保存大豆种质遗传完整性的策略——基于SSR分子标记选择纯系

The Strategy for Maintaining Genetic Integrity of Soybean Germplasms——Selecting Pure Lines Based on SSR Markers

【目的】遗传完整性是种质安全保存和更新的核心问题,从分子水平上鉴定大豆品种的纯度,为有效保存种质遗传完整性提供理论依据。【方法】利用均匀分布在大豆基因组的59个SSR标记对中国2794份大豆种质纯度进行分析。【结果】鉴定出2517份高纯度种质(占总体的90.1%),其中有1099份为纯系,说明中国栽培大豆资源中绝大部分种质的纯度较高;在277份低纯度种质中,94.2%为地方品种,占地方品种总数2475份的10.5%。t检验发现,地方品种的纯合率(0.965,P=0.001)显著低于选育品种或品系的纯合率(0.976,P=0.001)。【结论】低纯度种质在种子繁殖时需要保持较大的群体规模,否则将丢失低频率的基因型。为了节省人力物力和方便利用,建议在分子水平上对大豆种质进行纯系选择,其中以来自湖北、四川、江苏等省的大豆种质为纯系选择的重点。

Objective The objective of the study is to identify the purity of soybean cultivars using SSR markers for efficiently keeping the genetic integrity of germplasm during germplasm conservation.Method The purity of 2 794 soybean cultivars or lines was analyzed by utilizing 59 SSR markers.Result 90.1% of soybean accessions had high purity,which indicated that most of them could be easily used in the breeding and researches.277 accessions with low purity were identified.Among them,94.2% were landraces,accounting for 10.5% of total landraces（2 475）.t test also showed that the homozygosity of landraces was significantly lower than that of cultivars or lines.Conclusion The population size should be kept larger during the propagation for those lower purity accessions compared to high purity accessions,otherwise the low frequent genotypes were easy to be lost.In order to lower the cost of propagation and convenient utilization,it is strongly recommended that pure lines should be selected for the low purity accessions based on the molecular markers,and some accessions from provinces,such as Hubei,Sichuan,Jiangsu,etc.,should be put on the priority list.