Ten wheat genotypes of locally cultivated and exotic origins were grown under drought condition to determine the biochemical responses. Plants were grown in hydroponics in modified Hoagland solution in box container in the Growth Room with temperature, light and humidity control at the Plant Stress Breeding Laboratory (PSBL), at the dept. of Genetics and Plant Breeding, BAU, Mymensingh. Nutrient solution was refreshed after every ten days. Wheat plants were subjected to drought stress, induced by 3% and 6% PEG 6000 in hydroponic solution after 47 days of transferring seedling in full strength nutrient solution. Plants were kept in drought treatment for 42 days and on harvesting, leaves were collected for biochemical assays. Six biochemical traits were determined from leaf tissues following standard protocol. Concentration of leaf biochemical viz. Catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), hydrogen peroxide (H2O2), malondialdehyde (MDH) and proline were found in both increasing and decreasing trend of fluctuation. Not a single genotype was found with the entire biochemical traits with favorable actions, as some demonstrated better osmoprotectant attributes, some with gradient of ROS scavenging ability, some demonstrated to have both at a moderate level. The relationship among the biochemical traits were also determined, and found a positive significant correlation between CAT and POD. A ranking table was constructed considering mean performance of the genotypes under different PEG 6000 conc. based on that Sonalika, BARI Gom 21, BARI Gom 29, BARI Gom 30 Summa, Burr and Macya were found with better ranking under both 3% and 6% PEG 6000 induced drought, and recommend to consider for future wheat improvement program for drought tolerance.
Key words: Drought, biochemical responses, drought tolerance, PEG 6000, wheat
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