Chen Guolin, Wu Jianguo, Variath Murali-Tottekkaad, Shi Chunhai
Department of Agronomy, Zhejiang University, Hangzhou, 310029, People's Republic of China.
J Genet. 2011 Dec;90(3):459-68. doi: 10.1007/s12041-011-0120-8.
Experiments were conducted on rapeseed (Brassica napus L.) using a diallel design with nine parents: Youcai 601, Double 20-4, Huashuang 3, Gaoyou 605, Zhongyou 821, Eyouchangjia, Zhong R-888, Tower and Zheshuang 72. The seed developmental process was divided into five stages, namely initial (days 1-15 after flowering), early (days 16-22 after flowering), middle (days 23-29), late (days 30-36), and maturing (days 37-43) developmental stages. The variation of dynamic genetic effects for leucine and isoleucine contents of rapeseed meal was analysed at five developmental stages, across different environments using the genetic models with time-dependent measures. The results from unconditional and conditional analyses indicated that the expression of diploid embryo, cytoplasmic and diploid maternal plant genes were important for leucine and isoleucine contents at different developmental stages of rapeseed, particularly at the initial and early developmental stages. Among different genetic systems, nutrition quality traits were mainly controlled by the accumulative or net maternal main effects and their GE interaction effects, except at maturity when the net diploid embryo effects were larger. The expression of genes was affected by the environmental conditions on 15, 22, 29 or 36 days after flowering, but was more stable at mature stage. For the isoleucine content the narrow-sense heritabilities on 15, 22, 29, 36, and 43 days after flowering were 43.0, 65.7, 60.1, 65.5 and 78.2%, respectively, while for the leucine content the corresponding narrow-sense heritabilities were relatively smaller. The interaction heritabilities were more important than the general heritabilities at the first three developmental times. The improvement for isoleucine content could be achieved by selection based on the higher narrow-sense heritabilities. Various genetic systems exhibited genetic correlations among the developmental times or leucine and isoleucine contents. A simultaneous improvement of leucine and isoleucine contents seems possible because of the significant positive genetic correlation components from different genetic systems at different developmental times.
以9个亲本（油彩601、双20-4、华双3、高邮605、中油821、鄂油长荚、中R-888、Tower和浙双72）采用双列杂交设计对油菜（甘蓝型油菜）进行了试验。种子发育过程分为五个阶段，即初期（开花后1 - 15天）、早期（开花后16 - 22天）、中期（开花后23 - 29天）、后期（开花后30 - 36天）和成熟（开花后37 - 43天）发育阶段。采用具有时间依赖性测量的遗传模型，分析了不同环境下油菜籽粕中亮氨酸和异亮氨酸含量在五个发育阶段的动态遗传效应变化。无条件分析和条件分析结果表明，二倍体胚、细胞质和二倍体母本植物基因的表达对油菜不同发育阶段的亮氨酸和异亮氨酸含量很重要，尤其是在初期和早期发育阶段。在不同遗传体系中，营养品质性状主要受累积或净母本主效应及其基因环境互作效应控制，但在成熟时净二倍体胚效应较大。基因表达受开花后15、22、29或36天环境条件的影响，但在成熟阶段更稳定。对于异亮氨酸含量，开花后15、22、29、36和43天的狭义遗传力分别为43.0%、65.7%、60.1%、65.5%和78.2%，而对于亮氨酸含量，相应的狭义遗传力相对较小。在前三个发育时期，互作遗传力比广义遗传力更重要。基于较高的狭义遗传力进行选择可以实现异亮氨酸含量的改良。不同遗传体系在发育时期或亮氨酸和异亮氨酸含量之间表现出遗传相关性。由于不同遗传体系在不同发育时期存在显著的正遗传相关成分，同时提高亮氨酸和异亮氨酸含量似乎是可能的。
