大豆核心种质和微核心种质的构建、验证与研究进展

我国作物种质资源长期库中保存大豆资源2.3万余份，数量居世界之首。然而，在大豆新品种培育中的利用率仅为1%左右，导致大豆育成品种的遗传基础趋于狭窄。主要原因是缺少对其重要经济性状的鉴定，尤其是缺少多年多点的评价，难以有目的选择有重要价值的育种亲本。为了加速大豆种质资源的评价并促进其利用，在国家基础研究项目(973)的连续资助下，开展了“大豆核心种质构建(1998-2003)”和“大豆微核心种质基因多样性(2004-2009)”研究，目的是浓缩大豆资源的遗传多样性，强化其表型和基因型鉴定，为发掘和利用大豆资源中的优异基因提供指导。本文在研究构建不同比例(占总体2%~5%)大豆核心种质和大豆微核心种质(占总体1%)的同时，介绍了核心种质补充和完善的研究进展。为了验证核心种质的代表性，在构建方法方面，从SSR位点、样本组成、取样比例、低频率等位变异4个方面对代表性进行了分析，并用随机抽样方法对核心种质代表性进行了检测和验证。文中还介绍了利用核心种质和微核心种质在新基因发掘、种质创新和育种利用方面的研究进展，尤其介绍了与育种单位密切合作，建立基于核心种质的种质创新与利用体系的研究成效。围绕遗传多样性、核心种质利用方式进行了讨论，指出大豆核心种质为性状鉴定、新基因发掘、新种质创造和新品种培育等理论研究和实际应用提供材料基础，具有潜在的应用前景。实践证明，大豆种质资源的系统研究与利用，将促进我国大豆种质资源由数量保存型向研究应用型转变。

Establishment, Representative Testing and Research Progress of Soybean Core Collection and Mini Core Collection

China has the most soybean germplasm in the world, but only about 1% of them have been used in soybean breeding program, which results in narrow genetic base for developing varieties. This exiguous use of germplasm is due to lack of reliable information on traits with economic importance, which requires replicated multilocational evaluations to identify useful parents. In order to accelerate evaluation and utilization of germplasm, the projects of ‘Establishment of soybean core collection’ (1998–2003) and ‘Gene diversity of mini core collection in soybean’ (2004–2008) were carried out by the continuous supporting from National Basic Research Program (973 project) in case of large germplasm collections has been evaluated properly on the basis of the guideline from core collections. In this paper, the development of core (2–5% of entire collection) and mini-core (10% of core or 1% of entire collection) is introduced. Meanwhile, the complement of the core or mini-core collections is carried out in order to broaden their representative from national wide into international soybean accessions. For testing the representatives of the core collection, four parameters including SSR loci, sample components, sampling ratio and low frequency allele are analyzed, and then confirmed by the random sampling test. The core and mini-core collections have been used in identifying elite traits and developing new lines, in which the approaches have been introduced that based on core and mini-core collections. The further utilization of core and mini-core collections related to genetic diversity and utilization method of collections is discussed, it is pointed that core collections are basic materials for new trait identification, novel gene mining, germplasm enhancement and new variety development. It has been proved that systematic study and use of soybean germplasm will improve the research of the soybean germplam from conservation into wider use.