China to Sequence Hybrid Rice Genome

BEIJING--China last week announced plans to sequence the entire genome of a hybrid rice variety that its scientists have developed over the past 2 decades. The project is a first step in the National Bio-resource Genome Project, an ambitious initiative to sequence the genomes of a series of organisms that are either economically important or cause serious public health concerns (Science, 5 May, p. 795).

The Beijing Genomics Institute, an operating arm of the Chinese Academy of Sciences' Institute of Genetics, plans to sequence the so-called "superhybrid rice" that was cultivated from two rice varieties, Indica and Japonica. The project aims to produce a "working draft" covering 90% of the genome within 2 years, said Yu Jun, director of the institute, at an 11 May press conference. It builds on the work of Yuan Longping--also known as China's "father of rice"--and his colleagues at the Chinese Academy of Engineering Sciences (Science, 21 April, p. 429).

An international consortium of researchers is already sequencing Japonica, while a Chinese team led by Hong Guofan in Shanghai has taken on Indica. But Yuan hopes the new project may specifically help explain why hybrid varieties--not just in rice but in other crops as well--often outperform their parental strains in yield and resistance to disease. Scientists have come up with different hypotheses to explain this phenomenon, he says, and the sequencing effort could actually pinpoint the genes involved. Although Yuan has relied on conventional breeding techniques in the past, the information gleaned from the sequencing should enhance cultivation efforts. "Eventually we hope to further increase output of the superhybrid rice by 20% to 30%," he says.

To complete the project on schedule, the institute will have to increase its sequencing throughput up to 15-fold in the next few months. Toward that end, Yu's institute took delivery last week of 30 state-of-the-art sequencing machines made by Amersham Pharmacia Biotech, as well as a Chinese-made teraflop supercomputer, Dawning2000.

Next on the lab's list are the genomes of a pig and of Schistosoma japonicum, a tape worm (also called blood fluke) that causes schistosomiasis, the world's most prevalent parasitic infection after malaria.