Studies on Enhancing Drought Tolerance in Rice, Using Different Strains of Trichodermna Harzianuum (Rifai.)

Abstract

Rice is an staple food for human being all over the world and India is the second largest producer and consumer of rice at global level. Production of rice in India is limited by several biotic and abiotic stresses. Among the abiotic stress, drought is most important limiting factor for rice cultivation. The present investigation was undertaken to screen moisture deficit tolerant strains ofT. harzianum and also to test their efficacy for enhancing drought tolerance in rice. Among two Tree Born Oilseed's (TBOs) cakes, neem cake was the best substrate to support the population dynamics and longer shelf life of T. harzianum strains at 60 per cent moisture. Of eleven T. harzianum strains, [RRJ-1 and IRRI-2 could grow and multiply effectively at even 15 per cent level of substrates moisture. Enhancing the level of substrate moisture resulted in increasing the level of population dynamics ofT. harzianum Some selected strains of T. harzianum viz. IRRI-6, IRRI-1 and IRRI-3, suported elongation of root and shoot along with enhancement in root and shoot biomass. IRRI-1 IRRI-2 and IRRI-6 strains were able to enhance the drought tolerance in rice crop by decreasing the leaf rolling and proline content, and by enhancing the total chlorophyll content, leaf area index, relative water content and membrane stability index. Thus, these strains of Trichoderma harzianum have been found to be able to provide drought tolerance in rice plants by interfering in the morpho-physiological and biochemical activities of rice plants.