Strawberry Parent Clones US 70, US 159, US 292, and US 438 Resistant to Anthracnose Crown Rot

Abstract

The clones described in this germplasm release were originated during an extended cooperative team effort by U.S. Dept. of Agriculture (USDA) and state agricultural experiment station personnel to overcome anthracnose crown rot disease limitations on strawberry (Fragaria ×ananassa Duch.) production in the southeastern United States. Our efforts to originate anthracnose-resistant strawberry germplasm started in 1975 with strawberry selection and fungal isolate contributions from the USDA, Univ. of Florida, Louisiana State Univ., and North Carolina State Univ. Breeding to develop regionally resistant host materials started at Beltsville, Md., in 1976 under the direction of A.D. Draper, who is now retired, and it has continued since 1977 under the direction of G.J.G. Starting in 1975, disease epidemiology information and isolate culture and inoculation techniques were developed in Poplarville, Miss., under the direction of B.J.S. (Smith and Black, 1987, 1990; Smith and Spiers, 1982; Smith et al., 1990). Originally, anthracnose crown rot was thought to be incited by Colletotrichum fragariae Brooks (Bonde et al., 1991); however, C. acutatum Simmonds has incited severe strawberry fruit rot (Simmonds, 1965; Smith and Black, 1987). Colletotrichum gloeosporiodes (Penz.) Penz. & Sacc. also may cause strawberry anthracnose crown and fruit rot (Smith and Black, 1990). Although all three fungal species may cause strawberry plant death, C. fragariae is the usual incitant in the U.S. Gulf Coast states, and C. acutatum is the principal anthracnose fruit rot incitant in this region (Howard et al., 1992). Anthracnose crown rot resistance inheritance models were determined by Gupton and Smith (1991). In addition to showing a high