Identification of peanut genotypes with high water use efficiency under drought stress conditions from peanut germplasm of diverse origins.

摘要

A study was conducted to investigate the effect of drought stress on Total Dry Matter (TDM), pod yield, Water Use Efficiency (WUE), harvest index (HI), SPAD Chlorophyll Meter Readings (SCMR), Specific Leaf Area (SLA) and canopy temperature, to identify drought resistant peanut genotypes from a collection of peanut germplasm and to establish the relationships among drought resistance traits. Field experiments was conducted in a strip plot design with four water regimes (field capacity (FC), 25, 40 and 60 reduction percentage of amount of water regimes in FC) as main and sixty peanut genotypes as sub-treatments. Observations on TDM, pod yield and SLA were measured at harvest. SCMR and canopy temperature were recorded at 30, 60 and 90 day after emergence. WUE were computed using the data on amount of water input and TDM. HI was computed using the data on pod yield and TDM. The result showed that the effects of drought reduced TDM, pod dry weight, HI, WUE and SLA, but increased SCMR and canopy temperature. The correlation of WUE was positively related to SCMR under water limit conditions. The surrogate traits with well associated on WUE could be useful as selection criteria for drought tolerance. In this germplasm, the identical genotypes with high WUE in all of drought levels were Tifton-8, 14 PI 430238 and 205 PI 442925. KK 60-3, 101 PI 268659 only found high WUE in severe drought condition. The genotypes identified might be useful in future breeding programmes for drought tolerance.