基于表型性状与简单重复序列标记的浙江省芋种质资源遗传多样性比较

为探讨浙江省地方芋种质资源的遗传多样性,并挖掘特异芋种质,对25份浙江省地方芋种质资源进行调查鉴定,对15个表型性状进行了遗传多样性分析、主成分分析、表型性状与简单重复序列(SSR)标记相结合的聚类分析。结果表明,浙江省芋种质遗传多样性丰富,变异系数与多样性指数均值分别为31.32%与0.97。主成分分析显示,前5个主成分累积特征值为10.871,累计贡献率为77.649%,主成分1反映了多子芋株型综合因子,主成分2反映了芋叶形状综合因子,主成分3反映了母芋形状综合因子,主成分4、5分别代表母芋表皮棕毛、母芋颜色因子;另外,孙芋形状、母芋芽色、叶心色斑颜色、叶柄中下部颜色、母芋表皮棕毛可作为芋种质鉴别优先观测的形态性状指标。基于表型性状的聚类在遗传距离4.171处可将所有种质分为5个类别,其中第Ⅲ类与第Ⅴ类的子孙芋形状均为卵圆,商品性好。此外,在20份多子芋中还挖掘出2份紫红柄特异芋种质。20对SSR引物在所有资源中扩增共获得53个条带,具有多态性的条带为48条,多态性比率为90.6%,多态信息含量(PIC值)为0.22~0.64;SSR分子标记聚类在DICE遗传相似系数0.721处将所有种质分为5个类别,与表型性状聚类结果有类似之处,但又有所不同。2种不同的聚类方式在芋种质资源的鉴别中具有互补作用,均表明了亲缘关系的远近与地理来源并无直接关系。上述结果将为芋种质资源进一步保护、利用与创新提供重要的理论基础。

Comparative analysis on genetic diversity of Colocasia esculenta germplasm in Zhejiang Province based on phenotype and simple sequence repeats markers

In order to explore the genetic diversity of Colocasia esculenta germplasm in Zhejiang Province, and excavate special resources, 25 landraces were selected in the experiment. Genetic diversity analysis, principal component analysis (PCA), and cluster analysis were carried out on 15 phenotypic traits, and simple sequence repeats (SSR) molecular marker cluster analysis was combined based on these 25 resources. The results showed that the variation coefficient and diversity index were 31.32% and 0.97, respectively, indicating Colocasia esculenta germplasm in Zhejiang Province had a rich genetic diversity. Principal component analysis (PCA) showed that the accumulated eigenvalue of 5 principal components was 10.871, and cumulative contribution rate was 77.649%. The first principal component factor reflected the plant morphology of multi-cormels taro, the second principal component factor reflected the shape of taro leaf, the third principal component factor reflected the shape of parent-taro, the fourth and fifth principal component factor represent parent-taro epidermis hair (PTEH) and parent-taro colour, respectively. Moreover, grandson-taro shape (GTS), parent-taro bud colouring (PTBC), leaf junction colour (LJC), lower middle petiole colour (LMPC) and parent-taro epidermis hair (PTEH) could be preferentially observed in the Colocasia esculenta germplasm identification. All resources could be clustered into five categories at the genetic distance of 4.171 based on phenotypic traits. Among them the shape of son and grand-son taros in group Ⅲ and group Ⅴ was oval, which showed a well commodity nature. Otherwise, two special taro germplasm were excavated with purplish red petiole. 20 pairs of primers amplified 53 bands, of which 48 bands had polymorphism. The polymorphism rate was 90.6%. Polymorphism information content (PIC) ranged from 0.22 to 0.64. 25 taro accessions could be grouped into 5 clusters at DICE genetic similarity coefficient 0.721 based on SSR markers, this was similar to the phenotypic clustering, but also had some difference. Two clustering methods were supplement of each other among Colocasia esculenta germplasm identification, indicating there was no direct relationship between geographical origin. These results would provide an important theoretical basis for the further conservation, utilization and innovation of Colocasia esculenta germplasm.