Mapping of Tolerance to Cereal Yellow Dwarf Virus in Two-Row Spring Barley

Cereal Yellow Dwarf Virus (CYDV-RPV) is a serious viral disease affecting small grain crops around the world. In the US, it is frequently present in California where it causes important losses when infections start early in the development stage resulting in plant death. CYDV is transmitted by aphids, and it has been a major challenge to develop malting barley in California. A segregating population of 184 recombinant inbred lines (RIL) was created from a cross between the moderately susceptible malting barley line Butta 12 to the CYDV tolerant Madre Selva, and was used to construct a genetic map including 180 polymorphic markers mapping to 163 unique loci. Tolerance to CYDV was evaluated for the entire population in replicated experiments where plants were challenged by aphid mediated inoculation with the isolate CYDV-RPV in a controlled environment. Quantitative trait loci (QTL) analysis revealed the presence of two major QTL for CYDV tolerance from Madre Selva on chromosomes 2H (Qcyd.MaBu-1) and 7H (Qcyd.MaBu-2), and 4 minor QTL from the moderately susceptible parent (Butta 12) on chromosomes 3H, 4H, and 2H. This poster discusses the contribution of each QTL and their potential value to improve barley resistance to CYDV.