RESEARCH NEWS China’s Breakthrough in Hybrid Rice Research

A new early-maturing hybrid rice, S/D34, has been produced through inter-subspecies crossing by the National Engineering Research Center for Hybrid Rice in Changsha City, Hunan Province. S/D34 has a growth period of 105 days, and a portion of the husked rice has attained second-grade quality. According to the director of the center, Professor Yuan Longping , the success of this hybrid is yet another breakthrough in hybrid rice research using the two-line system, which he developed during the mid 1980s. The new hybrid has also achieved several A Brief Introduction to Yuan Longping and his Accomplishments goals set up by the center, namely, high yield on a large scale, superior quality, Professor Yuan Longping was born in Peking in 1930. He graduated from the and early maturity. The success of this South-west Agricultural College. Prof. Yuan was assigned to teach crop genetics hybrid provides new opportunities for and breeding at the Anjiang Agricultural School, Hunan Province . In further development in rice production 1971, he was transferred to the Hunan Academy of Agricultural Sciences, where he served as a research professor. and extension of land for rice cultivation in China. Prof. Yuan began his research in hybrid rice development in 1964. After nine years of study he developed the genetic materials, namely the A-, B- and R-line, Hybrid rice breeding can also be for breeding hybrid rice varieties in 1973. The method was successful, and conducted by the three-line system, hybrid rice was produced commercially in China from 1976 onwards. Prof. Yuan’s which involves the use of the male sterile research provided an effective approach for China to increase its rice yield on a line, the maintainer line, and the restorer large scale — in general, the yield from hybrid rice was 20% higher than from line. However, thus far, this method has conventional varieties. He also played a leading role in the nationwide research failed to produce a hybrid with both the program on hybrid rice development. He has shared his knowledge and ideas with characteristics of early maturity and foreign scientists, providing them with crucial breeding materials for the commercial superior quality. In 1994, Prof. Yuan production of hybrid rice in their respective countries. focused his research on breeding hybrid In 1984, Prof. Yuan developed several new approaches for hybrid rice breeding: rice using the two-line system. For his the one-line system — for the development of distant hybrids with fixed heterosis; research, he worked on selected varieties the two-line system — for the development of inter-subspecies hybrids; and the of early-maturing and middle-maturing three-line system — for the development of inter-varietal hybrids. Much progress hybrid rice which exhibited superior in the development of hybrid rice has been made using these three systems. hybrid vigor. He went on to develop the Some superior two-line hybrid varieties were commercially produced in 1995. technique for the two-line system and At present, he is serving as a member of the Chinese Academy of Engineering, how to implement it. The two-line and as the director of China’s National Hybrid Rice Research and Development system became a success in 1995. By Center (CNHRRDC) and Hunan Hybrid Rice Research Center (HHRRC). 1996, 2.5 million mu of land in China In recognition of his outstanding contributions in the research and development of had been cultivated with the two-line hybrid rice, Prof. Yuan has been awarded the following honors: hybrid rice. The yield of the hybrid rice 1981 China’s First Special Class Invention Prize was 502.7 kg per mu, which is higher 1985 WIPO Gold, for the development of hybrid rice than the provincial average by 80.2 kg. 1987 UNESCO Science Prize, for outstanding contributions in the field of Many other superior hybrids have been science and technology developed by this method within the last 1988 UK Rank Prize for Agronomy and Nutrition few years. Prof. Yuan is confident that 1992 Conferred the title ‘Meritorious Scientist’ by the Hunan Provincial before the turn of the century, the three- Government line hybrid rice will gain in prominence, 1993 US Alan Shawn Feinstein World Hunger Award, for research and and the area under cultivation for the education 1995 FAO Medal of Honor for Food Security and Sustainable Development two-line hybrid rice varieties will 1996 Nikkei Asia Prize increase to 2000 mu. 1997 Conferred the title ‘International Hybridization Pioneer Scientist’ at the Mexico International Agricultural Hybridization Seminar

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US, China Collaborate to Clone Gene Causing Bone Warts

In August 1996, SmithKline Beecham from the US collaborated with the Hunan University of Medical Science to clone the EXT2 gene, the second gene that causes multiple, exogenous bone warts — a classic genetic disease. The research effort was a success, and they have also found two variations of this gene. During his visit to Hunan University, the representative from SmithKline Beecham expressed his interest to take this collaborative research effort further. With the technique of human gene cloning, i.e. the process of decoding and cloning human genes, more genes responsible for classic genetic diseases can be studied. To date, the international scientific community has only managed to clone approximately 260 genes out of at least 3000 known to cause genetic diseases. The cloning of the EXT2 gene has been hailed as China’s first successful attempt at cloning a gene which causes a classic genetic disease, and as the first international effort in cloning this gene.

