Guo Yanli, Si Ping, Wang Nan, Wen Jing, Yi Bin, Ma Chaozhi, Tu Jinxing, Zou Jitao, Fu Tingdong, Shen Jinxiong
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China.
Center for Plant Genetics and Breeding, School of Plant Biology, the University of Western Australia (M080), 35 Stirling Highway, Crawley, WA, 6009, Australia.
BMC Genet. 2017 Jan 5;18(1):1. doi: 10.1186/s12863-016-0468-0.
As seed oil content (OC) is a key measure of rapeseed quality, better understanding the genetic basis of OC would greatly facilitate the breeding of high-oil cultivars. Here, we investigated the components of genetic effects and genotype × environment interactions (GE) that govern OC using a full diallel set of nine parents, which represented a wide range of the Chinese rapeseed cultivars and pure lines with various OCs.
Our results from an embryo-cytoplasm-maternal (GoCGm) model for diploid seeds showed that OC was primarily determined by genetic effects (V) and GE (V), which together accounted for 86.19% of the phenotypic variance (V). GE (V) alone accounted for 51.68% of the total genetic variance, indicating the importance of GE interaction for OC. Furthermore, maternal variance explained 75.03% of the total genetic variance, embryo and cytoplasmic effects accounted for 21.02% and 3.95%, respectively. We also found that the OC of F seeds was mainly determined by maternal effect and slightly affected by xenia. Thus, the OC of rapeseed was simultaneously affected by various genetic components, including maternal, embryo, cytoplasm, xenia and GE effects. In addition, general combining ability (GCA), specific combining ability (SCA), and maternal variance had significant influence on OC. The lines H2 and H1 were good general combiners, suggesting that they would be the best parental candidates for OC improvement. Crosses H3 × M2 and H1 × M3 exhibited significant SCA, suggesting their potentials in hybrid development.
Our study thoroughly investigated and reliably quantified various genetic factors associated with OC of rapeseed by using a full diallel and backcross and reciprocal backcross. This findings lay a foundation for future genetic studies of OC and provide guidance for breeding of high-oil rapeseed cultivars.
由于种子含油量（OC）是油菜籽品质的关键指标，深入了解OC的遗传基础将极大地促进高油品种的培育。在此，我们利用9个亲本的完全双列杂交组合，研究了控制OC的遗传效应成分和基因型×环境互作（GE），这9个亲本代表了中国油菜籽品种和具有不同OC的纯系的广泛范围。
我们对二倍体种子的胚-细胞质-母体（GoCGm）模型的研究结果表明，OC主要由遗传效应（V）和GE（V）决定，它们共同占表型变异（V）的86.19%。单独的GE（V）占总遗传变异的51.68%，表明GE互作对OC的重要性。此外，母体变异解释了总遗传变异的75.03%，胚和细胞质效应分别占21.02%和3.95%。我们还发现F种子的OC主要由母体效应决定，受异粉受精的影响较小。因此，油菜籽的OC同时受到多种遗传成分的影响，包括母体、胚、细胞质、异粉受精和GE效应。此外，一般配合力（GCA）、特殊配合力（SCA）和母体变异对OC有显著影响。品系H2和H1是良好的一般配合系，表明它们将是改善OC的最佳亲本候选系。杂交组合H3×M2和H1×M3表现出显著的SCA，表明它们在杂种发育中的潜力。
我们的研究通过使用完全双列杂交、回交和正反交，全面研究并可靠地量化了与油菜籽OC相关的各种遗传因素。这些发现为未来OC的遗传研究奠定了基础，并为高油油菜品种的育种提供了指导。
