :j A ■ A./.AIOAXAAA; to 00 a. . : A/ ! .. 3 A .,3 . • 3A . ' A aAA a: A;a- aX.OO aX IA^bIa ;aA Ao A . . A . '.a:-, A. a A.- a;. A.» X oAoe xirXsOiinu aojaxa 7 ;7 aa.-axta; which had grown in variable native habitats. About one hundred native plants were collected in the above manner during the summer of 1929. 4. Seed of the various Agropyron species w as collected wherever possible. Seventy-five samples of seed of native species were procured. Additional seed samples of both native and introduced species were obtained from the Uni¬ versities of Manitoba, Saskatchewan and California. It was felt that an attempt should be made to obtain seed of the Agropyrons from European countries where conditions are similar to our own, and consequently the following species were introduced. Botanical Gardens of Tiflis, U.S.S.R. Caucase, Georgie. A. repens (L. ) Beauv. A. dagnae Grossh, A. repens P.B. var glaucescens A. orientale R. & S. A. cristatum Schrb. R.B. A. sibiricum W. Eichw. Experimental Station, Omsk, Siberia. A. sibiricum A. cristatum A. repens . at a ' . ' lfiBV n : _ ... .-..'L-J 3 3 . 'i o . ■ . ' * * ~ " . : :. , . . .' . J. .0, -;:JSoo x 3:,v :r 3 anni-iev 3.;x xC 33 ~ ■ ' ■ - _ ; ... : - . ..: a . to 3v . . 3' ' .. 3 ;• . s. J ‘ • 3 8^ic>8ri&v . . . ' ; . \..ov. .. noe ■■■:: >o bn.e «r:..'o i; o . isJ.ird a .boou jcrxXni 3*x s\v :e;T ( . I) an cere*... . A. • noaon-O e.en^B.0 . A. ... • . 3 3 3 0 i. • ? -1. ■ ¥35 V . ..I . ' .. 3 HS Cf3¥ ..... .o ¥ .H sXBjneino .A . . ' . . cridoC FfXJd-sj oi'io . A . w rl o i A * \ sin o i * x x a i a . k xx.-o.X.-..' ! . • . ' ifxjd-jsc aito .A Site nn ¥ ■' 5. Experimental Station, Krasnyi Kut (gov. Saratov). A. desertorum A. cristatum A. tenerum Botanical Gardens of Copenhagen, Denmark. A. caninum (L. ) R. & S. A. " R. & S. A. glaucum R. & S. A. junceum (L. ) Beauv. A. obtusiusculum Lange. A. orientale A. repens (Triticum repens L. ) A. sibiricum var. desertorum A. repens (L. ) Beauv. A. villosum Link. Distribution of the Agropyrons . General Distribution.- There are about sixty species in this genus, which are widely distributed over the temperate regions of the northern hemisphere. Approximately thirty-five species occur in Canada and the United States, and of these about ten are native to Alberta. All of the native species observed in Alberta are valuable as forage plants, the two most important being western-rye grass (A. tenerum Yasey) and western-wheat grass (A. Smithii Rydb.). The former has been . ( ,o . ,YUV.) dia'a r^a.cri}i ;:i?ed*B Ia;tn©ir;ir£©qx2 11; if: -J ‘I,. :iC 1 . iiifji- O'oiiio lii. ... i . , 'i.i. .. «; cvn.Y.::.r';0 ‘io a, : 0 l::o criBt oS . .8 . £ iTSJo.a.alg .4 .Vi' so :: J . . . ooi r . . O : ::: ' li ■ J. i . o G . i C u 1 0 i . A olii. : •• ■■bizo .i { .0 a a o gov: ■ ic iu . i m ivi-ii . ' ' .omiJ taiisoilrv .A rv . ; .001 .igG.acef >::n- oil ... oil j Ac arto i . oo • . • ■ on,,/ : loll 1 a j; ij. oo c i aipe ga . J 11 . 1; 1 1 i ''i .; ..11: lid’ CIO (23 •'...o i" f -i: ■ o; ... t ’ • . , 1,1 ■ - . i. gg .i ' • v-.. . g ■ . ..in diooi -r. •, . i 1,1 . 6. successfully grown under cultivation in western Canada sinfce 1885. The latter is extremely drought hardy and is a very important constituent of the range grasses of the western plains Distribution in Albert a*-- The distribution of the common native species was studied in a general manner from information obtained while on field trips. The points at which the various species had been collected were marked on a map, and it was ob¬ served that, in general, various species groups seemed to be confined largely to the soil types and vegetative zones to which they were best adapted. This is illustrated in the map of southern Alberta, Plate I. The four major soil types are marked off on the map by single lines. The triple line marks the nor¬ thern and western limits of the prairie zones, while the double line indicates the western border of the parkland. West of this zone are the wooded areas. The most common species on the typical grey-wooded and black soils are A. Richardsonii and A. tenerum. These grasses are generally found in the same associations. Robinson (26) re¬ ports A. tenerum growing in St ipa-Boutelona associations near Macleod, frequently with the "prairie wooln of the plains. The observations made by the writer indicate that A. tenerum and A. Richardsonii are not common in the typical St ipa-Bouteloua associations of the south-eastern part of the province, except in unusual associations where the moisture supply is abundant, such as moist ravines, shaded hillsides, etc. ■ '■ ■ at, ,-', c erO ":® */ ■ ;:• , ■■; “ ' -•'iO.xO : - 0 i'OO-. O:, _ : . ' tan no el £ + i i co JO 'ib >n ■' be i a. ...vo iv. seieoea swoixev ,£e‘xo:eee . ' : . ' ' \ ■ x; O/L . - ;x ■ c ...... : ... . • .. Si::. ■::■’£■ 'tec.:. ... ; -I ^ ‘ ■ ■ : . .. I i : i . sol . f£a£I ■ ; :d- 1 o: ■ ' : 1 , jdoo-ooy/ i' oxe artofi : - : I oni . o -3 o i • o :-;o " . i. •: ; r'- 8 'J'Ci , ■ : ' . . 00 ■ *. : J -Ti: - - ■ ■ ■ ' x-9' • . ; •. .. ' ■ ' ' T-' ; : ( ° , j 1 i at npxPiLOO ion Qeis l lac /' - P 0 O 00 ©Oi 0 © 0 0 0 i 0 .0 I 0 G 3 £8 ■ :• . ' i - ■ 0-: . I • •' Plate I ra\| Woodt, A. bene rum. A . Richarcisonl BlacK boils A. t er.erv.m /l.tensram ■ A. Richardsorm A. Smi rhn A.dflS'JsVacWsMnn 'AlStif f f ! h sS A, SpTCflUm— FS.OVIMCS ALBERTA Preirse Umit ParK land Types of Q Distribution of the Agropyron species in southern Alberta 7. In the brown soil zone which corresponds roughly to the short grass plains, A. Smithii and A. dasystachyum are very common and are frequently observed in the same associations. A. Smithii is perhaps the more abundant. Large areas of pure stands are found scattered throughout the dry range country. It seems to thrive particularly well on abandoned farms in this area. In the transitional belt between the brown and black soils there exists an intermediate condition both in soil and vegetation. In the northern part of the belt of which Yfainwright is the centre, there are localized areas of very light typical prairie soil dispersed among patches of heavier soil which is more typical of the parkland. Naturally in this area species representative of both soil types were observed. This district was not visited by the writer but conclusions were largely based on observations made by Dr. E.H. Moss and on herbarium specimens collected from that district by the Botany Department, University of Alberta. In the typical prairie associations in this region A. Smithii and A. dasys¬ tachyum are found while in the typical park-land associations A. tenerum and A. Richardsonii are common. On the open prairie in the southern part of this transi¬ tion soil zone A. tenerum and A. Richardsoni i were not fre¬ quently observed, whereas A. Smithii and A. dasystachyum were quite common. A. Griff ithsii was also an important species in this region and was often found associated with A. Smithii t©0. :8 ■ - yp iloixi ’ • . , ■ ■ e : . ■ :■ ' . V. o \© -n ©• -© © ■ - ' - " : - 00 •xo 8;r; tbJ .:©©©©■ 0 ef£Oiz edt \ n- ^ --.XXXXX -L -iia© .©:© ©no X©ncerd'i?oa in© : ©n.j ©©-©78 © 0.U G©©3 d© HO II©© V lflG XiJO I © TS ' JV 1*1- :.J ©V ©1^908 0 J. ■ ... . . - . ..© I 9 1 . . ■■ ’ xoi © • ;1&V ic ©non© XovilGC :•! on© e>r©ild <©3© ... © nX z.i Twnis^r • .; .. • . 3-i : .©? no a lanai© .©©©; '©.©:.. © / .. * *•-• ■ . . ■ . ■ • ■ - • . :jt -- ■ ■- -■ .-a'- . W% ■ : z'£*w - ■© ©d b c* X i: a xv . o' oil • s © •.*. tci*xa zib sirlj . f_ ;• - . , • ©. ©870 ©Hoc arxe©i. ©- ©.• ©©©©©dTon n© .at? t , ; ;; • • • • •; . X. ;L , f ; 13 © © £ ©7 liX SiiO X J © 7 © © © 0 © © 1 © © J - b. © _ -©©© © !©-_©© ©•© ©©© n.c ••. 1. ~. . - - -© ;©©;>©^X©L ■ • . © •©©': _ n..©.C - ©. .:;©'■ © •: ©;.; ; . © © . ©©... ©, .7 . J. uV-L©; © © 0£it IX 0 ©a t , ( • . . . fc.os t I . i assiaifw - ?f)©v4i9sdo '© i . : ... ■ ... •'v-.©'. .. ..v. .:.©•.’ . . ©a •• ;i* . . . © . • ' 8. and A. dasystachyum especially in the western part of this zone extending from Didsbury to Cardston. The distribution of A. spicatum is very uncertain. Dr. %E. Clarke of the Dominion Range Experiment Station reports this species in the south-western part of the province. Sampson (28) states that this species has a very wide distribution and that it oc¬ curs from northern Michigan and central Alberta to Alaska. However in a reply to a personal letter in this regard Dr. Sampson states that he made no collections of this species in Alberta, but relied on herbarium specimens at the Rational- Herbarium at Washington. He states (28) "As this is a highly drought enduring grass, the best growth is made on well-drained lands, particularly on light sandy loam soils. In the north-west at medium elevations it often constitutes the controlling type of plant growth. It is often the chief grass species on scab-lands, bench-lands, and on gritty poorly disin¬ tegrated soils of low water content.” The uncertainty which exists in regard to the occur¬ rence and distribution of A. spicatum is probably due to its similarity to A. G-riff ithsii in all but root characters. One of the plants in a collection made by F. Robinson (26) was first identified as A. (Griff ithsii and was later identified as A. spi¬ catum. Dr. R. Newton and Dr. O.S. Aamodt of the Department of Field Crops collected specimens at Faterton Lakes Park which were typical A. spicatum in spike characters but their identifi¬ cation was uncertain since the roots were not collected. This general study of the distribution seems to indicate that the species groups are in general largely confined to definite soil types or vegetation zones, but there are many ■ '..I '■ - / ; '• • . .. , ■. v ' . . X'JV... ■ -;o iV; 3 v';:. tv , • . • 1 t ■ ' i I : . : ; . .. \ : V - iL - ... ... j- . ■ s . ■ v. .v.v .. " ”. . ■ v .vo v i : J. . t eXfoo i. ;. XJ'o o - ©.oro;.. -.X: ,..v..vv ; v .. Or V . V . . • -—o' I V uO . O..0i. V.- . :OV;l "VV V V-'i V O.XV ... ; .1 .... - ..... o j 0 : ;.o ... .. ... t • . •' t v . • ■ . - ■- - . ... • ;rj .. r ■, • . ■ .. a&c, rl c t . i , .: , i i , r:o .; " I voo‘, ■>■.;* : :. ..r.v . X' Xpm ■ ' r.l _J. v; ,ov i:‘_ xXasbi 1 . : . - . X’/vX. f- v 0. : V-:‘. 00 0 :.,7/ :V 00 jovvvolloo o O'QV. v . : . ‘ 74 ' 9. exceptions in so far as these zones contain localized areas on which the vegetation is not typical of the zone as a whole. Small associations may be observed in the wooded area, which are typical¬ ly xerophytic in character and may closely resemble the typical dry plains associations in both soil type and vegetation. Morphological Tar i ability. Literature review.- The morphological variability in A. tenerum was recognized by Malte (22) who states, nThis species occurs in a tremendously large number of forms in Canada. " His observations were made at Edmonton, Alberta, where a large number of western-rye grass forms occur in great profusion. Kirk (17) collected seed of 150 individual plants of A. tenerum within a radius of ten miles of Saskatoon and remarks that one is impressed with the variability exhibited in this material. He states, "Some of the more obvious characters in which the strains differ are color; width and texture of leaf; fineness, height and strength of stem; length and density of spike; earliness and productivity." Raunkiaer (25) made a detailed morphological study of the native species of Agropyron from different localities in Denmark. He differentiated between the various forms by means of small morphological characters which he called "isoreagents." He studied 12,000 plants of A. repens from different localities, and observed especially the pubescence, color, etc. He found that there seemed to be no definite relation existing between these different characters and the environment. He studied . fl; : ■ I-soi: . ;i -si • i- - ■ - ■’ ■■■ ■ . J ; ..i a.av‘a:ai,C ; . t. iaV : -- " - ■ , ’ : - - ■ ,v tUiy.. ..r:.v\ X ol olcdcoi o' i ; -v Ib-i. -olvoonor:;. OiO" . ~XX; - ::£Mi c30,i - ... . . ) J. . . J r;,: '■-r-OCb-rO: 0'.O- 0 l OOYO-Oj OOLOOYO 3±XlH . - , i Ll , .~atW;o':a Ja-'i ■ : a. I. aaao'- 3..a: sia-iaoa a-w;’ r ; a.;;: ;f , a. J ;• . a - . .£ x a/Xc • ' - .»_■ r c .: .; --'tbiX' 10. similarly A. .junceum (L. ) Beauv. , A. litoral -e (Host) Dum. and interspecific crosses between the three species. The seed characteristics of A. tenerum, A. repens and A. Smithii have been thoroughly studied by Dalberg (6), Foulds (10) and Henry (13). Foulds1 paper describes the seeds of the three species mentioned above and also those of A. cristatum, A. BiQhardsonii and A. divergens , and deals more briefly with seeds from herbarium specimens of five less common species. Foulds also noticed distinct seed types within A. tenerum, A. Smithii and A. das ystac hymn. Miss Henry1 s paper presents in an especially lucid manner the distinguishing characteris¬ tics of the typical seeds of A. repens, A. Richards onii and A. tenerum, which are well illustrated by drawings. Observations. - A study of the native species of Agropyron growing in Alberta indicated a wider range of variability than hitherto reported in the literature. This was especially true of A. tenerum and A. Richardsonii . There appeared in nature such a complete gradation of forms between these two species that it was nearly impossible to determine which species certain of these intermediate forms more hearly resembled. Plate III, illustrates this condition. These spikes were collected in Alberta in 1929 from native plants. Spikes Nos. 1 to 5 are typical A. Richard- scmii and correspond with a few minor exceptions to Rydberg's (27) description: "spikes 7-10 cm. long, one-sided; spikelets 3-4 flowered; empty glumes 12-16 mm. long, short-awned or awn-pointed; lemma 10-15 mm. long, scabrous on the margins." - V/./B 9S - . - ' ' .soil -o, oo* .: :f oOi Ae: 8oo:o'ro oOiiosqai;©! rr£ : • : ; _ - JO O.^OOOO—,; 'O>00 ©00* ‘ ; 9 ' ■ : . « £1 . . • ' ■ 1 sJdXjj - . ■ . o' ■ ■ : ; : • •• - ' q. .q; . . o • • _ q JO . .©. . . . .Oo. * a. -o'- r/0£-ii SC C SOl 0T 1 1 iO BO. 9.0X00 r- 3 Ojjl ’I aOlSU HiOOi aOoea oo 00"0 O ; 1.0 jo..; i- £o . . Oo . C SO iiJ o 3 O - . 0. • .0 •'1-0 i ... '■ -o'. .. - 0 ooor.i . oO-/. • , oo oo :.o -.. ./. to o' •" : ' ■ ••'Oo.oo i: . ' . o • o . . iXOAo/OSo oo • '' - : o o, o.o ' .. . . oo qooo V - - o o.-O . VoO V so2 • • "O', o oo.o io ooo'oi oooOio/ Oo o.,,:o.o o. oi '.... : si: qr£J:wo^J| . ©i :. . o o oe 0 i; I. o -O' r; .1: h t ) o . ■ a ; ■; ... o o o'. © i .© t xl ■O' 1 .. £ £0 O o: ■ 10 1. O DIO • :OoO 33 . ' lO s'-..-.:.. . . .... oo o o. -o o . o ... ...... ■ . . " . . t . C . . . X - ... . ' . oo . . 30 ... i ■ A " ic Oi o .o .' • o'. . ■ ... ■ ..._ 00. : 0 O C 3. i 3 : . : • . '. .0 • - V 0 0.0, ... - .. • • •'..... 0-O00..O o-o o:o.£ . oo, OX *-01 a©rirIo cocos • . ■ : ., s.i O Ov OO. . o o. . •_ 01- . 0 • . ©I Plate III. Spikes Nos. 1- 5 typical A. Richardsonii. " " 25-28 n A. tenerum. " " 6-24 intermediate forms. 11. These five spikes vary in color of empty glumes, Nos. 1 to 3 being a dark purple. The spikes are longer than the limits given by Rydberg. The remainder of the A. Richardsonii -like spikes differ in many respects. The awns vary in length from 1.5 to 30 mm. The length of the awns in these cases ?/as not considered by the writer to be a satisfactory criterion of species. Spikes Nos. 7 to 13 have very short awns but they closely resemble typical A. Richardsonii in the other spike characteristics such as density, one-sidedness of the spikes, etc. Dr. J.R. Swallen of the Grass Herbarium, United States Department of Agriculture, identified specimens v/ith this form of spike as A. tenerum. He evidently considered that the awns on these spikes were not of sufficient length to allow the plants to be classified as A. Richardsonii. This illustrates the difficulties encountered in attempting to identify these intermediate forms. Spikes Nos. 25 to 28 are typical A. tenerum, according to Rydberg (27), He describes this species as follows: "Spikes slender, 1-1.5 dm. long, lax; spikelets 3-5 flowered; empty glumes 10-12 mm. long, acute to awn- pointed, 5 nerved; lemma 8-10 mm. long, smooth often, mucronate or with short a?/ned tip." The remainder of the tenerum- like spikes vary from the normal in many respects. Length of spike varies from 8 dm. in No. 14 to 32 dm. in No. 29. The awns on the lemmas of seven of these spikes are very short, less than 1.5 mm.; the remaining four have awns from 5 to 16 mm. long. The density of spike varies * ■■■' .bOIl'Uj.:, -;v X O ‘IGlOi £ll v*I.Cv _ 7 i V ©soxfT ...... . . ‘ - ' - ' ' , - . 3 . . < . • ; '• ' ' • . :v • ... . - , .. * ■ ; , ■ '• - ' ' - x ■ , . c ; . 7. . eq-a • - . - . ; . - I - -xXG t . a?;,..; c 8 ±73X7^-183.0 . ; -X -i:v'v ± .. . ‘ro £ ta t orris. . : m u .. £q;a e •--■..vJ ^Oj: x- ox s^nnl^ . • ^ i ?i o c ■ ;/ .c i b x ! i 7 3 cr n x t -C..':, : ' :-xll xx c.:r ox ■i30t>: ae r-;jc c> 3 : CXYollx ± or; XOiX;eX8 aj:r j 8e( noo ; - • • . r xxx a — o aiixJ x.x .b .-xoa aoonuie'i'xxL ecU cr.eno os; .■ . : ' - -ir . .;> *xc •. -J t b x- x iC • ' a l*1 orid* in hot :e h 0 . 5 - . . : xoixx x,o x. x,xxx ' c x ; . ,3do.x'/ . x" aeoxxoax x.i: xxx ‘X/xx:x xxx-:^ .4 ?xxxoxxa xii*T •• x ; :■ ; ■ x j • x xo‘ :..x h xx jxxxxg 3*.: , _x:ix xxxbu ai ' X' L.LX-> -XXrX'' XxXxXX.X iXXXX; XXXdXxXX 0 3 J> 30 . .x . . V x • .x x. x.X XXX arrlli 2.6 . . '• i-L, XV C X: ■■■ X •xxtd'ix X' •• x XX..