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| December 1999 Super Hybrid Rice An End to Famine By To Shun Kei RELATED ARTICLE: A new kind of cereal called super hybrid rice is being developed in Hong Kong using biotechnology, and it may help solve the problem of food shortage in China. “Super hybrid rice can feed about 1.5 billion Chinese people per year in a few years’ time,” said Prof. Samuel S.M. Sun from Department of Biology at The Chinese University of Hong Kong. Explained he: “Super hybrid rice is originated from hybrid rice, which was first introduced by Prof. Yuan Longping, the ‘father of hybrid rice’, in China in the ’60s.” According to Prof. Sun, Prof. Yuan has been studying hybrid rice for 30 years. Prof. Yuan discovered that seeds formed by pollination within the same rice plant are of lower quality compared with those formed by pollination across two different species of rice plants. The former ones are regular seeds, while the latter ones are hybrid seeds. Said Prof. Sun: “The hybrid seeds can yield a larger quantity of rice. And the rice is of a higher quality, and there is greater immunity to pests and disease-causing microorganisms. “In other words, the hybrid seeds inherit of the advantages of both parent plants, which are of different species.” Prof. Yuan adopted the hybrid rice technologies in Chinese rice production successfully in the ’70s. And to date, hybrid rice has occupied 51 percent of the total rice cultivation area in China, and its yield is 31 percent higher than that of regular rice, on average. It is estimated that more than 1 billion Chinese have been eating hybrid rice. Prof. Sun said Prof. Yuan then tried to improve hybrid rice even further in two ways. Explained he: “Prof. Yuan first tried to increase the yield of hybrid rice by 15 to 20 percent. “He did so by making the leaves of super hybrid rice plants narrow and erect. This can enhance the effectiveness of photosynthesis and increase the density of planting the seeds. “Besides increasing the yield, Prof. Yuan wants to improve the quality of the rice, as both hybrid rice and super hybrid rice are of unsatisfactory nutritious value, texture and taste.” Prof. Sun said he would join Prof. Yuan and help him improve the quality of super hybrid rice in three ways. First, they would improve the nutrition value by transferring a gene of lysine from winged bean to the super hybrid rice. Said he: “Lysine is one of the eight essential amino acids, a component of protein, for animals. “Our bodies cannot produce lysine. And therefore, by adding lysine to rice, people can get sufficient lysine already when they eat rice.” Then, Prof. Sun said, they would improve the stickiness and the texture of the rice. In fact, Prof. Sun said they had invited Dr. Yuan Dingyang, an expert in manipulating starch compositions, to be responsible of this second area of the project. Added Prof. Sun: “Prof. Yuan will try to rearrange the patterns of the straight chains and the branch chains in starch. “He has to increase the number of chains, as the more branches the starch has, the more sticky the rice will be.” According to Prof. Sun, the last area of the project is to accelerate the development of the super hybrid rice by using DNA chips. Usually, hybrid rice needs half a year to grow. It is too long for the scientists to wait in order to observe the shape of the crop’s leaves and panicles. Nowadays, with the installation of DNA chips, devices that can identify DNA, scientists can check the molecular markers of the plants. Molecular markers can give information about the characteristics of the rice. They can show whether the plant will have erect and narrow leave when the plants are still young. As a result, scientists can estimate the grain yield earlier. Prof. Sun said the project is expected to end in 2003 and the rice will be sold in 2005 in China. Said Prof. Sun: “Although the project has just been started, we already have several difficulties to tackle. “Owing to the prosperity of Hong Kong, most local people are not aware of the problem of food shortage in China. Therefore, we cannot get enough support in Hong Kong, “Fortunately, we get the appreciation of some foreign authorities of biotechnology. Our project is chosen to be one of the Areas of Excellence by our government that will be widely developed in these few years.” Prof. Sun said another difficulty was the technical problem in gene transfer. Explained he: “As this technology is still new and young, very few successful examples can be referred to. “We therefore invited Dr. Xiao, a Chinese expert in gene transfer in plants, to help us transfer lysine into super hybrid rice.” Prof. Sun said transportation of materials was the third difficulty, as most of the materials for growing super hybrid rice came from China. He said it was inconvenient to transport the tested samples and raw materials between Hong Kong and China. And the last difficulty mentioned by Prof. Sun was that most local professors and students who were studying biotechnology know little about the skills of agriculture. He said they would solve the difficulty by inviting a few experts in agriculture from China to join them. When asked about the possible negative consequences resulting from super hybrid rice, Prof. Sun said he did not think there was any, as the whole process is under control. “Hybrid rice pollination requires human intervention, as the pollen grains of the hybrid rice plants have to be transferred from one rice plant to another. “Farmers will use tools like bamboo and ropes to help transfer the pollen grains. “This means the spread of pollen grains can be controlled manually. And mixing of plants of other species will not happen.” Concerning the impact the rice may have on human beings, Prof. Sun said super hybrid rice “has no way to harm human beings” because what they were doing was just rearranging the patterns of the starch. Said he: “Hybrid rice is almost the same as the rice that we eat everyday. It is just with different combinations of straight and branch chains. “Turning to the issue of lysine, it is safe as well since the lysine is taken from winged beans. Winged beans are edible and we have been eating them for a long time.” Prof. Sun said that the most important procedure was to have a reliable safety test before the products were sold in the market, and a set of safety regulations for other experts to follow. He said: “It is normal for people to feel worried or frightened about new technologies. “But I think that they will change their attitude when the regulations and safety test are proved trustworthy.” |
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