Effect of Drought Stress and its Interaction with Two Phytohormones on Vigna radiata Seed Germination and Seedling Growth

Effect of drought stress was studied at water potentials of 0.5, 1.5 and 5 bars (by using PEG-6000) on mung bean seed germination and seedling growth. In this investigation, percent germination, radical and plumule length, fresh and dry matter of mung bean seedlings were estimated. Effect of priming with aliphatic alcohols, Triacontanol (TRIA) and homobrassinolides (HBR) and interaction of these two phytohormones were studied on germination and seedling growth under normal and imposed drought conditions. Drought inhibited percent germination and reduced seedling growth in this plant. TRIA and HBR increased germination and lessened mean time taken for germination under drought conditions. The seeds that were primed with TRIA and HBR, radical and plumule length, fresh and dry matter of both were enhanced. The data indicated that both TRIA and HBR lessened damages of drought stresses on mung bean germination and seedlings growth. Priming significantly relieved the deleterious effects of drought on germination and growth parameters. Seemingly, priming with the two phytohormones enhanced the tolerant ability of the seedlings to drought stress.