Business Potential for Agricultural Biotechnology - Asian Productivity ...

Business Potential for Agricultural Biotechnology Products
overall production to meet an ever-increasing demand for seafood products. On the other hand,
commercial production of transgenic fish will depend on the assessment of risk to wild aquatic
species. The concern includes ecological impacts, which may be a cause of extinction of the wild
type. Therefore, genetically modified fish, for safety, should be sterile, and the infertile technology
now has been developed for ornamental fish. In foundation research, mice and rats were
commonly used as animal models for studying human diseases; however, recently fish was
developed for use as an animal model because the vertebrate has many advantages that permit
gene transfers to be more easily manipulated. In the foreseeable future, there will be a number of
new and developing technologies that will have a profound impact on the genetic improvement
of animals. The technologies will be incorporated into production schemes and make possible
more efficient production to meet consumer and market demands.
Development and Application of Biofertilizers in the Republic of China
The Republic of China is a subtropical island characterized by high temperatures and heavy
rainfall. Intensive agriculture practices have served as a strong foundation for the Republic of
China’s commercial and industrial “economic miracle.” In recent years, agrochemicals (pesticides
and fertilizers) have been extensively applied to obtain higher yield. Intensive application
of agrichemicals leads to several agricultural problems and poor cropping systems. Farmers may
use more chemical fertilizers than the recommended levels for some crops. Excessive application
of chemical nitrogen fertilizer not only accelerates soil acidification but also risks contaminating
groundwater and the atmosphere. Organic fertilizers offer a safe option for reducing the
agrochemical inputs. Biofertilizers have been developed in several laboratories in the Republic
of China over the years. Microorganisms including rhizobium, phosphate-solubilizing bacteria,
and arbuscular-mycorriza (AM) fungi are continuously being isolated from various ecosystems
and their performance in laboratory and field conditions assessed. The extensive research program
over the years on beneficial bacteria and fungi has resulted in the development of a wide
range of biofertilizers which not only fulfill the nutrient requirements of various crop species but
also increase crop yield and nutrient composition. Numerous experiments in greenhouses and in
field conditions have shown that many different crops respond positively to microbial inoculations.
In particular, successful rhizobial inoculants were applied to leguminous plants and AM
fungi for muskmelons in order to increase yield. Multifunctional biofertilizers were developed to
reduce chemical fertilizer application by about one-third to one-half. Enhancement and maintenance
of soil fertility through microorganisms will be an important issue in future agriculture.
Long-term conservation of soil health is the key benefit of biofertilizers, equivalent to the most
sustainable form of agriculture.
Current Status of the Transgenic Approach for Control of Papaya Ringspot Virus
Production of papaya has been limited in many areas of the world by Papaya ringspot virus
(PRSV). PRSV causes severe mosaic and distortion on leaves, ringspots on fruits, and watersoaked
oily streaks on upper stems and petioles. It stunts the plant and drastically reduces the
size and the quality of the fruit. PRSV is a member of the genus Potyvirus and is transmitted
nonpersistently by aphids and is also sap-transmissible in nature. PRSV was first reported in
Hawaii in the 1940s and then became prevalent in Florida, the Caribbean countries, South
America, Africa, India, the Far East, and Australia. Although tolerant selections of papaya have
been described, resistance to PRSV does not exist in the species of C. papaya, which makes conventional
breeding difficult.
A CP gene of a native Taiwan strain, PRSV YK, was used to transform Taiwan papaya cultivars
by Agrobacterium-mediated transformation. The transgenic lines showed various levels of
resistance, ranging from delay of symptom development to complete immunity. Several lines
highly resistant to the homologous strain (PRSV YK) provided wide-spectrum resistance to
three different geographic strains from Hawaii, Thailand, and Mexico. During four repeats of
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