Response of Lentil Genotypes Under PEG-induced Drought Stress: Effect on Germination and Growth

Drought has a negative impact on plant growth and is responsible for considerable crop yield loses worldwide. Given the importance of improving yield under drought, the ability to select tolerant genetic material is a prerequisite in all relevant plant breeding activities. Lentil is an economically important crop which often suffers from inadequate soil moisture. In this study, seed germination potential and seedling growth were determined in various genotypes exposed to drought as a means to explore the possibility of identifying drought-tolerant germplasm at an early stage. Drought stress experiments were carried out using six lentil cultivars, representing local and imported germplasm. Stress was induced by varying concentrations of polyethylene glycol (PEG6000: 0%, 5%, 10% and 20%). Genotype performance was assessed on a daily basis and referred to germination percentage (%), seed water absorbance (%), seedling water content (%), shoot and root length (cm) and number of seedlings with abnormal genotype. Our findings revealed that drought stress substantially affects parameters associated to germination and growth, with its effect being analogous to the stress level applied. Genotypic differences also were evident, with cultivars Elpida, Samos and Thessalia proving as the most tolerant and cultivar Flip 03-24L as the least tolerant genotypes under severe drought stress. Overall findings provide evidence that identifying drought tolerant germplasm might be accomplished by scoring seed germination and early growth potential under water deficit conditions. Such possibility is of outmost importance for a time- and cost-efficient selection of drought tolerant lentil genotypes to be exploited in breeding programs