The efficacy of Bacillus subtilis var. natto, a beneficial food microbe, was tested as a control for gray mold of strawberry. When five isolates of Bacillus subtilis var. natto were cultured with the gray mold fungus on potato sucrose agar plates, all isolates inhibited fungal growth. Isolate No. 2, which was the most inhibitory of the fungus in vitro, reduced disease progress in both detached leaves and flowers. These results suggest that isolate No. 2 of B. subtilis var. natto has potential as biological control agent of gray mold of strawberry plants.
In an evaluation of the susceptibility of three Musa species grown in Okinawa Island, Japan, to Banana bunchy top virus (BBTV), the virus was widely distributed among edible banana cv. Dwarf Cavendish and cv. Shima. However, bunchy top symptoms and BBTV infection were not observed and detected from all plants of fibre banana cv. Itobasho (Musa balbisiana var. liukiuensis) tested. Furthermore, none of the Itobasho plants were infected with BBTV via viruliferous banana aphids (Pentalonia nigronervosa Coq.) that had been propagated on BBTV-infected pseudostems, whereas 78% of the edible bananas were infected under the same conditions. Thus, Itobasho seems to have an immunity to BBTV but is not resistant to aphid infestation or colonization.
In 2009, Asiatic hybrid lily plants with mosaic symptoms were observed in Akita Prefecture, Japan. In a RT-PCR assay, using universal primers for the detection of potyviruses, a potyvirus different from Lily mottle virus was detected. The conserved area of the virus coat protein (CP) shared the highest amino acid (aa) sequence similarity (95.7%) to that of Rembrandt tulip breaking virus (ReTBV). As far as we know, this report is the first on the occurrence of ReTBV in Japan and on the full aa sequence of the CP for this virus.