Seed germination and seedling growth responses of tomato cultivars to imposed water stress

Abstract
The germination and seedling growth of tomato cvs Arka Saurabh, Pusa Ruby, Pusa Early Dwarf (PED), Arka Vikas and a wild sp. L. pimpinellifolium were studied under water potentials induced by polyethylene glycol-6000. Germination declined progressively in response to decreasing (more negative) water potentials. Germination in all cultivars occurred within 24 h after priming the seeds for 10 days at –0.6 MPa. The critical value of water potential for germination was found to be –0.4 MPa in nearly all the cultivars. A less negative critical water potential exists for the initiation of radicle growth (germination) than for growth itself. The water-sensitive phase of germination in tomato occurs prior to radicle growth.