Based on its highly diverse phenotypes and genotypes, strains of Pseudomonas syringae pv. actinidiae (Psa), causal bacterium of kiwifruit canker, have been subdivided into biovars 1–3, 5 and 6. In comparative genomic analyses of numerous strains with various histories by our research group and others around the world, to clarify the genetic background that contributes to biovar differences, repertories of toxin biosynthesis gene clusters and genes encoding type III secreted effectors were found to differ greatly among biovars. Many mobile genetic elements, such as plasmids and genomic islands including integrative and conjugative elements (ICEs) and integrative and mobilizable elements (IMEs), were also found in the Psa genomes and may also have contributed to the diversification.
トルコギキョウの水耕栽培の安定生産を目的とし,立枯病の発生を抑え,なおかつ栽培終了時において,処理した薬剤の養液内における薬効成分が不検出となる施用方法の検討・試験を行った.その結果,ベノミル水和剤の500倍または1000倍液を200穴セルトレイ1枚当たり500 ml灌注後,翌日にトルコギキョウを定植することにより,立枯病の発生を抑制することが可能となり,なおかつ栽培終了時の養液において,薬効成分およびその分解産物が不検出となった.同様の試験を2カ年に渡り実施した結果,同様の病害防除効果が得られ,薬効成分およびその分解産物が不検出となり,ベノミル水和剤処理が養液栽培におけるトルコギキョウ立枯病の防除に有用であることが明らかとなった.
Fruitlet core rot of pineapple (Ananas comosus) has been found in Okinawa Prefecture, Japan since a few decades ago. A fungus frequently isolated from the diseased fruits was identified as Fusarium ananatum based on morphological and cultural characteristics and molecular analyses of EF-1α,β-tubulin and histone H3 DNA sequences. The isolates reproduced the symptoms on pineapple fruits after inoculation using toothpicks and were reisolated from the inoculated symptomatic fruits. This is the first report of fruitlet core rot of pineapple caused by F. ananatum in Japan, and we propose the Japanese name “shoka-fuhai-byo” of pineapple.