Transferring genes from wild species into rice

摘要

Three cereal crops - rice, wheat and maize - feed the world. These crops supply 49 percent of the calories consumed by the world population; 23 percent come from rice, 17 percent from wheat and 9 percent from maize. Rice is the primary food source for more than a third of the world's population. It is planted on almost 150 million ha annually or 11 percent of the world's cultivated land. More than 90 percent of rice is produced and consumed in Asia. It is also an important staple in Latin America, Africa and the Middle East. Rice is grown under a wide range of agroclimatic conditions. Four major ecosystems are generally recognized: irrigated (55 percent), rain-fed lowland (25 percent), upland (12 percent) and flood-prone (8 percent).