橡胶树杂交子代遗传特性及遗传多样性分析

Genetic characteristics and genetic diversity of hybrid progeny of Hevea brasiliensis

【目的】从表型性状和分子标记两个方面分析亲本和杂交子代群体的遗传特性和遗传分化,为亲本组合的甄选和杂交子代的差异分析等工作提供参考依据。【方法】以35份橡胶树杂交后代群体为供试材料,利用表型性状和SSR分子标记进行遗传特性及遗传多样性研究。【结果】32个表型性状的变异系数平均值为32.59%,其中叶枕沟的变异系数最大为60.90%,小叶柄沟的变异系数最小为0;多样性指数分布在3.22~3.53,平均为3.49。杂种优势分析表明,F_(1)杂种在树围、年平均增长量和产量上具有较强的杂种优势,分别为101.2%、117.2%和95.38%。在35个杂种F_(1)中,产量最高的是材料A38,最低的是材料A9。2017—2020年4年间,材料A22每年都是树围最大的杂交子代;35个F_(1)杂种的年增长量分布在5.6~10.4 cm,年平均周长增量居6.7~8.8 cm。根据分子标记分析结果,从104对引物中筛选出扩增效果较好的引物15对,利用15对SSR标记亲本和后代群体遗传多样性分析,共扩增出15个等位基因,多态信息含量值(PIC)在0.2710~0.6827,Shannon’s信息指数(I),观测杂合度(H_(o))和期望杂合度(H_(e))分别处于0.5004~1.3459、0.1714~1.0000和0.3246~0.7400;采用UPGMA方法进行聚类分析,结果表明杂种可分为3个类群。【结论】亲本选配合理,杂交子代多样性丰富,解析了杂交子代遗传变异和遗传多样性,为杂交育种及亲本选配提供材料和理论支持。

【Objective】The genetic characteristics and genetic analysis of parents and hybrids were analyzed in terms of phenotypic traits and molecular markers,which provided reference for the selection of parental combinations and the difference analysis of hybrids.【Method】The genetic characteristics and genetic diversity of 35 Hevea hybrid progeny populations were studied using phenotypic traits and SSR molecular markers.【Result】The coefficient of variation of 32 phenotypic traits was 32.59%,the maximum variation coefficient of the pulvinus largening was 60.90%,and the minimum variation coefficient of the petiolule groove was 0.The diversity index ranged from 3.22 to 3.53,with an average of 3.49.Heterosis analysis showed that F_(1) hybrids had strong heterosis in girth,annual average increase and yield,which were 101.2%,117.2% and 95.38%,respectively.Among the 35 F_(1) hybrids,the material of A38 had the highest yield and A9 had the lowest yield.In each of the four years from 2017 to 2020,the material of A22 was the largest hybrid in girth.The annual increase of 35 F_(1) hybrids ranged from 5.6 to 10.4 cm,and the annual average girth increment ranged from 6.7 to 8.8 cm.According to the results of molecular marker analysis,15 pairs of primers with good amplification effect were screened out from 104 pairs of primers.By using the genetic diversity analysis of 15 pairs of SSR marker parents and progeny populations,a total of 15 alleles were amplified with polymorphism information content(PIC)of 0.2710-0.6827.Shannon’s information index(I),the observed heterozygosity(H_(o))and expected heterozygosity(H_(e))were 0.5004-1.3459,0.1714-1.0000 and 0.3246-0.7400,respectively.Cluster analysis using UPGMA showed that the hybrids could be divided into three groups.【Conclusion】The genetic variation and genetic diversity of hybrid progeny were analyzed to provide material and theoretical support for hybrid breeding and parental selection.