Low water supply differentially affects the growth, yield and mineral profile of kabuli and desi chickpeas (Cicer arietinum)

The climatic events predicted to increase in intensity and frequency in the near future, including drought, may influence the quality and productivity of several important crops for human nutrition, such as legumes. Herein, two chickpea genotypes (Cicer arietinum) were analysed for their resilience to low water supply: a commercial white chickpea (kabuli) and a traditional black chickpea (desi) with marginal production in occidental countries. Plants were grown under four levels of water supplies (90%, 75%, 50% and 25% of field capacity) and biometric variables (root, shoot, pods and seeds), proxies of plant fitness (water content and oxidative stress) and the seed nutritional profile (protein and mineral concentrations) were analysed at plant maturity. The results show that the water content in shoots and roots decreased with the decrease in water supplies, with kabuli plants generally having higher water content in shoots and desi in roots. The shoot length was significantly higher in kabuli compared to desi, while the root length increased up to 11% in both species with the decrease in water supplies. The root-to-shoot ratio was higher in kabuli and increased with the decrease in the water supply, being negatively correlated with the number of pods and seeds per plant. Lipid peroxidation also increased with the decrease in the water supply, having slight positive correlations with plant growth parameters while being negatively correlated with plant productivity. No significant effects of plant genotype and water supply were observed on seed K, Ca and protein, but desi was able to sustain higher P, Mg, Zn, Fe, Mn and B concentrations than kabuli, including at lower water supplies. The results suggest that water stress negatively impacts plant growth and productivity and that the two chickpea genotypes have distinct biomass and water allocation strategies to cope with low water supply. These findings may be useful in strategies for improving the productivity and nutritional profile of chickpea crops under water-limited conditions.