Physiological, agro-morphological, and germination responses of a worldwide chickpea (Cicer arietinum) collection subjected to drought stress by applying polyethylene glycol (PEG) on germinating seeds and by exposure plants to water restriction at the vegetative stage

Abstract

Given that agriculture uses considerable quantities of water to meet food requirements, the scarcity of rainfall and the drying up of water tables could compromise agricultural production. Faced with the urgency of a world undergoing demographic change and a current agro-climatic trend marked by low rainfall at the vegetative stage, the sustainability of chickpea production requires new varieties with resilience and adaptation to climatic change. The aim of this study is the selection genotypes that are tolerant to early drought stress and able to avoid terminal drought. To this end, a collection of 159 genotypes was evaluated, using an augmented-RCBD (Randomized Complete Block Designs), in two experiments (drought stress by water restriction and stress imposition by Polyethylene glycol (PEG) application) simulating the effect of drought. Our results show significant genetic variability and a fairly significant genotype effect in both trials. We noted an interesting positive correlation between germination percentage in the presence of PEG and pod and seed production under water stress at the vegetative stage, and these same traits showed strong heritability. 16 genotypes had a germination percentage ≥50% in the 20% PEG treatment. In addition, 18 Desi and 4 Kabuli genotypes performed well in both trials, with good germination percentage, pod and seed production, good canopy coverage, better normalized difference vegetation index, and low to medium wilting. It would therefore make sense to exploit these genotypes in hybridization programs for the creation of pure drought-tolerant lines, and also to evaluate them in different arid and semi-arid regions over several years.