极小种群野生植物巴郎山杓兰的CDDP遗传多样性分析

CDDP genetic diversity analysis of a very small population of wild plant Cypripedium palangshanense

摘要:

巴郎山杓兰（Cypripedium palangshanense）是中国特有的珍稀濒危保护植物，属于狭域分布的极小种群野生植物.为研究其遗传多样性，采用CDDP分子标记技术对卧龙和王朗自然保护区巴郎山杓兰的2个野生居群6个试验点的92份材料进行了遗传多样性评价，并进一步探讨了遗传多样性与环境因子之间的相关性.遗传分析结果表明，筛选的12条引物，在物种水平上，共检测到131个位点，多态位点条带百分率（PPL）为100%，观测等位基因（Na）为2.0000，有效等位基因（Ne）为1.5026，Nei’s遗传多样性指数（H）为0.3141，Shannon多样性指数（I）为0.4856，巴郎山杓兰表现出较高的遗传多样性；在居群水平上，卧龙居群的遗传多样性高于王朗居群，其中，Na的变化范围为1.4504~1.9160；Ne的变化范围为1.2446~1.4336；H在0.1464~0.2679之间；I在0.2231~0.4153之间；PPL的变化范围为45.04%~91.60%.巴郎山杓兰的遗传分化系数（Gst）为0.2863，遗传结构和AMOVA分析均表明巴郎山杓兰居群间出现了遗传分化.Mantel检验表明巴郎山杓兰居群之间的遗传距离和地理距离之间有显著的相关性（R2=0.3830，P＜0.05）.UPGMA聚类分析表明卧龙居群和王朗居群各聚为一支.遗传多样性与环境因子的相关性分析表明，观测等位基因（Na）、多态位点数（Np）、多态位点百分率（PPL）与速效钾含量（AK）呈显著正相关；有效等位基因数（Ne）、Nei’s遗传多样性指数（H）和Shannon信息指数（I）与海拔（Alt）呈显著正相关；其余环境因子与遗传多样性指数之间没有显著相关性.本研究结果表明CDDP分子标记适用于巴郎山杓兰的遗传多样性研究，并且表现出较高的多态性.

Abstract:

Cypripedium palangshanense is a rare and endangered protected plant unique to China. It is an extremely small population of wild distributed in a narrow area. To study its genetic diversity CDDP molecular marker technology was used to evaluate the genetic diversity of 92 materials from 6 experimental sites in 2 wild populations of C. palangshanense in Wolong and Wanglang Nature Reserves, and further explore the relationship between genetic diversity and environmental factors. The results of the genetic analysis showed that a total of 131 locus were detected at the species level with 12 primers, the percentage of polymorphic loci (PPL) was 100%, the observed allele (Na) was 2, the effective allele (Ne) was 1.5026, the Nei′s genetic diversity index (H) was 0.3141, and the Shannon diversity index (I) was 0.4856; At the population level, the genetic diversity of Wolong population was higher than that of Wanglang population, and the variation range of Na was 1.4504 ~ 1.9160; the variation range of Ne was 1.2446 ~ 1.4336; H was between 0.1464 and 0.2679; I was between 0.2231 and 0.4153; the variation range of PPL was 45.04% ~ 91.60%. The genetic differentiation coefficient (Gst) of C. palangshanense was 02863. The genetic structure and AMOVA analysis showed that there was genetic differentiation among the populations of C. palangshanense. Mantel test showed that there was a significant correlation between genetic distance and geographical distance among Cypripedium palang shanense populations in Balang mountain (R2 = 0.3830, P<0.05). According to UPGMA cluster analysis, Wolong population and Wanglang population are clustered into one branch. The correlation analysis between genetic diversity and environmental factors showed that there was a significant positive correlation among observed allele (Na), the number of polymorphic loci (Np), percentage of polymorphic loci (PPL) and available potassium content (AK); The number of effective alleles (Ne), Nei′s genetic diversity index (H) and Shannon information index (I) were significantly positively correlated with altitude (Alt); There was no significant correlation between remaining environmental factors and genetic diversity index. The results showed that CDDP molecular markers technology was suitable for the study of the genetic diversity of C. palangshanense, and was highly polymorphic.