Monday, June 18, 2007 - 11:20 AM
Evaluation of the U.S. Peanut Mini-core Collection for Heat and Water-deficit Stress Tolerance at Reproductive Stage Growth.
Kameswara Kottapalli1, Mark Burow2, Naveen Puppala3, and Paxton Payton1. (1) USDA-ARS, 3810 4th Street, Lubbock, TX 79415, (2) Agricultural Experiment Station, Texas A&M Univ., 1102 E. FM1294, Lubbock, TX 79403, (3) New Mexico State University, New Mexico State University/ASC at Clovis, 2346 Sr 288, Clovis, NM 88101
Virtually all-agricultural regions of the world suffer from inadequate water supplies that reduce crop productivity. Global climatic trends may accentuate this problem by combining heat and water-deficit stresses. While efficient irrigation technologies help to reduce the gap between potential and actual yield, many regions are relying upon the intrinsic genetic improvement of crop productivity under arid conditions as a sustainable and economically viable solution to this problem. In the present study the U.S. mini-core collection was independently evaluated for heat and water-deficit stress tolerance using a battery of physiological assays including leaf-level photosynthesis, stomatal conductance, chlorophyll fluorescence yield under elevated respiratory demand, membrane thermostability, and leaf sugar synthesis. Additionally, selected accessions were evaluated for biomass accumulation, specific leaf area, and water use efficiency under water-deficit stress. Our results suggest that a novel chlorophyll fluorescence bioassay designed to measure source leaf responses to abiotic stresses in cotton can be employed to screen peanut accessions for tolerance to both heat and water-deficit stresses. Additionally, the use of rapid physiological measurements was used to identify two mini-core accessions that were selected for enhanced abiotic stress tolerance. These accessions will be used to investigate the molecular responses to water-deficit and heat stress via gene expression profiling studies. The detailed results of this project will be presented at this meeting.