Responses of Released Cultivars of Peanut to Terminal Drought for Traits Related to Drought Tolerance

Abstract

The use of the surrogate traits with simple inheritance as selection criteria for drought tolerance should speed up the selection programs. The objectives of this study were to investigate the responses of released cultivars of peanut to end of season drought for traits related to drought tolerance and agronomics traits and to identify the released cultivars with tolerance to end of season drought. Ten peanut genotypes and two water regimes (field capacity; FC and 1/3 available water; 1/3 AW) were laid out in a split plot design with four replications for two years. The data were recorded for SPAD chlorophyll meter reading (SCMR), Specific leaf weight (SLW), biomass, pod yield, harvest index (HI), number of mature pods, 100-seed weight and number of seeds per pod. Drought increased SCMR and SLW and reduced biomass production, pod yield and seed size, whereas harvest index and number of pods per plants were not significantly affected. Maintaining high pod yield and number of pods per plant depended solely on high potential under well-watered conditions, whereas maintaining high biomass production and seed size and harvest index was dependent on both high potential and low reduction. SCMR and SLW were well associated and they had high correlations with biomass and pod yield. SCMR seemed to be more stable than SLW and it is recommended to be used as a surrogate trait for drought tolerance in peanut. The released cultivar KKU 60 was identified as drought tolerant by SCMR and SLW and by pod yield