Biotechnology Quietly Changes Asian Agriculture
By Anne Marie Ruff
Tissue culturing, also known as micropropagation, was developed more than three decades ago by researchers at Thailand's Kasetsart University and the University of Hawaii. They were searching for a way to reproduce slow-growing and notoriously temperamental orchids. Since then, the process has been profitably applied to dozens of other crops in the region. While tissue culturing will likely never replace the conventional sowing of seeds in Asia, it`s having a profound impact on agricultural research and production.
The process starts by placing a group of cells from a plant, or a little piece of a plant, on a gelatin medium in a test tube. Specific chemicals are added to make the cells grow. Under fluorescent lights and controlled temperatures, the process yields plantlets, or miniaturized versions of the "parent" plants, within a few weeks. Plantlets are then cut up to make even more plants, or taken out of the test tubes and placed in soil and eventually in the ground. It costs under 10 cents to produce each plantlet in the laboratory, about the same cost as planting a seed in the ground.
The process has yielded amazing results. A single banana tree, for example, can produce up to 30,000 offspring in one year, compared with the five-to-10 offspring it would naturally produce. Thailand is the leader in tissue culture in Southeast Asia, producing 50 million plantlets a year. Most are orchids, which have helped the country become the biggest exporter of whole and cut orchids in the world. Based on its success in mass-producing orchids, commercial plantation company Thai Orchid one of the biggest producers of tissue-cultured plants in Asia is now using micropropagation to speed the production of crops such as teak, eucalyptus and jackfruit.
While micropropagation is a biotechnology, it doesn't face the same testing and regulatory hurdles as genetically engineered crops, which insert genes from unrelated species. "The selection we do relies on random genetic events and natural variations or mutants which are either induced or spontaneous. No genetic manipulation is involved," says Suhaimi Napis, a research fellow at the Department of Biotechnology at University Putra Malaysia. With no opposition from consumer or environmental groups, the turnaround from investment to profit can be much faster.
Other countries are jumping on the bandwagon. Indian plant-producing company AVT Biotechnology produces 8 million plantlets a year from tissue culture. It says the ability to quickly multiply superior varieties via tissue culturing has led to a threefold increase in the productivity of their plantation crops, including date palm, asparagus, calla lily and orchids. Researchers from Laos and Vietnam are learning tissue-culture techniques in Thailand to use in their own cut-flower industries and reforestation efforts.
Japan, Europe and the United States also make use of micropropagation, but mostly as a step in the hi-tech development of genetically modified organisms. Since genetic modification takes place on a cellular level, tissue culturing provides the critical link that allows a cell to turn into a whole plant.
But industrialized countries don't use the process widely for agricultural production. Their major commodities are mostly annual crops such as corn, soybeans and wheat, which are produced efficiently by traditional seed-and-soil cultivation methods. Many commodities of tropical Asian countries, however, come from trees, which produce few seeds and can be difficult to multiply.
Chalermpol Kirdmanee is the manager of the tissue-culture laboratory at Thailand's National Centre for Genetic Engineering and Biotechnology. There lie hundreds of sealed glass jars filled with miniature orchids that he's multiplying, though he shrugs them off as "just a hobby."
Chalermpol's real work takes advantage of tissue culture's ability to dramatically speed up the research and development of improved plant varieties a process that can take months or years using traditional propagation methods such as sowing seeds or growing plant cuttings in soil. He's currently working with 100 tree species to determine which grow best in the saline soil of northeastern Thailand.
"Researchers have worked on this problem for 30 years, with almost no progress. What would take years to observe in the field, I can do in a few days," he says with pride. Adding salt to the gelatin growing medium, Chalermpol finds which plantlets survive. So far, the project has identified several species that not only can be used to reforest saline areas, but that also can reduce the salinity of soil.
That same speed is being harnessed by seed companies and industry groups, such as the Malaysian Palm Oil Board, to screen for resistance to diseases in papayas and oil palms. Work to produce disease-resistant coconut and rubber trees that contain synthetic proteins used in pharmaceutical drug production is still in early stages in India and Malaysia respectively.
Meanwhile, Chalermpol's lab has developed a strain of the medicinal plant Artemisia annua, which produces twice as much of a compound called artemisinin as any other variety in the world. Artemisinin is the essential ingredient in next-generation anti-malaria drugs. Chalermpol estimates it will take three years to produce enough plants to start commercial production, but he predicts "farmers could earn more by growing improved Artemisia than by growing rice."
Even traditionalists, like Thailand's royal family, are promoting tissue-culture techniques as a way to help the country's rural poor. Disease-resistant varieties of jackfruit, banana and bamboo, developed by royal-sponsored researchers, are micropropagated to speed their distribution to farmers around the country. Taking it a step further, Thailand's National Centre for Genetic Engineering and Biotechnology has developed techniques for micropropagating the microbes used in fermented meat products and fish and soy sauces, and has passed this process on to commercial food processors. Like plants, populations of microbes can be grown on a gelatin medium from just a few cells and the right chemicals.
So far, labour costs have prevented tissue-culture techniques from becoming a major source of agricultural output. Attempting to tackle the problem, researchers in Japan developed a robot a few years ago that could automate the labour-intensive part of the process, culturing as many as a million plantlets in a few days. The project was later abandoned, following an outcry from tissue-culture technicians, who come from a relatively small and highly paid pool of university-educated workers.
To bring down costs, companies and research institutes now are tapping inexpensive, unskilled labour pools, from housewives in southern India to hilltribes in northern Thailand. Labs developed strictly for propagation often work well without the expensive temperature-control facilities used by research-oriented labs.
A reforestation project in the north of Thailand required thousands of banana trees as the first step to reducing soil erosion and paving way for the reintroduction of forest species in the Mae Chan and Mae Salong river basin watershed. Local hilltribes were to provide the trees themselves, and then profit from any of the trees' produce. But when the Chiang Rai-based Hill Areas Development Foundation began three years ago, hilltribe villagers were able to produce only 3,000 trees in a year using the traditional method of separating banana pups from their mother trees far too few to make the reforestation project viable.
To support the project, Chalermpol taught two foundation staff members tissue-culture techniques, and the National Centre for Genetic Engineering and Biotechnology developed a low-cost micropropagation laboratory for about $2,500, which it donated along with disease-resistant strains of bananas. The foundation in turn passed the technique on to the villagers, who are now producing 20,000 banana trees a year. The improved strains also are efficient at using nutrients, allowing villagers to spend less money on fertilizers and pesticides.
Indeed, tissue-culture techniques are being applied to conservation efforts in other parts of Asia. Reforestation efforts in Indonesia were slow because many wild forest tree species are very difficult to grow from seed, or produce few seeds in the first place. Sumitomo Forestry of Japan used tissue-culturing to grow 400,000 plantlets of the native Indonesian timber tree Shorea roxburghii, which have been planted in an experimental Indonesian forest with help from Indonesia's Ministry of Forestry.
While tissue culturing can help speed the production of trees for reforestation, it can't restore the biodiversity of an area. Like most modern agriculture-production methods, tissue culturing has the potential to reduce genetic diversity by displacing several species with a single, genetically identical plant.
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