烟草种质资源的遗传多样性分析

Analysis of genetic diversity of germplasm resources of Nicotiana tabacum

从200对SSR引物中筛选出69对条带清晰、多态性强的引物,对80份烟草种质资源材料（来自多个国家和地区）的全基因组DNA进行扩增,采用荧光ABI–3500 xl遗传分析仪进行多态性检测,结果 69对引物在烟草种质材料中共检测出503个多态性条带,平均每对引物可检测到的等位变异数为7.91个,观测杂合度（Ho）平均值为0.276 4,预期杂合度（He）平均值为0.574 7。Shannon’s信息指数I为1.082 6;Nei’s多样性指数H为0.571 1、遗传分化系数Fst为0.141 6,基因流Nm为1.515 3,遗传相似系数为0.55~0.90。说明80份烟草种质的遗传多样性相对丰富,居群间的遗传分化为14.16%,大部分位点均表现偏离Hardy–Weinberg平衡,杂合度不足,居群间基因交流少。

Total genomic DNA of 80 tobacco materials （originated from China, America, Poland, Zimbabwe, Japan, Bulgaria, Zambia, Terkey, Yugoslavia, India, the Soviet Union, Albania） were amplified by 69 polymorphic SSR markers screened from a total of 200 SSR primer pairsand the length polymorphism of the amplified fragment was analyzed using Biosystems 3500x! Genetic Analyzer. The results revealed that a sum of 503 polymorphic bands were amplified using 69 SSR primer pairs. And an average of 7.91 alleles were observed for each primer pair with average heterozygosity（Ho） 0.2764, average expected heterozygosity（He） 0.574 7. Shannon＇s index was 1.082 6, Nei＇s index was 0.5711, coefficient of genetic differentiation was 0.141 6, gene flow was1.515 3 and genetic similarity coefficient ranged from 0.55-0.90. The results showed that the genetic diversity of 80 tobacco germplasm was relatively abundant, the genetic differentiation was 14.16% between populations, most sites were seriously deviating from the Hardy Weinberg equilibrium indicating a low heterozygosity and a low gene flow between populations.