Efficacy of putrescine and benzyladenine on photosynthesis and productivity in relation to drought tolerance in wheat (Triticum aestivum L.).

An experiment was conducted to find out the efficacy of putrescine and benzyladenine on photosynthesis and productivity in wheat. Seeds of wheat genotype HD 2329 (widely adapted under irrigated condition) were grown in ceramic pots under standard package and practices. Putrescine (0.1 mM) and benzyladenine (0.05 mM) were sprayed on the aerial portion of these plants at the time of anthesis. After spray, half of the plants were subjected to water stress by withholding irrigation. The non stressed plants were irrigated to keep the soil humidity at field capacity. Results showed that drought stress severly reduced the photosynthetic attributes, water status and chlorophyll content which were significantly improved by foliar application of putrescine/benzyladenine. The levels of free proline, amino acids and soluble sugars were higher under water stress conditions which were enhanced further by putrescine/benzyladenine. Memrane injury was also reduced by both the chemicals. Yield and yield attributes reduced under water stress conditions, but putrescine and benzyladenine treated plants exhibited significantly higher values over control. Most of these parameters were found significantly correlated with grain yield. It is suggested that both benyzladenine and putrescine were able to impart drought tolerance in wheat but the response of putrescine was more promising owing to better management of various physio-biochemical processes, particularly under water stress conditions.