If a single plant species is crowned by popular vote, it would be rice (Oryza sativa L.): a model genome, an experimental model plant, a model crop, and above all, it is the most important crop for human consumption, providing staple food for more than half of the world population. The rice genome holds fundamental information in its biological "power", including physiology, development, genetics, and molecular evolution. This justifies the timely delivery of its basic genomic information, the genomic sequence, to the perhaps the largest agriculture-related research community around the globe. It, together with another model plant whose genome has been sequenced to completion, Arapdopsis thaliana, has opened new avenue for the plant genome research.
      The estimated rice genome size is about 430 Mb, the smallest among all the cereal crops. It is about one seventh of human and 3.5 times of Arapdopsis. The well-established and high-efficiency gene transformation, the availability of high-density genetic and physical maps, and the high degree of synteny among genes in cereal genomes, all make the rice a unique model organism for studying physiology, developmental biology, molecular genetics, evolution, and genomics of plants. The essential biological information from the rice genome will undoubtedly, through comparative genomic studies, improve our understanding in basic genomics and genetics of other related and economically significant crops, not only the crops of the Gramineae family, but also dicotyledonous crops such as soybean, potato, cotton and many more.
      Launched in 1997 and with eight member nations and regions, the International Rice Genome Sequencing Project has been delivering genomic sequences from a subspecies of rice, japonica (Nipponbare). It deploys a traditional chromosome by chromosome, clone by clone approach, and deposits BAC/PAC-sized contigs to the public databases, including the complete sequence of a single chromosome (Chromosome 1). Monsanto and Syngenta, two US-operating companies, have also announced the establishment of working drafts of the rice genome at different coverage, again from japonica, in April of 2000 and February of 2001, respectively. However, neither have made their sequence data unconditionally and fully available to the public research communities.
      To accelerate and to broaden the scope of the rice genomic and genetic research, and to determine quantitative trait loci for the vegetative growth or vigor of the Chinese hybrid cultivars from indica cultivars, we, the genomic sequencing team from Beijing Genomics Institute, set out to sequence the rice genome using a "whole genome shotgun" strategy. The project was initiated in May, 2000 and the working draft was done in Oct. 2001.
      While the complete analysis of the genome scaffold is being reviewed and revised, we here nevertheless release the draft sequence assembly of the rice genome from 93-11, a cultivar of Oryza sativa L. ssp. indica (domesticated rice subspecies) the major rice subspecies cultivated in China and many other Asian-pacific regions. This particular cultivar of indica is the paternal cultivar of a "super" hybrid rice breed, called Liang-You-Pei-Jiu or LYP9, that has 20 to 30% more yield per hectare than the average of other rice crops in the fields. A preliminary analysis on a subset of these data was published, in a brief form, in Chinese Science Bulletin in Oct. 2001. We also release assembled contigs of cDNA from ten different libraries. The released data and the preliminary analyses will lay a firm foundation for researchers in the rice genomics research field to generate the complete sequence map in the near future and for others to exploit the value of genomic information in biological experimentation.
      Click here to get more information of genomic and cDNA data.