Environmental Challenges (Aug 2022)
Increased significance of chickpea (Cicer arietinum L.) senescence trait under water-deficit environment
Abstract
Characterizing stress–inducing trait(s) and deploying their genetic diversity are crucial for developing stress–tolerant cultivar(s). The study aimed to investigate the genotypic variations in chickpea senescence traits and their significance in yield sustainability under water–deficit stress conditions. Therefore, a panel of eighty–eight chickpea that differ in maturity duration [early–maturing (≤ 100 days) and late–maturing (> 110 days)], were grown under soil water deficit conditions. The parameters viz. days to onset of senescence (DTSI), senescence duration (SD), days to flowering (DF), reproductive period (RP), and days to maturity (DM) were recorded for each genotype and their relations with grain yield were evaluated. The parameter DTSI defines the earliness or delay in the onset of senescence; while SD represents the pace of senescence. Temporal dynamics of senescence were visually scored following a 0–10 scale. The trait senescence duration (SD) exhibited negative correlation with yield, being higher in the late maturing genotypes over the early maturing genotypes. The senescence index [SD/RP], which exhibited a higher genotypic variability over the parameter SD, was found to have a significant negative association with yield. While the index [DTSI/DM] exhibited a strong positive correlation with yield (p < 0.01) in both early and late maturing groups (p < 0.01). Multivariate regression analysis demonstrated that SD and cumulative degree–days of senescence period had a strong negative influence on chickpea yield under water–deficit conditions. Hence, the study suggested that delayed and faster senescence could serve as the selection criterion for drought tolerance in chickpea. The findings suggested that the indices [SD/RP] and [DTSI/DM] could be more realistic indicators when characterizing senescence of chickpea under water–deficit environments.