-X;Vj:T2 . d x XX ix.:2 a ax xtoll • x • • V . ;• Xi • X;. Lx XXX \X L XX , XX XXv 'XX: 3 ±13*1 ■ ■ ■ ' - ■ • X . ■; : ■ X. • X- 07: X ■ : L • n'O . x x X b XXT 3 ' ■ ■■ X i X ' x,X-: X'l ■ bxXxXXX. o -..XX 1XX jxtj Plate V. Spike forms of A. repens PLATE VI Spike forms of A. cristatmn 15. the effect of environment must not he overlooked. Some of the variation observed is likely due to the specimens being grown under varying conditions of soil and climate. An esti¬ mation of the extent to which this is true awaits the results that may be obtained from growing this apparently variable material in the same environmental conditions. However many cases have been observed where widely different forms were growing side by side. These intergrading forms may be genetically pure lines and may therefore breed true on further test. Malte [22) found this to be the case in A. tenerum. He used nine indi¬ vidual plants representing nine widely different types. The progeny of each of these plants did not exhibit the slightest observable morphological variation. Kirk (17) obtained the same results in the main but he states that some degree of self-pollination takes place, since he found by observing large numbers of individual plant progenies that occasional families showed segregation for one or more characters. Further breeding work is needed on a large number of forms of all the species to determine adequately what proportion of the native forms are genetically pure lines. Interspecific hybridization may be responsible for the appearance of these intermediate forms. If there is a high percentage of self-fertilization, and sufficient time has elapsed since the cross occurred, many of the segregates may breed true. However if the cross is of recent origin, . . .3. : .. ■ , ...• Cv 3 ■ J - ■■ ' - ' • • '• : l ' - - ' ■ • ' •- I- : 0.0 v : -• “ x - ^ •- - x. 5 ixoo aia • j - - •• x , [©J £ ■ . ■ ' - : ® ■- ,- . , : .j. .. yxg IX . - X . ©! ti f x ■ a m ft ' - ’ - - ' . . j . • v '.. ‘ • , . ©] . . • j. t sac j ec d . . . :i . i ■ I - .... - x - • ■ - tH .noi [ST Iori>TX 5 - : ;■ . vo ;.:G: cc: cor..'.. t90Bicr aeHoc iig ore cciic x c •.giigxvdoc ccrL aoiveqoxq inslq XBJj.5iv.tDni: *xo axecmuii o&ml rio1 .... :. 1 . . B . » . 9 9 I . ’ ‘XG . £ - ■ ■ - ' - 3 ■ .'. - . 5 . , . - l j q ■ ; SS o i v on c , ex c axcx o I c v i c e n o x > j 1 o ; •;i ■ \ Ic il . ac.xol Ow czsifii a a a rid* lo oonBXBsqqB . ... , u . osivij ‘Gsl-llac lo ecaixiaoxsq n o : • . • Tfi'. , •. cr'c.'ooo a '.oxo ani oofcL a jxesqsls ' . ■ ■ 16. segregation for the various characters would be expected. Numerous indications of interspecific hybridization in this genus have been observed in European countries. Troitzky (32) states that in the steppe Hared ja (Central Transcaucasia) in places where A. cristatum J. Gaerfn. grows along with A. repens (L. ) P.B. var. glaucescens. Engl. , specimens were observed transitional in all their recognizable characters between the two above-mentioned species and forming moreover, a series of very gradual transition from A. repens to A. cris¬ tatum. Of these specimens, those occupying an intermediate position between A. repens and A. cristatum cannot be dis¬ tinguished morphologically from A. sibirioum Eichw. Hitherto the latter species has not been met with in Transcaucasia. It is however scattered over south-eastern Russia, western Siberia and Turkestan. Troitzky concludes that this phenomenon may be attributed to a secondary formation of A. sibirioum through hybridization or it is a convergent formation identical to the existing species. Raunkiaer (25) reports that in Denmark many types were found which he believed to be hybrids between A. junceum and A. repens and which were very similar to A. ohtusiusculum Lange . He further reports forms some of which he believes to be hybrids between A. junceum and Aj_ litorale, and others of which he re¬ gards as hybrids between A. repens and A. litorale. The findings of these two workers are of great interest to us since it appears that we have a very similar situation 0--; I .. : v v 3isx X:av ei.X v:-X . axlja^ i .a el :.u bevies ■ - • • . " - X • .:• ) "XXeTxX e^-^ecrc eriu '-'si-. ' aacraira X .j . _ . . . • • . ■ ' -:..j . vj: axa \X' .X . ■ . ; X—v ~ - sell .--'S 3 c. ...... . •. - . X .. . - . ' • ' j XXX J t oi • . - X-, ol - . - . ' * \a,c ■ ■ • ax. l ceed .. . - seioe tj 6 - , ^ ■ ■. va . .. • . :”J . '.a'. ■■ s-.-.L aa «r J. ; - . , • : .riBu ae . ' c , ft . :: • . .;.. - : J X..-': a aru-.:;i;' . oers ; ;»X j a X;.,. eXX oi • X' a ■ . - • . X . 3 , . 9c - v ... led - . a x .... X.. . XX .3 . • X ;,ii Xe Xc or.os axxoX aXioqoi loilaiul eH . . ; : . - \ • . ; . ; © . I . a a. .:-ii o.. X -o-asaJ to GgraJbniXi .aXT t ' • . • ,. .. X : ... . a . ; XI ca ... : -< .• -• O u 17. in the occurrence of intergrading series between A. Richard- sonii and A. tenerum, and also between A. Smithii and A. dasys tachyum. It was noted above that A. Smithii molle appears to occupy an intermediate position between A. Smithii and A. dasystachyum. This condition parallels identically that reported by Troitzky for the Russian species, especially when we consider that the species which show the intermediate forms are always found closely associated in the same com¬ munity under ideal conditions for natural hybridization. The evidence presented so far seems to point strongly to natural hybridization as being responsible for the appearance of these intermediate forms. The cytological data presented in Part II of this paper provides further evidence in support of this hypothesis. . -I bus ti£L~ an- .i. not;- jev oaJV baa .aurcsixc .A ' iinqc _elXc; . ' . '■ i; •£ . X ... .ri^jXOBj avaJBjj : C . •.. ... ... : . ■ oj - ... g. • . .. .. i .... ■ . ... . a . - iuC 0 la J:o9m"v o oj naiaaijH exiu :2vl1v *t scpq ai.dX lo £ X GfX£cf xji *B';.2::GGX.. •• ....: . o • 18. PART II. CYTO LOGICAL STUDIES. Literature review. The chromosome numbers of a great many species of Gramineae have been established during the last twelve years. The counts for the principal cereal crops were listed by Stolze (30) in 1925 and by Aase and Powers Cl) in 1926. In the last four years a mass of cytological data has been accumulated on the cereals, so that in this group of plants our knowledge of the chromosome numbers is fairly complete . There is relatively little information available on the cytology of native and cultivated grasses. Evans (9) in 1926 reported counts in various species of Lolium and Festuca. Davies (7) a year later announced counts for Dactylis glomerata. Church (4) and ('5) published in 1929 the results of extensive cytological studies in 31 species of the tribes, Festuceae, Avene ae , Agrostideae, Chlorideae, Phalarideae , Paniceae , and Andropogoneae . A review of the literature revealed only one instance where any cytological work had been done on the Agropyrons . Stolze (30) included in the Triticum group the counts of Triticum ( Agropyron) repens L. and reported 21 chromosomes in pollen-mother cells and 42 in somatic cells. The early cytological findings in this investigation •io:.ioc [ox ' - - \L ■ - - ■ - ' , . , i: • . • . ' ■ .. . .. » _ ■ _ ' ; - • _ ; ; J.v a? ao i 5 s I -.r.; .jXxd';o ovi 8:io ."xo 10 bxjjjoo'i oiId“ • . . ' ■ • ' : • ' S c c ... iO' 8 1 "J O ■ ni : l '■ ■ ... ' . ■ “iXGr/ In 0 £'’\Ol.Otr 0 , 3X8ftW . ... ■ ■ . .dr L / ' r,:dd iiX .bSijx’lOi.-X {’Jo j exiodd . . . : . fj.-. . . , :.ca :::: .... Bldvo o.x-ii 8„l,.£o(t n i' . ' . . . 19. were reported by the writer (24) in a short article in which the chromosome counts of six species of Agropyron were given. These species were found to fall into three groups with haploid chromosome numbers of 7, 14 and 21. Material. Most of the cytological preparations were made from mate¬ rial that had been grown in the greenhouse during the winters of 1928-29 and 1929-50. This was made possible by the use of artificial lighting for a part of the night. The greenhouse was essential for this work, since the material for root-tip study had to be grown in pots. For chromosome counts in pollen- mother cells material grown in the greenhouse was found superior to that grown in the field, because of the difficulty of getting the material at the correct stage. The plants in the field developed very uniformly and all the spikes on the plant reached the stage about the same time, which alloYfed only a short time in which it was possible to get anthers at the correct stage. It was found that this difficulty could be overcome to some extent in the greenhouse by controlling the growing conditions and cutting back the plants. The plants ?