NOTICE- Return or renew all Library Materials! The Minimum Fee for each Lost Book la $50.00. The person charging this material is responsible for its return to the library from which it was withdrawn on or before the Latest Date stamped below. Theft, mutilation, and underlining of books are reatona for discipli- nary action and may result in dismissal from the University. To renew call Telephone Center, 333-8400 UNIVERSITY OF ILLINOIS LIBRARY AT URBANA-CHAMPAIGN UNiV ILLINC <\T URF3A AGRICI L16I— O-I096 t, Co-op 27, 28, 29, 30, and 31: Five Disease-Resistant Apple Selections Released for Advanced Testing S.S. Korban, PA. O'Connor, S.M. Ries, }. Janick, J.A. Crosby, and P.C. Pecknold Bulletin 789 Agricultural Experiment Station — College of Agricul- ture—University of Illinois at Urbana-Champaign in co- operation with the Agricultural Experiment Station of Purdue University, West Lafayette, Indiana. Five new apple selections — Co-op 27, 28, 29, 30, and 31 — are being offered for advanced testing. These selections have field immunity to apple scab caused by Venturia inaequalis (Cke.) Wint. and varying degrees of resistance to fire blight incited by Erwinia amylovora (Burr.) Winslow et al., to cedar-apple rust incited by Gymnosporangium juniperi-virginianae (Schw.), and to powdery mildew incited by Podosphaera leucotricha (Ell. & Ev.) Salm. This is the sixth in a series of releases from a cooperative breeding program at the agricultural experiment stations of Illinois and Indiana. This new series differs from previous ones in that all selections mature relatively late in the harvest season. They represent our continued efforts to increase resistance in apple to these diseases. The selections are identified by the designation, "Co-op," to emphasize the cooperation and joint effort of this program. Co-op 1 through 5 were described in Purdue University Agricultural Experiment Station Research Progress Report 271 (1967); Co-op 6 through 11, in Purdue University Agricultural Experiment Sta- tion Research Progress Report 399 (1972); Co-op 12 through 18, in Purdue University Agricultural Experiment Station Bulletin No. 69 (1975); Co-op 19 through 22, in University of Illinois Agricultural Experiment Station Bulletin 755 (1977); and Co-op 23 through 26, in Purdue University Agricultural Experiment Station Bulletin No. 456 (1984). Only a small amount of propagation wood is currently available; therefore, distribution must be limited. All distributions will be bound by an agree- ment in which further propagation of the material is prohibited without prior consent of the experi- ment station involved. It is our intention to patent worthy selections. PARENTAGE Co-op 27 through 31 descend from crosses involving a small-fruited ornamental crabapple, Malus floribunda 821, made early in this century by the late C.S. Crandall of the University of Illinois. Co-op 27 derives from F226830-2, and Co-op 28 through 31 are derived from F226829-2-2. i— 9433-2-2 — , F,26829-2-2 — F,26830-2 L— 9433-2-8 —I Rome Beauty Malus ' floribunda 821 The present program, initiated by J.R. Shay, formerly of Purdue University, and L.E Hough, then of the University of Illinois, utilized these resistant selec- tions derived from Malus floribunda 821 along with many other genetic sources of resistance. The fruit of F226829-2-2 was the largest and highest in quality of the resistant material then available. Of the 31 Co-op selections released since 1967, 28 descend from this clone, and 3 descend from its sister seedling, F226830-2. BREEDING SYSTEM The "floribunda" resistance to apple scab is conditioned by a single dominant gene, Vf. Both F226829-2-2 and F226830-2 are heterozygous for this gene. When crossed to susceptible genotypes, they produce seedlings, half of which are