Intra-species genetic variability assessment is an effective tool in formulating genetic improvement and germplasm conservation strategies. Houttuynia cordata Thunb. is a semidomesticated medicinal herb consumed widely in traditional diet in North-Eastern India. In the present study, an effort has been made to assess the genetic diversity of H. cordata Thunb. from Brahmaputra valley of North-East India. A total of 545 genotypes from 18 populations of H. cordata Thunb. from four different regions, i.e. North-East, North-West, South-East and South-West, with respect to river Brahmaputra were collected and population genetic diversity and structure were analysed using ISSR molecular markers. Population genetic structure analysis using unweighted pair group method with averages (UPGMA)-based hierarchical cluster analysis, principal coordinate analysis (PCoA) and model-based clustering in STRUCTURE program revealed that the population of H. cordata Thunb. grouped according to regional distribution and forms four genetically distinct clusters. The analysis of molecular variance showed that differentiation among regions was significant with 60% genetic variation among region, 3% genetic variation among population within region and 37% genetic variation within population. We found wide variation in Nei’s gene diversity (Hj) ranging from 0.07782 in Margherita population to 0.13634 in Barapani population. Furthermore, Nei’s gene diversity within population (Nei’s Hs) and total gene diversity (Ht) were found to be 0.1081 and 0.1769 respectively. The genetic differentiation among 18 population was high (Fst = 0.3894; p < 0.001) with relatively restricted gene flow (Nm = 0.6564). Based on the result of this study, we suggest ex situ conservation could be an appropriate measure to adequately capture the total genetic diversity of H. cordata Thunb. populations of North-East India by selecting few individuals from different populations. Supplementary Information The online version contains supplementary material available at 10.1007/s11105-020-01260-9.

中文翻译：

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药材鱼腥草的遗传多样性和种群结构。印度东北部

种内遗传变异性评估是制定遗传改良和种质保护策略的有效工具。鱼腥草。是一种半驯化的药草，在印度东北部的传统饮食中广泛食用。在本研究中，已努力评估 H. cordata Thunb 的遗传多样性。来自印度东北部的布拉马普特拉河谷。来自 18 个 H. cordata Thunb 种群的总共 545 个基因型。收集了来自东北、西北、东南和西南四个不同地区的雅鲁藏布江，并使用ISSR分子标记分析了种群遗传多样性和结构。种群遗传结构分析，使用基于平均值（UPGMA）的未加权对组方法进行层次聚类分析，STRUCTURE 程序中的主坐标分析 (PCoA) 和基于模型的聚类揭示了 H. cordata Thunb 的种群。根据区域分布分组并形成四个遗传上不同的集群。分子方差分析表明，区域间差异显着，区域间遗传变异为60%，区域内种群间遗传变异为3%，种群内遗传变异为37%。我们发现 Nei 的基因多样性 (Hj) 变化很大，范围从 Margherita 种群的 0.07782 到 Barapani 种群的 0.13634。此外，Nei 的群体内基因多样性（Nei's Hs）和总基因多样性（Ht）分别为 0.1081 和 0.1769。18 个群体的遗传分化程度较高（Fst = 0.3894；p < 0. 001) 具有相对受限的基因流 (Nm = 0.6564)。根据这项研究的结果，我们建议异地保护可能是充分捕获 H. cordata Thunb 总遗传多样性的适当措施。通过从不同种群中选择少数个体来研究印度东北部的种群。补充信息 在线版本包含补充材料，网址为 10.1007/s11105-020-01260-9。