/ere grown in either pots or wooden boxes. The latter, being larger, were most satisfactory for growing pollen- mother-cell material, since more spikes usually developed. The plants used for root-tip study were grown in pots. The young growing root-tips were easily collected after carefully remov¬ ing the plants from the pots. . . ;,j_; /• ■: -j.:: C3 iu: oi " rd • :. . . ancir^.^. 3 -■ • J'^:-.. i:,,. 1 : ’ ■ ; ■ .. J3f.. C, 01 U X :4f'u 'U.iV.j ‘X-a^OCi r j.ri-; :’.l . ■ i 'io ;>■ ■ ■■■ t •><■’ , xex'i - , , , . i: - . c;. ■ - - r ■■ ‘ ' °* 1 ■ ■ - ■ ' ■ . ■ . ' •;■.•.-■ • ; ' ■ ' -■ - ' "-.n - :e-r;\s . . L 'or ' . - xi;? . v r'i r Jrz -■ ■ OJ *1 ■ - I ... - . . c •.>: -r'.: .. ^7 ?. *xc’i beaiJ 83'rssXq; . ■ ■; . v 3 ‘ • • /r ^ ' ) so. There has been as yet no opportunity to cheek the identity of some of the plants reported in this investigation. Methods. Pollen-mother-cell preparations . - The anthers were killed and fixed when the majority of pollen-mother cells were undergoing either the heterotypic or homotypic divisions. This stage is reached at widely varying times in different species. In A. tenerum the proper time to examine the plants is when the tip of the spike is still 1 or 1.5 inches below the point of emergence from the leaf-sheath, while in A. cristatum this stage is not reached until the spike has emerged £ or 3 inches* The proper stage was quickly ascer¬ tained by preparing temporary mounts by Belling Ts (£) aceto- carmine method. One or two stamens were placed on a slide and covered with a few drops of strong aceto-carmine solution which contained a trace of ferric hydrate. A cover glass was placed over them and gently tapped sufficiently to burst the anthers and allow the pollen-mother cells to exude. These were stained sufficiently in a minute or two, so that the chromosomes could be distinguished. When the proper stage was observed, the florets from the same position of adjacent spikelets were used for making permanent mounts. For the preparation of permanent mounts, the anthers with the enclosing lemma and palea were fixed in Carnoy’s 6-3-1 . . : •• ■ .. -re :> > - * sl.D Oliv' S“*i . a. o; ' . • . / ' /- : 'V . -noil.: ■ t ■ . - • "■ - : '• ■ : " 'Zl L # • ; • ' .-.■o ‘--a" \ o 3' — ’ I . - t . • . r - j' j; ./ ■ . ... ic -1.:: ..v.:'. 0 u O lu . V ^ -i 0-:<’ - _ ■ .. ... or ;:.r : o U 3 ;. ■ w ■■13^12. * . . ■ . : ■ :• .. - : •... • • 'X . ' • ’ . .berts ■■■ . r no c • ; •. ' r f;, z> ''"'O-Od’Ot)" '\aO,lCi'a ‘10 QUO*Xb W 6‘.t 8 iiuiv/ JjS'Tc’VQO . ...... g I j i )io . e * : - &hs 0 • . . : oiooo n. .1. ijjQsn $ix&x&n?$q anJteJsm- not . . . . . : i too:-’ : m t nn - - . ■ .j...- . 1 ' i -• . - orit 21. solution for two minutes and then for twenty-four hours in ZenkerTs fluid, Lee (19). The material was then washed in running water over night, after which it was dehydrated by treatment for 30 minutes in each of the following alcoholic solutions: 5, 10, 20, 30, 40, 50, 70, 85 and 95% and three changes of absolute alcohol. Xylol and chloroform were both used as clearing agents with satisfactory results. The fol¬ lowing proportions of these with absolute alcohol ?/ere used, and changes were made every hour; 1 chloroform (or xylol) - 3 absolute alcohol 1 TT ft tt _ p n rt 3 " «*»-!« tt This was followed by two changes of pure chloroform or xylol. The only advantage chloroform has over xylol is that the paraffin does not need to be changed in the oven during infiltration when the former is used. The xylol has the advantage of being cheaper and not so unpleasant to handle. Cold paraffin was added to the clearing solution and allowed to infiltrate slowly into the material for 24 hours with the vials corked, another 24 hours with the vials un¬ corked and 6-12 hours in the oven . The sections were cut 20 u. thick, attached to the slide with Mayer’s fixative, and allowed to dry on the warming plate over-night. The slides were then handled according to the following schedule: . ■■ ■ ■ . } - tts ,iA t 1 v ' * ' - n oso 1 ' - ■ ' ' ' . 1 ' ' v-ieve oSam jj[:- . c o L . ■ - : . ... _rc. ‘ievo c;/;.X cixo'.. ox: oli.x e:\z~S civ; 0 3 vj.:iu Oili. XiOVO 9il^ ill J5*#fiSXl© SCf Oif 1 tOXX 8 90& Ii.m.e*XSq » * B ■ ' ' ■ ^ - a - / : fjrrp : .Vr " • X, - it 0(1’ £>©£X." V.1-,. lii XX VIP X XloO - £ ■ .. ■; ; ' ..... •rc-.'lJ' Oi'LC 0 0 aJ> O.' -■•- lH-r - ; ; <:'x XX .yi CX tuo 3T6\v oxoitoea oxiT. • - '.... :• . -• • • ‘ - Jo '■ •• XX . Washed with xylol using dropper. Xylol - 5 minutes. -§- xylol % abs. alcohol - 2 minutes. Washed with abs. alcohol using dropper. Abs. alcohol - 2 minutes. 95% alcohol - 2 minutes. 50% " - 2 " Washed in running water - 15 minutes. Stained in 1% solution of gentian- violet - 5-7 minutes. Rinsed rapidly in water. Iodine solution - 30 seconds. Passed rapidly through 2 jars of absolute alcohol. Differentiated in clove oil. Xylol 1 - 2 minutes. "2-5 " " 3-10 Mounted in Canada balsam. The iodine-gentian- violet method as described above proved very valuable for pollen-mother-cell preparations, especially in conjunction with Zenker Ts killing and fixing agent. It seemed particularly well suited for studying the various prophase stages in addition to giving excellent chromosome counts in the heterotypic metaphase. It had the advantage of being quicker than Heidenhsinfs Iron-Haematoxylin method, and gave better results with the Agropyrons . W. C.F. Newton of John Innes Horticultural Institution devised this .. i . t jjxi ± a - IoI;X ' t 3 ' ' X OOl « ■ ; ' . : v;\: V'. . a et is I i x .0 i u - X o :i o o I ' X c G * S ~ M 3;0c . . 1.. .. . ',i. - • : .a-.- •*. ' ■ ■ ’ ' - • ■ - t it ul * . : nl .. Xi X 3*1 f>c ai ... ( ~ _ _o .... .C r: ©tiflj.au?! to S • \r.t rU '•*: bssajt . X vole ai Ij :■ X o .1: X fia Tsl ' . i(I .aoj JJJ 3 - X XoI'^j ?1 o - S. . " " OX - s .riaalad bj-biisD ni isetitaoM ' a: . . . - - it . .. . tXw j '. x . 1 . £ . 3 . I - % ’ . . ' . .. . - / EMC ■ • . b cat Bd ■ • • . j . " ■ - -X . • ... . . .. a Xna .Xcritam . . . ... X u 23. adaptation of the Gram method, Huskins (14). Root- tip preparations.- The root-tips were taken from young vigorously growing plants. It was found advisable to water the plants the night before fixing In order to enlarge the cells. The root-tips were fixed in Karpetschenko rs solution for 24 hours. The procedure followed from this point until the sections were ready for staining was the same as that given for the pollen-mother-cell method, except that the sections were cut to 10 u. thick instead of 20 u. The icdine-gentian- violet method was found unsatisfactory for root-tip work and Heidenheinrs iron-haematoxylin was used with excellent results The slides after being passed' through the alcohols and washed in water for 15 minutes were treated in the following manner: Hydrogen peroxide 25$ solution - 1 hour. Washed in running water - 15 min. Iron alum 4$ - 2 hours. Washed in running water - 15 min. Haematoxylin -§$ solution - over night. Washed in running water - 15 min. Destained in 2$ iron alum, watching process under microscope . Washed in running water - 1 hour. 5Q$ alcohol - 2 min. 95$ " 2 ,/•>£■ p;xiV.orrI fj;O;1J'8J0 -OB' -i-0 tiOL$3$C£On ;. - ' 00 cx -• * 31 _ ';. .; . . ■ ■ " i ll ■ ♦ . •alleo i ::J- \ < ■ _•- ; • ; . ; ■ 000 ool oio.^ ■■■ -O •: o o'oo: ■ • •• - -;:- Cd-093 - : ■ tie . . •; ;;J: . xf OS io ■: ’ - -a at go ,.o . 01 C ' o 0 -o £_t/' x-xow -'it-$0Z’ei id soo; bcifreM leloiv : . : ; o^ j ; V c •• ? oioBioo&i: oH , • ■ Ol iO BOO. O' '..0 - VO . 0X0 ' 0: B ... O:.; OOT o. I t — S? ;j £ M i ■ • - : • 'Xu on j.'. - n o- o ' jJ.c-3 .(•:.■ ooircoaoo c 00 0-. .0000x1 I' - XYCOOLO - ii . e xisi rloa all . . . . .r ■ -; . 100 o , .• gni ana i a 1; 0 e r( 00 v : . ■: ooo -ox.; . ; .1 • o'n;l: ■ o \..l: DsooslseG . . , 000080*10 £0i ' : 1 0. 0 000800 lo ,;0g 24. Washed with abs. alcohol using dropper. Absolute alcohol -§• abs. alcohol i xylol Washed with xylol using dropper. Xylol Washed with xylol using dropper. Mounted in Canada balsam. 2 min. 2 " 10 " Formulas for reagents.- Belling fs Iron-Aceto-Carmine, Belling (2). Heat a 45 per cent, aqueous solution of glacial acetic acid to the boiling point with an excess of powdered carmine. Cool and filter. Add trace of ferric hydrate dissolved in 45 per cent, acetic acid to the acetic carmine until the liquid becomes bluish red, but no precipitate forms. 2. Carnoy's fixing agent. - 6 parts. - 3 " - 1 Lee (19). 5 per cent, of corrosive sublimate (Bichloride of mercury) and 1 or 2 per cent, of glacial acetic acid dissolved in a Mtlller's solution (acetic acid to be added just before using). Absolute alcohol Chloroform Glacial acetic Zenker rs fixing agent. Mtlller’s Solution. Potassium bichromate Sodium sulphate - 2 - 2.5 parts . - 1 " »» Water 100 «■ a „9fi3 80 .