resistant. The susceptible progeny are identified by green- house screening tests and eliminated at the seedling stage. Seedling trees grown for first fruiting test in the field receive no fungicide protection, thus allowing for selection for field resistance to several other diseases. The breeding system that produces these selections involves a modified backcross pro- gram with the horticulturally most resistant selec- tions of each generation crossed to high-quality susceptible types. In the illustrated pedigrees, the seed parent is the upper selection in each bracketed cross. NOV 1 * 1998 AODini II TIIDC I IDDAttX/ SELECTION DESCRIPTIONS 'Jonafree' (Co-op 22), in 1979; 'Redfree' (Co-op 13), Co-op 1 through 26 in 1981; 'Dayton' (Co-op 21), named in honor of D.F. Dayton in 1988; and 'Williams' Pride" (Co-op Seven selections from this group have been 23), named in honor of E.B. Williams also in 1988. named: 'Prima' (Co-op 2), in 1970; 'Priscilla' (Co- The distinguishing characteristics of all Co-op op 4), in 1972; 'Sir Prize' (Co-op 5), in 1975; selections are summarized in the table. Co-op 1 through 31: Fruit Color and Maturity Season Maturity relative to Co-op Progeny number' Color Prima Delicious weeks .... 1 1235-101 red -2 -6 2 (Prima) 1225-100 red 0 -4 3 1686-1 red -1 -5 4 (Priscilla) 1659-1 red +2 -2 5 (Sir Prize) 673-20 yellow +4 0 6 1500-100 red -P/2 -S'/z 7 2023-1 red -1 -5 8 1326-1 red +lVi -2>/2 9 1677-2 red +3 -1 10 1659-10 yellow +4 0 11 1947-104 red +6 +2 12 2175-25 red -4 -8 13 (Redfree) 2175-7 red -3 -7 14 1325-101 red -2 -6 15 1569-100 red + 1 -3 16 2174-3 yellow +4 0 17 1689-110 yellow +7 +3 18 1983-207 red +5 + 1 19 2318-104 red -4 -8 20 1691-100 red -2 -6 21 (Dayton) 2259-100 red 0 -4 22 (Jonafree) 2016-100 red +3 -1 23 (Williams' Pride) 2845-1 red -3 -7 24 2058-2 red +3 -1 25 2712-4 red +3 -1 26 1659-100 red +4 0 27 1947-105 red +5 +1 28 2929-104 red + 2'/2 -l'/2 29 2050-4 yellow + 6'/2 + 2'/2 30 2693-1 red +6% + 2>/2 31 2463-101 red +6 +2 ' Selections 1 to 99 selected at Lafayette, Indiana; 100 to 199, at Urbana, Illinois; 200 +, at Cream Ridge, New Jersey. Co-op 27 1947-105 — — Winesap — open pollinated — 1042-100 — - Idared — 187-6 — — Jonathan ^49-102— — F,26830-2 — Delicious This selection ripens from October 5 to October 10 at Urbana, Illinois, about five weeks after Trima'. Fruit 21/? to 3 inches, round to roundish oblate. Color 90 percent medium to dark red, splashed over a pale yellow ground color. Flesh cream colored, fine grained, firm to crisp, and juicy. Mildly to sprightly acidic, spicy, and full flavored. Dessert quality is good to very good. Co-op 27 keeps well in refrigerated storage until late spring. Field immune to scab and cedar rust, Co-op 27 has a high level of resistance to fire blight and moderate resistance to mildew. Its spur-type growth pattern is similar in habit to that of 'Red Delicious' strains, and it blooms moderately early. First selected by D.F. Dayton and tested as PWR37T131. Co-op 28 -1982- {Crandall rtt. 14-226 _J 2929-104- — NJ37 L- F,26829-2-2 T Golden Delicious -Prima— L_F226829-2-2 I- NJ 11 7637 -NJ 123249- -C IMelba Wealthy x Starr -NJ12— T Red Rome Melba This selection matures from September 10 to September 18 at Urbana, Illinois, from 2 to 2Vz weeks after Trima'. Fruit 23/s to 23A inches, oblate- conic. Color 75 to 99 percent medium red on a greenish yellow background, bright and attractive with conspicuous lenticels. Flesh white, crisp, medium textured, and moderately juicy. Mildly acidic, spicy, and full flavored. Dessert quality is very good to excellent. Fruit hangs well and retains texture and quality for several weeks. Co-op 28 is field immune to scab and has good resistance to cedar rust and mildew. In 1989, this selection exhibited susceptibility to fire