Abstract:

To breed short growth period rapeseed varieties， taking the early maturing and excellent breeding germplasm of Brassica napus L. as the research materials， 11 main agronomic traits of 48 materials were analyzed and evaluated through methods including genetic diversity analysis， correlation analysis， regression analysis and principal component analysis under late sowing. The results showed that the genetic diversity index and coefficient of variation range of the 11 quantitative traits were relatively large， indicating that these materials had rich genetic information. Correlation analysis showed that the vegetative growth period， the pod growth period， the pods number per plant， the seeds number per pod， 1 000 seeds weight and flowering duration were closely related to yield per plant. The regression equation for yield per plant was mainly significantly influenced by the pods number per plant， the seeds number per pod and 1 000 seeds weight， with a coefficient of determination of 0.852. The first two principal components extracted by principal component analysis had a cumulative contribution rate of 51.46%， representing most of agronomic traits. Principal component analysis divided 48 germplasm into 4 quadrants， and the first quadrant （Ⅰ） showed that materials with shorter flowering duration， longer vegetative growth period， and longer pod growth period could be used to breed early maturing， short growth period and high-yielding varieties. Above results provided a theoretical basis for the selection of parents and hybrid combinations of early maturing rapeseed with short growth period in the middle reaches of the Yangtze River.

Key words: Brassica napus L., breeding, growth period, early maturity

摘要：

为选育短生育期油菜品种，以早熟甘蓝型油菜优良材料为研究对象，通过遗传多样性分析、相关性分析、回归分析、主成分分析等方法，评价迟播条件下48份材料的11个主要农艺性状。结果表明，48份油菜11个数量性状的遗传多样性指数和变异系数范围较大，表明这些材料具有丰富的遗传信息。相关性分析表明，营养期、角果期、全株有效角果数、每果粒数、千粒重、花期与单株产量关系紧密。单株产量的回归方程主要受全株有效角果数、每果粒数和千粒重的显著影响，决定系数为0.852。主成分分析提取的前2个主成分，累计贡献率达51.46%，代表了大部分的农艺性状。主成分分析将48份材料分为4个象限，第1象限（Ⅰ）花期较短、营养期较长和角果期较长的材料可以选育早熟短生育期高产品种。研究结果为长江中游区早熟短生育期油菜亲本选择和杂交组合选配提供理论依据。

关键词: 甘蓝型油菜, 育种, 生育期, 早熟