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ARS Home » Southeast Area » Tifton, Georgia » Crop Genetics and Breeding Research » Research » Publications at this Location » Publication #234623
Title: Relationship between biomass production and nitrogen fixation under drought stress conditions in peanut genoytpes with different levels of drought resistance

Author
item PIMRATCH, S - KHON KAEN UNIV.
item JOGLOY, S - KHON KAEN UNIV.
item VORASOOT, N - KHON KAEN UNIV.
item TOOMSAN, B - KHON KAEN UNIV.
item PATANOTHAI, A - KHON KAEN UNIV.
item Holbrook, Carl - Corley

Submitted to: Journal of Agronomy and Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/5/2009
Publication Date: 2/15/2009
Citation: Pimratch, S., Jogloy, S., Vorasoot, N., Toomsan, B., Patanothai, A., Holbrook Jr, C.C. 2008. Relationship between biomass production and nitrogen fixation under drought stress conditions in peanut genoytpes with different levels of drought resistance. Journal of Agronomy and Crop Science 194:15-24..

Interpretive Summary: Drought is a major factor limiting yield of peanut under rainfed conditions in many countries. Drought resistant peanut lines have been identified, however, the physiological basis for achieving high yield under drought stress is not known. Information on physiological traits contributing to high yield under drought stress might reveal the underlying mechanism from which improved strategies could be developed to enhance the effectiveness and progress in breeding for drought resistance in peanut. The objective of this study was to determine the effect of drought on biomass production and N2 fixation by evaluating the relative values of these two traits under well watered and water-stress conditions. Twelve peanut genotypes with varying levels of drought tolerance were tested under field conditions in two dry seasons in Northeastern Thailand. Data were recorded on biomass production and N2 fixation under well watered and water-stress conditions. Positive relationships between N2 fixed and biomass production were found at both levels of drought stress, and the relationship was stronger the more severe the drought stress. These results suggested that the ability to maintain high N2 fixation under drought stress could aid peanut genotypes in maintaining high yield under water limited conditions.

Technical Abstract: The relationship between biomass production and N2 fixation under drought stress conditions in peanut genotypes with different levels of drought resistance is not well understood. The objective of this study was to determine the effect of drought on biomass production and N2 fixation by evaluating the relative values of these two traits under well watered and water-stress conditions. Twelve peanut genotypes were tested under field conditions in two dry seasons in Northeast Thailand. A split-plot design with four replications was used. Main-plot treatments were three water regimes [field capacity (FC), 2/3 available soil water (AW) and 1/3 AW], and sub-plot treatments were 12 peanut lines. Data were recorded on biomass production and N2 fixation under well watered and water-stress conditions. Genotypic variations in biomass production and N2 fixation were found at all water regimes. Biomass production and N2 fixation decreased with increasing levels of drought stress. Genotypes did not significantly differ in reductions for biomass production, but did differ for reductions in N2 fixation. High biomass production under both mild and severe drought stress conditions was due largely to high potential biomass production under well-watered conditions and, to a lesser extent, the ability to maintain high biomass production under drought stress conditions. High N2 fixation under drought stress also was due largely to high N2 fixation under well-watered conditions with significant but lower contributions from the ability to maintain high nitrogen fixation under drought stress. N2 fixation at FC was not correlated with the reduction in N2 fixation at 2/3 AW and 1/3 AW. Positive relationships between N2 fixed and biomass production of the tested peanut genotypes were found at both levels of drought stress, and the relationship was stronger the more severe the drought stress. These results suggested that the ability to maintain high N2 fixation under drought stress could aid peanut genotypes in maintaining high yield under water limited conditions.