黄芪ISSR标记遗传多样性及其与主要药用成分的关联分析

Genetic Diversity and Association Analysis between Medicinal Components and ISSR Markers in Astragali Radix

目的为深入研究并充分利用中药材黄芪(Astragali Radix),寻找与有效成分表型性状相关联的分子标记。方法利用ISSR分子标记技术对43份黄芪进行遗传多样性分析,用13个分子标记结果对供试材料做群体遗传结构分析,并在此基础上用Tassel 2. 1的GLM对标记与表型性状进行关联分析。结果 43份黄芪间有一定的遗传多样性,遗传距离在0. 050 6~0. 743 8之间,平均遗传距离0. 274 1;来自宁夏和甘肃的人工栽培黄芪与采自宁夏六盘山镇的野生黄芪亲缘关系较近,而No. 340与其他黄芪的亲缘关系最远;43份黄芪多糖含量7. 693~27. 840 mg·g^-1,总皂苷含量7. 167~17. 579 mg·g^-1,总黄酮含量2. 212~6. 164 mg·g^-1,甲苷含量6. 070~107. 920μg·g^-1;线性回归分析表明,总皂苷和总黄酮含量呈极显著正相关(r=0. 650 5,P=2. 3×10^-6<0. 01),但甲苷与总皂苷含量、与总黄酮以及多糖含量均无显著相关关系。通过群体遗传结构分析43份黄芪划分为4个亚群,以GLM模型分析发现,在P <0. 01水平上,有13个ISSR标记共34个位点与多糖、总皂苷、总黄酮以及甲苷含量4个表型性状发生关联,各标记对表型变异的解释率在8. 14%~51. 39%。其中高阈值(P <1×10^-5)下与甲苷含量相关联、解释率超过30%的位点有15个;与多糖含量相关联的位点1个,且解释率达到了51. 38%。结论研究结果为黄芪的鉴定、保护及分子标记辅助育种提供依据。

OBJECTIVE To study and exploit Chinese medicine Astragali Radix,the molecular markers that relates to the phenotypic traits on medicinal components of Astragali Radix and would be detected. METHODS The genetic diversity of 43 Astragali Radix samples was analyzed with ISSR molecular marker technique and then the population genetic structure was studied through 13 selected markers. The association analysis between ISSR markers and 4 phenotypic traits of medicinal components were performed with GLM( general linear model) programs in Tassel 2. 1. Certain genetic diversity was discovered among the 43 Astragali Radix samples.RESULTS The genetic distance varied between 0. 050 6 and 0. 743 8,with an average of 0. 274 1. Moreover,the cultivated Astragali Radix from Ningxia and Gansu province closely related to the wild Astragali Radix collected from Liupanshan town in Ningxia. On the other hand,No. 340 had the farthest relationship with other Astragali Radix. The content of polysaccharide,total saponins,total flavonoids,and Astragaloside IV ranged between 7. 693-27. 840 mg·g^-1,7. 167-17. 579 mg·g^-1,2. 212-6. 164 mg·g^-1 and6. 070-107. 920 μg·g^-1,respectively. Meanwhile,linear regression analysis indicated that there was a significant positive correlation between the content of the total saponins and that of flavonoids( r = 0. 650 5,P = 2. 3 × 10^-6< 0. 01),while the content of astragaloside Ⅳ had no significant correlation with that of polysaccharide,total saponins and total flavonoids. The population genetic structural analysis showed that the 43 samples were divided into 4 subgroups. There were total of 34 locus in 13 ISSR markers significantly associated( P < 0. 01) with the content of polysaccharide,total saponins,flavonoids and astragaloside Ⅳ,and the rate of explanation on the phenotype of related marker ranged from 8. 14% to 51. 39%. Among the locus,15 were related with astragaloside Ⅳ content at interpretation rates above 30%,1 with polysaccharide content an interpretation rate reached as high as 51. 39% with high threshold( P < 1 × 10^-5). CONCLUSION These results would provide supporting evidence for identification and protection of germplasm resources as well as molecular marker-assisted breeding.