Bulletin Autumn‧Winter 1999

Super Hybrid Rice Super hybrid rice originates from hybrid rice, developed by Prof. Yuan Longping at the China National Hybrid Rice Engineering Research and Development Centre in Hunnan in the 60s. Dubbed the 'father of hybrid rice Prof. Yuan discovered that hybrid seeds, formed by pollination across two different varieties of rice plants, show hybrid vigour like the children of mixed couples: they have a larger yield, by 31 per cent, and demonstrate greater immunity to diseases and other stresses than regular seeds. Hybrid rice was first grown for mass consumption in the 70s. It now occupies 51 per cent of the total rice cultivation area in mainland China. The increased output is sufficient to feed 100 million more Chinese each year, valued at about 100 billion RMB a year. Super hybrid rice, expected to be ready for consumption in 2005, is estimated to increase the yield by a further 15 to 20 per cent. This is done by rendering it morphologically—by making the leaves narrow and erect and having its panicles, or cluster of seeds, positioned close to the ground. Narrow and erect leaves enable the plants to absorb more light, strengthen their resistance to wind, and allow them to be planted more densely. The lowered panicle prevents the plants from collapsing. The only setback to super hybrid rice, like hybrid rice before it, is its nutritional value, taste and texture 一 both are classified Grade 2 in those aspects. The CUHK team w i ll join the China National Hybrid Rice Engineering Research and Development Centre in improving the quality of super hybrid rice. They will improve the nutritional value by transferring a gene rich in an essential amino acid, lysine, from winged bean, a staple in tropical regions, into super hybrid rice. Then they will improve the stickiness and the texture of the rice by increasing the straight chains and the branch chains in starch. The more branches the rice has, the stickier the rice will be. Using molecular markers, the researchers will not have to wait till maturation to know if the crops possess the desired qualities. All they have to do is to run fingerprinting with a tiny sample when the plant is still young to find out what it will be like when mature. U s i ng B i o t e c h n o l o g y t F e e d , C u r e , a nd I m p r o v e Life