Blast is a serious disease caused by a fungal pathogen Pyricularia oryzae Cavara of rice (Oryza sativa L.). The use of resistant varieties is considered one of the most efficient ways of crop protection from the disease. In addition to a large amount of information accumulated during the long history of genetic studies on resistance to rice blast, recent progress in rice genomics has enabled us to use DNA markers for breeding the resistant varieties by marker assisted selection (MAS). In this report, we summarize the reported rice blast resistance genes and their selection markers to encourage further utilization for breeding. First, we assemble the information about the reported genes with regard to their number, chromosomal locations, patterns of resistance, donor strains, and molecular characterization of the cloned genes by reviewing the literature. In addition, we present some remaining issues about the nomenclature system and identification of the resistance genes. Then, we provide the first assembled list of the reported DNA markers for blast resistance genes, including the sequences of the primer pairs, genetic distances from the resistance genes, and cross combinations of the parental strains used to detect the polymorphisms. This information will help rice breeders to improve the resistance to rice blast by MAS.

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Orius strigicollis is a predatory bug that attacks small arthropods, such as thrips, and augmentative release of commercial strains has been widely conducted in greenhouses in Japan. The accurate evaluation of its effectiveness is essential for successful biological control programs. However, because Orius species occur naturally in the field, it is difficult to discriminate O. strigicollis from other Orius species. Furthermore, it is necessary to discriminate commercial strains of O. strigicollis from field populations. In this review, we introduce two types of molecular procedures: (1) a multiplex polymerase chain reaction technique to identify Japanese Orius species, and (2) microsatellite DNA markers that can be used to measure genetic diversity within populations of O. strigicollis and to discriminate field and commercial strains. The usefulness of molecular ecological approaches is also discussed.

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The use of insect-virus insecticides has been very limited and the development of new insecticides has not been pursued actively. This is mainly because the cost of pest control using the insecticides is very high considering its effect compared with the cost versus effect of using synthetic insecticides. One way of diffusing insect-virus insecticides is to strengthen the ability of the viruses in the formulation to kill pests. Strengthening the virus activity will lead to a drastic reduction in the amount applied per unit area, cost of control will be lowered, and the use of such insecticides will spread. Several groups have studied the synergistic effect of an entomopoxvirus protein, fusolin, on the infectivity of insect viruses to strengthen their ability to kill pests. Fusolin is the main component of entomopoxvirus inclusion bodies called spindles, and the spindles of several entomopoxviruses have been found to strongly enhance many nucleopolyhedroviruses. The enhancement occurs through the disruption of the peritrophic membrane, a barrier against virus infection, by the spindles. Two of these fusolin genes were cloned, and two and one of these genes were expressed in foreign gene expression systems and a crop species, respectively. As a result, the gene products enhanced viral infection. Finally, the functional region for the enhancement in this gene has been shown and the detailed mode of action of fusolin was estimated.

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We examined the relationship between the breaking stress of tofu made with 0.25% MgCl₂ and protein content, the ratio of 11S protein to 7S protein (11S/7S ratio), calcium content, and phytic acid content using six soybean cultivars: Enrei, Sachiyutaka, Fukuyutaka, Tachinagaha, Hatayutaka, and Ayakogane. Among the four components, protein content, 11S/7S ratio and calcium content showed cultivar differences, while the phytic acid content showed little cultivar variation. No single component was found for explaining the breaking stress of tofu and its cultivar difference. Among the six cultivars, only Ayakogane showed a significant correlation between the protein content and the breaking stress of tofu (r = 0.72*), which might be due to high variation of the protein content within Ayakogane. For the 11S/7S ratio, each cultivar showed a positive correlation, however, correlation coefficient was 0.56 at most. Tachinagaha, showing the highest calcium content, showed the lowest coefficient of determination for the relationship between the phytic acid content and the breaking stress of tofu. In contrast, Sachiyutaka, showing the lowest calcium content, showed the highest coefficient of determination. These results implied that the calcium affects the relationship between the phytic acid content and the breaking stress of tofu, however, further study is required to clarify the mechanism of the effect of the phytic acid and relationship between phytic acid and calcium.

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The concentration and distribution of isoflavones in 19 representative commercial douchi products and their acetylcholinesterase (AChE) inhibitory activity were investigated in this study. Isoflavone aglycones are the predominant isoflavone forms in Chinese commercial douchi samples. The total content of isoflavones in douchi extracts were observed from 24 to 1,471 μg/g (dry matter). Results indicated that Aspergillus-type douchi had more isofiavone aglycones content than that of Mucor-type and Bacillus-type douchi. Nineteen samples also showed various extents of AChE inhibitory activity. The IC₅₀ value of AChE inhibitory activities of douchi extracts ranged from 0.040 to 2.319 mg/mL. Aspergillus-type douchi extracts exhibited significantly higher AChE inhibitory activity than that of Mucor-type and Bacillus-type douchi. Some brands of douchi which have low contents of isofiavone aglycones showed much lower inhibitory activity. However, high inhibitory activities did not mean high isoflavone content, maybe some other substances contributed to the inhibition which should be further studied.

