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United States Department of Agriculture

Agricultural Research Service

Title: Molecular Characterization of the US Peanut Mini Core Collection Using Microsatellite Markers

Authors
item Kottapalli, Kameswara - NEW MEXICO STATE UNIVERSI
item Burow, Mark - TEXAS A&M EXP STATION
item Burow, Gloria
item Burke, John
item Puppala, Naveen - NEW MEXICO STATE UNIVERSI

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 1, 2007
Publication Date: August 1, 2007
Citation: Kottapalli, K., Burow, M., Burow, G.B., Burke, J.J., Puppala, N. 2007. Molecular characterization of the US peanut mini core collection using microsatellite markers. Crop Science. 47(4):1718-1727.

Interpretive Summary: Peanut is the second-most important legume crop in the United States. A limitation to increased peanut productivity is that peanut improvement is hampered by relatively low genetic variability in the germplasm commonly used by breeding programs. To facilitate accessibility to diverse germplasm sources for breeding applications, a core subset of the United States Department of Agriculture (USDA) peanut germplasm was previously established that later on was refined to develop a mini core collection consisting of 112 accessions. In this study we determined the genetic diversity of the US peanut minicore collection at the molecular level using microsatellites or simple sequence repeat markers. Microsatellites are well known for their potentially high information content and versatility as molecular tools. They are also amenable to high throughput genotyping and have proven to be highly versatile and useful markers for germplasm characterization. Seventy two peanut accessions from the US peanut mini core were genotyped with 73 SSR markers; all but 6 produced reliable, polymorphic bands. Moderate levels of genetic variation were found with genetic distances (D) values between accessions ranging from 0.088 to 0.254 which was improvement of detection of variability for cultivated peanut as compared to previous results. Distinct groupings of the accessions based on subspecies classification and on botanical (market) type groupings were observed from phylogenetic analyses of allelic variation of the SSR markers. Twelve of the markers, with known map positions in the A genome, were found sufficient to identify both subspecies and botanical types, and gave a clustering pattern very similar to the entire 67 SSR marker set. The genetic variation observed within U. S. peanut mini core can be utilized for selection of diverse parents for breeding and development of mapping populations.

Technical Abstract: Peanut (Arachis hypogaea L.) is the second-most important legume crop in the United States. A limitation to increased peanut productivity is that peanut improvement is hampered by relatively low genetic variability in the germplasm commonly used by breeding programs. To facilitate accessibility to diverse germplasm sources for breeding applications, a core subset of the United States Department of Agriculture (USDA) peanut germplasm was previously established that later on was refined and used to develop a mini core collection consisting of 112 accessions. This report details the first extensive characterization of genetic diversity and relationships in the US peanut mini core collection using microsatellites or simple sequence repeats marker (SSRs). Seventy two peanut accessions from the US peanut mini core were genotyped with 73 SSR markers; all but 6 produced reliable, polymorphic bands. Moderate levels of genetic variation were found with genetic distances (D) values between accessions ranging from 0.088 to 0.254. Distinct groupings of the accessions based on subspecies classification and on botanical (market) type groupings were observed from phylogenetic analyses of allelic variation of the SSR markers. Twelve of the markers, mapped previously to the A genome, were found sufficient to identify both subspecies and botanical types, and gave a clustering pattern very similar to the entire 67 SSR marker set. The genetic variation observed within U. S. peanut mini core can be utilized for selection of diverse parents for breeding and development of mapping populations.

Last Modified: 12/20/2014