^oo. Loci' si; v o ns ;c: . o .. . . .0. - .odo 93 9 .9 .(o) >£il£lsK ■ lgsJjjI co 10 oceoxs mo oofi c drriog o. id" od' bios - ; ‘ . ■ ■ • oxd'eoB s it < bXds oiteo.s rfaeo leg S£ , ;• " . v ./ rui c :l* aooDCoo .0 iUy?:L .atxsq o .LC/:'OOir o iso *ie - r-fioX oroide 0 - oiLooo i^ioaix : cam ' ' . (qni; 3;.i eioteo ooir j; bob bp ocf od* £ X oa ©iteoj? ) . XiC i: TU loo 3 1 ‘It 19 W:i ■'3 • . . - - .3! "• (3:3 oir ^;;.bon,;'Oi ■ I - od’encoLoa rrs/iboS 001 - *i MbC- 25. 4. Karpetschenko * s fixing agent. Solution A. Distilled water - 65 eic. Glacial acetic - 10 c.c. Cr03 - 1 gram. Solution B. Distilled water - 55 c.c. Commercial formalin - 40 c.c. The two solutions are mixed in equal proportions just before putting in the fresh material to be fixed. 5. Mayer’s fixative. Chamberlain (3). White of egg - 50 c.c. Glycerine - 50 c.c. Salicylate of soda - 1 gram. 6. Iodine Solution. Huskins (14). 1 per cent, iodine. 1 " n potassium iodide. 80 Tt " alcohol. . . ' n. jit; /lo6 - . ■; , o r G:ed - • S v g *:(•; . . . •, e •. - o lo :;•? iT-io.iI-i.' PQ*zO o , ;I ao.*: j.ulv£ . f> , * 7.' . .... " : ■ ■ L'. . 0 . i, - rj'iorDTfj al bsz.Z:a , •• : -2£U‘>i :;jL^z cr?r$ gxIT ; . £ *1 t X ' . . •. . ; • :• ;. .0. ,c - exij-xoo^X:; . . ■ • 1 - bJjOC “ v ;o ,:I-. . .acd - ©ni I . e n i: . ■ c ,> i . -t n 8 o q 1 .eo ib^z i:'S.C’;c.gXg*t ” ”1 • Ic. .go.:.-. ’ " Co 26. Cytology of Species. A. tenerum Vasey. A large number of counts were made on eight plants representing two cultivated strains and six native plants from widely different sources. Seven of these plants had 14 bivalent chromosomes in the heterotypic metaphase (Plate VTII, Fig. 1), and meiosis appeared to be normal with the ex¬ ception that slight lagging of one or two chromosome pairs was observed in the heterotypic anaphase in a few cases. This lagging did not appear to be sufficient to prevent these chromo¬ somes being included in the daughter nuclei. The root-tips of these plants had 28 chromosomes (Plate VII, Fig. 1). The shape of these chromosomes was characteristic of all the species. They were very long with single or double bends. The extent of flexure in individual chromosomes did not appear to be constant and there were no marked differences in size and shape of any of the chromosomes that would be of value in identifying the species. One plant studied was abnormal both in chromosome number and behavior at reduction division. In external appearance the plant differed from typical A. tenerum in having awns 5 mm. long. Twenty-two chromosomes were observed in root-tip cells of this plant, (Plate VIII Fig. 3) and somatic mitosis appeared to be normal. The behavior during meiosis was ex¬ tremely irregular. The chromosomes evidently failed to pair nor¬ mally in the prophase, since from 14 to 18 univalents and from 2 to 4 bivalents with occasional trivalents were observed at the * \j xo . aeiooqX *ic ^oXotvD j. - .•' • .. . c IV.' - -/' . . :£ .... V • ■ o.Xoy o . -VI cV- - -' V 'Xooaoq dor XX a - ;.. L- v_ ;?ve. . v^oxoo'x -i o . - oe V.: -X 00:0, . ... - oXo.X. - o xoX oi sainoao^GT-lo dvielBYiu xx bBd r;V- " Xvvvox.1 9C ox .ox VVT3 ai-aolex. DO t(l . : -iX. .11 IV i : • . •. x.oo oo- : o o.oX x. xr xX;q.-Xx v; ■ - : - o x ' • i: :v: , ' • , - ox X • - . .. • ' . x\ : . . .!: •• . ■ oo, ■ - - ' ci ‘ - -- *x . .)■ ■ o . o ... i . c. oo. x....: ... o o . - ( 2 - ■ - ■ X -■ < 1 • OXW 0 OXOOOOCXXO , XcO'c IC eX’' .0 £'fU . ■ i ~0 ■ ■ eIIV XcooX *■••‘0 ; .Coni a rX io qnol vxev oxoo; oeXI . -oX Xls Xo . • o. o XX : .. x .. X ' 0X0 e:i,: .- ooX . Xe.OO-’O ■ OO 0X90 OX- 9 0 OO. ' 0X0 0 O.-v'O OO O-j XXOCfOB J Oil :X: : lox o •-" ' 36xo ■x:'-r.._.’XL:||x:ro o: o o oo Xo ... ... ■ ; X: x X . . . ox ex ox x in. . - . : jo-xxi,; o... -.. :. ■ . ooioo j a drool c o nC v I ■ :aivi not ■ os xx o x . ... t * x . . •. . • o.. : ox :.;;X0 o o.oo • . . I . X tXX. . oXX, . :x x.o'..-- Xoj ... oIXoo . . . .o . ... :,o o-o 0.0 eoi o: o._ -oaorooxiio oXX voolxxoxxi ill oj X l;x . ooo so ... . X co 27. heterotypic metaphase. These bivalents and trivalents appeared to exhibit very weak end to end synapsis ( telosynapsis ) , which was quite distinct from the appearance of the normal bivalents in normal plants. In Plate VTI, Fig. 4 there appears to be one bivalent and one trivalent chromosome. These, are very weakly conjugated. In the heterotypic division the univalents wandered presumably at random to the poles while the bivalents aligned themselves at the equatorial plate. The condition is shown in Plate VII, Fig. 2. The resulting daughter cells of such a division were often of unequal size and contained varying numbers of chromosomes. In the homotypic division the chromosomes apparently divided equationally. The resulting tetrads are very abnormal and are probably sterile since this plant produced no seed. A. Richardsonii Schrad. The meiotic divisions in all the plants examined were normal; very clear counts of 14 chromo¬ somes were obtained in both the heterotypic and homotypic divisions (Plate VIII, Fig. 2). The morphology of the chromo¬ somes in somatic tissue is illustrated in Plate XII, Fig. 3. This represents the late metaphase since the chromosomes are just beginning to split. A number of distinct forms within this species which showed variation in spike density and length of awn were examined cytologically but no abnormalities could be noted in chromosome behavior. Hybrids between A. Richardsonii and A. tenerum. Crosses- • e.:/£ieLsYZd ■ l aia-piT • BO. j; - ‘1C 50XfJ a eiid’ IxV era. . • . ' o t £ ' £ V .et;:-!, l^rnon at ... 3d . i< ■' -x ; - ' ; - : : . : : ist a ■ ' ■ : j. _ . 00 Sri? .si ilq Li i ' ' - : c . 3 ' • • - ■ ■ : ' ' .X ' Si ' ' ' ... . . . ■ . ■ - ■: . , ;:.d ;> J: t o ::£>: s..\ : ■ 'L-j1 - •rasXo x‘ - ~ IB Ol . : i i ■ J- ; ' . ;i dot Bit V".\ , ol e.-iSo it Olt'’ -Of. S 9X803 .r . - . . _• -j. . / • ; • •./ . •: X ' d o x . ‘ - 3 1 n L ) ■ . . • •; . . '.tile--. : x tzui ■ • ■ ; ;;t .3 i*::' v ;i.3.x: ' i x.-..d; - •• -- - axrij ; :u ‘ ■ - --- axoivxx.'od Di!i030f:*cr£:io ni bet on ad £ '. . . B .. j n a a ; ; 3 o d a i) x 1 x/ r l 28. were made between these species during the summer of 1926 by W. Robinson (26). The F. 1 plants were sterile which indicated that the cross had been effected. These plants resembled the A. tenerum parent and were more vigorous than ei¬ ther parent. The examination of the pollen-mother cells proved to be very interesting, since they did not show any of the ir¬ regularities such as incomplete synapsis or lagging chromosomes which are typical of hybrids. The appearance of the bivalent chromosomes in the heterotypic metaphase is illustrated in Plate XII, Fig. 1. In contrast to this, Fig. 2 of the same plate shows the chromosomes in the homotypic metaphase. These chromosomes more closely resemble those in somatic tissue. The bivalent chromosomes of the heterotypic metaphase differ in being much thicker; they are rectangular in general outline and show the indentations initial to the disjunction of the synaptic mates. A. Smith!. i molle (S. & S. ) Tones. A study was made of two plants of this species which were collected in adjacent districts at G-ranum and Claresholm, Alberta. These plants were very similar and were identified at the Grass Herbarium, United States Department of Agriculture. In view of this it was surprising to find that they had different chromosome num¬ bers. Plate X, Fig. 2 shows 28 chromosomes in a root-tip cell of one plant, while Fig. 4 of the same plate shows 56 chromo¬ somes in a root-tip cell of the other plant. Root-tip cells of the latter plant were slightly larger, but contained smaller chromosomes of the same general shape as the 28- chromosome form. 8UF- Q X T o T XXXIXJ / 3 X ,:€C v : xx see, n ■ ' ■ - - . • .. ■: XL X.Ti.CXj \ l . - * - 3' : » -X- J - ' - X TXTTorfi-Liellox oi ' xx . :■ -Vodt . v*iav ed oX X : XX XT8 -LXX. ST. ; ... ; ;. . . - xex ; ; x xr « 'xx rj_ iC L xix . ' - - * • . - C X £ r- 0 . L • - • • -j SC - . • ■ ; 8 ' - ■ - - • t . o si ' ' - - • • £ ;i o c la . . l t ai : ' 3 = ' ■ „ • : - .3.. xx . . . : - ; -7. *4 . . ■ . r do lit - 0-6 a aids &£ ; ; •■; ' • - y a :1 . . . • fUSj . . .... 0 X. - ' t • x . y xlx enc cio cox .. o*iov 3ovc aciTO^io erne Ibv ivl M ‘xo . . . - : . :-/?x -x . ' :x.v ■ o..v ; . o • J.x- joci . ’• • • ...... ■■ • x ■ .. ... ex,: ; • ■ . • . ... '. . vv avoix/evv b ; i • • • I l r v. . . .. o £ Qi . ;< . . d ' ' I . i V ©U B . y ... • : ... . :• . .. :.• x: ox. ■. ;. . • - . . ., v lx." ... . 1 x.v'xxl..' asavO . • ■ - ■ ■ . . ... ■: x . i x x o ., „;X a _xo o ... 