Dynamic genetic effects on threonine content in rapeseed (Brassica napus L.) meal at different developmental stages

Dynamic genetic effects on threonine content (TC) of rapeseed (Brassica napus L.) meal were analysed at 5 developmental times/stages using the genetic models for diploid plant seeds. Results indicated that the expression of diploid embryo, cytoplasmic and diploid maternal plant genes were all important for the performance of TC at various developmental times/stages of rapeseed, especially at the early and middle developmental stages. Among different genetic systems, TC was mainly controlled by the cumulative or net maternal main effects and the genotype × environment (GE) interaction effects, followed by the embryo main effects and GE interaction effects. The expression of genes was more easily influenced by the environmental factors at the first three developmental stages. The total narrow-sense heritabilities for TC on 15, 22, 29, 36 and 43 days post anthesis were 46.50, 62.60, 57.10, 84.70 and 59.50%, respectively, of which the interaction heritabilities were more important at the first three developmental stages of rapeseed. The improvement in TC of rapeseed meal could be expected by selection based on the higher narrow-sense heritabilities near maturity. The predicted genetic effects of parents showed that TC of progeny could be improved by using the parent Gaoyou 605.