Genetic and molecular insights into the enhancement of rice yield potential

Rice is one of the most important global food crops and a primary source of calories for more than half of the world's population. Rice production increased steadily during the green revolution era primarily as a result of introducing high-yielding rice varieties. World rice production increased at a rate of 2.3-2.5% per year during 1970s and 1980s, but this rate of growth was only 1.5% per year during the 1990s. The yield growth rate for rice has further declined during the first decade of this century. However, the populations in the major rice-consuming countries continue to grow at a rate of more than 1.5% per year. According to various estimates, world rice production must increase at the rate of 2 million tons per year. To meet this challenge, rice varieties with higher yield potential and greater yield stability are needed. Various strategies for increasing the yield potential of rice include; (1) conventional hybridization and selection, (2) F<SUB>1</SUB> hybrid breeding, (3) modification of plant architecture, and (4) enhancement of photosynthesis. Many genes and QTLs have recently been identified which will assist with rice breeding objectives