Agronomic and quality impact of a shortened translocation for wheat streak mosaic virus resistance

Abstract

Wheat streak mosaic virus (WSMV) is a mite-vectored virus with substantial economic impact on wheat production. One of the effective sources of resistance to WSMV, Wsm1, is carried on a translocation from Thinopyrum intermedium. The original whole arm form of this translocation (T4DL·4JsS) was highly effective against WSMV but carried a substantial yield penalty in the absence of the virus. Shorter recombinants of the Th. intermedium translocation are now available. This study characterized the agronomic performance of near-isogenic sib-pair families in 10 yield trials using one of these shortened T4DL·4DS-4JsS translocations, named “rec213,” in the absence of visible disease. This translocation had no effect on heading date, was associated with a modest reduction (≤ 4.8 cm) in plant height, and the translocation had a favorable effect (≤ 12.6%) on grain yield in those environments where highly significant genotype effects were detected. The translocation did not affect protein concentration or lactic acid-sodium dodecyl sulfate solvent retention capacity, a measure of gluten quality. However, families with the translocation had slightly (≤ 5%) lower protein quality scores than paired families without the translocation. We do not expect this modest difference in quality to be a barrier to utilization of the rec213 translocation for Wsm1, but we encourage breeders to work within high-quality genetic backgrounds when using the rec213 translocation and to monitor the quality of breeding selections. Improved codominant PCR-based marker assays were developed to facilitate the use of the rec213 Wsm1 trait in breeding programs.