Elucidating Drought Tolerance Potential of Maize (Zea mays L.) Inbred Lines through Polyethylene Glycol Induced Drought Stress

Abstract

Drought is one of the most distressing environmental stresses restraining the crop production . Drought undermines the plant growth from seedling to maturity and the studies have unveiled that the harmful impact of drought results in crops due to the damages perceived during crucial stages of development namely, germination, seedling development and flowering stages. Biometric elements and indices at an early growth stage could be employed in designing the selection criteria to figure out the drought tolerant genotypes. Breeding for drought-prone environments is constrained by lack of suitable selection indices of drought stress resistance. The present study was conducted to determine the reliability of in-vitro screening method for initiating drought breeding programme. Poly ethylene glycol (PEG) has been used often as abiotic stress inducer in many studies to screen drought tolerant germplasm. The present investigation was carried out to reveal the drought tolerance potential of 103 maize inbred lines  by in-vitro screening under three  levels of PEG levels viz.,  0%  as control, 10% and 20%   and evaluating their effect on the root parameters like primary root length, number of seminals roots , number of lateral roots and root biomass. The seedlings exhibited a significant variation for all the traits analyzed. All the root parameters had highest value under control and had significant decline with increasing PEG concentrations (0% < 10% < 20%). The inbreds showing  the best level of drought tolerance at all levels of PEG induced stress can be used as a source of drought tolerance for the improvement of drought tolerant hybrids . The variation among maize inbreds for these traits was found to be an ideal indicator to screen the drought tolerant genotypes at early growth stages.