川产羌活种质遗传多样性的RAPD分析

目的考察羌活Notopterygium incisum的遗传特征,探讨不同产地且有形态变异的羌活种质资源的遗传多样性、遗传分化及与环境因子的相关性。方法用RAPD方法选择15个随机引物对四川西部4个居群33株个体叶片DNA进行扩增,从个体间遗传关系及居群间遗传分化方面对羌活的遗传结构进行分析。结果RAPD共检测到185条谱带,其中128个位点为多态位点,多态性百分率为69.19%,Nei's基因多样性为0.2237,Shannon's信息指数为0.3375;壤塘和九龙居群聚为一类,理县和泸定居群聚为一类;茎秆颜色花纹性状与遗传差异间未表现明显相关性,不同性状的羌活个体仍主要按居群,即产地来源聚类;羌活居群内和居群间的变异分别占总变异的74.67%和25.33%;羌活居群间的遗传距离与地理距离间没有明显相关性(r=-0.1105,P=0.5855);羌活4个居群遗传多样性大小与年均温负相关,未达到显著水平(r=-0.771,P=0.229);与年均降雨量正相关,但相关不显著(r=0.291,P=0.709)。结论本研究表明羌活遗传多样性水平较高;羌活的遗传变异主要分布在居群内,但居群间已形成一定的遗传分化;壤塘和九龙羌活个体间的遗传距离较小,各自遗传背景较为相似。产地差异对遗传变异的影响大于因其茎秆颜色花纹不同所造成的影响。

RAPD Analysis of genetic diversity of Notopterygium incisum in Sichuan

Objective Notopterygium incisum is an endangered species endemic to China and is one of the Chinese and Tibetan traditional medicinal plants.The genetic diversity of germplasm resources with morphological variation of N.incisum from different habitats was investigated using RAPD markers and the relation of genetic differentiation to the environmental factors was also analyzed.Methods Thirty-three samples of four populations collected from Luding(LD),Jiulong(JL),Lixian(LX),and Rangtang(RT)in west Sichuan were DNA amplified with 15 random primers selected by RAPD method.ResultsFifteen random primers detected 185 sites of which 128 were polymorphic.The percentage polymorphic loci(PPB)was 69.19%,Nei's gene diversity(h)was 0.223 7,and Shannon's information index(H)was 0.337 5 at the species level.The RT and JL for a category,LX and LD were clustered together.There is no obvious correlation between the stem character and the genetic diversity.N.incisum with different characters is one cluster according to the different origin.Nested analysis showed variations within populations and among populations of N.incisum were 74.67% and 25.33%.Nei's unbiased genetic distance matrix compared with a corresponding geographic distance matrix showed the two matrices were not significantly correlated(r=-0.110 5,P=0.585 5>0.05).The negative correlation between the genetic diversity and the average annual temperature was not up to significant level statistically(r=-0.771,P=0.229);The positive correlation between genetic diversity and the average annual rainfall was related,but not significantly correlated(r=0.291,P=0.709).Conclusion The primary results showed that N.incisum populations are characterized by high genetic diversity.Though there are obviously genetic variations between populations,genetic variability principally existed within populations.Genetic distances among the individuals of RT and JL with similar genetic background are very small.The influence of habitat where it grows on its genetic diversity is greater than the influence caused by the difference colour and figure of its stem.