Over-production of rice has been a problem for the past 40 years in Japan. On the other hand, there is also a need for an increase in the production of domestic bulk feed in Japan. Whole crop silage (WCS) rice is being promoted by the government. The whole aerial parts consisting of grains, leaves and stems are harvested at the yellow ripening stage. At present, about 12 WCS rice varieties have been bred and are commonly used in Japan. The total digestible nutrients (TDN) yields of WCS varieties are 3 to 27% higher than those of ordinary rice varieties. The lodging resistances of most of the WCS varieties are “High”. Most WCS varieties are basically Japonica, but a few Indica varieties have been used in their parentage.

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Malting barley breeding in Japan has witnessed major changes in the past 15 years. Breeding research programs to identify agronomical and quality-related problems, including the spread of new strains of the barley yellow mosaic virus (BaYMV), the excessive degradation of malt protein, and environmental stresses such as frost damage, wet-injury and grain damages (hull-crack and ventral swelling) have been introduced with consideration to the situation of malting barley production in Japan. Further, promising high-quality breeding lines such as lipoxygenase deficient lines and those with extremely high diastatic power or low protein content have also been described.

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Inactivated vaccines have been incorporated in the control strategies for highly pathogenic avian influenza (HPAI) in several countries. However, these conventional vaccines confer protective immunity in the hemagglutinin (HA) subtype-specific manner and inevitably promote antigenic drifts in HA of target viruses. Therefore, the efficacy of the conventional vaccines needs to be evaluated occasionally to assure that they still provide immunity against emerging or circulating field virus strains. To cover these pitfalls, novel vaccine strategies which target conserved viral antigens are currently being investigated. We hypothesize that such vaccines can be developed by utilizing cytotoxic CD8⁺ T cell-mediated immunity. However, we do not fully understand the mechanisms of the generation, maintenance and recall of cell-mediated immunity to influenza virus infections. Here we briefly review the current knowledge of cell-mediated immunity to influenza virus infections based on the studies using mouse models and discuss the future application of this immunological arm to the vaccines against HPAI in poultry.

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Bt plants are insect-resistant plants engineered to carry the gene coding the insecticidal protein of a soil bacterium, Bacillus thuringiensis. These transgenic plants provide a highly effective method of insect control and reduce dependence on pesticide chemicals. In consequence, they have provided higher yields, reduced crop mycotoxin levels because of the effective lowering of the insect damage, and have decreased the pesticide spraying work and cost. However, there are public concerns about the safety of Bt plants for humans, animals and the environment. This review describes recent research on the safety evaluation of Bt plants, focusing on our results in the toxicological studies of Bt11 corn.

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Actinobacillus pleuropneumoniae is a causative agent of porcine pleuropneumonia that is one of the important bacterial diseases of the respiratory tract of pigs. The disease occurs worldwide and results in serious economic losses to the pig-rearing industry. In this review, new typing methods based on the antigenic and genetic diversity of a protective outer membrane lipoprotein (OmlA), that have been developed for control and epidemiological study of the disease, are described. First, the gene for the OmlA of an A. pleuropneumoniae field isolate (serotype 5a) has been cloned and characterized. The lipoprotein has been shown to be a protective antigen of the organism. Southern blot and the nucleotide sequence analysis of the gene for the lipoprotein have revealed the presence and diversity of the gene in A. pleuropneumoniae. Secondly, based on the antigenic diversity of OmlA, Western blot analysis with specific antisera against three antigenically distinct OmlAs has been developed. The antisera can differentiate A. pleuropneumoniae into three groups. Finally, based on the genetic diversity of OmlA, a PCR-Restriction Fragment Length Polymorphism (RFLP) typing method has been developed. This method can divide A. pleuropneumoniae into five groups. The grouping results by the Western blot analysis were correlated with that by the PCR-RFLP typing method. In addition, the PCR-RFLP typing method can be performed in almost all veterinary diagnostic laboratories since the method does not require specific antisera and expensive reagents and apparatus. Therefore, the PCR-RFLP typing method can be substituted for other OmlA typing and seems to be the most convenient and practical OmlA typing method at present. The new typing methods developed in this study should be used as tools which are effective and practical for control of porcine pleuropneumonia caused by A. pleuropneumoniae.

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This study investigates rice productivity in the coastal area of the Mekong River Delta, Vietnam focusing on relationships with the influences of seawater intrusion and recent changes in the land use at regional scale. We examined the statistical data on rice production at 30 districts of 4 provinces in the coastal area for the years 2003-2005, together with the average salinity concentration observed at 48 points in canals and rivers during the dry season. As an index of the extent of seawater intrusion to be compared with rice statistical data in each district, average salinity of each district was derived by using spatial interpolation from the data in the observation points. It was shown that seawater intrusion was the major factor leading to regional differences in rice cropping systems and land use patterns in the region. Rice cropping intensities, which is defined as the ratio of planted area to district area, decreased with increasing salinity level in canal water, but rice yields averaged over the district are independent of the salinity level. To avoid salinity stress to rice growth, rice cultivation in the coastal area is mainly undertaken during the period when seawater intrusion is weakened by the seasonal decrease in salinity in the rainy season. Specifically, in districts with high salinity, the salinity-free duration required for rice cultivation is short. There, rice cropping intensities are potentially limited by the salinity. In addition, recently, the area of paddy fields in the coastal area has been decreased through land use conversion to aquaculture, especially shrimp farms. Intensity of aquaculture, which requires brackish water, was also limited by seawater intrusion. Thus, rice production in the coastal area of the Mekong Delta was limited by the interrelationship between seawater intrusion and land-use diversification.

