Effect of 28-homobrassinolide on salinity induced changes in growth, ethylene and seed yield of mustard

The seeds of Brassica juncea were soaked for 6 hours, in water, 50, 100 or 150 mM of NaCl and sown in pots. The plants were sprayed with water, 10⁻¹⁰, 10⁻⁸ or 10⁻⁶ M aqueous solution of 28-homobrassinolide (HBL) at 15, 30 or 45 day after sowing (DAS) to the foliage of the plants. Sodium chloride retarded growth of root and shoot observed at day 60 (post-flowering) and lowered seed yield, at harvest (140 DAS). However, spray of HBL at 15, 30 or 45 DAS increased the values significantly for the above characteristics. 30^th day spray was best among them. Moreover, the plants released more ethylene, under NaCl stress or HBL treatments. The ill effect of the lowest concentration (50 mM) of the salt was completely overcome by the spray of HBL (10⁻⁸M) at 30 day stage.