野生二倍体草莓的SSR分子标记开发及核心种质的构建

Development of SSR Molecular Markers and Construction of Core Collection of Wild Diploid Strawberry

用MISA程序搜索森林草莓(Fragaria vesca L.)基因组获得106829个SSR位点,比对森林草莓等8种二倍体草莓的基因组获得唯一且共同的SSR序列5778个,其中单、二、三、四、五、六核苷酸类型以及复杂重复类型分别为3461、1223、999、57、7、5、26。在26个复杂重复类型中,有18个SSR位点在森林草莓、中国草莓(F.chinensis Lozinsk)、东北草莓(F.mandshurica Staudt)、黄毛草莓(F.nilgerrensis Schlecht.)、西藏草莓(F.nubicola Lindl.)、峨眉草莓(F.emeiensis Jia J.Lei)、五叶草莓(F.pentaphylla Lozinsk)和绿色草莓(F.viridis Duch.)等8个二倍体种的176份资源重测序数据中具有较高的覆盖度,通过检测获得了444个等位基因,平均有效等位基因数为7.899,Shannon信息指数在0.836~3.362之间,观察杂合度在0.006~0.477之间,期望杂合度在0.324~0.953之间,多态信息含量(PIC)介于0.315~0.951,平均值为0.756;利用选择的18对SSR标记构建野生二倍体草莓的核心种质,并利用t检验对核心种质进行评价,筛选出的43份材料保存了80%以上的遗传多样性,代表性较高,确定为野生二倍体草莓的核心种质。同时构建了每份材料的分子身份证并生成二维码。本研究中开发的多态性SSR位点以及筛选出的核心种质能够为今后野生草莓物种的鉴别、分子标记辅助育种等提供工具。

Core collection can reduce the number of resources and maximize the genetic diversity of the population.The 106829 SSR loci were obtained by searching the genome of Fragaria vesca L.with MISA program,and 5778 unique and common SSR sequences were obtained by comparing the genome of eight diploid strawberries such as F.vesca L.Among the 26 complex repeats,18 SSR loci were found in F.vesca L,F.chinensis Lozinsk,F.mandshurica Staudt,F.nilgerrensis Schlecht.,F.nubicola Lindl.,F.emeiensis Jia J.Lei,F.pentaphylla Lozinsk and F.viridis Duch.Among them,the single,two,three,four,five,six nucleotide types and complex repeat types were 3461,1223,999,57,7,5,26,respectively.Among 26 complex repeat types,18 SSR loci have high coverage in 176 diploid strawberry re-sequencing data,which are used for construction of core collection.The results showed that 444 alleles were obtained from 176 accessions of wild diploid strawberry with 18 pairs of conservative sequence,the average number of effective alleles was 7.899,the Shannon's information index was 0.836–3.362,the observed heterozygosity was 0.006–0.477,the expected heterozygosity was 0.324–0.953,the PIC value was 0.315–0.951,and the average value was 0.756.The core collection of wild diploid strawberry was constructed with 18 pairs of SSR primers selected,and the core collection was evaluated by t-test.The fourty-three accessions were selected,which preserved more than 80%of genetic diversity and were highly representative.They were identified as the core collection of wild diploid strawberry,and at the same time,the molecular ID of two-dimensional code of core collection was constructed.The polymorphic SSR loci developed in this study can provide research tools for identification and molecular marker breeding of wild strawberry in the future.