DROUGHT STRESS EFFECTS ON SEED YIELD, YIELD ATTRIBUTES, GROWTH, CELL-MEMBRANE STABILITY AND GAS-EXCHANGE OF SYNTHESIZED BRASSICA-NAPUS L

Drought stress effects on leaf gas exchange, cell membrane stability, seed yield and yield attributes of synthesized Brassica napus L. cv. B angla kale and Bangle cabbage were compared. Drought stress treatments were imposed at early vegetative, late vegetative and flowering stage s by withholding watering. Bangla cabbage produced greater pods/plant, larger seed size, greater total dry matter/plant, seeds/pot, and 17% greater yield than Bangla kale. The seed yield in plants stressed at e arly vegetative, late vegetative and flowering stages were 59, 74, 88% lower respectively, than watered plants. Drought stress reduced leaf photosynthesis by 67 to 97 %. Bangla cabbage had 68 % greater photosyn thesis and 56 % greater stomatal conductance than Bangla kale under st ress at flowering stage. Leaf temperature was 1 to 2 degrees C higher in stressed plants than watered plants. The cell membrane stability (C MS) increased up to 83 % at flowering stage under stress compared to 2 1% under watered conditions. Although Bangla cabbage had high seed yie ld, yield attributes and photosynthesis under stressed conditions at f lowering stage, its CMS values were lower than those of Bangia kale.