天麻种质资源的SSR指纹图谱研究

天麻(Gastrodia elata Bl.)为中国珍稀濒危传统药用植物,其不同种质之间形态特征差异微小,而药用成分差异较大,种质资源混乱。为了构建天麻种质资源的DNA指纹图谱,该研究应用SSR分子标记技术对天麻的3种变型(乌天麻、红天麻和绿天麻)、12个种群,共计120个样本进行了群体遗传分析。研究结果表明:(1)7对SSR引物均能对天麻样本成功进行PCR扩增且多态性丰富,每对引物的等位基因数(N_a)在5~7之间,平均为6.43;引物多态信息含量(PIC)范围为0.626 2~0.823 5,平均为0.759 5。(2)群体遗传分析结果表明,天麻在物种水平上和变型水平上均有较高的遗传多样性(物种水平:A=6.428 6,H=0.789 0,I=1.682 9;变型水平:A=2.666 6,H=0.523 9,I=0.812 3)。(3)分子方差分析结果显示,种群间和变型间均存在强烈的遗传分化(F_(st)=0.558 6,F_(ct)=0.381 8)。(4)种群聚类分析结果显示,相同变型的天麻种群首先聚在一起,3种变型能被完全分开,SSR指纹图谱在变型水平上鉴定效率良好;从120个样本中共检测出有112种基因型,Simpson指数(D)为0.99 8,说明SSR指纹图谱对天麻样本在个体水平上也有着良好的鉴定效率。该研究结果揭示了天麻的遗传背景,并建立了天麻的SSR指纹鉴定图谱,为其种质资源的保护、选育及药材鉴定奠定了科学依据与技术支撑。

SSR Fingerprinting on Gastrodia elate Bl. Germplasms

Gastrodia elata Bl. is a rare and endangered traditional medicinal plant in China.The difference among germplasms is tiny in morphological characteristics, while is prominent in medical components, which results in its germplasm confusion in both cultivation and pharmacy. With the aim to construct DNA fingerprinting for G. elata germplasm, we used simple sequence repeat (SSR) molecular markers in this study to analyze the population genetic structure for G. elata with its 120 samples collected from 12 populations of its 3 forms (G. elata Bl. f.glauca S. Chow, G. elata Bl. f.elata, G. elata Bl. f. viridis Makino). As the results shows: (1) seven pairs of SSR primer were successfully used in the PCR amplification, and performed abundant polymorphism, the number of allele per primer pair (N_a) ranged from 5 to 7 with the average of 6.43, while the polymorphism information content (PIC) ranged from 0.626 2 to 0.823 5 with the average of 0.759 5. (2) Genetic diversity analysis of all samples of G. elata showed that the genetic diversity was high (species level: A=6.428 6, H=0.789 0, I=1.682 9; form level: A=2.666 6, H=0.523 9, I=0.812 3). (3) Analysis of molecular variance (AMOVA) analysis revealed strong genetic differentiation was happened among both populations and the forms (F_st=0.558 6, F_ct=0.381 8). (4) Cluster analysis showed that the populations of the same form clustered together firstly, 3 forms were separated completely. SSR fingerprinting had a good identification effect at the form level; 106 genotypes were detected from the 120 samples in total. The Simpson index (D) was 0.998, indicating the SSR fingerprinting has good ability of identification on the individual level. The study revealed the genetic background of G. elate, which provided scientific and technical basement for its conversation,germplasm selection and identification.