Genetic Behaviour of Some Rice (Oryza sativa L.) Genotypes Under Different Treatments of Nitrogen Levels

The present investigation was carried out at the experimental farm of Rice Research and Training Center, Sakha, Kafer El- Sheikh, Egypt during 2008 and 2009 seasons to study the physio-morphological behaviour of some rice genotypes under low and high nitrogen application. Twenty one genotypes were tested under three different nitrogen levels viz, 0, 75 and 150 kg N/ha for ten traits viz, flag leaf area, chlorophyll content, days to heading, panicle weight, , no. of filled grains/panicle, no. of panicles/plant ,1000-grain weight, grain yield t ha-1, grain yield efficiency index (GYEI) and agronomic nitrogen use efficiency (ANUE). The genotypes were divided into three groups i.e., japonica/japonica (J/J), japonica/indica japonica (J/IJ) and indica japonica/indica japonica (IJ/IJ). GZ6296 x Giza178-1 and GZ6296 x Giza 178-3 gave the highest values of no. of filled grain/panicle and no. of panicles/hill under low input of nitrogen. Giza177/Sakha101 and Giza176/GZ6944 (J/J) gave the highest grain yield under low input of nitrogen followed by the genotypes derived from Giza178/GZ6296 (IJ/IJ).