Decoding the heat stress resilience in Chickpea (Cicer arietinum L.): multi-trait analysis for genotypic adaptation

Abstract

Increasing heat stress is detrimental to chickpea (Cicer arietinum L.) growth and production. Therefore, dedicated efforts are urgently needed to develop heat tolerant chickpea genotypes for food security. This study evaluates the tolerance of 26 chickpea genotypes under heat stress and non-stress conditions across three years (2017-18, 2018-19, and 2019-2020) under field conditions. Significant genotypic variation was observed for phenological (days to flowering, pod initiation, maturity) and physiological traits (chlorophyll content, nitrogen balance index, membrane stability) under both environments. Heat stress resulted in a considerable reduction in biomass and yield-related traits. Under heat stress, days to 50% flowering and maturity were reduced by 4 days and 24 days, respectively, while a 34.7% average yield reduction was observed compared to non-stressed conditions. Genotypes 'IPC 2014-55', 'IPC 2011-78', and 'ICC 92944' exhibited the least yield loss and showed better resilience under heat stress. The GGE biplot analysis identified genotypes with superior performance and stability, genotypes 'IPC 2014-55' and 'IPC 2011-78', performed consistently across both stressed and non-stressed conditions. AMMI analysis and PCA-based clustering revealed significant genotype-by-environment interactions, with certain genotypes like 'IPC 2019-05' exhibiting distinct variations under stress, because of extra early maturity. The study concludes that genotypes 'IPC 2014-55', 'IPC 2011-78', and 'IPC 2019-05' are promising candidates for breeding heat-tolerant chickpea. Correlation analysis indicated that selection of genotypes with high cell membrane stability, chlorophyll, high seed yield plant^-1, and high pods plant^-1 under heat stress environment are suitable for developing heat tolerant chickpeas.

Keywords: Advanced breeding lines; Genetic variability; Genotype × heat stress interaction; Principal component analysis; Stability.

Fig. 1

Mean maximum and minimum temperature (⁰C) at different crop growth stages of chickpea growing months (November to April) during 2017-18, 2018-19, and 2019-20.

Fig. 2

Mean vs. stability (a), which won where (b), discriminativeness vs. representativeness (c), and ranking of genotypes (d) based on GGE biplot analysis of 26 genotypes (mean of heat stress and non-stress conditions of three years). No transformation of data (transform = 0); and data were cantered by means of the environments (centering = 2).

Fig. 3

Mean vs. stability (a), which won where (b), discriminativeness vs. representativeness (c), ranking of genotypes (d), biplot of normal sown non-stress (e), and biplot of late sown stress condition (f) based on GGE biplot analysis of 26 genotypes. No transformation of data (transform = 0); and data were cantered by means of the environments (centering = 2).

Fig. 4

Phylogenetic tree (a) and principal component analysis (PCA)-based clustering (b) depicting the networking and grouping of different genotypes studied (mean of stress and non-stress conditions of three years).

Fig. 5

AMMI analysis depicting the stress tolerance index (STI) vs. PC1 for cell membrane stability (CMS) (a) and total flavonoids (FLV) (b) of chickpea under genotype x stress x year interaction. S = stress condition (~ late sown), NS = non-stress condition (normal sown); for genotypes code please see Table 1.

Fig. 6

AMMI analysis depicting the stress tolerance index (STI) vs. PC1 for days to pod initiation (DPI) (a) and days to maturity (DM) (b) of chickpea under genotype x stress x year interaction. S = stress condition (~ late sown), NS = non-stress condition (normal sown); for genotypes code please see Table 1.

Fig. 7

AMMI analysis depicting the stress tolerance index (STI) vs. PC1 for number of pods plant⁻¹ (NPP) (a) and seed yield (PY) (b) of chickpea under genotype x stress x year interaction. S = stress condition (~ late sown), NS = non-stress condition (normal sown); for genotypes code please see Table 1.

Fig. 8

Pearson’s correlation matrix among various plant phenological, physiological and yield parameters (mean of stress and non-stress conditions of three years); DFF = days to first flowering, DF50 = days to 50% flowering, DPI = days to pod initiation, DM = days to maturity, PH = plant height (cm), NDVI = normalized difference vegetation index, CHL = total chlorophyll (mg mL⁻¹), NBI = nitrogen balance index, FLV = total flavonoids (mg quercetin equivalent g⁻¹), CMS = membrane stability index, BM = biomass (g plant⁻¹), NPP = number of pods plant⁻¹, SYPP = seed yield plant⁻¹, PY = seed yield (kg ha⁻¹).

Fig. 9

Yield difference of tested genotypes under various growing condition (stress - non-stress) based on the mean yields of three years under stress and non-stress conditions.