Disease and Insect Resistance in Hybrid Rice

摘要: The rice crop is affected by many serious diseases and insect pest problems caused reduced genetic variability, improved cultural practices continuous cropping—factors for increased production. Although the exact number of in world difficult to determine because uncertain nature some misidentification others, 45 fungal (Ou 1972; Phytopafthological Society Japan 1975), 10 bacterial 1972), 15 virus virus-like (Ling 1979) six nematode Birchfield et al. 1978) are well characterized. Similarly, about 100 species attack crops, 20 these, including different stemborer, planthopper, leafhopper, gall midge, etc., great economic importance (Khush 1984).