|SONGSRI, P - Khon Kaen University|
|JOGLOY, S - Khon Kaen University|
|JUNJITTAKARN, J - Khon Kaen University|
|KESMALA, T - Khon Kaen University|
|VORASOOT, N - Khon Kaen University|
|Holbrook, Carl - Corley|
|PATANOTHAI, A - Khon Kaen University|
Submitted to: Australian Journal of Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2014
Publication Date: 6/1/2014
Citation: Songsri, P., Jogloy, S., Junjittakarn, J., Kesmala, T., Vorasoot, N., Holbrook Jr, C.C., Patanothai, A. 2014. Association of stomatal conductance and root distribution with water use efficiency of peanut under different soil water regimes. Australian Journal of Crop Science. 7:948-955.
Interpretive Summary: Unpredictable rainfall creates conditions of drought stress which reduces the yield of peanut in areas throughout the World. Breeding peanut varieties with improved water use efficiency would help in alleviating this problem. The objective of this study was to evaluate a select group of peanut genotypes to identify those with improved water use efficiency. Eleven peanut genotypes were evaluated in studies using variable soil moisture levels. Genotypes with improved water use efficiency were identified. These genotypes should be valuable parents to use in peanut breeding programs.
Technical Abstract: Drought is a major abiotic stress limiting crop productivity worldwide especially in rain-fed areas. Plant physiologists and crop breeders have aimed to better understand the mechanisms underlying drought resistance to increase the success in breeding for drought resistant crops. The objectives of this study were to i) determine the effects of different soil water availability on stomatal behavior and water use efficiency (WUE) of diverse peanut genotypes and ii) to investigate associations between surrogate physiological traits for drought tolerance. Eleven peanut genotypes and three soil moisture levels (field capacity, 2/3 available water and 1/3 available water) were assigned in a split plot design with four replications for two experiments. WUE, stomatal traits and root distribution (indicated by root length density, RLD, in the soil layer at 0-40 cm and 40-100 cm depths) were measured at 37, 67 and 97 days after sowing (DAS). Drought reduced stomatal aperture and stomatal conductance but increased WUE. Differential responses among genotypes were observed for WUE, and stomatal conductance. ISGV 98300 and Tifton 8 had high stomatal conductance and WUE under moderate water stress. Stomatal conductance and %RLD (40-100cm) play important roles in increasing WUE under mild drought stress.