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

Abstract

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) so that 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 thesoybean germplam from conservation into wider use.