基于SSR分子标记的面包果资源遗传多样性分析

Genetic Diversity Analysis of Breadfruit Complex Based on SSR Mo-lecular Markers

面包果被认为是最有潜力解决热带饥荒的粮食作物,具有较高的经济价值。我国面包果资源引种于多个国家,来源较丰富,目前未对其进行系统的分类和遗传多样性分析。为明确面包果资源间遗传距离,揭示其亲缘关系,本研究从75对SSR标记中筛选出33对扩增条带清晰、多态性高、稳定性好的标记,用于面包果资源的遗传多样性分析。对面包果资源进行PCR扩增,使用8%变性聚丙烯酰胺凝胶检测PCR扩增产物,利用NTSYS软件进行遗传多样性相关分析。结果表明:33个SSR标记的扩增条带多态性比率为94.57%,共检测出199个多态性位点,平均每个标记检测出6.030个;SSR标记的PIC值在0.623~0.940之间,平均为0.865;面包果资源间遗传相似系数在0.517~0.951之间,平均遗传相似系数为0.685,且硬面包果Ⅰ型ZZP资源内个体间差异最大,平均遗传相似系数为0.626,无核型面包果XYS1-3资源内个体间差异最小,平均遗传相似系数为0.723;遗传相似系数为0.713时,将30份面包果资源聚成5类,XBL(Artocarpus odoratissimus)和园林栽培硬面包果Ⅰ型种质(ZZP、LX、STH、HJ5)聚为一类,无核型面包果(SLLK、XYS2、XYS3、XYS5、XYS6、YN)聚为一类,硬面包果Ⅱ型(SLM2、YDNXY1、G1、G2)聚为一类,硬面包果Ⅱ型(W1、W3、SMY、8-4、8-3、5-5、5-6)聚为一类;三维图能较好地将XBL和园林栽培硬面包果Ⅰ型与食用价值较大的无核型面包果和硬面包果Ⅱ型区分开。依据聚类分组情况,可推测XYS2、XYS3、XYS5和XYS6可能引种于越南,XYS1-3、YBG和XYS1可能引种于印度尼西亚,FJ可能是无核型面包果。该研究阐明了30份面包果资源间的亲缘关系,为面包果品种选育、鉴别提供理论依据。

Breadfruit is considered as the most potential food crop to solve tropical famine with high economic value.Breadfruit was introduced from several countries,and there are no research on the systematic taxonomic and genetic diversity analysis about it.The objective of this study was to specify the genetic distance and relationship among bread-fruit and its closest wild relatives.For genetic diversity analysis,33 pairs of SSR primers with clear amplified bands,high polymorphism and good stability were selected from 75 pairs of SSR primers.PCR amplification was performed,and the products were detected by 8%denaturing polyacrylamide gel.Genetic diversity correlation analysis was per-formed by NTSYS software.The results showed that the polymorphism ratio of amplified bands of the 33 SSR markers was 94.57%.199 number of polymorphic sites were detected,with an average of 6.030 per marker.The PIC values of the SSR markers ranged from 0.623 to 0.940,with an average of 0.865.The genetic similarity coefficients among the breadfruit resources ranged from 0.517 to 0.951,with an average genetic similarity coefficient of 0.685.Furthermore,germplasm ZZP possessed the greatest variation among individuals,with an average genetic similarity coefficient of 0.626.Germplasm XYS1-3 possessed the least variation among individuals,with an average genetic similarity coeffi-cient of 0.723.At the genetic similarity coefficient of 0.713,the 30 breadfruit resources were clustered into five groups,with XBL and breadnut type I(ZZP,LX,STH,HJ5)which used for landscaping clustered into one group,breadfruit SLLK,XYS2,XYS3,XYS5,XYS6 and YN clustered into one group,breadnut type SLM2,YDNXY1,G1 and G2Ⅱclustered into one group,breadnut type W1,W3,SMY,8Ⅱ-4,8-3,5-5 and 5-6 clustered into one group.The three-dimensional diagram could better distinguish XBL and breadnut type I ZZP,LX,STH,HJ5 from the breadfruit and breadnut type resource with edible value.Based on the cluster analysis,we speculated that XYS2,XYS3,XYS5 andⅡXYS6 might be introduced from Vietnam,XYS1-3,YBG and XYS1 might be introduced from Indonesia.Furthermore,FJ was regarded as a breadfruit germplasm.The present study reported the genetic diversity of breadfruit resources in China firstly,and elucidated the genetic relationship among breadfruit resources.In addition,the results could provide theoretical basis for variety breeding and identification of breadfruit complex.