Proposed Potato Variety Release

Proposed Potato Variety Release Proposed name: Owyhee Russet Experimental designation: AO96160-3 Botanical name: Solanum tuberosum L. Intended Market: French fry processing/fresh Market General Description: AO96160-3 originated from a cross made in 1996 by J. Pavek (USDA/ARS, Aberdeen, ID) between A89384-10 and A89512-3 (Figure 1). AO96160-3 was selected in Powell Butte, OR, in 1998 and was evaluated throughout Oregon from 1999 through 2002. It entered Tri-State (OR, ID, WA) evaluations in 2003 and Western U.S. evaluations in 2004. Oregon State University will take the lead in the release of this variety. The USDA/ARS and the Agricultural Experiment Stations of Idaho and Washington will be invited to join OSU in the release. AO96160-3 is a medium to late maturing selection with long, medium-russeted tubers. Total yields are similar to those of Russet Burbank, but AO96160-3 has higher percent of U.S. No. 1 tubers. AO96160-3 has high specific gravity, light fry color, few sugar ends, and few internal and external tuber defects. Relative strengths include high yield with a very high proportion of U.S. No. 1 tubers, good tuber appearance, excellent processing quality, resistance to common scab and Fusarium dry rot, moderate susceptibility to PVY and PLRV. Weaknesses include susceptibility to foliar and tuber late blight and susceptibility to metribuzin herbicide injury. Plant Characteristics: AO96160-3 has semi-erect medium sized vines (Table 1. Figure 2A) with medium to late maturity (120-125 DAP). Flowers are purple violet (Figure 2B) with some pollen production. Berries are usually not produced under field conditions; however, AO96160-3 is both male and female fertile under greenhouse conditions. Table 1. Comparative plant characteristics of AO96160-3 and Russet Burbank. Characteristic AO96160-3 Russet Burbank Maturity Medium-late Medium-late Growth habit Semi-erect Semi-erect Leaf type (silhouette) Open Open Leaflet shape (terminal) Medium ovate Narrowly ovate Terminal leaflet waviness Slight Slight Flower color Purple violet White Pollen production Some None Tuber Characteristics: AO96160-3 produces long, medium-russeted tubers (Table 2, Figure 2C). The 1

average tuber weight is higher than Russet Burbank. The tuber eyes are evenly distributed and moderate in number (Table 2). AO96160-3 light sprouts (Figure 2D) are conical, with overall (tip and tip of base) strong pubescence and strong blue-violet anthocyanin pigmentation. Some root initials are present on the base of the sprout and the tip of the sprout has intermediate habit. Table 2. Physical tuber characteristics of AO96160-3 compared with those of Russet Burbank. Characteristic AO96160-3 Russet Burbank Skin color Tan Tan Skin texture Russeted Russeted Size 1 Medium (Av = 7.0 oz.) Medium (Av = 6.2 oz.) Shape 2 Long (L/W ratio = 1.82) Long (L/W ratio = 1.97) Thickness Slightly flattened Slightly flattened Eye depth Shallow Intermediate Eye number Intermediate Intermediate-high Eye distribution Evenly Evenly Eyebrow prominence Slight None Flesh color White White Tuber set Medium Medium Dormancy Medium Long 1 Tuber size data were collected from 3 Tri-State and 5 Western Regional late harvested trials, 2003-04. 2 Length/width (L/W) ratios collected from 12 Oregon Statewide variety trials, 2001-04. Tuber Yield: Total yield potential for AO96160-3 is similar to that of Russet Burbank and Ranger Russet but significantly higher than Russet Norkotah based (Table 3). U.S. #1 tuber yield of AO96160-3 is significantly higher than Russet Burbank and Russet Norkotah, resulting in substantially more yield of marketable quality potatoes (Table 3). 2

Table 3. Tuber yields of AO96160-3 compared to those of Russet Burbank, Ranger Russet and Russet Norkotah in Western Regional 1 trials from 2004-2006. Variety Total yield U.S. #1 yield 2 U.S.#1 cwt/a cwt/a % AO96160-3 572 491 85 Russet Burbank 584 353 61 Ranger Russet 575 450 78 Russet Norkotah 427 346 81 Mean 539 410 76 CV (%) 15 20 11 LSD (0.05) 46 48 5 1 Western Regional variety trials were conducted at 8 locations in California, Colorado, Oregon, Idaho and Washington. 2 US#1 yield considering only tubers greater than 6 oz. Tuber Quality Characteristics: AO96160-3 produces tubers with significantly higher specific gravity than Russet Burbank and Russet Norkotah. Color of fried strips following tuber storage at 40 F and 45 F is also significantly lighter for AO96160-3 than the comparison varieties (Table 4). Table 4. Tuber specific gravity French fry color and dry matter of AO96160-3, Russet Burbank, Ranger Russet, and Russet Norkotah. Variety Specific gravity 1 Fry color (40 F) 2 Fry color (45 F) 2 AO96160-3 1.0887 2.49 0.72 Russet Burbank 1.0791 3.59 1.61 Ranger Russet 1.0875 3.08 1.50 Russet Norkotah 1.0726 _ 1.77 Mean 1.0820 3.05 1.40 CV (%) 0.4748 20.15 46.45 LSD (0.05) 0.0034 0.60 0.43 1 Specific gravity data from Western Regional potato variety trials grown in Oregon, Washington, Idaho, Colorado, and California from 2004-06. 2 French fry color of tubers stored at 4 C (40 F) and 9 C (45 F) sampled from the Western Regional potato variety trials. USDA color chart [0 (lightest) 4 (darkest)] Internal and External Defects: AO96160-3 tubers are less susceptible to growth cracks, second growth, hollow heart/brown center, internal brown spot and blackspot bruise than are Russet Burbank 3

