Hokuriku district in Japan is a major producing area of six-rowed barley, which is mainly consumed as pearled grain. However, the barley cultivated in this region has been damaged by scald, and commercial scald-resistant cultivars need to be developed. The influence of scald on yield reduction (previously addressed in many reports) and on pearled-grain quality was investigated. The whiteness of pearled grain, which is the most important quality in pearled barley, was not affected, but the pearling time tended to increase with the incidence of disease. Appropriate methods to evaluate resistance or susceptibility of cultivars in breeding programs were considered. Artificial inoculation in seedlings is not adequate to determine the resistance of cultivars because an outbreak of the disease has at times occurred after the heading stage. A field test with a source of infection, i.e., scattering leaves that were badly infected by prior inoculation of scald, accelerated the incidence and prevalence of the disease. When the source of infection was applied before the winter snows, it was especially effective in spreading the disease. The field test helped to determine resistant cultivars and breeding lines that inhibited the incidence of scald after the heading stage, although the occurrence of scald fluctuated according to weather conditions. Most Japanese commercial cultivars are highly susceptible in the field, whereas some foreign cultivars exhibit resistance to the dominant race of scald in Hokuriku district. We analyzed the resistance of “Brier” and showed that it was possibly controlled by one dominant gene at the heading stage, an observation that was in agreement with previous reports. On the other hand, three recessive genes are expected to confer resistance at the grain-filling stage. The heritability of resistance at the grain-filling stage was high, which means it is relatively easy to select resistant individuals in a breeding program even if it is controlled by several genes.

抄録全体を表示

The presence of pesticide residues in crops is a matter of global public concern, and simple, rapid, and reliable methods for pesticide residue analysis are essential to ensure food safety. In this review, I evaluate a commercially available kit-based enzyme-linked immunosorbent assay (ELISA), which uses specific or selective antigen-antibody interactions, for simple and rapid pesticide residue analysis in crops, particularly before shipment of the crops. The evaluated ELISAs were found to be sufficiently sensitive to detect three pesticides (imidacloprid, fenitrothion, and chlorothalonil) at levels close to the maximum residue limits. Simple dilution of sample extracts alone was sufficient to surmount the problem of matrix interference, which can be troublesome with ELISA. The average recovery rates of the three pesticides exceeded 84%, and the average coefficients of variation were less than 13% for all tested crop samples. The results obtained with the ELISAs correlated well with those obtained by reference chromatographic methods for all three pesticides (r > 0.96). These findings strongly suggest that ELISA is a suitable method for quantitative and reliable screening analysis of these pesticides in crops without the need for sample pretreatment. Elimination of this need can be expected to save time and money and considerably increase sample throughput.

抄録全体を表示

Participatory irrigation management (PIM) is an approach in which farmers participate in all stages of irrigation development through to operation and maintenance, and is implemented in many developing countries. Irrigation management transfer (IMT), a program of transferring the management of irrigation system from government to local user groups, has also been promoted. However, in most cases these approaches have not been successful, because, for example, of the unfair cost sharing and financial weakness in farmers’ organizations. This paper summarizes the current problems of PIM/IMT, proposes basic principles for sustainable PIM, which can be applied to IMT, through a review of the previous studies, and discusses future areas for the sustainable use and management of irrigation systems. The key issues that have contributed to the failure of PIM/IMT are a lack of awareness among farmers of the role and necessity of water users’ associations (WUA) and the inherent weakness of WUA. We propose the following principles for functional sustainable irrigation management: (1) The roles of WUA and governance are clear and adequate; (2) Through participation in WUA, farmers are guaranteed that their demand for water is supplied in a timely manner; (3) Farmers receive financial benefits through the use of water, which then allows them to cover the costs of water and associated services; (4) All members are treated equally with respect to water allocation, cost sharing, and decision-making; and (5) Information on the financial status and transactions are disclosed to members of WUA in a transparent manner. These principles are simple but can be applied to all irrigation systems.

