Rice is the most important cereal crop which feeds more than half the population of the world. It is being grown in more than 144. 641 million ha with a production of over 468. 275 million tons (in 1988). Rice is attacked by a large number of pests and diseases which cause an enormous loss in its yield. Therefore, the major objectives in rice breeding are the development of disease resistance, tolerance to insects, adverse soil water, and drought; and improvement of quality including increased protein content. Tremendous efforts being made at the International Rice Research Institute have...