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Discharges of zinc, arsenic, cadmium, and lead from farmland were examined based on field measurements conducted between June 15 and July 13, 2006. The study fields are located in a lowland area where the irrigation water was contaminated with water drained from upstream farmlands (cyclic irrigation). The area of the farmland is 11.2 ha, of which 7.6 ha and 3.6 ha had been used for rice and soybeans, respectively. Heavy metal loads accompanying the rainfall runoff were considered to become higher with the increase in rainfall. Seventy percent of the zinc load, 62% of the arsenic load, 70% of the cadmium load, and 69% of the lead load were discharged with the rainfall runoff even though the rainfall runoff time was only 21% of the observation period.

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Agriculture is multifunctional, and the value of each function should be expressed in a form that is easy for anyone to understand. One function, for example, is water purification, and recently much effort has been expended to quantify this function. The author proposed a new replacement cost method for the economic valuation of the nitrogen (N) removal function of paddy fields and of the N effusing function of upland fields, and then economically valuated cultivated lands Japan-wide. The N removal function of cultivated paddy fields and fallow paddy fields was valued at approximately 0.3 JPY m^-2 d^-1 and 0.6 JPY m^-2 d^-1, respectively, when replaced by the sum of maintenance and depreciation costs of water quality improvement facilities. Upland fields have a negative economic value of approximately 0.08 JPY m^-2 d^-1. However, paddy fields function effectively in N removal only when the irrigation water is strongly contaminated with N. Consequently, 85% of the area used for paddy fields does not function in N removal. The use of N-contaminated water from upland fields for paddy field irrigation throughout the year might be environmentally and economically effective with respect to the conservation of water quality in agricultural areas.

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Ozone gas concentrations (OGC) and population densities of airborne bacteria and fungi on plant leaves were investigated in a naturally ventilated greenhouse cooled by a fogging system with ozonated water [OW; dissolved ozone concentration (DOC) of 10 mg/L at a generator outlet] or tap water (TW; DOC of 0 mg/L). The fog cooling occurred for 30 min with a combination of 20 s on and 100, 80, 60, 40, or 20 s off using 5 μm (catalog-specified fog size) nozzles and of 16 s on and 44 or 74 s off using 50 μm (catalog-specified fog size) nozzles. The population densities of airborne bacteria and fungi attached on the leaves of poinsettias (Euphorbia pulcherrima) and pothos (Epipremnum aureum) were determined using an agar stamp method before and after the fog cooling. There was no large difference in the greenhouse cooling efficiency between the TW and OW treatments. The highest OGC in the greenhouse never exceeded 0.04 mg/L with all treatments, even with a combination of fogging 20 s on and 20 s off. This result indicates that the OGC in the greenhouse cannot accumulate to harmful levels (over 0.05 mg/L during 8 ordinary working hours) because of the natural ventilation required for fog cooling. Although population densities of airborne bacteria and fungi on the plant leaves showed a slight decrease during OW-fogging, these levels were not significantly different from population densities during TW-fogging. However, it is still unknown whether repetitive OW-fog cooling for more than 30 min and/or several days of OW-fog cooling will reduce the population densities of airborne bacteria and fungi on plant leaves.

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Leaf ecophysiological responses and height growth were studied in four indigenous tree seedlings planted under different size gaps in degraded tropical secondary forest. Dyera costulata, Dipterocarpus baudii, Neobalanocarpus heimii, and Pouteria sp. were selected for study species. The leaf photosynthetic rate at light saturation (A_max), light compensation point (I_c), leaf nitrogen content, and SPAD value were measured at two months after planting. The ratio of variable to the maximum fluorescence (F_v/F_m), which represents the maximal photochemical efficiency of photosystem II was also determined at two months after planting. All measurement leaves were old leaves, which had acclimated before the planting light condition. Canopy openness above the seedlings was estimated from a hemispherical photograph, ranged from 6 to 53%. The relationships between canopy openness and A_max among species were categorized into two groups. The first group (N. heimii and Pouteria), which had relatively high wood density and late successional status, showed that the maximum A_max appeared under relatively low canopy openness such as approximately 10%. A_max of the second group (D. costulata and Dip. baudii), which had relatively low wood density and high light demand, maximized from 20 to 40% of canopy openness. Seedling height growth of the first group was lower than the second group. The first group also showed lower F_v/F_m at high canopy openness than the second group. These responses indicated that the first group may be categorized to less tolerant species for strong light conditions during the early transplanted stage. I_c of D. costulata, N. heimii and Pouteria decreased with decreasing canopy openness. These species have high acclimation ability to shade conditions from the early transplanted stage, since these responses contribute to raise the photosynthetic efficiency under shade conditions.

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