The "rice" we usually talk about is called "Asian cultivated rice" in taxonomy. It belongs to the genus Gramineae. There are more than 20 species of rice in the genus, most of which are wild rice. There are three kinds of wild rice in China, namely common wild rice, medicinal wild rice and wart grain wild rice. At home and abroad, there are more than ten kinds of wild rice, such as long stamen wild rice and small grain wild rice. Through the research of cytogenetics, population genetics, physiology and biochemistry, ecology and other disciplines, we all agree that the ancestor of Asian cultivated rice is common wild rice.
Common wild rice grows mainly in ponds, streams and marshes in warm and humid tropical and sub tropical regions. Natural populations of wild rice have been found in Yunnan, Guangxi, Guangdong, Hainan, Hunan and Jiangxi provinces. Common wild rice is a perennial plant, with plant height of more than 140 cm, thin stems and slender leaves, reaching more than 40 cm. The seeds are awn and easy to fall off. After a period of dormancy, the seeds can germinate and grow into new plants.
Wild rice is a valuable genetic resource, rich in a large number of excellent genes, can be used to improve the current varieties. Scientists use these excellent genes, breeding a large number of varieties, in the production of large-scale promotion. For example, in the 1970s, Li Bihu, a student of Mr. Yuan Longping, discovered the male sterility of wild rice in Hainan, and then bred a Wild Abortive cytoplasmic male sterile line, realizing the three line matching of hybrid rice sterile line, maintainer line and restorer line. However, the research and application of Hybrid Rice in China has always been at the advanced level in the world.
In Africa, there is also a kind of Rice called African cultivated rice, which is different from Asian cultivated rice in morphology, and has strong drought resistance. Its ancestor species is wild rice with long stamens.