抄録全体を表示

In our previous study, a genetically-modified (GM) rhizosphere bacterium, Pseudomonas putida strain 101-97 harboring the chitinase-expression vector pKAC9-p07, showed over-production of chitinase and suppressed the damping-off of cucumber seedlings caused by the plant-pathogenic fungus Rhizoctonia solani. To assess the effects of the GM bacterium on other soil microorganisms, we monitored the microbial population in the cucumber rhizosphere after inoculation with the GM bacterium by culture-dependent and -independent methods. In the culture-dependent analysis, total bacterial and fungal populations in the cucumber rhizosphere did not differ after inoculation with either the GM bacterium or its parental strain, P. putida 101R. In the culture-independent analysis, we determined changes in the microbial communities by PCR-denaturing gradient gel electrophoresis (DGGE). The DGGE profiles of bacterial 16S rDNA genes differed significantly depending on whether they had been inoculated with the GM bacterium or its parental strain, whereas the profiles of fungal 18S rDNA genes remained similar.

抄録全体を表示

The development of resistant soybean varieties is an efficient way to manage soybean rust in Brazil. To date, resistant varieties effective in Brazil have been limited due to the presence of highly virulent rust populations. This study aimed to identify effective resistant varieties/resistance genes in selected soybean genotypes against a highly virulent Brazilian rust population, BRP-2. Sixty-six soybean genotypes, including 57 soybean rust-resistant/tolerant genotypes previously identified, were exposed to BRP-2 and their resistance was evaluated based on lesion characteristics. PI 587905 produced typical resistant and susceptible lesions and was excluded from the resistance classification. Hence, 47 (72.3%) of the 65 genotypes tested were classified as susceptible, 14 (21.5%) were classified as slightly resistant and 4 (6.2%) were classified as clearly resistant. Although 18 genotypes were placed into resistant categories, PI594767A was the only genotype on which neither uredinia nor urediniospores were produced in two weeks after inoculation. In addition, urediniospores were observed in all 16 varieties carrying one of the five known resistance genes (Rpp1-Rpp5) and in one genotype in which two resistance genes, Rpp2 and Rpp4, were pyramided. Conversely, our screening of soybean genotypes by the rust population, BRP-2 inoculation revealed that two Chinese varieties, ‘Lu Pi Dou’ and ‘Hei Dou’, possessed a leaf-yellowing prevention characteristic. Leaf-yellowing, which might cause rapid defoliation leading to yield loss, was observed not only in susceptible varieties but also in a resistant variety ‘Shiranui’. The use of the resistance and/or tolerance identified in this study will assist in the development of resistant cultivars capable of enduring soybean rust in Brazil.

抄録全体を表示

The effects of an agropastoral system on the production of soybean and wheat were investigated by comparing (from 2007 to 2009) agropastoral plots that had been reconverted from 4-year pasture (Guinea grass: Panicum maximum; 2003 to 2007) to crop cultivation, with control plots that had been continuously cropped over 13 years with soybean and wheat at CETAPAR-JICA. In 2003, Guinea grass pastures were converted from 10-year continuous cultivated soybean and wheat fields, and then grazed intensively from 2004 to 2007, while the control plots continued to be cultivated with soybean and wheat. Animal production in converted pastures was very high and the weight gain per hectare was 1,113 to 1,500 kg/ha over 3 years after introducing an intensive grazing system with supplemental feeding in dry season. The average daily gain was maintained at 0.554 to 0.621 kg/head/day despite a high stocking rate (4.5-6.0 UA/ha). However, after the reconversion in 2007, the soybean yields from 2008 to 2009 were 3.71 and 1.24 ton/ha, which were 1.02 and 1.43 times higher than those in the control plots, respectively. In 2008, the wheat yield was 2.72 ton/ha, the same as that in the control plots. Thus, we concluded that the agropastoral effects on the soybean and wheat yield were small after reconversion to intensive grazing. The reason for the small effect is likely to be the low supply of Guinea grass litter under high grazing pressure, which did not result in any accumulation of the organic matter in the soil.