3.3:1 os .1 o 6 qa 3 iild* •' -3 J. JVC XX Cl X. XXOd XV x; .Vi iXJJxO VQ • X c • J £L .X. 5 ■ ... X I i . XI IV . : od'B i . ... . 30. A. dagnae Grossh.- Only one plant grew from the seed of this species which was obtained from Caucase, Georgie, U.S.S.R. The root-tip cells of this plant were examined and gave clear counts of 14 chromosomes. (Plate IX, Fig. 4). A. repens (L. ) Beauv.- This species was studied exten¬ sively. All the native plants investigated gave clear counts of 21 bivalents in pollen-mother cells. Slight lagging of one pair of chromosomes at the heterotypic anaphase was observed in a few cells of all the plants studied. Root- tip counts were made of 5 distinct types of A. repens collected in western Canada and they all had 42 chromosomes. Four plants of A. repens (L. ) Beauv. introduced from Caucase, Georgie, U.S.S.R. were studied. Three of these plants gave counts of 42 somatic chromosomes (Plate XX, Fig. 2), while the other gave clear counts of 35 (Plate XX, Fig. 3). This latter count was checked very carefully since it is unusual to have root-tip counts of uneven numbers. A. re P ens (L. ) var. glaucescens was also introduced from Caucase, Georgie. Root-tip counts for four of these plants showed 42 chromosomes. A. cristatum. - Pollen-mother-cell preparations of three plants gave counts of 14 bivalent chromosomes in the hetero¬ typic metaphase. (Plate VIII, Fig. 3). Root-tip counts on one plant gave a count of 28 chromosomes. (Plate XI, Fig. 4). o e&$ . TrssI - • ■ .. . . . . 3- :v‘0 : ' • BOB'.: ... B. B BCB-J 8 .8 VC U V 1 f.UV 381000^ Olflu ' - ' si ■ to - • • - ' B . li; 1 i - lie , llQO IQdt I 2 t ' - ' — _ /b.bib: biiibbcbib •: bbbv ibb;/ : . cbb xo rii3$ , ■■'_:■ ' ' - cBb.BB~ B:b'' J'/.-' ‘XO S-JbBB • &3 B ill l ,811 101 ...DC- • .■ 1- 1 • ' . ' : BX3 BB ' H8 b :BO;ilOrrf'fli: . V 1 3 6 7 •, . .. , . 8„BjBB£ V-:o llil J- ; BBO'i ;• . . 9 c • ■ . , i - : B - 1 - lC - . ■' b .■ i- . ii-ilA) ac ‘ic iinBo.:- bbiIb ivsb bibbo eiiit Bli . . - 5 1. EJJOO * . b . : ;. ' 1 ' •:■ '. ;.i: cb, ,1 Bill . I) cBICBbb^ .A ■" . c-1 it icbc b'„. -bi ; . . ei.i a- , bojbO , lie C ... ... B-1.BC . IBB . . ■ • . - .:'.... -• .■ . ' B , /';-Kb • ' 1 B .'CB. , I ‘11 SB BB.,0 6 3-j‘XtB I $ • - . . - . ■ ■ t i - ; - : ; . . : b- ‘to cic i. -., .o IB;' eIticbb; 3fXQ 31. A*, sibiricum (W. ) Eichw.- Root-tip preparations of this species introduced from Caucase, Georgie and the University of Saskatchewan gave counts of £8 chromosomes. (Plate XI, Fig. 1). A. desertorum. - Only one plant was studied which was ob¬ tained from the Manitoba Agricultural College. Pollen-mother- cell preparations showed 14 bivalents in the heterotypic metaphase, (Plate VIII, Fig. 5) and the root-tips gave counts of 28 chromosomes. A. pungens (Pers. ) R. and S.- This species was introduced from Sutton & Sons, Reading, England. Pollen-mother-cell preparations were made from three plants and 21 bivalent chromosomes were observed in the heterotypic metaphase. (Plate IX, Fig. 2). Slight lagging of two or three pairs of chromosomes was frequently observed in the heterotypic anaphase . t v:.;" ,'V:. ■ _ r -.1 { . . j L . •. j • /,-• ;:/• -.:0?C , V-V; 20.:.CeqS • ■ jaiL .0'u\0 8 iO ?. j £iiJ X O UTS': • • ' ' -*33 • o ; . . . j : • : i: -,j - j:.--. • 8 8 x. ; I8oo . c o : :. o o : o ; • o 8 S. 1* o ;;; i: ■ - • - ■ . . - ■ c • : . e 81.88 *\:o 008 8o /'.x8: - a. * { 8 .^.tr i ,M 3 rruju soiqa ,,I - os ay. ob SS M rn-y-yy yyei ' SS * sa . 31 ± ta Qzo'ra: via • « yirva o a Israel . 31 riaai-irirzC . as 31 Mixfisi - i:xo . ~ im/oixio is _ il * as - . S'XXoia iiri 3im8 * - srrsqaT. - X A IS : -A - arieasQOij.eXq . x;5 v * - ■ a^IOXllI/n - ~ j; iiiii'iA allom - .. ... • :j .... ■ r An;. : o niiivBii inlA * . a qjx c x ; ,u i o I qv lo c 33. The polyploid series reported in this investigation i s very similar to that found in most of the genera of Gramineae which have been studied. Sax (29) found the wheats to fall into three definite polyploid groups - diploid, tetraploid and hexa- ploid. Tschermak and Bleier (3) produced an octoploid form from crosses between Aegilops ovata with Triticum dicoccoides and T. durum. Griff ee (11) reported the groups in the genus Horde urn with 7, 14 eand 21 haploid chromosomes. Kihara (16) reported the same series in Avena. Church (4) studied the meiotic phenomena in a number of species of the tribes, Festuceae , Avene ae , Agrostiaeae , Chlorideae and Phalarideae and obtained with few exceptions counts which showed the same polyploid series as reported for the cereals. Evans (9) found haploid chromosome numbers of 7 and 21 for species of Festuca and of 7 for Lolium pererme . The tribes, Paniceae and Andropogoneae were studied by Church (5). The species fell into the same series of multiples with the exception of Andropogon scoparius , which gave a decaploid count of 35 haploid chromosomes, which is the highest number reported for any species of Gramineae . The basic number varied somewhat, however, in these tribes, since five species were reported with haploid chromosome counts of 9, and fifteen species with haploid counts of 10 or multiples of 10. Cytological evidence of natural hybridization.- The hybrid origin of many of our cereals has already been demonstrated by - t - : ; 1. o .300. .o go: ::c o go - oi: 8 0O 1' ’ - — ' •• ' 'v • xxbv ot otioolo eili rooo ( Q8. ) xaZ - • ’ & i xooo evo : ’• . . o 1; ojI ' 00 . 1 ' , o.-oo..,. ... ' - 3 .. o o • o..*- - • - • o {£ ~ ■ • ' ' 0 ■ . 0- :oo av i 3' o ox .. :1 *3 * . £ 1 - . ' s . . . ■ • . . ' ... . ... • ;; O cnr 1 ' j ■ ‘ G - '■ - 81 t ' I C ' Oil 0 . i 8 L ■ \ v 3 8 1 Lii .'. 0 3.1 - O $ jO 0 . \S V Si il 7 IW 0,1 joi'oo ■ ( 3 ) 30Ov8' *3 Lb UO 3 b7 ' . ■ . .0 c.' J 0 '■ • ~0j. r*x ‘X 8 3 •• 8 8:8'" 188 8. lOOOJ . DUO V t o alt 8 880 0.00 . 883 Oil? » 8 8 : -80 8 1 o.ljlo 1 0 0 t -V Oi.SC , .1 18 0-1 .? ... 8 3 0 1 8 . 81 80 8 • • lloOOOlO 11: 8.001 80. JO' 3808(1003 JlCOOCTlO ‘0.J0 1:0 0 8.1: 080818 3101 1..8 .8 3 8- i 08 81800 10 08,OiO8 i ofiioTEi . -o no £ 1 ■ ■' . . ; . b 7 *1 • - . 3 so ioor sioil .8. .icO Giiorl . o-- ... .88 ioeloov 0000000 o .l joo erIT . ; . o, iol /. .8 i 8 8-1 8 . . 3* . - .1 3 . £09 1 08.1 1 $ 0 [£ . 3 ' 8 . ' . .. ..... - . .oxro - . o . .1 1 • i i o • i ; o .1 oxxoxoo .o. to. 1. cj. :-r ;/? ; • : o ' o . 1 ' 8'1 o! o.o;i o 1.8 x-o. ... olo.ioo 34. careful genetical and cytological research. Sax (29) studied the chromosome relationships in wheat, and suggested that the 14 and 21 haploid chromosome numbers are the result of reduplication of the 7 chromosomes of the Einkorn wheat. In a paper in 1922 (reviewed by Church (4)j, Sax considers that the differential mating of chromosomes in crosses between these groups indicates the probable hybrid ancestry for the polyploid members. Huskins (14) in his studies of fatuoid oats makes this statement : "Probably hybridization and polyploidy are related phenomena in the origin of wheat and oats, and are equally and jointly responsible for the origin of speltoids and fatuoids as well as many of the peculiar features discovered in hybridization studies." Jeffrey (15) believes that hybridism has clearly played a large role in the acceleration of the processes of evolution. He states, "Where interspecific crossing is possible, there is often clear evidence of its presence in the form of a high degree of variability, accompanying a considerable mani¬ festation of sterility in the gametic cells, particularly the pollen. " Cytological evidence has been used in a number of instances in recent years to aid in the solution of some of the more perplexing taxonomic difficulties. This is parti¬ cularly true in the genus Rosa. A recent paper by Erlanson (8) of the University of Michigan is worthy of careful review, since the situation found here has many points in common with Xjjte-rmo , If . ■j i.;.jrh, lo- ; j' .j 8‘a3 a \:sl=f a ..t a^oac-rio-TiIo Moxcrsn IS .ona f ai fi8q/;(r al . ;t a^nvv naojiuiE: ©11 xo ©©‘©oBcixcario V all M*o ' 0 r : . .t ac;j~-'T:z o ' 7 aesvl'©! ae-^cno ©X. aornDao© QEiio Eo ^nUrsm i-oXcr^Ioq . -, . 3>n,;- ;.; < .iXo :■ ' a 0 i a u j aEi n.i: (El; c iii a ;. : to: sHiEJ at 3 ' j . ■": . •_•■ ©EE ool X..X; :c a ©•'-•© .'it to - o’* loo :;X Coo ■ 0 1 xii ■ - ' - pi . .. ... ©Jbi . ■ ' ■ • - I ' •a ibo©;.afq Y^aaXo a©X • ..ai f a..:. la at aovsiloc' (SI) va'ilto! Io\ :. •; •••..••• r It '.,o . .' . .. Coca - .. a. snl , ast t' ©K xa:it t ©Idi a aoq ai ; ns a 30x0 oil to 0 0 e rest xi i eresilW' ! to a :. 1: • -it i: ©aria a. . a ©0.1- a xaclo ;. ... •••- . ... : • ;;; •. ; . ;t i; 1 i: EC© X ,©•©', ,a ■ :ti .. %o j t? ..©.oil© a ©0 v 'at ' • i £ ' ; l )jt 3 • t ' , £ t ■; X ■ a .. • 1 ' , a ....a:- oil' ni ©oat ^ItbIuo ■ .. .