tubers. However, AO96160-3 tubers show more vascular discoloration than Russet Burbank tubers (Table 5). Table 5. Internal and external tuber defects for AO96160-3 and Russet Burbank. Defect 1@ AO96160-3 Russet Burbank Growth cracks 2 4.9 4.2 Second growth 2 4.8 2.8 Shatter bruise 2 4.4 4.6 Blackspot bruise 3, % 5 7 Hollow heart/brown center 3, % 0.7 6.5 Internal brown spot 3, % 2.7 9.2 Vascular discoloration 3, % 11.7 5.5 1 Second growth data taken from Tri-State and Western Regional trials conducted in 2003 2004. All other data were taken from 8 to 16 trials grown in Oregon from 2001 2004. 2 1 5 scale where 1 = severe occurrence of the defect and 5 = no occurrence of the defect. 3 Percent of tubers >10/12 ounce with the defect. Biochemical Composition: The biochemical makeup of AO96160-3 is very similar (not significantly different) to that of Russet Burbank (Table 6). Table 6. Biochemical composition of AO96160-3 and Russet Burbank tubers. Data were taken from 2004-2006 Aberdeen, Idaho trials. Component AO96160-3 Russet Burbank Solids (%) 21.73 20.20 Dextrose (% FWB) 0.08 0.11 Sucrose (% FWB) 0.15 0.16 Protein (% DWB) 1 6.2 5.0 Vitamin C (mg/100g) 24.7 23.2 Glycoalkaloids (mg/100g) 3.1 3.1 Disease Reactions: AO96160-3 tubers are resistant to common scab and moderately resistant to Verticillium wilt, foliar early blight and bacterial soft rot (Table 7). AO96160-3 and Russet Burbank and approximately equal susceptibility to foliar late blight infection (Table 7). 4

Table 7. Disease reactions of AO96160-3 and Russet Burbank in trials conducted in Idaho and Oregon, 2003-04. Disease AO96160-3 Russet Burbank Common scab (Streptomyces) (%) 1 0.7 1 Verticillium wilt (Verticillium) 2,3 5.4 7.9 Foliar early blight (Alternaria) 1,3 5.3 3.8 Dry rot (F. sol. var. coer.) 1,4 1.6 3.7 Pectobacterium soft rot 1,4 3.2 2.9 PVY 2 (%) 75 94 PLRV foliar infection 2 (%) 65 93 Late blight (P. infestans) foliar 5,3 8.8 8.7 1 Evaluations made at Aberdeen, Idaho 2 Evaluations made at Hermiston, Oregon. Virus readings are from evaluation of plants grown under high virus pressure 3 Scale used was 1-9, highest number being most severe 4 0-5 scale, highest number being most severe 5 Evaluations made at Corvallis, Oregon Protection, seed availability and licensing: Plant Variety Protection (PVP) will be requested for Owyhee Russet. Diseasefree pre-nuclear plantlets and minitubers are available from the Foundation Potato Seed Program at Oregon State University and from the University of Idaho Tissue Culture Laboratory. Based on an agreement between OSU, the Oregon Potato Commission, and the Potato Variety Management Institute (PVMI), Owyhee Russet will be licensed to PVMI, a non-profit organization working on behalf of the Tri-State Potato Breeding Program. The mode of release (public or semi-exclusive) is still under consideration. 5

AO96160-3 A89384-10 A89512-3 A79046-10 A84281-5 A79172-7 A74133-1 A84069-5 A78016-14 Lemhi Russet COO80014-1 WNC672-2 A75032-1 A83041-5 A75188-3 A68113-4 A70365-6 A70365-6 Lemhi Russet A66107-51 A67089-7 A69327-5 A70906-1 Pioneer A63126-8 A63034-20 Lenape A66102-13 NDA86094-3 A67089-7 A66110-7 Figure 1. Pedigree of AO96160-3. AO96160-3 resulted from the hybridization between A89384-10 (female) and A89512-3 (male) 6

A B C D Figure 2. Photographs of AO96160-3 showing: A) whole plant; B) flowers; C) whole tubers; and D) light sprout. 7

NOTICE OF NAMING AND RELEASE OF Owyhee Russet A RUSSET VARIETY WITH HIGH YIELD OF MARKEATABLE TUBERS, HIGH PROCESSING QUALITY AND FEW TUBER DEFECTS Director, Oregon Agricultural Experiment Station Date Director, Washington Agricultural Experiment Station Date Director, Idaho Agricultural Experiment Station Date Administrator, USDA-Agricultural Research Service Date 8