Location: National Peanut Research Laboratory
Project Number: 6044-21000-004-000-D
Project Type: In-House Appropriated
Start Date: Jul 30, 2013
End Date: Jul 29, 2018
Objective:
1. Develop genome-wide molecular marker approaches to determine the genetic variability of important pathogens, such as those causing early and late leaf spot (Cercospora arachidicola and Cercosporidium personatum), to facilitate phenotyping and breeding for resistance to these pathogens in peanut.
2. Develop RNA interference (RNAi) technology and apply it to identify genes that can be used to prevent aflatoxin accumulation in peanut, and assess the utility of other novel techniques to access useful genes in peanut.
3. Identify key components of the drought response regulation system in peanuts through transcriptome and small RNA (sRNA) mining.
4. Develop and release high yielding peanut cultivars with biotic and abiotic stress tolerance for the United States using conventional breeding and marker-assisted methods.
Approach:
The causal agents of leaf spot will be isolated from symptomatic leaves to determine their genetic diversity. We will develop molecular markers and fingerprint the isolates. We will also develop molecular markers for peanut plants. Multiple peanut lines will be grown in multiple locations, phenotyped for leaf spot resistance, and fingerprinted with molecular markers to find association between markers and disease resistance. For the use of RNA interference (RNAi) in the control of aflatoxin, multiple approaches will be used, including making multiple constructs that target 2-5 genes in the pathway, genetic transformation of Aspergillus spp., transformation of Arabidopsis to characterize the effectiveness of the system, genetically transform peanut plants with the most promising constructs and finally test for accumulation in seeds after challenging them with aflatoxigenic strains of the pathogen. For drought tolerance, multiple peanut genotypes that have shown different response to drought will be grown in multiple locations, under drought and irrigation conditions. Genes potentially regulated by drought will be identified from transcriptome sequencing, also genes potentially regulated by epigenetics (i.e., small RNAs, methylation) will be identified and later verified the expression profiling. Both, genes and molecular markers identified in the various areas, will be incorporated into the breeding program.