- i n ;nr ij.l lo a a i -aiav ,:/■ r to (R) ia 35. that found in the Agropyrons . They both are widely distri¬ buted and extremely variable native genera, and both contain certain wild species between which there is no clear line of morphological demarcation. Srlanson studied 107 wild roses from known stations in North America. The majority of the specimens on cytological examination fell into three classes with diploid, tetraploid and hexaploid numbers, the basic number being seven. One specimen was octoploid, two were triploid, and three aneuploid with the somatic number not a multiple of seven. Many of the diploid roses exhibited ir¬ regularities during meiosis. Incomplete pairing at diakinesis, lagging chromosomes, and polyspory were frequently observed in some individuals; these were believed to be spontaneous hybrids produced by the crossing of different species. In the aneuploid plants two contained sixteen somatic chromosomes and one fifteen. These plants appeared to be a later generation of a cross between the diploid R. blanda and the hexaploid R. acicular is. It was believed that the uni¬ valents probably lagged in the heterotypic division and gave some fertile garnets with only seven or eight chromosomes which by self-fertilization gave rise to fertile diploid and aneuploid plants. Nearly all of the tetraploid plants examined resembled hybrid forms in their cytological behavior since they exhibited irregularities during meiosis and polyspory. The tetraploid forms often exhibited some rings of four chromosomes at or/ ri* ui /a; r o :X.t •i '• il: ‘00 03 .100 : : X' . .300, uX3, 60X1X0, ^XX 6 iXCO V 0 X OT'OOX'X 9 000 i)b, .'0 ■ rloi 98 0 € 1 1 t j use :: . ,00: XI X’ V01 000L 0. Xo 000.0IO: .00 I 00 0.0 oX l£oXx0: 1 00X0000 ' f . • . ,0 . t 00000X0 0-.'......: oluX rioX :t X 7 lool xolccroo .00. oxxo-ioorvo •.. Xi :• eol . axcea-ujo ijicl ;.8xeX. 0:0.0 ,:o.X 000: ,1X0X0.00 000 cv, . ■ £ ■ . 000 00 - 0 0 - . otXB X 00. .. f. • 00 ,or one ,.1001.000 -0- boXX0'ilxs 0 0 ,0 ocgX^Xr 000 *ro rn^':! ' .xievoo Xo 9J0 ■ iX Lum ‘ t ■ . .O0v0 0-.cc ; IX -0 - : " 00X0 C0 0.: '0, 0 :y'0;' 00 000 ,060000000x0. 00., :-0‘ 3 r 000:00 .000 ed 00 Levelled 00.0. " o 0 0 , . X * 00? 0X1000001 ,0003 at % •X00 ': .. X. ..X0X 0 ,• ..'X I 0.0o 0 0. 0 00.: 0 Jo 0XOX 0/000-' -o- '0 . X X 0 • .0 • ■ 00 -0X000. X 00.0; 000X00I, 000 .00- .0 . ... 0 0.11X0 X. • io. i . 1 . c ' 1 X ■ .0 , -0 i.30X 0 X".0l 0 oX 7 .X ' XX:. Io ell ..X XO00B.X x:;X sloaq 3,0 0 .X. 0. J;0i 03X00000 X ' X .. 00. 3 0V03 X;.::0XO IIX-V/ 30 00X0. eXiuOO'i 0:.0:.; X .. X:. i X 00 -X: 00 xx 0 Xf 0: \Xf0 -x 0. -0 0 3 . 0 0 '.X . '. j ■. 70 XX; 3 ■ • ' • 0 X'30': • 0 ■ 00 i-olod X 0 0 X : cX X'X'xo oio.00 xX aooio'x X .XicXoi 3 : ‘X ■ ■■ ’ ' V r ,r r. :r 00 • 3 X 3 O X O X ill ‘X 1 00 3 oX 0 X 0 0X10 . Cj0o; X X00- 0 ■ ■. 00X0 'X 00 3 011 j; ‘I toxoo, 003000., 0X'.J .0 .. ' 0J 30 00'! 36. diakinesis, but none were found that were completely quadri¬ valent. It was concluded that they originated by duplication of diploid hybrids and had hybridized with each other. The cytological evidence presented by Erlanson certainly indicates that hybridization between many of the wild forms of Rosa is of common occurrence in nature. Other lines of evidence supporting this conclusion are based on: (a) the results of artificial crosses between the various species belonging to different chromosome groups; (b) the variation in the progeny obtained from seeds taken from individual wild plants in the field; (c) the large and variable percentage of sterile pollen present in many wild individuals. Church (4) in his studies on 16 species of the tribes of G-r amine ae mentioned above concludes that, "Polyploidy or cytological abnormalities of the maturation divisions or both are considered as evidence of the hybrid origin of all the species except Phalaris arundinaceae. " The cytological evidences of natural hybridization in the Agropyrons is relatively meagre. This by no means indicates that hybridization may not be responsible for a great deal of the variability. The Agropyrons are probably highly self-fer¬ tilized according to Malte (22), Robinson (26) and Kirk (17). This decreases the chances for natural hybridization and increases the homozygosity of those types that have arisen through hybridization. This inbreeding in the progeny of hybrid •XXfoB 1O0 *X 'O' ' 1 - - - ■ , - o' oe&sulid-io -seiij &£df XsooXonoo acc XI . jczeSsv X',.. iio.c‘0 .olio; oog:I ^ o: ; \ . o oo- 2 X.o- -X lielqlo to t t 0 0 . . - . : ■ ■ X Xboi X ■ : X £71 Situ ■ iioi - f - ■ ' • . . . ••; ' . / . - l ' - ; .. ... .. . • .• IIOioBlOflOO 3 X;.C %iLZ 3 000010 0 O 0 v 3 X V o 0.1 : B-O/uOO .jI'Xj COiJQ'Iiio XCOoO Oli X £} CO l'S~l £0X0CC[3 : : ... . ; X ; .. .XX. ccX ■ , . 00 :. 'O' reXXoo cXXc.cc3 •c 0 x~o' . .. o \ elcXXoioro brio •. - .. -;o (0) , . - X c‘ . I -XX .. ;. . X X .. ; : . 3C0IT3 0X0 to 36X000 3 XI no G3ii.Ju0 aXi ill ( j. ) .ciooocbO . . . \. X y '..3, o..X: XJXx 0 0 ? Xc'oX 0X0X03; 00 /oioIqvIoT' '• O GOO-: . 0 XoioXoxXI I^ooo.o ceicoca co.X ll.e to nXgixO Lioicl/a f '• . i cool c-X o crv;rf X o-oX-- Xo aeon-si £ve loo I; ol; .03; sriT X 0 X ocgogo. 0; -3 ...XX. .ov::.;.3sr-. X--"..v.X. ..Xo. oc '0_ . X., X--. 9;^‘ o Is eb - e :o.c 0 tot X • i o xo; oc ton X-oo n . .X0-00.X' X;c x ' obXX 0 . -o.X : X x' 0 0 oo ; v.- 3.300 3 ;o .... ■. I XoX.clX oo.? coco ... . •. X X . ■ . .j 33 ... ,X; o.X. X; . 3 : X-oo/X -co 0:0 X ouougXo sol csoosoroso axnT I .. • .0 „ .3: £30i-:/.X0 3 o' X c 03 3 30: lOo .. o 3 0 3 ; 00 o; X; - • 37. plants would have the tendency to eliminate rapidly disadvan¬ tageous recessives and abnormalities in meiosis which might be perpetuated much longer in cross-fertilized populations. It might therefore be expected that the cytological evidence of hybridization would not be as plentiful in the Agropyrons as in cross-fertilized species such as Rosa. About fifty plants representing fifteen species of Agro¬ pyrons have been carefully studied cytologically and in this limited number certain phenomena were observed that apparently can only be satisfactorily explained by assuming interspecific hybridization. Lagging chromosomes were observed in some instances in the heterotypic anaphase in A. tenerum, A. repens and A. p ungens , but other meiotic phenomena such as polyspory, incomplete pair¬ ing at diakinesis. and cytomyxis were not common except in the following cases. The abnormal plant of A. tenerum which had 22 somatic chromosomes is probably a hybrid bet ween A. tenerum which has 14 bivalent chromosomes and some species of the 7- chromosome group. Synaptic pairing is for some reason deficient and as a result only from two to four bivalent chromosomes and an occasional trivalent are observed in the heterotypic metaphase. The unpaired univalents apparently wander to the poles at random. This is typical hybrid behavior similar to that found in hybrids arising from crosses between Zea Mays (10 pairs) and Ruchlaena ' :v ..•••• r acixlv aiGciaid ni Cc zi GIg./ gogc x ggo sncoBoJ' . U - - - : - I ■ - ' ;c ocxgg iv3 JGgoxxggXg'vo odd gg x roooecc-:e ed ■. gg . xgcGX gg-x.i, g- , -'■ . - G 1 ’ fTC; ' ‘ ;; ■"■ g\j G . g S X GG. IGG XXX'ig rji ■ •;G' ' 'GO GgGGG :.XX“ G: ; GGGGXXGG GX GOGOlC ; "cjlii G.'. C GG.G gG . • :: . g •: .go. g iGXGO.ro ;ggu ox.-' ggo xrxoqo :G GG X.G' o G G.'iG GOvGGaGG GGG-.. G. -GGG G CG B V G G . 0 G G : GO Gtv 0:11 . . . : . ' . 1 ■ £ ' . fX Cf XCGX BOGGCO G.gG. GGGGG 8.GOgGOG;0 G>IIO , 3.XGG LxsGG -to £ll£ X . . . . g . . Li - t mi o gg.;G9g DIGCiGil 0 " ; j.'. ■ G o g q a i u . ■ Ccjm;;- v;c . c o2. ,ci 2,'? to! ?:im. 2, . ; B Bo .: . .c at ‘moo ' . 7 :. 2 7 2 M,;-: . 0 C 2 7 rM: 7 ;; 1 702 o2 2 2S2 .. ,7 CM;, -7 B -M3 2:7 B 2 2.M. '721 B-*i 72' £H ... . • • . ‘ . ■ - . .... 7. • • . . . ' . ..'. • . . . 2. ■ C.B . 2. . • ' 2, ■ 0 2 2.2". _ -., .. jci:o3,;3 .,722 : -/ nocvBoo o. . . ..• : 1 2oi .. B 22 ! X7cmB cjoud^L ■ ■ . ■...■' . ..2 3 v-‘- ... 2 - . 0 i X ■ 7 rj i ■ B • 2'.... 7 2. " ':. .. M- . . 7 372 . • - O ’ 3 7 ‘7727X7.7 “IJjJOO : ■ .1-2 . . ' 7, 7 ..222 :... 077 2720X3 . 