Research on Vaccine for Infectious Horse Anemia and AIDS

Infectious horse anemia, also known as horse leukemia, is a chronic viral disease. The Harbin Institute of Veterinary Science, Chinese Academy of Agricultural Science, developed a vaccine from donkey white blood cells for this disease in the late 1970s. This discovery was awarded the first prize at the national level. The vaccine is considered to be one of the most effective vaccines for the prevention of the disease. Statistics from the Chinese Ministry of Agriculture has shown that in the last ten years, this vaccine has prevented losses amounting to 7.5 billion yuan (US$905 million) for the country. The horse infectious virus is similar to the human AIDS virus, as both are chronic viruses, so when the horse vaccine was developed, the possibility of developing a vaccine for AIDS was looked into. Early this year, with strong support from the Chinese Ministry of Agriculture and the Chinese Academy of Science, the Harbin Veterinary Institute, the US and Holland signed an international research collaboration pack to jointly research on the immune mechanism, preventive methods and attenuated vaccine for horse infection in China. Under this agreement, latest immunology and molecular biology techniques will be used for research, and animal models for studies on AIDS vaccine will be developed.

220 APBN • Vol 1 • No. 9 • 1997 Silkworm Factories an Up-And-Coming Industry in Japan

Japanese scientists have been designing insect factories to mass baculovirus. The foreign gene is then introduced into silkworms produce useful biological substances. Currently, Japan is leading by infecting them with the virus. The technology to mass produce in the R&D of insect factories, according to Japan’s Ministry of gp120 at low costs will benefit research in AIDS therapies. In Agriculture, Forestry and Fisheries. The idea for insect factories another case, researchers from Mie University in Tsu engineered originated from the method of using genetically-engineered silkworms to mass produce a blood-thinning agent secreted by yeast and bacteria cells to produce biological substances. But a blood-sucking variety of stink bug. This agent, a heme protein the focus has now shifted to using larger organisms with the which carries nitrogen oxide instead of oxygen, is capable of capability to produce greater quantities of more structurally- relaxing the blood vessels when injected into the bloodstream. complex substances. Researchers believe that the same function can be applied to develop a drug to treat high blood pressure, and to prevent the The silkworm is commonly used for R&D on insect factories in occurrence of heart attacks and strokes. Japan. Throughout history, this insect has been utilized in various ways by the Japanese, especially in Japan’s thriving silk industry Insect factories using silkworms are already in commercial during the Meiji era (1868–1912). With precursor proteins making application in Japan. In 1994, Toray Industries used silkworms up 20% of its body weight, the potential for protein production to produce veterinary medicine for cats infected with feline by the silkworm is tremendous. At present, Japan is genetically calicivirus. In July 1997, textile manufacturer Katakura Industries engineering silkworms in sterile rooms to produce not only silk Co. began a consignment business offering to produce chemical for textile works, but also drugs. Dr. Iwao Murakami, director of reagents in genetically-engineered silkworms. The National the Research Institute of Agricultural Technology of Silk Insects Institute of Sericultural and Entomological Science has plans to set up an insect factory at its site in Tsukuba, Ibaraki Prefecture, under Japan’s Ministry of Agriculture, Forestry and Fisheries, during the next fiscal year for the production of medicines and believes that various medicaments can be produced by altering other useful substances in genetically-engineered silkworms. silkworm genes. In fact, some medicaments for pets currently The goal of the institute is to develop the technologies for available in the market have been produced by mutating silkworm large-scale production of useful substances in silkworms. The genes. Other silk proteins have also been used to manufacture institute will be well equipped and include a research laboratory artificial ligaments and tendons, and cosmetics. For example, with the capacity to culture 24 000 silkworms at a time, and sericin, a water-soluble protein extracted from silkworm cocoons, another laboratory for culturing genetically-engineered viruses. has been utilized widely in the manufacture of cosmetics and The first substance to be mass produced by the institute will bathing agents, in the treatment of skin inflammation, and as a either be the gp120 protein or the blood-thinning agent. general skin protectant against bacteria and parasites. In terms of productivity and cost, insect factories face direct In China more than 200 000 tons of silkworm pupae are competition from animal factories that use genetically-engineered produced annually. The pupae can be used to produce health sheep and cows to produce biologically useful substances. foods. So far, China has already marketed internationally However, Japan lacks the space required for the establishment over ten types of health food products from silkworms. A of such an industry. This therefore gives Japanese researchers key project in Hubei Province has been identified as the motivation to establish a fully competitive industry of insect ‘New Techniques of Comprehensive Utilization of Silkworms.’ factories using silkworms. It is led by Associate Professor Chen Huaixin from Hubei University. Using new improved technologies, the researchers simultaneously extracted fats, proteins and chitin from silkworm pupae. Chitin is used for manufacturing artificial skin, kidney membranes, waterproof clothes, and for keeping food fresh. Two recent R&D successes in Japan have enforced the idea that silkworms are suitable insects for producing useful substances. Researchers from Kyushu University in Fukuoka Prefecture have created silkworms with the ability to mass produce gp120, a surface protein found on the AIDS virus. The virus uses gp120 to attach itself to CD4, another protein. By this method, it infects the cells of the immune system. gp120 is inserted into a

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