It is proposed that the PCR-RFLP method is a reliable tool for the rapid detection of CAA-fungicide-resistant P. viticola isolates. Only 4 h was required from the sampling of symptoms to the phenotyping of fungicide resistance.

No abstract

It is proposed that the nested PCR-RFLP method is a high-speed, sensitive and reliable tool for detecting azoxystrobin-resistant P. viticola populations.

Japan comprises thousands of islands and is physically isolated from other countries by the sea. Monitoring the emergence, incidence and distribution of QoI fungicide resistance in P. viticola populations in Japan is necessary to improve pest management strategies for downy mildew disease in Japanese vineyards.

Characteristics and antifungal activity of chitinases in Semillon grapes were investigated. Chitinases were isolated from the juice of Semillon grapes by chitin affinity chromatography. Native and SDS-PAGE analyses of the fraction showing chitin affinity (active fraction) demonstrated only the presence of protein bands of chitinases. Three types of class IV chitinases (chi-1a, chi-1b and chi-2) were purified from the active fraction. These chitinases actively hydrolyzed chitin under acidic conditions (pH 4.0-4.5). The isoelectric points and the molecular weights of chi-1a, chi-1b and chi-2 were 4.73, 4.60, and 7.87, and 32.1 kDa, 31.6 kDa, and 29.0 kDa, respectively. The active fraction was found to inhibit Botrytis cinerea mycelial growth and the inhibitory effect was due to the activity of chitinases. The active fraction inhibited twenty strains of B. cinerea collected from the experimental vineyard. The effect of chitinases was enhanced in media containing more than 20% sugar. When the active fraction was tested on Glomerella cingulata, the growth inhibitory effect observed was markedly less than that seen on B. cinerea.

No abstract

Soil microbes play an important role in the management of soil environment. They form various microbial communities in response to environmental factors, including soil texture and chemical components. Because of this, it is difficult to determine the microbial community structure of soil. In vineyard soils, the overall microbial community structure has yet to be unraveled. To understand the microbial community in vineyard soil, we surveyed comprehensively microbial communities in Japanese vineyard soils by using a culture-independent molecular approach. We identified 681 fungal clone sequences and 1076 bacterial clone sequences in soil samples collected from nine independent Japanese vineyards, and the results suggested that Ascomycota is the dominant group in the fungal community, whereas Proteobacterium and Acidobacterium are the dominant groups in the bacterial community. DNA was directly extracted from the soil samples, and the fungal internal transcribed spacer 1 (ITS 1) region or the bacterial 16S ribosomal DNA (rDNA) region was amplified by polymerase chain reaction. The recovered fungal clones were sorted into 225 operational taxonomic units and the majority of the clone sequences were assigned to Ascomycota. Meanwhile, the recovered bacterial clones were sorted into 17 phyla, and the abundant phyla were Proteobacterium and Acidobacterium. These results differed from the reported fungal and bacterial community structures in forest and agricultural soils. Moreover, we preliminarily generated a catalog of Japanese vineyard soils. The microbial community structures in the vineyard soils were extremely complex, suggesting that the microbial community structure in each vineyard soil has individual characteristics. Our study comprehensively showed for the first time fungal and bacterial community structures in Japanese vineyard soils, and is most likely to provide a clue to understand the nature of Japanese vineyard soils.