Genetic analysis of plant height using mixed major gene plus polygenes inheritance model in non-heading Chinese cabbage

The mixed major-gene plus polygene inheritance model was used to analyze the inheritance of plant height in the non-heading Chinese cabbage(Brassica campestris ssp.chinensis Makino)cross between SI and Qiu 017.The results showed that the plant height was controlled by one completely negative complete dominant major-gene plus additive-dominant polygenes.The additive effect for major-gene was 5.79,the additive and dominant effect for polygenes were-7.85 and 14.95,respectively.The major-gene heritabilities in B1,B2 and F2 were 33.28%,37.05% and 51.68%,respectively,and the corresponding polygenic heritabilities were 5.84%,12.67% and 1.34%,respectively.These results indicated that major gene in F2 was a key factor and environment factor was also relatively important.This implies that in the genetic improvement of plant-height major-gene is a main factor whereas environmental effect should be taken care of.