blight in the orchard at Urbana, Illinois, and therefore is not recommended for areas where fire blight is a problem. Its vigorous, upright spreading tree blooms early to mid-season. First selected by D.F. Dayton and tested as PSER8T19. Co-op 29 —Golden Delicious 2050-4 — •Winter Banana -1050NJ1 {VVIIIlt 2-19 {Mclntosn F,26829-2 26829-2-2 This selection matures from October 10 to October 18 at Urbana, Illinois, about 6Vz weeks after Trima'. Fruit 3 inches, round to short-conic. Color is self yellow with a moderate pink blush. Russet on stem end and lenticels. Flesh cream colored, coarse textured, very crisp, breaking, and juicy. Mildly to sprightly acidic, spicy, and full flavored. Dessert quality is very good to excellent. Field immune to scab, cedar rust, and fire blight, and moderately resistant to powdery mildew. Co- op 29 has an upright tree type with limber wood and blooms early to mid-season. It retains its quality after 7 months in storage at 34°F (1°C). First selected by E.B. Williams and tested as HCR14T125. Co-op 30 — Mclntosh —1661-2 — 2693-1 — — 612-1 — — Mclntosh —1661-1 — — 612-1 — — Starking Delicious, Giant Limb — Golden Delicious -14-126 _ — F226829-2-2 ,— Starking Delicious, Giant Limb I — Golden Delicious -14-126 — — F,26829-2-2 This selection matures from October 10 to October 18 at Lafayette, Indiana, about 6 '/a weeks after Trima'. Fruit 23/s inches, round. Color is 75 to 100 percent medium red to orange, washed over a greenish yellow background. The Mclntosh-like finish is very bright and shiny. Co-op 30 is attractive with inconspicuous lenticels. Flesh pale yellow to cream colored, medium textured, very crisp, break- ing, and juicy. Mildly acidic, spicy, and very full flavored. Dessert quality is very good to excellent. Co-op 30 is field immune to scab and moderately resistant to cedar rust, fire blight, and mildew. This selection retains quality after 6 months in storage at 34°F (1°C). It blooms moderately late. Fist se- lected by E.B. Williams and tested as CLR4T3& Co-op 31 i— NJ 381049- i— ROCK41-112- 2463-101- Yellow \ Newtown — NJ 55737— I— Edgewood r- Red Rome — NJ 35437 J L Jonathan This selection matures from October 10 to October 15 at Lafayette, Indiana, about six weeks after Trima'. Fruit 2% to, 3 inchest' round. Color is 100 percent dark purple* rod, striped and splashed ^^ >v • l "Q . . . l * , •JS? over a greer\^fc^e.llo*«j| .«||fcjgfbt8ifd'. tffne finish is moderate to Bngnt and tends to have scarf y skin. Flesh cream colored, medium to coarse textured, very crisp, and juicy. Mildly acidic, spicy, and full flavored. Co-op 31 blooms in mid-season. Dessert quality is very good. Field immune to scab with good resistance to fire blight and moderate resistance to mildew, it is moderately susceptible to cedar rust. Co-op '31 retains its quality after about eight or nine months in storage at 34°F (1°C). First selected by D.F. Dayton and tested as PAR4T215. -841-103- -Cox Orange Pippin {Jonathan F226829-2-2 — Starking Prepared by S.S. Korban, associate professor of plant genetics, Department of Horticulture, University of Illinois at Urbana-Champaign P.A. O'Connor, research specialist in agriculture, Department of Horticulture, University of Illinois at Urbana-Champaign S.M. Ries, associate professor, Department of Plant Pathology, University of Illinois at Urbana- Champaign J. Janick, James Troop Distinguished Professor, Department of Horticulture, Purdue University, West Lafayette, Indiana :}.•&, jCrosfcy,' professional assistant coordinator, Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana PC. Pecknold, professor, Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana.'* The Illinois •Agricultural Experiment Station provides equal opportunities in programs and employment. 2M— 4-90— United— AD