澳洲坚果种质资源的遗传多样性分析

Genetic Diversity Analysis of Macadamia ssp.Germplasm Resources

以85份澳洲坚果种质为试材,利用22对高多态性SSR引物对其进行毛细管电泳检测,分析其遗传多样性及群体结构,以期为澳洲坚果种质资源收集和杂交育种亲本选择提供参考。结果表明,1)22对SSR引物共检测到269个等位基因,变幅为6~18个,平均每对引物12.2个;有效等位基因数为1.987~8.794个,平均5.087个;Shannon指数为1.020~2.327,平均1.854;Nei’s指数为0.497~0.886,平均0.779;多态性信息含量为0.461~0.875。进一步分析发现,相较于从美国引进、国内实生选种及杂交育种途径获得的3个种质群体,从澳大利亚引进的种质资源有效等位基因数、Shannon指数和Nei’s指数均更高,遗传多样性最丰富。2)UPGMA法聚类分析结果显示,供试种质未发现明显的划分规律,种质间的遗传差异较小。群体结构分析表明,当K=6时,ΔK值最大,即该研究中的85份种质可划分为6个类群,每个类群分别包含12、19、10、17、9、18份种质,其中34份(40%)供试种质遗传背景较为复杂。

Using 85 Macadamia ssp.germplasms as test materials,the capillary electrophoresis dectection was conducted with 22 high polymorohism SSR primers,the genetic diversity and population structure were analysed in order to provide reference for germplasm resource collection and parent selection of crossbreeding in Macadamia ssp..The results showed that a total of 269 alleles were obtained from 22 pairs of primers,ranging from 6 to 18 per marker,12.2 per pair of primer with an average of 5.087.The number of effected alleles ranged from 1.987 to 8.794,with an average of 5.087.The Shannon index varied from 1.020 to 2.327 with an average of 1.854 and the Nei's diversity index ranged from 0.497 to 0.886,with an average of 0.779.The polymorphic information content ranged from 0.461 to 0.875.Further analysis indicated that the Macadamia ssp.germplasms from Australia were the most abundant genetic diversity and higher in effective number of alleles,Shannon index and Nei's index than 3 germplasms from American and China with seeding selection and crossbreeding.UPGMA cluster analysis showed that the test germplasm had no obvious regular,and genetic diversity was small among all the germplasms.Popular structure analysis showed that the maximum ΔK was observed when K=6,and 85 germplasms in this study were sorted into 6 subpopulations which contained 12,19,10,17,9,18 germplasms,respectively,of which 34(40%) test resource had complicated genetic background.