Project Number: 6217-21220-007-00
Start Date: Feb 05, 2013
End Date: Feb 04, 2018
Objective 1: Parental lines being used in such crosses include Arachis hypogaea L. cultivars, advanced breeding lines, and plant introductions (PIs) with demonstrated disease resistance and high oleic acid content. New and existing potential parent lines with high oleic acid content are continually tested in the greenhouse and field plots for resistance to Sclerotinia blight and southern blight and are readily available for use in the peanut breeding program. Included in our annual screening of germplasm for disease resistance are cultivars, breeding lines, and germplasm accessions. Also, collaborators include the curator of the U.S. peanut germplasm collection as well as other breeders who are continually evaluating accessions for value added traits. Molecular markers for Sclerotinia resistance will be identified and verified by phenotypic reaction. Advanced breeding lines will be tested in local, regional and national tests for agronomic performance before release as a variety. Objective 2: Response to oxalic acid, stem lignin content, and specific canopy architecture appear to be correlated with Sclerotinia resistance among cultivars of other legumes. We will determine if these traits are also useful for predicting resistance to Sclerotinia and southern blights in peanuts. Development of pod rot-resistant cultivars is significantly slowed by unpredictability of the disease occurring under field conditions. We will develop a reproducible greenhouse protocol for screening germplasm for resistance to pod rot by: 1) identifying and quantifying Pythium spp. and Rhizoctonia solani from Oklahoma and Texas fields with high incidences of pod rot using quantitative real-time PCR; and 2) evaluating symptoms in greenhouse-grown pods exposed to different inoculum levels of the three most common pod rot pathogens found in Oklahoma and Texas.