Water stress induced changes in growth characteristics and proline content in seedlings of B. juncea cultivars differing in drought tolerance

摘要

Drought is one of the main environmental limitations responsible for plant growth and crop productivity in arid and semi-arid regions of land. Water stress results in cellular dehydration within a plant cell which invokes cellular responses like decreased shoot growth (Meyer and Boyer, 1981) and photosynthetic activity (Boyer and Bowen, 1970) and increased praline content (Voetberg and Sharp 1991). B. juncea is an important oil seed crop whose production is affected by drought conditions. B. junceacultivars differing in drought tolerance viz. Varuna, PPMS, RH 819 and Prakash were obtained from the Department of Plant Breeding and SR-3 from Department of Biotechnology and Molecular Biology, CCS Haryana Agricultural University, Hisar. Seeds were germinated in sterilized petri plates lined with Whatman #1 filler paper in an incubator at 25+2 deg C. A stress of -0.3 MPa and -1.0 MPa using PEG 6000 was given at the time of sowing and after 48h of sowing (after germination) respectively. Control seedlings contained sterile water only. Fresh weight, epicotyl length and hypocotyl length were measured at 7 days after sowing (DAS) stage after washing the seedlings with chilled sterile water. Proline content was estimated by the method of Bates et al (197