Wheat streak mosaic virus resistance studies in winter wheat.

摘要

Wheat streak mosaic virus is a major threat for wheat (Triticum aestivum L. em. Thell.) worldwide. Little information is known on the genetics controlling WSMV resistance in winter wheat. Our objectives were to (i) evaluate the winter wheat genotypes grown in South Dakota Advanced Yield Trials for their resistance to WSMV, (ii) determine the combining abilities using diallel analysis, and (iii) determine the inheritance of WSMV resistance in winter wheat. Fifty winter wheat genotypes were used for the first study. Nine parents with different level of resistance to WSMV were used for the diallel study. Two crosses of winter wheat involving three parents, 'OK65C93-8': resistant, 'Tandem': susceptible, and 'Vista': susceptible were used for the inheritance study. Dawn and Jagger were among nine winter wheat genotypes classified as resistant to WSMV (LSD = 0.58) in both greenhouse and field conditions. Both general combining ability (GCA) and specific combining ability (SCA) were highly significant (P < 0.01). The GCA effects were higher than SCA effects, indicating that additive gene effects largely control the inheritance of WSMV resistance in the plant material used. One major single recessive gene and one single dominant gene control the resistance to WSMV in OK65C93-8 winter wheat line. Additive, dominance, and epistasis are all involved in the inheritance of WSMV resistance. Due to the highly significant (P < 0.01) additive genetic variation observed in both crosses, selection for WSMV resistance in the early generations should be effective. Narrow sense and broad sense heritabilities were intermediate to high (0.43--0.91), indicating that WSMV resistance is a heritable trait. These results demonstrate that considerable progress may be expected from selection for WSMV resistance in segregating winter wheat populations.