中国白菜型油菜种质表型多样性分析

Analysis of phenotypic diversity in Chinese collection of Brassica rapa L.

以保存于油料作物中期库中的1 962份白菜型油菜种质为基础材料,按照地理位置、表型性状分组并按比例取样,选择具有代表性的244份地方品种,对其13个表型性状进行分析。结果显示,来源于山西省的冬油菜生育日数较长,来源于青海、内蒙古、甘肃等省的春油菜生育期较短;来源于四川省的半冬型油菜株高较高;来源于云南、四川省的半冬型油菜全株角果数较多;来源于西藏的材料千粒重较大。多样性指数结果表明,我国白菜型油菜地方种具有丰富的形态多样性,平均多样性指数为1.709,高于国外材料(1.250);就不同生态类型而言,半冬型油菜多样性指数最高,其次为春油菜,冬油菜最低。聚类分析结果显示,在相似系数为0.204时,244份白菜型油菜地方种质划分为四簇,每簇包含的种质数分别为117、38、34和55;簇I以半冬型油菜为主,簇II、III以春油菜为主,簇IV以冬油菜为主。主成分分析结果显示,白菜型油菜分为春油菜、半冬型油菜与冬油菜三个明显的基因库,其结论与聚类分析结果一致。

According to their geographic regions,phenotypic traits group and proportion of sample,a collection of 244 Brassica rapa landraces was selected from 1 962 B.rapa germplasm in oilcrops middle-term genebank of China.13 phenotypic traits were evaluated to investigate the variation degree of these resources.Results indicated that winter-type accessions from Shanxi province had longer growth periods,while spring-types from Qinghai,Gansu and Inner-Mongolia provinces had shorter growth periods.Semi-winter-types from Sichuan and Yunnan provinces had more pods per plant,and those from Sichuan province had higher plant height also.Spring-types from Tibet had larger seed size.Chinese B.rapa landraces possessed abundant morphological polymorphism with higher average diversity index（as 1.709） than that of alien germplasm（as 1.250）.Genetic diversity of different ecotypes showed that semi-winter-type had the richest diversity,and then followed by the spring-type and the winter accessions.UPMGA（unweighted pair group method with arithmetic mean） results showed that 244 representative B.rapa landraces could be classified into 4 groups（I,II,III and IV） with a genetic similarity coefficient as 0.204.The 4 groups involved 117,38,34,and 55 landraces,respectively.The group I,II,III and IV were mainly consisted of semi-winter ecotype,spring ecotype,spring ecotype and winter ecotype,respectively.Based on principal coordinates analyses,244 landraces were separated into 3 gene pools including spring,semi-winter and winter resources,which were consistent with UPGMA result.