Hybrid rice is grown from hybrid rice seed which is produced by growing an inbred rice variety having sterile pollen which is cross pollinated with normal pollen from adjacent rice plants of a different inbred variety. Hybrid rice therefore has two genetically different parents. As with other types of hybrids, hybrid rice typically displays heterosis (or hybrid vigor) such that when it is grown under the same conditions as comparable high-yielding inbred rice varieties it can produce up to 30% more rice. High-yield crops, like hybrid rice, are one of the most important tools for combating world food crises.
The first commercial hybrid rice varieties were released in China.
In crop breeding, although the use of heterosis in first-generation seeds (or F1) is well known, its application in rice was limited because of the self-pollination character of that crop. In 1974, Chinese scientists successfully transferred the male sterility gene from wild rice to create the cytoplasmic genetic male-sterile (CMS) line and hybrid combination. The first generation of hybrid rice varieties were three-line hybrids and produced yields that were about 15 to 20 percent greater than those of improved or high-yielding varieties of the same growth duration.Chinese scientist Yuan Longping,"the Father of Hybrid rice", is the most famous researchers on hybrid rice. In the 1960s, he made his seminal discovery of the genetic basis of heterosis in rice. This was a unique discovery because it had been previously thought that heterosis was not possible for self-pollinating crops such as rice. According to the China Daily, in 2011, Yuan developed a new hybrid rice that can produce 13.9 tons of rice per hectare.Another Chinese agronomist, Li Zhengyou, developed the Dian (or Yunnan)-type hybrid rice, and was a pioneer in the research of high-altitude hybrid rice. He published the book Dian-type Hybrid RiceIn China, hybrid rice is estimated to be planted on more than 50% of rice-growing land there and it is credited with helping the country increase its rice yields, which are among the highest within Asia. Hybrid rice is also grown in many other important rice producing countries including Indonesia, Vietnam, Myanmar, Bangladesh, India,[9] Sri Lanka, Brazil, USA, and the Philippines.A 2010 study published by the International Rice Research Institute (IRRI), reports that the profitability of hybrid rice in three Indian states varied from being equally profitable as other rice to 34% more profitable.Outside of China other institutes are also researching hybrid rice, including the International Rice Research Institute, which also coordinates the Hybrid Rice Development Consortium.