芥甘杂交创制新型甘蓝型油菜的表型多样性分析

为拓宽甘蓝型油菜遗传背景，明确油菜新种质表型变异水平，筛选优异基因资源，本研究利用芥菜型油菜与甘蓝型油菜种间杂交创制新型甘蓝型油菜54个品系进行田间表型鉴定，分析其表型多样性水平及其性状间相互关系。结果表明，（1）22个数量性状的变异系数范围为4%~99%，遗传多样性指数1.64~2.04；22个形态特征性状的遗传多样性指数为0~1.86。其中角果长度、单株有效角果数、单株产量、生育期、有效分枝高度、蛋白质含量和含油量等7个性状的多样性水平高于国内外已报道的其他甘蓝型油菜的多样性水平，表明芥甘种间杂交能够创制丰富的遗传变异，拓宽甘蓝型油菜遗传背景。（2）主成分分析将44个表型性状转化为10个综合指标，其中主花序有效角果数、单株有效角果数、每角果粒数、单株产量芥酸、亚油酸、油酸、蛋白质、含油量等与产量和品质相关性状是反映新型甘蓝型油菜表型特征的主要差异指标，表明通过这些产量和品质性状的选择可获得目标品系。（3）受甘蓝型油菜定向选育的影响，本试验参试材料具有偏向甘蓝型油菜的表型特点；聚类分析综合44个表型性状将54个参试油菜品系划分为3个类群，其中29个品系与甘蓝型油菜亲本聚为一类，代表了甘蓝型油菜亲本群；18个品系聚为一类，与甘蓝型油菜亲本类群距离较远，营养生长无优势，产量较低，综合性状较差；7个品系聚为一类，与甘蓝型油菜亲本类群距离较近，表现较强的营养生长优势和丰产特点，综合性状优良，可作进一步选育对象，为西藏高产优质甘蓝型油菜品系的选育奠定种质基础。

Phenotypic diversity analysis of new rapeseed germplasm materials derived from interspecific hybridization between Brassica juncea × B. napus

In order to broaden the genetic background of Brassica napus, 54 new lines of B. napus were created by interspecific hybridization between B. juncea and B. napus, and their phenotypic diversity was analyzed. The results showed that， （1） the variation coefficient of 22 quantitative traits ranged from 1.64 to 2.04. The genetic diversity index of 22 morphological traits ranged from 0 to 1.86. Among them, the diversity level of silique length, siliques per plant, seeds weight per plant, growth duration, branch height, protein content and oil content were higher than those of other B. napus reported at home and abroad, which indicated that interspecific hybridization between B. juncea and B. napus could create rich genetic variation and broaden the genetic background of B. napus. （2） Principal component analysis transformed 44 phenotypic traits into 10 comprehensive indexes. The yield and quality related traits such as silique number of the main inflorescence, siliques per plant, seeds per silique, erucic acid , linoleic acid, oleic acid, protein, oil content and other yield and quality related traits were the main indicators reflecting the phenotypic characteristics of new type B. napus. The target line might be obtained by selecting. (3) Affected by the directional breeding of B. napus, the materials tested in this experiment have the phenotypic characteristics biased to B. napus. Cluster analysis integrated 44 phenotypic characteristics, and divided 54 lines into 3 groups, of which 29 lines and parents of B. napus were clustered into one group, representing the parent group of B. napus. The 18 lines were clustered into one group, which was far away from the parent of B. napus group, having less advantage in vegetative growth, and poor comprehensive characteristics with low yield. The 7 lines were clustered into the same group, which was close to B. napus parent, having strong nutritional growth advantage with high yield. For the 7 lines had excellent comprehensive characteristics, they might be used as further breeding objects in this area.