走马胎种质资源遗传多样性的ISSR分析

Efficiency of ISSR markers in assessing genetic diversity and relationships in Ardisia gigantifolia germplasm

关键词:  走马胎, 分子标记, ISSR分子检测, 种质资源, 遗传多样性广西植物37卷1期毛世忠等： 走马胎种质资源遗传多样性的ISSR分析

Key words:  Ardisia gigantifolia, molecular marker, ISSR analysis, germplasm resources, genetic diversity

摘要:

走马胎(Ardisia gigantifolia)是紫金牛科(Myrsinaceae)紫金牛属(Ardisia)多年生小灌木植物。走马胎作为我国传统中药材，已有多年的药用历史。目前，走马胎不再局限于临床药用，在食疗和保健方面的开发利用崭露头角，大大扩展了其应用范围。随着走马胎市场需求量增大，野生走马胎的过度采挖，导致野生走马胎资源几近枯竭。人工栽培走马胎逐渐成为供应药用市场的主力军，但是人工栽培走马胎种质、种子来源混杂，常会造成质量和疗效的不稳定，利用分子标记技术可以从分子水平上对走马胎进行种质的区分和评价。该研究利用ISSR分子标记技术，对来自广西地区的36份走马胎种质资源进行了遗传多样性分析，采用 POPGEN32 进行数据分析，UPGMA 绘制聚类图。结果表明：14条ISSR引物共检测到136个清晰的扩增位点，多态性位点112个，多态位点百分率为82.35%；Nei’s基因多样性指数(H)为0.296 5，Shannon多样性指数(I)为0.441 7，基因分化系数(Gst)为0.855 8。个体间的遗传相似系数为0.667 8～0.838 2，平均为0.739 1。基于聚类分析可知，所有的个体被划分为5类，其中绝大多数来自相同或者邻近地区的个体严格按照地理位置聚为相同的一类或者亚类，只有少数个体在归类上与地理位置相悖。研究证明ISSR分子标记技术在评价走马胎种质资源亲缘关系和遗传变异等方面有很好的适用。该研究结果可为该药用植物的种质资源评估和引种栽培提供科学依据。

Abstract:

Ardisia gigantifolia is a medicinal plant that belongs to genus Ardisia. This plant has been an important traditional Chinese medicine in China for thousands of years. Now, with the development of pharmacological research, A. gigantifolia is not only used as a clinical medicine, but also plays a role in diet and health aspects. The pharmacological validity of its medicinal value has extended in an enlarged market. At present, the wild A. gigantifolia in our country is rare, and the cultivars become the new important source. However, the quality and efficacy of cultivars often suffer from intraspecific variation, unstable quality and other issues. Moreover, the cultivars were also affected by origin, age and environmental conditions. In order to efficiently utilize and conserve this medicinal plant resource, ISSR analysis was employed to reveal genetic diversity of 36 A. gigantifolia germplasm which were collected from different places of Guangxi Zhuang Autonomous Region in China. Data were analyzed by POPGENE32, and a cluster diagram was presented by UPGMA. The results indicated that fourteen ISSR primers generated a total of 136 bands among which 112 (82.35%) were polymorphic bands. Nei’s genetic diversity index (H) was 0.296 5, Shannon diversity index (I) was 0.441 7, and the coefficient of gene differentiation (Gst) was 0.855 8. The genetic similarity coefficient among the populations ranged from 0.667 8 to 0.838 2 in an average of 0.739 1. Based on the clustering analysis, all accessions were clustered into five groups with UPGMA method. Most of the accessions from the same or adjacent regions were clustered into the same group or subgroups. A few accessions, however, were greatly different from the majority of all accessions. The results suggested that ISSR marker was an effective tool for the study of genetic variation in Chinese natural A. gigantifolia germplasm resources. These results can also be used for germplasm characterization and plant breeding.