Location: Crop Protection and Management Research
2013 Annual Report
2. Evaluate corn germplasm for drought tolerance, understand the underlying molecular mechanisms, and develop molecular markers for identifying drought tolerant corn germplasm. 2.A. Identification and re-sequencing of genes in response to drought stress and development of polymorphic markers associated with drought tolerance in corn. 2.B. Corn germplasm and breeding lines re-evaluation for preharvest aflatoxin resistance and drought tolerance and genotyping with the polymorphic markers for association study.
2. Marker-assisted breeding will be employed as an example to combine two different traits with known linked marker(s) for faster and accurate transfer of trait from donor to elite lines through a back cross program or pedigree selection. Two traits can be combined into one productive peanut cultivar. Available markers for nematode, rust, and high oleic traits and new markers identified for TSWV and leaf spots will be compiled. The outcome of these efforts will enable more precise and effective molecular breeding for peanut improvement.
3. Drought stress during the late kernel development enhances aflatoxin contamination before harvest. The differences in drought-tolerance or -sensitivity of different corn accessions will display different profiles of expressed genes in developing kernels in response to A. flavus infection and the drought stress. It is possible to identify different genes responding to drought stress, and characterize the genes that may be associated with drought tolerance in different corn lines. Genes/markers associated with drought tolerance will be identified as “candidate” genes for association studies of resistance to Aspergillus flavus and preharvest aflatoxin contamination (PAC) and used in germplasm screening for drought tolerance.
4. Drought tolerance is a characteristic that has the potential to serve as an indirect selection tool for resistance to preharvest aflatoxin contamination (PAC). The outcome of these efforts will enable effective method to screen germplasm for drought tolerance and resistance to PAC in breeding program using marker-assisted selection.