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Submitted to: Peanut Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/9/2013 Publication Date: 1/2/2014 Citation: Chamberlin, K.D. 2014. Characterization of ICRISAT peanut mini-core accessions with regards to a molecular marker associated with resistance to Sclerotinia blight. Peanut Science. 41(1):42-49. Interpretive Summary: Peanut is the second most economically important legume crop throughout the United States and the third most important oilseed in the world is consistently threatened by various diseases and pests. Sclerotinia blight is a major threat to peanut production in the Southwestern US, Virginia, and North Carolina and can reduce yield by up to 50% in severely infested fields. Cultivars currently available for production offer only moderate resistance to Sclerotinia blight and thus peanut farmers must apply fungicide several times throughout the growing season to control the disease. Peanut breeders are constantly striving to find new sources of resistance that might be incorporated into cultivated peanut and thus reduce the farmers' input cost per acre. Although host plant resistance would provide the most effective solution to managing Sclerotinia blight, limited sources of resistance to the disease are available for use in breeding programs. This study describes the use of a molecular marker for Sclerotinia blight resistance in peanut to screen the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) germplasm collection for potential new sources of resistance. One hundred twenty-four (124) accessions from the collection were available and genotyped using the marker and 67 were identified as potential new sources of resistance and targeted for further evaluation in field tests for Sclerotinia blight resistance. Capillary electrophoresis profiles of oil extracted from each accession determined that none were high oleic in composition. Technical Abstract: Cultivated peanut, the second most economically important legume crop throughout the United States and the third most important oilseed in the world, is consistently threatened by various diseases and pests. Sclerotinia minor Jagger (S. minor), the causal agent of Sclerotinia blight, is a major threat to peanut production in the Southwestern US, Virginia, and North Carolina and can reduce yield by up to 50% in severely infested fields. Although host plant resistance would provide the most effective solution to managing Sclerotinia blight, limited sources of resistance to the disease are available for use in breeding programs. Peanut germplasm collections are available for exploration and identification of new sources of resistance, but traditionally the process is lengthy, requiring years of field testing before those potential sources can be identified. Molecular markers associated with phenotypic traits can speed up the screening of germplasm accessions. The objective of this study was to characterize the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) mini-core collection with regards to oleic acid composition and a molecular marker associated with Sclerotinia blight resistance. One hundred twenty-four (124) accessions from the collection were available and genotyped using the SSR marker and 67 were identified as potential new sources of resistance and targeted for further evaluation in field tests for Sclerotinia blight resistance. Capillary electrophoresis profiles of oil extracted from each accession determined that none were high oleic in composition. |