23 C/- .2.70 2 ,7. .03 0320 72. Bo 41. paper. These can only be satisfactorily accounted for by the supposed occurrence of interspecific hybridization. Lofigley (21) states, "A review of the taxonomic, genetic and cytological findings in the genus Frag aria will demonstrate that variability is associated with polyploidy which in turn may represent a latent hybridity. n He suggested that the same conclusions could be drawn from the variability that characterizes polyploid forms of Rubus Rosa or Crataegus. It is evident that we have a very similar situation in Agropyron since the species exhibit a high degree of variability, they are closely associated in the field, and form a complete polyploid series containing species of chromo¬ some numbers ranging from 14 to 56. It is perhaps unsafe to draw definite conclusions until further information is available from certain other lines of investigation which have not yet been undertaken. These should include studies on: pollen sterility, the frequency of segre¬ gation in the progeny of intermediate types, and the hybrid behavior of artificial interspecific crosses. We can, however, safely conclude that natural hybridization is responsible for at least some of the variability exhibited among the Agropyrons. ■\-r: oxo" - booxofou : o :Xi/fccoo.3‘f o fi // xo: 0.1 o© ooo e .. : i - off; 0 o ; o f 0 © vo . ^ i: o o OcjvXrf.a© oc --©fo. ■ .. /ox; ■: > f© x V .; ( X a ) vel^neJ IeoiyoXou'i;o ©a • oifenog ? ataGncx&tf exit to o© xo: £1 t. of ©j^iencuri©/; L.Iitj a rmey» o-:j; ’of .1 o '... oil' xif •,:•[ o x bxoIcrcXog litiw bsthoioxaaBs si vtidlcslzev . fufl.ofxfo. ioior.ol 8 oo oo got . .. v a to .ooo. ; ©. .-ox .. ./. . „ Loo© ;:u ; o x o Is n c o c ■■ ©ui oxox 0 2 3 X' -os ©K o. . . /ox 0 ox oioxxof - x f , • - x . : fo / osa o . f . - ili oi.fi x to 1.1 -ox: oo ' o .-■ cvsii ev. xo-oi one live at *1 .a;ooes;fe*:.0 *io $ Id l toe 3 ©onia etc lain r x • \ ie ,.5Xexi ©fl i Bclxofoooos v;lc>aolo coxo :ii .1* ilidaiTso to ; to - • £ ■ - . i >( o;r :>1 i/.oal ton.corno.. aaodif/tja. ©no 3 . oro-l ooxloaoo ©-.-ini loo o.ox ox et^sxrj o £ il s/oofl *, , x hxx :-£ xow- f ool sioo.f x xv.o of oo: is/orc/for xxxo • ' V;o'o ...... , ■ Ho : ' ‘.v ■ ; : o/ o inx ? f f o ; t oxxi . • of : to f.x xiooxg •; t-fj x.i .oX/ls© X ;< ■ ? ilf efr .3X33: JOG Ollf GOOOOOOXfi: 1000 Ilf GOO iO aoiVSilSd 00 0.0 L 0 0/003 GO 3-i fioio o-oi: f OOCfOl I rofl/iOI; 0 Oiiv' fOfiOaOO Oiet.©6 •r ie; ©off f,j . i - ..ox ;. / -ixo vtf Xioo i ffov oxfo Oo eo/o© Xooel os 42. SUMMARY. 1. The distribution in Alberta of the native species of Agropyron was studied in relation to the various soil and vegetative zones. The members of the various species groups were only commonly observed within the soil type and vegetative zone to which they were ap¬ parently best adapted. 2. A wide range of variability was observed both within and between the native species of Agropyron. Complete series of intergrading types were found between certain species growing together in the same regions. 3. Cytological studies were made on fifteen species. The chromosome numbers formed a polyploid series with two diploid, eight tetraploid, three hexaploid, and two octoploid species. 4. The polyploid series found in the Agropyrons is typical of the G-ramineae in general. 5. The species could not be distinguished on chromosome morphology since no striking differences were noted between the chromosomes of the various species. 6. A plant resembling A. tenerum was observed with only 22 somatic chromosomes while the normal number is 28. Its J.r, i Gvj;toB ;? it to "dOociVV^ no aoi jojO i %j eit ariT ■i --' ' ; > V go.VjG/J 3D'. q ; ; q • q. __ 3 ■ . G .. * ■'~o-- vq>oJ ooj;.do; ot go": : e'o;-:o :..vv' one ooq, IV'oa . be . - ■■ ; - iO£C . ■ -• ' . U i . S ^j'voo ..loco jo:!' ooj od; dgdx- :v c.. or:. oo Vo oo.r:o.o . no Vo o .. olio o ’ ;■ :Vt rr.± oo &$ ■ qo 1 qoro - •• : V o eq o oiIT . soie-:" u09jV.i:‘ n gogo . ObiUnVo ^soioolc VqO ' t : . iol 1 : I D * SJl ' . cor . jjVoIqox- o 8 ooo- qq;c.o- boogt orVoVo ..niolqiij , B: 0;0 0; jioiorod'no ' ' . 1 : . G O - DO: oVX ; DO' 0 1 .V dOD. 0:G'O jOI 0 0 O’O 8:. Vo ■ . ' V . ■ £ i 0 43. abnomal behavior at reduction division suggested hybrid origin. 7. Two plants which were collected in the same region and identified as A. Smithii molle were found to have different chromosome numbers. One had 28 and the other 56 chromosomes. 8. A number of plants introduced from Russia as A. repens were studied. One of these had 35 chromosomes while the remainder had the normal number of 42. This plant probably represented the F^ of a cross between A. repens and some member of the 28 chromosome group. 9. The F^ plants of artificially produced hybrids between A. tenerum and A. Richardsonii did not exhibit any meiotic abnormalities which would indicate hybridity. 10. The combined results obtained from distributional, morphological and cytological studies indicate that interspecific hybridization is responsible for some of the intermediate forms which have been found growing in the same region with the typical species. ooX w:-; "o noid.tviiD. mtZQubo'z Xo tcoiva r£ed Iztvricrtde X.XO ■ io . : . i j : ;.a ; . . '■ 3 3 • : 3 o e ox n i: X e & o e 1 X o o e*i e - c ■ o X liv; a X x: to X j o v/ 1 r T - ■ o.X " 3 : -XX.. .LX' X I - : • • ' X X •/' -- XX . . . X O : ' X d'X ' X' , a • - ooo ' cix x cu -rond o r? : , 30 ’X 3 3;.. o:o xd: X o o.x jog *i;t n i. xLiroiq X. :■ 33 OX.X. X ■ X X : ' . . . T 3 -X 1 . . 3 n. : - ' r >*■ J ■ ■ ■ .. ot . , ;; o evX • ; X o o o ‘I o - X o j-'X e/s X i; o X tie a & £ qe *L Y, X 0 x e Orc ■/ . , .jjcxx. eoioacoori; i'd 8X oiIX Xo u axaoa xno ; x - x.x . ' . . [ I) &0 01 o ' : X • .X . - .3 i ©icrii oitfoic ?xoaoid'jjo x^Xsio riciX beiiiojOG aXIi/aox: . x: text do -XX I . l.soi 001X3 o;o'l oldXonocox-i oi o:. ioxi ' Loo ;:I ox lieooxxioXnX - .. ■' bo -X : X ; o x : ' • : . aexcoco i.ooiqvd' sXd' Xtiv; noixex axis a eXL xx . ACKNO'-^LEDGMENTS . The writer wishes to make grateful acknowledgment to all those who have given help in this investigation, especially to the following persons: To Dr. J.R. Fryer for suggesting the problem and making available the collection of Agropyrons brought together by W. Robinson, and for critising the manuscript; To Dr. O.S. Aamodt, for helpful suggestions in developing the plan of the work; To Mr. A.E. Clarke for assistance in. cytological methods; To Dr. l.H. Moss for information on the distribution of Agropyrons in certain sections of Alberta; To the following persons who supplied seed of the various species of Agropyrons Dr. L.S. Kirk, University of Saskatchewan Mr. P. Gussew, U.S.S.R. Institute of Applied Botany and New Cultures, Leningrad; The Secretary, Botanical Gardens of Tiflis, Caucase, Georgie, U.S.S.R.; Mr. A. Lange, Botanical Gardens of Copenhagen, Denmark; the late Dr. P.B. Kennedy, University of California. : : • • /. ' ■ '• J.'. / 'O J" ' ‘ . C _ - 1 — ; : t. I .O' ■- > ■ - -o- o . ; - iv;.:; o : o j c -f .. o u <«tEGi . • •-> - • '• o : . o/o o o \ ; nc so" ■ : : cl o o‘... ccoo'o . * o'-? . /.. : ' . ' - ' . o " ■ ' oo\; ' . • - • • ; . . O) ' o ■ , .o ..:o ■ . O J . . . . ■ . ■ . • •• • - ‘:o o o ‘ oo - . * . I o v .’0 :c.‘-v _ rv ' L- O Z ; T. ' C v , . / J . , :i.ul : . . - •• Cl . J • O £ c ‘.J J 0-1 , .. . . , .o., .o o':;- o:o:o.. ' . ; -ec ' oo; i. -O; soodooO ■ : • . : . oil. ; . . :J 44. LITERATURE CITED. (1) AASE, H.C., and POWERS, L. Chromosome numbers in crop plants. Amer. I. Bot. 13:567-372. 1926. (2) BELLING. JOHN. On counting chromosomes in pollen mother cells. Amer. Naturalist. 55:573-574. 1921. (3) CHAMBERLAIN, C.J. Methods in Plant Histology. The University of Chicago Press, Chicago, Ill. 1924. (4) CHURCH, G.L. Meiotic phenomena in certain Gramineae, I. Bot. Gaz. 87:608-629. 1929. (5) _ _ Meiotic phenomena in certain Gramineae, II. Bot. Gaz. 88:63-84. 1929. (6) DALBERG, R.C. Identification of seeds of species of Agropyron. J. Agr. Res. 3:275-282. 1914. (7) DAVIES, J.G. The chromosome number in Dactylis glomerata. Nature, 119:236-237. 1927. (8) ERLANSON, E.H. Cytological contributions and evidences for hybridity in North American wild roses. Bot. Gaz. 87:443-506. 1929. (9) EVANS G. Chromosome complements in grasses. Nature, 118:841. 1926. 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S v * o . j & x l.eo: . : u . : :■ xjxx.. .l o0':7'I A X do Olof j X 3 *X ■; r rTT 3TU fil dQ az Baemoaoziq o. ,SBx> ."1 ■ t © bc - . - : o i X . • ’ : - -t - . 'j- tit ' Of 9- f f ~ r ’• ' . ^ 7 • •• ,7 : 0.7; • ; . ’ • . ■; 8, . ■ 0 ,toc! . . . - ' . ■ • . X" -- X ’• • ?/x i . . C - • . ■ - • X .. : i o' oXc, Uri o, ov i X s*xb f f f; o eix : X : . t . c •: c • , i • t c ;; • x; i ■: f ' .o a o : . :• X } (OX) (XX) I ... . XX: a • - .o1,? - . .. ao ... ■ • . • .1 . a I i if1 X : ' fO'Xj '-.Xffo' X XX - , (SI) XX:,, . , x x X bob t , on. 1 t . OX Xce XX 11 LK o.fxXoo: vo f .f ■ • XX 0 ©0080 - 8'XX) . « -i n . . .. ■ - -■ ■ ■ - .D0‘ 73 r:: 00 3 0 3,2 3 13 Moi/Ib ‘i to ■: ole X 7 o fff aoXXoii ox ::Xx nO; n - . ... . : 1 - x. : It . . o o bit 1 - X . V ;■ XXX 9fl O' has noil X .. , ( ax ) am xx,x -“XXX : jci -xx llfXffXxxl: - 3:xiO'8GO I: r:.' n : ■ . ~.c, r ... 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