Effect of inoculation with Azospirillum brasilense on yield and some chemical constituents of rice grain

A field experiment was conducted at Sakha Station on rice (var. Giza172) to investigate the effect of inoculation by Azospirillum brasilense as a biofertilizer under different nitrogen fertilizer levels on chemical constituents of grain like carbohydrates content and protein fraction using different solvents and electrophoretic patterns. The data showed that the inoculation by A.brasilense Sp7 decreased the grain yield of rice, meanwhile mineral nitrogen fertilizer, as urea, gave a highly significant increase p=0.01 which reached about 22% and 27% at applying low level and high level of urea, respectively. Crude protein of rice grain significantly increased (p=0.01) as a result of inoculation; such increases represented about 14% over the control. Biofertilization increased Albumins and globulins but not grain content. Total soluble carbohydrates of grain are generally decreased upon nitrogen fertilization: Biofertilization compensated the negative effect of nitrogen fertilization. Regarding to separation of total protein of rice grain using SDS-PAGE technique, inoculation treatments gave more density bands than uninoculated ones irrespective of the level of nitrogen fertilization. (Résumé d'auteur