Inheritance of resistance of Chinese cabbage ( Brassica campestris L.) to diamondback moth ( Plutella xylostella ).

摘要

In order to understand the genetic mechanism of the pest-resistance in elite Chinese cabbage germplasm and effective utilization of the pest-resistant gene resources for pest-resistance breeding and further study in Chinese cabbage, crosses between eight inbred lines with different resistances to diamondback moth (DBM) were used in this study. Combining ability, genetic components and genetic models were estimated by using Griffing II, Hayman methods and joint analysis of six generations. The results showed that the parents with high G.C.A could produce good F₁ with high S.C.A. The resistance to DBM was recessive and the susceptibility was partially dominant. The narrow sense and the broad sense heritability of the pest-resistance were 65.71 and 77.87%, respectively. The inheritance of pest-resistance fit the 'additive-dominant' model. The additive effect played a major role. The best fit model of the resistance inheritance was one pair of major additive-dominant gene plus additive-dominant polygenes (D-1 model). The heritability of the major genes in BC₁P₁, BC₁P₂ and F₂ populations was respectively 58.26, 3.27 and 41.11%, and the heritability of polygenes in the corresponding populations was separately 0, 34.11 and 5.9%.