Growth, water status, and leaf characteristics of Brassica carinata under drought and rehydration conditions

This study has analyzed the response of Ethiopian mustard (Brassica carinata A. Braun) to induced drought stress and subsequent rehydration in terms of plant growth, water status, chlorophyll concentration, chlorophyll fluorescence (F-V/F-M), net photosynthetic rate (Pn), transpiration rate (E), and stomatal conductance (g(s)). Potted plants were subjected to drought stress for 15 days and then to a daily irrigation for 5 days with 100 % field capacity (FC), and then extent of possible loss due to stress and gain due to rehydration was analyzed. The control population was maintained on normal watering schedule with 100 % FC. Drought stress reduced the growth rate of root and shoot, number of leaves, dimensions (width, length, and area) of leaves, and the biomass accumulation in different plant parts. With increase in drought stress, the relative water content, chlorophyll content, F-V/F-M, Pn, E, and g(s) were reduced. After rehydration, a complete or partial recovery was seen for all the parameters studied. On the whole, B. carinata employs a morpho-physiological drought-avoidance strategy.