SCMR: A more pertinent trait than SLA in peanut genotypes under transient water deficit stress during summer

Abstract

Peanut cultivation is habitually threatened by drought which affects the plant at all stages of development. The transient water deficit stress was imposed during 30–60 days after sowing (DAS) and 60–85 DAS in summer seasons of 2011 and 2012, respectively. As a surrogate of transpiration efficiency (TE), soil plant analytical development (SPAD) chlorophyll meter reading (SCMR) and specific leaf area (SLA) were evaluated and correlated with the pod yield (PY). The SCMR value increased at 60 and 85 DAS due to water deficit stress imposed during 30–60 DAS and 60–85 DAS, respectively. The SLA ranged from 129 to 156 cm2 g-1 at 60 DAS and from 131 to 152 cm2 g-1 at 85 DAS. Water deficit stress during 30–60 DAS did not affect the PY but, the water deficit stress during 60–85 DAS had resulted in 26 % PY loss as compared to normal irrigated crop. Variation in total dry matter (TDM) among peanut genotypes was observed. The positive correlation between SCMR and TDM; and SCMR and PY; at 60 and 85 DAS under water deficit conditions categorized the SCMR as a more pertinent trait than the SLA in peanut genotypes. Thus, it is advised to record SCMR at 85 DAS as a rapid technique to screen a large number of peanut genotypes submitted to water deficit stress during summer which can minimise the labour and work load of breeders during varietal development programs