抄録全体を表示

Various preservation methods at low temperature have been reported for several powdery mildew fungi, but the conidia of Podosphaera aphanis causing powdery mildew of strawberry could not be preserved either at low temperature or by freeze-drying and liquid-drying of conidial suspensions or diseased leaf discs. Here, we developed a new technique for a labor-saving preservation of the conidia of the fungus by using the aseptic seedling culture of strawberry. Conidia produced on the seedlings could be preserved at 5°C for six months. Using this method, we could obtain the stable stock cultures of 12 strains collected from various regions in Japan.

抄録全体を表示

This paper presents a useful process for the detection of Apple chlorotic leaf spot virus (ACLSV) in apple trees. The 3′-terminal 1.8-kb genomic cDNAs of 15 ACLSV isolates, of which 11 induce a decline (of varying severity) in the condition of inoculated Malus prunifolia var. ringo rootstock and four do not, were amplified by reverse transcription (RT) coupled with polymerase chain reaction (PCR). Single-strand conformation polymorphism analysis of the cDNAs revealed that most of the isolates inducing the decline were composed of at least two to four sequence variants per apple tree, whereas isolates inducing no decline were occupied with a major type sequence. Direct sequencing of the cDNAs showed heterogeneity in the nucleotide sequence of the analyzed region; most of the variation in these positions appeared to specify the same amino acids upon translation of the 50K protein and capsid protein (CP). To detect all isolates, degenerate primers were designed with consideration of the sequence varieties of the viral genomes. RT-nested PCR and its improved methods have a 10⁴-fold higher sensitivity than conventional RT-PCR, and consistently amplify ACLSV genomic cDNA in RNA extracts from apple leaf and bark during growing and dormant seasons, respectively.

抄録全体を表示

Genes encoding endopolygalacturonase (endoPG) were isolated from pathogens of the Asian pear scab, Venturia nashicola races 1, 2, 3, and 4, and European pear scab, V. pirina. The Vnpgr1 gene of the V. nashicola race 1 consists of a 1,116-bp open reading frame, encoding a protein of 372 amino acids with an estimated molecular mass of 37.5 kDa and an isoelectric point (pI) of 6.56. The sequences of Vnpg genes from different races and Vppg gene from V. pirina showed high identities (95-100%). The deduced amino acid sequence of the V. nashicola race 1 endoPG showed 63-68% identity to the endoPG sequences of Penicillium olsonii, Colletotrichum lindemuthianum, Cryphonectria parasitica, Fusarium oxysporum, Sclerotinia sclerotiorum, and Alternaria citri. The deduced amino acid sequence of the race 1 endoPG was identical to the N-terminal amino acid sequence of the previously purified endoPG enzyme from the mycelia of this race. The results of a southern blot analysis indicated that V. nashicola race 1 (isolate JS-115) had a single copy of the Vnpgr1. Restriction fragment length polymorphism (RFLP) analysis of the polymerase chain reaction (PCR) products of the endoPG gene digested with HincII, BspEI, and BsrGI was performed; thereafter, agarose gel electrophoresis yielded race-specific RFLP patterns.

抄録全体を表示

We conducted grain drying tests using exhaust heat from a direct combustion type husk burner (HB) and compared the results with those of a conventional system using a kerosene burner (KB). The thermal efficiency of the direct combustion type HB was high, and 88 to 90% of the energy from husk combustion was available for grain drying. Grain drying could be properly controlled, and the quality of rice and wheat were almost equivalent to when dried using a conventional KB, but with only 10 to 15% of the CO₂ emission required. Therefore, we considered the system using heat from the HB for grain drying to be useful in reducing the environmental load resulting from fossil-fuel consumption.

