Abstract:In order to establish a high efficiency breeding technic course of BYDV resistance in wheat, BYDV resistance genetic character was studied through inoculating GAV plant strain with young plant leaves, female with three materials including BYDV resistance gene and male with four fertility varieties. Combining ability and genetic ability of BYDV resistance were analyzed using 3×4 incomplete diallel in F1, in which two combinations were selected for yield and disease resistance. Separating scatter, genetic variance and genetic ability of BYDV resistance were analyzed from F2 to F4. The results showed that the heredity of BYDV resistance is controlled by the effect of gene, with additive and non-additive in the ratio of 38.2 ∶ 1. BYDV resistance heredity is decided by sensitivity of sense parent to BYDV. The colony separate scatter and variance are different in same generation of different genetic background, while average BYDV resistance value has a litter variation in different generations of same genetic background. Variance coefficients of BYDV resistance value reduces rapidly when generation added, and BYDV resistance gene purify rapidly. There has a high genetic ability of BYDV resistance. Its narrow sense heritability is between 75% and 90%, and the broad over 90%. So BYDV resistance character can be identified and selected in early generations in disease-resistance breeding work.