Li Na, Peng Wei, Shi Jiaqin, Wang Xinfa, Liu Guihua, Wang Hanzhong
Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, Hubei Province, 430062, China.
Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, Hubei Province, 430062, China; College of Life Science, Hubei University, Wuhan, Hubei Province, 430062, China.
PLoS One. 2015 Apr 27;10(4):e0125360. doi: 10.1371/journal.pone.0125360. eCollection 2015.
Seed weight is a very important and complex trait in rapeseed (Brassica napus L.). The seed weight of rapeseed shows great variation in its natural germplasm resources; however, the morphological, cytological and genetic causes of this variation have remained unclear. In the present study, nine highly pure inbred rapeseed lines with large seed weight variation and different genetic backgrounds were selected for morphological, cytological and genetic studies on seed weight. The results showed the following: (1) Seed weight showed an extremely significant correlation and coordinated variation with seed size (including seed diameter, seed surface area and seed volume), but it showed no significant correlation with bulk density, which suggests that seed weight is determined by size rather than bulk density. (2) Seed weight showed a higher correlation with the cell numbers of seed coats and cotyledons than the cell sizes of seed coats and cotyledons, which suggests that cell number is more tightly correlated with final seed weight. (3) Seed weight was mainly controlled by the maternal genotype, with little or no xenia and cytoplasmic effects. This is the first report on the morphological and cytological causes of seed weight natural variation in rapeseed. We concluded that the natural variation of seed weight is mainly controlled by maternal genotype. This finding lays a foundation for genetic and breeding studies of seed weight in rapeseed and opens a new field of research on the regulation of seed traits in plants.
种子重量是油菜（甘蓝型油菜）中一个非常重要且复杂的性状。油菜种子重量在其天然种质资源中表现出很大的变异性；然而，这种变异的形态学、细胞学和遗传学原因仍不清楚。在本研究中，选择了9个种子重量变异大且遗传背景不同的高纯度自交油菜品系，对种子重量进行形态学、细胞学和遗传学研究。结果如下：（1）种子重量与种子大小（包括种子直径、种子表面积和种子体积）呈极显著相关且协同变异，但与容重无显著相关性，这表明种子重量由大小而非容重决定。（2）种子重量与种皮和子叶的细胞数量的相关性高于与种皮和子叶的细胞大小的相关性，这表明细胞数量与最终种子重量的相关性更强。（3）种子重量主要受母本基因型控制，几乎没有或没有异粉性和细胞质效应。这是关于油菜种子重量自然变异的形态学和细胞学原因的首次报道。我们得出结论，种子重量的自然变异主要受母本基因型控制。这一发现为油菜种子重量的遗传和育种研究奠定了基础，并开辟了植物种子性状调控研究的新领域。
