Identification and detection of Bougainvillea spectabilis chlorotic vein‐banding virus in different bougainvillea cultivars in Taiwan

Abstract

AbstractA new virus disease of bougainvillea occurred in Taiwan and proved to be caused by a Badnavirus, which is similar to the pathogen tentatively named ‘Bougainvillea spectabilis chlorotic vein‐banding virus (BsCVBV)’ in Brazil according to pathological and molecular results. In electron microscopic observations, typical bacilliform virions measuring 130–158 × 27–42 nm were observed in infected bougainvillea tissues. The transmission tests demonstrated that the virus could be easily transmitted among different bougainvillea cultivars by bud grafting but not by mechanical inoculation. BsCVBV showed different pathogenicity to various bougainvillea cultivars in our inoculation tests. The Taipei‐Red and Thimma cultivars showed the apparent foliar symptoms of chlorosis, chlorotic spots, wrinkling and leaf‐distortion; the original species of Bougainvillea glabra produced chlorotic spots and vein clearing on leaves without wrinkling or leaf distortion; both ‘Mrs. Eva Mauve Variegata’ and Hati Gadis showed mild mottling and faint spots of leaves; Helen Johnson was tolerant to BsCVBV. Our devised PCR‐based assays demonstrated that BsCVBV could replicate and persistently survived in all tested bougainvillea cultivars used in this study although it induced different symptoms in them. The BsCVBV‐1 primer pair devised from our cloned BsCVBV‐specific DNA fragments proved to be efficient in the PCR assays for the rapid and specific detection of BsCVBV in Taiwan, and this PCR‐based method is helpful in the quarantine, inspection and ecological studies for BsCVBV in Taiwan.