Identification of quantitative Loci for tolerance to barley yellow dwarf virus in oat

ABSTRACT Molecular markers linked to quantitative trait loci conditioning tolerance to barley yellow dwarf virus (BYDV) were identified in oat (Avena sativa) using amplified fragment length polymorphism (AFLP) analysis. Near-isogenic and recombinant inbred lines (NILs and RILs, respectively) derived from a cross of Clintland64 (BYDV-sensitive) and IL86-5698 (BYDV-tolerant) were evaluated for their responses to an Illinois isolate of the PAV strain of BYDV. Individual markers identified in the analysis of the NILs explained up to 35% of the variability seen in the tolerance response. Single-point analysis of the marker data from the RIL population identified 24 markers in three linkage groups that were associated with tolerance to BYDV infection at P /= 3.0. These loci explained about 50% total of the variation in BYDV tolerance in multimarker regression analysis in both years. The BYDV tolerance loci A, C, E, and R were mapped to hexaploid oat restriction fragment length polymorphism linkage groups 2, 8, 36, and 5, respectively, by analyzing the segregation of the AFLP markers in the Kanota x Ogle RIL population.