甘蓝型油菜育种亲本单株产量与农艺性状相关性分析

Correlation Analysis of Yield per Plant and Agronomic Traits in Breeding Lines in Brassica napus L.

油菜是我国重要的油料作物,提高油菜产量是油菜育种的首要目标之一。油菜育种中,考察和分析油菜种质的主要农艺性状是筛选育种亲本材料配制优良组合的前提基础,可以为高效开展重要性状的改良提供有效的科学依据。以213份长江流域油菜主产区育种单位提供的甘蓝型油菜育种亲本为材料,采用相关分析、通径分析、多元回归分析及主成分分析等方法,探讨在成都平原气候条件下,油菜单株产量与10个相关农艺性状之间的关系,明确甘蓝型油菜产量形成的主要决定因子。结果表明,不同地区油菜资源农艺性状存在较大差异;单株产量与株高、主序有效长度、一次有效分枝数、主序有效角果数、角果长度、每角果粒数和千粒重呈极显著正相关,与营养生长天数呈显著负相关;对单株产量直接影响最大的是株高,其次是每角果粒数和一次有效分枝数,间接作用最大为主序有效长度,其次是主序有效角果数和一次有效分枝高度。逐步回归分析表明,株高、每角果粒数、一次有效分枝高度和一次有效分枝数是决定单株产量的主要因子;通过主成分分析,可将相关性状综合为4大类:株高控制因子、生育期控制因子、产量性状控制因子和株型控制因子。本生态区域内决定产量形成的关键性状为株高、每角果粒数、一次有效分枝高度和一次有效分枝数,本研究得出的结果对于充分利用各育种单位亲本材料优良性状提供了有价值的参考。

Rapeseed acts as an important oil crop in China and breeding for high yield is of great interest.Analyzing agronomic traits of rapeseed germplasm can provide foundational information for selecting excellent parental materials, which will be subjected for making crosses, e.g.to improve important traits in rapeseed.In the present study, 213 breeding lines of B.napus L., which were collected from the main rapeseed production area of the Yangtze River, was used for exploring the relationship between 10 agronomic traits and yield per plant, under the climatic conditions in Chengdu Flat.The statistical analysis including simple correlation analysis, path analysis, multiple regression analysis and principal component analysis, were conducted.The results showed the great divergence on the agronomic traits of rapeseed resources from different regions.The yield per plant was positively correlated to plant height, the effective length of main inflorescence, the number of first effective branch, the number of effective silique on main inflorescence, the length of silique, seeds per silique, and 1000-seed weight, while negatively correlated to the period of vegetative growth.The yield per plant was directly contributed by three factors including plant height, seeds per silique and the number of first effective branches.The indirect effect on plant yield was the effective length of main inflorescence >the number of effective silique on main inflorescence >branch height.By stepwise regression analysis, the yield per plant was mainly determined by plant height, seeds per silique, branch height, and the number of first effective branches.Based on the phenotypic variation using the principal component analysis, these genotypes were grouped into four major categories, consisting of plant height related factors, growth period related factors, yield related factors and plant type related factors.Taken together, the yield per plant in the ecological region of Chengdu Flat was largely contributed by plant height, grain number per pod, primary branch height, and number of primary effective branch.These results would provide a valuable information for selecting elite parental lines in rapeseed breeding.