抄録全体を表示

To elucidate the molecular mechanism underlying the toxicity of nivalenol, we investigated the involvement of heat shock protein 90 (Hsp90), a molecular chaperone, in nivalenol-induced cytotoxicity in human promyelocytic leukemia HL60 cells using an Hsp90-specific inhibitor geldanamycin. Cytokine levels and cell proliferation were investigated after 24-h treatment. Nivalenol significantly elicited interleukin-8 (IL-8) secretion, conversely, geldanamycin faintly altered. IL-8 secretion in cells co-treated with these chemicals was much lower than that with nivalenol alone, indicating the importance of Hsp90 for nivalenol-induced IL-8 secretion. Both nivalenol and geldanamycin alone reduced monocyte chemotactic protein-1 (MCP-1) secretion. Regardless of geldanamycin, the values in the nivalenol-treated samples were almost the same. If Hsp90 is indifferent to the nivalenol signal transduction, the effects of these chemicals should be additive. However, statistical analysis shows that these effects are not additive, indicating that geldanamycin mitigates nivalenol’s effect on MCP-1 secretion. While nivalenol markedly hindered proliferation, geldanamycin retarded it moderately. The value of cells co-treated with these chemicals was lower than that with nivalenol alone, meaning that geldanamycin does not protect against nivalenol-caused retardation of proliferation. In this study, we showed that Hsp90 is involved in nivalenol-associated changes in cytokine secretion, however, it is unclear whether Hsp90 is involved in the nivalenol-caused retardation of proliferation.

抄録全体を表示

Shanxi aged vinegar (SAV) and Zhenjiang aromatic vinegars (ZAV) are representative of minor grain crop vinegars in the north of China and rice vinegars in the south, respectively. The nutritional composition of five Chinese vinegars, including three typical SAV and two ZAV, were determined. Investigations showed that these vinegars differed from each other in terms of the organic acid content (75.32-175.95 g/L), and amino acids (1215.9-2878.8 mg/100 g). SAV, especially oat vinegar, were 9-40, 2-211, 4-210, 1-3 and 1-1.5 times higher than ZAV in calcium, phosphorus, iron, zinc, and manganese contents, respectively. Nicotinic acid, nicotinamide, phenolics, alkaloids and saponin in these vinegars were shown to be 2.33-37.83 mg/100g, 1.23-35.03 mg/100g, 382.4-4518.1 μ g/mL, 0.088-1.209 mg/mL, and 0.183-0.662 mg/mL, respectively. SAV seemed relatively better than ZAV in terms of essential amino acids, minerals and vitamins and also exhibited strong α-glucosidase inhibitory activities. These results suggested that both types of typical Chinese vinegars could be used as health foods, despite their different raw materials and processing technologies.

抄録全体を表示

Distiller’s Dried Grains with Solubles (DDGS) derived from ethanol production with corn grains contained about 3 times more fat than the corn. The concentrated fat containing vitamin E and other components derived from the fermentation process is thought to possess an antioxidative function, although information about the antioxidative function of DDGS feeding to animals is limited, hence the effect of DDGS feeding of dairy cows on oxidative stress markers in plasma at high environmental temperatures was investigated. Six Holstein cows were divided into 2 groups, one of which was fed total mixed ration (TMR) including 20%DM of DDGS, while another control group was fed similar TMR without DDGS for 17 days at a high environmental temperature. The dry matter intake in the DDGS group was similar to the control group. In the DDGS group, the milk protein content was lower and the milk lactose content higher than those of the control group (P < 0.05). Concentrations of SH residue and ascorbic acid in the plasma seemed higher in the DDGS group than the control, but not significantly. However, the concentration of thiobarbituric acid reactive substances in plasma was lower in the DDGS group than the control (P < 0.05). DDGS feeding to cows might be effective in reducing oxidative stress during hot seasons.

抄録全体を表示

The predation of cultured larval fish by water insects presents a serious issue for aquaculture development in rural areas of the Lao People’s Democratic Republic (Lao PDR). In this study, the species composition of predatory water insects was monitored in a fish nursing pond. Laboratory predation experiments were then performed to examine the predation potential of water insects on 3 major cultured fish species, including Barbonymus gonionotus, Cirrhinus cirrhosus, and Cyprinus carpio. Anisops spp. was considered to have the highest impact on mortality by predation in Lao PDR. It was estimated that Anisops bouvieri can prey on 10.4-46.7% of larval fish within 24 h under standard rearing conditions recommended by FAO.

抄録全体を表示