Preface

Rice is a staple food for half of the world population. Its total production is next to wheat production. Rice is very much consumed in Asian countries. Hence, cultivation of rice is extensive in these countries. Though the land area under rice is decreasing slowly, the productivity is to increase, to feed the growing population, with the high yielding super rice varieties. Furthermore, high yielding climate resilient varieties are now also available for the service of farmers. The high yield of rice is associated with the high demand of plant nutrient fertilizer, especially nitrogenous fertilizer. The consumption of nitrogenous fertilizer has shown a gradual increase over the years. Meanwhile, The cost of fertilizer is also increasing. At this juncture it is important to increase the nitrogen use efficiency. This will also enable us to reduce the environmental pollution globally. This could only be achieved by efficient fertilizer management practices and better understanding of nitrogen utilization in plant system so that a high production and high quality harvest can be achieved. The better understanding of nitrogen utilization may help in breeding efficient rice varieties, mutants and transgenic rice. So, it is necessary to actively consider all aspects, namely management practices, understanding of biochemical and physiological aspects of nitrogen assimilation and crop improvement in rice for efficient utilization of nitrogenous fertilizer.

Rice is a model monocotyledonous plant as it is of small genome. Much of rice gene data are now available and utilized for crop improvement. However, under varied climatic situations and varying biotic– abotic stress conditions rice crop improvement is in progress. Nitrogen use efficiency in rice, i.e. nitrogenous fertilizer required per kilogram of rice grain production, is similarly important and has received much attention.

Rice grain quality is considered mainly on the basis of protein composition and the availability of essential amino acids. For human consumption, thus, proteins along with energy supplying carbohydrate in high quality rice are important. Therefore, manipulation in crop improvement is also necessary to elucidate high quality protein-rich grains as the high yield grains. Hence, nitrogen efficient high yield, high quality rice plant is a goal for coming days.

The present book discusses, in details, different facets of nitrogen metabolism in rice plant. The metabolic pathways, ontogenic changes, biotic and abiotic factor influences and genetic progress related to nitrogen metabolism of rice is discussed in a simple way. Students, researchers and teachers will find the book useful for having details of rice nitrogen metabolism with the hope that it will provide the basic as well as current concept of the subject to further research so that rice crop improvement can be achieved with high nitrogen use efficiency