Location: Tropical Crops and Germplasm Research2012 Annual Report
1a. Objectives (from AD-416):
Utilization of untapped genetic diversity through the conversion of germplasm and the incorporation of key traits into common bean improvement programs for abiotic stress tolerance and disease resistance. Application of genetic analysis and TILLING (targeting induced local lesions in genomes) for identification and mapping of important traits in common bean. Development and release of improved germplasm for specific agriculturally important biotic and abiotic stress tolerance traits and identification of associated molecular markers.
1b. Approach (from AD-416):
Increase genetic diversity in common bean germplasm through conversion of specific abiotic and biotic traits from tropical germplasm. Elucidate the genetics of drought and heat tolerance, and other agriculturally important traits, using molecular markers, TILLING, and classical genetic approaches. Develop germplasm with improved disease resistance and abiotic stress tolerance through phenotypic selection and marker assisted selection.
3. Progress Report:
Advanced lines from the 2nd cycle of recurrent selection for drought were generated with adaptation, photoperiod insensitivity and for the presence of drought and bacterial blight resistance. Selections are currently underway with these materials in Nebraska. In addition, germplasm is undergoing final testing with the University of Idaho (common bacterial blight and white mold resistance), and Cornell University (root rot resistance) before consideration for release. A recombinant inbred line (RIL) population (350 lines) was evaluated for response to drought in replicated trials in Nebraska and Puerto Rico. The population is currently being genotyped using SNPs (single-nucleotide polymorphism) and indel (insertion-deletions) markers. An Association Mapping (AM) population of Andean germplasm was developed as part of a Feed the Future project, increased at Tropical Agriculture Research Station (TARS), and sent to collaborators in WA, MI, MD, PR, and South Africa. Another AM population (100 lines) developed by the BeanCAP project was evaluated for a second year under drought stress. The EMS (ethyl methanesulfonate) mutant population (>2,500 lines) is being evaluated for a nutrition related seed trait at an ARS laboratory. Two manuscripts describing the development of germplasm by the U. of Puerto Rico for virus resistance and for web blight resistance were accepted for publication in the Journal of Agriculture of the University of Puerto Rico and in the Journal of Plant Registrations, respectively. ARS-TARS participated in the evaluation of lines resulting in both releases. Advanced lines for drought, root rot, and Empoasca resistance are being tested for potential release. In addition, advanced lines of tepary (Phaseolus acutifolius) were generated, for potential release, with improved seed size and with abiotic stress tolerance.
1. Development of improved tepary (Phaseolus acutifolius) germplasm. Improved lines of tepary, a desert native sister species of common bean with far higher levels of abiotic stress tolerance, have been developed in collaboration with the University of Puerto Rico. These lines have larger seed size than most teparies and have multiple stress tolerance, including tolerance to high ambient temperature and drought stress, and resistance to bacterial blight. Once released, these lines could be used by farmers to increase legume production in arid/high temperature environments, or by breeders to improve tepary.
Mcclean, P.E., Burridge, J., Beebe, S., Rao, I.M., Porch Clay, T.G. 2011. Crop improvement in the era of climate change: an integrated, multi-disciplinary approach for common bean (Phaseolus vulgaris L.). Functional Plant Biology. 38:927-933.