Accordingly, the world’s cultivated rice species include Asian and African cultivated rices. However, due to the interspecific hybrid sterility gene, varietal hybridization and gene exchange used to be impossible between Asian and African varieties. This restricts the cultivation of high-quality rice varieties. Later, researchers successfully cloned the interspecific hybrid sterility gene and bridged interspecific gene exchanges.

“A rice variety you plant once and harvest for several years on end” sounds like a dream but has become a reality through researches made by Tao Dayun at the Yunnan Academy of Agricultural Sciences and Hu Fengyi at the School of Agriculture of Yunnan University.

The two researchers started their work from the long stamen wild rice originated in West Africa. As a perennial herbaceous plant, long stamen wild rice has a well developed subterraneous stem and strong resistance to pests and diseases.

With the embryo rescue technique, Tao Dayun and Hu Fengyi obtained the F1 hybrid generation of RD23 and long stamen wild rice and bred many progeny populations. In addition, based on the perennial characteristics of long stamen wild rice, they bred a series of perennial varieties. These perennial rice varieties can overwinter while most ratoon rice varieties cannot.

“Twenty years ago, I thought of converting rice from an annual crop into a perennial one, just like fruit trees,” said Hu Fengyi. So far, the perennial rice cultivated by Hu Fengyi and his colleagues has been planted on 825 acres of land. Some varieties are so strongly perennial that you can plant them once and harvest them for four or five years; they have good overwintering ability and produce stable yield. Last year, the yields per acre of early rice and late rice were 74.17 kilograms and 74.28 kilograms, respectively.

According to Hu Fengyi, this perennial rice can be harvested twice a year in places such as Xishuangbanna Dai Autonomous Prefecture where double-cropping rice is planted and once a year in places where single cropping rice is planted. This year the perennial rice will be planted in Kunming, Yuxi and other places in Yunnan Province to see whether it is suitable for these places.

Box:

Characteristics: Strongly perennial, good overwintering ability, and stable yield.

Yield per acre: 74.17 kilograms for early rice and 74.28 kilograms for late rice in last year’s trial planting.

Taste: The perennial rice tastes the same as normal rice when cooked, though the quality also varies.

Harvesting method: Cut off the superterranean part and leave the subterraneous stem; no tillage is needed. The next year, new rice plants will grow from out of the subterraneous stem and can be harvested again. Plant the perennial rice once and it can be harvested four or five years.