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This paper reveals the industrial structure of Cambodia, based on some results from input-output analysis, and discusses the role of the agriculture and fishery sectors for its pro-poor growth. As a preparation for the analysis, we estimated an input-output table of Cambodia. An input-output analysis shows the following results. In Cambodia's economy, the garment industry plays an important role, realizing 14% of GDP and 500% of self-sufficiency. However, it induces smaller domestic income than the former Thailand fiber industry. This means that, compared with Thailand, it is difficult for Cambodia to actualize high savings and to secure funds for domestic investment. The agriculture, fishery, and food industry sectors have a tendency to induce both wide and high distribution of domestic income. These sectors have high potential to realize pro-poor growth in Cambodia.

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In many Asian countries, agricultural industrialization led by agro-industries has been progressing, and agricultural production has been shifting from staple foods to high value commodities such as vegetables, fruits and livestock products. This trend is considered to have contributed to improving agricultural profitability as well as to expanding rural employment. The purpose of the paper is to test the hypothesis that the foreign direct investment (FDI) promotes high value agriculture through development of the food processing industry. We estimated factors that determine labor productivity in the food processing industry and agricultural sector, and obtained cross country statistical results that provide supports to the hypothesis. The typical case of this FDI-food industry-farm linkage is seen in contract farming, in which firms provide technical assistances and guaranteed markets to farmers. The results of a farm household survey implemented in China by the authors provide the farm level evidence to the linkage, in which foreign affiliated enterprises play important roles in technology transfer in compliance with food safety standards.

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Effects of social capital on household welfare (rice yield, income, health) were examined in a rice granary area of southern peninsular Malaysia. Social capital is categorized into structural and cognitive. OLS and 2SLS were used for estimation on data from 59 randomly selected households. As for productivity, structural social capital (frequency of community activity attendance) contributes to higher rice yield. To enhance economic welfare, cognitive social capital (group norm) which is expected to strengthen work ethic appears important. As for self-rated health status, those actively involved in educational organizations (PTA) feel themselves less healthy. On the other hand, those who put high value on local organizations tend to be healthy. On the whole, both structural and cognitive social capital enhancement are expected to improve Malaysian farmer welfare.

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The World Rice Model (WRM) was developed based on a partial equilibrium approach in this paper. The impact of a Renminbi (Chinese Yuan) appreciation scenario on the world rice market was projected to 2020 by WRM. The result indicates that Renminbi appreciation in the short term will lead to a drastic change in the international rice price index. When the Renminbi appreciation rate is greater than 4%, the international rice price index will continue to rise; when it is greater than 8%, China will become the largest rice importer in the world.

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Soil respiration is a crucial carbon fiux for determining carbon balance in the forest ecosystem. In Kanchanaburi, western Thailand, we measured soil respiration at different stand ages (1, 6 and 21 year-old) of teak (Tectona grandis) plantations. There were no significant differences in soil respiration among plots of different ages. Soil respiration rates showed a clear seasonal pattern of a high rate in the rainy season from April to November and a low rate in the dry season from December to March. The contribution of organic layer, roots and soil to total soil respiration was 17, 15 and 68%, respectively, in the 6 year-old teak plantation (T-Y plot). Total soil respiration rate was significantly correlated with soil water content in the 0-30 cm layer. The annual amount of CO₂ effiux from the forest fioor was estimated to be 1,062-1,154 gC m^-2 y^-1 in the teak plantations in 1997. In 1998, annual CO₂ effiux declined to 80% of that in 1997 in the T-Y plot, probably due to low rainfall.

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Low salinity rearing of Litopenaeus vannamei requires the transfer of postlarvae (PL) from high salinity hatchery systems to low salinity conditions. In order to determine effective transfer methods, fifteen-day-old postlarvae (PL15) were acclimated from a salinity of 30 ppt to endpoint salinities of 1 and 5 ppt using single-step and gradual salinity reduction procedures. Higher survival rates were obtained with gradual acclimation than with single-step acclimation. Survival of PL15 acclimated to 5 ppt was better than that of PL15 acclimated to 1 ppt. Survival of PL15 and juvenile stages in various low salinity treatments ranging from 0-5 ppt was also compared. In the PL stage, survival rates were good (›85%) in salinities over 1.5 ppt. Tolerance to low salinities increased with age and survival rate of juveniles (65%) was higher than that of PL (2%) in freshwater. In our long-term growth trials of juvenile shrimp maintained in different salinities, optimal growth comparable to that in normal seawater was observed in animals reared in a salinity of 5 ppt, demonstrating that L. vannamei can be successfully cultured in low-salinity inland systems.

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