Assessment of grain yield and quality improvements in rice by modern breeding techniques in Bangladesh and projections of future rice improvements

摘要

Increased grain yield and improved rice quality are absolutely necessary to feed the world's galloping population and to maintain its health and nutrition. Thus, the recent approach for rice production includes the improvement of both yield and grainquality to cater for consumer demand and also to increase the nutritional level of the general public. But grain yield and protein content are generally correlated negatively (Govindaswami and Ghosh, 1974); therefore, improving both without breaking theexisting con-elation is not possible. There are many modern techniques for improving rice, but a suitable method for improving one particular trait has not yet been identified. After the development of 1RS, on the basis of the proposed rice ideotype model by morphological defect elimination, other similar miracles in rice improvement could not be achieved because of the unavailability of superior characters in the available germplasm. The first international symposium on hybrid rice, which was held in China in 1986, felt that the productivity of modern semi-dwarf varieties of rice had reached a ceiling in many countries with advanced production technology (Ikehasi, 1990).