Characterization of the ICRISAT mini-core peanut germplasm collection regarding Sclerotinia blight resistance and oleic acid composition

Authors: Chamberlin, Kelly; Melouk, Hassan

Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2011
Publication Date: 8/12/2011
Citation: Chamberlin, K.D., Melouk, H.A. 2011. Characterization of the ICRISAT mini-core peanut germplasm collection regarding Sclerotinia blight resistance and oleic acid composition [abstract]. Phytopathology. 101:S30.

Interpretive Summary: Peanut production is consistently threatened by various diseases and pests. In the Southwestern U.S., the fungal disease, Sclerotinia blight, threatens profitable peanut production each year. Sources of resistance to this disease are scarce, but germplasm collections offer possible new resources. In this study, the ICRISAT mini-core collection was screened using a marker associated with Sclerotinia blight resistance. The collection was also screened for high oleic accessions using capillary electrophoresis, however, none were determined to be high oleic in nature. Results from this study identified 67 new sources of possible resistance to Sclerotinia blight which may be incorporated into peanut breeding programs.

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 U.S., 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. This study objective of this study was to characterize the 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.