First Report of Banana bract mosaic virus in ‘Cavendish’ Banana in Ecuador

Abstract

Banana bract mosaic virus (BBrMV), a member of the genus Potyvirus, family Potyviridae, is the causal agent of bract mosaic disease. The disorder has been considered a serious constraint to banana and plantain production in India and the Philippines, where the virus was first identified (3). To date, the presence of BBrMV has been reported only in a few banana-growing countries in Asia (3). In the Americas, BBrMV has been detected by ELISA tests in Colombia only (1). The efficient spread of BBrMV through aphids and vegetative material increases the quarantine risk and requires strict measures to prevent entrance of the virus to new areas. In Ecuador—the world's number one banana exporter—the banana industry represents the main agricultural income source. Thus, early detection of banana pathogens is a priority. In June of 2012, mosaic symptoms in bracts and bunch distortion of ‘Cavendish’ banana were observed in a commercial field in the province of Guayas, Ecuador. Leaves from 35 symptomatic plants were tested for Cucumber mosaic virus (CMV), Banana streak virus (BSV), and BBrMV using double antibody sandwich ELISA kits from Adgen (Scotland, UK). Twenty-one plants tested positive for BBrMV but not for CMV or BSV. In order to confirm the ELISA results, fresh or lyophilized leaf extracts were used for immunocapture reverse transcription (IC-RT)-PCR. In addition, total RNA was extracted from the ELISA-positive samples and subjected to RT-PCR. The RT reactions were done using both random and oligo dT primers. Several sets of primers, flanking conserved regions of the virus coat protein (CP), have been used for PCR-detection of BBrMV (2,3,4). The Ecuadorian BBrMV isolate was successfully detected by three primer sets with reported amplification products of 324, 280, and 260 nucleotides long, respectively (3,4). Amplification products of the expected size were purified and sequenced. All the nucleotide sequences obtained from 20 PCR-positive symptomatic plants were 100% identical between each other. However, 99% identity was observed when PCR products from the Ecuadorian isolate were compared with the corresponding fragment of a BBrMV isolate from the Philippines (NCBI Accession No. DQ851496.1). PCR products of the Ecuadorian isolate, amplified by the different CP primers described above, were assembled into a 408-bp fragment and deposited in the NCBI GenBank (KC247746). Further testing confirmed the presence of BBrMV in symptomatic plants from four different provinces. To our knowledge, this is the first report of BBrMV in Ecuador and the first BBrMV partial nucleotide sequence reported from the Americas. It is worth mentioning that primer set Bract 1/Bract 2, which amplifies a 604-bp product (2), was not effective in detecting the Ecuadorian isolate. It is hypothesized that nucleotide variation at the reverse primer site is the cause of the lack of amplification with this primer set, since the forward primer is part of the sequenced product and no variation was found. Sequencing of the entire CP region is underway to conduct phylogenetic analysis and determine genetic relationships across several other BBrMV isolates. References: (1) J. J. Alarcon et al. Agron 14:65, 2006. (2) M. F. Bateson and J. L. Dale. Arch. Virol 140:515, 1995. (3) E. M. Dassanayake. Ann. Sri Lanka Dept. Agric. 3:19, 2001. (4) M. L. Iskra-Caruana et al. J. Virol. Methods 153:223, 2008.

Prevalence of viruses infecting plantain (Musa sp., AAB genome) in the major growing regions in Cote dIvoire

“…Banana bract mosaic virus known for a long time to have been associated with the genus Musa has been reported for the first time on cardamom plants (Elettaria cardamomum Maton), an herbaceous monocotyledonous rhizome of the Zingiberaceae family, in India (Siljo et al, 2012). Among the 5 viruses, only 4 (BBTV, BSVs, BanMMV, CMV) have been reported in Africa (Pietersen and Thomas, 2005), BBrMV being limited in some Asian countries has been detected in Colombia and Ecuador in Latin America (Alarcon et al, 2006, cited by Quito-Avila et al, 2013Quito-Avila et al, 2013). The spread of these viruses takes place, according to each species, either by insect vectors from primary foci of infection, or through the use of propagation materials already infected or by agricultural tools for CMV (Pietersen and Thomas, 2005).…”

First Report of Bean Common Mosaic Virus Infecting Flowering Ginger (Alpinia purpurata) in Hawaii

“…(banana) from the Philippines in 1979 and later reported from many other countries including India, Samoa, Sri Lanka, Thailand, Vietnam, Colombia, Ecuador and Hawai'i. [2][3][4][5][6][7] BBrMV can spread quickly and causes significant economic losses worldwide. BBrMV was first reported in Hawai'i in 2010 from a new host, flowering ginger.…”

Aplicación de la electroterapia para la eliminación del virus del mosaico del pepino (CMV) en plantas micropropagadas de banano (Musa spp.)

“…Para obtener la fuente viral inicial de Banana Mosaic Virus (CMV), se procedió a identificar en campo plantas con la sintomatología correspondiente y detectar la presencia viral mediante RT-PCR y ELISA 14 . Las plantas infectadas, fueron llevadas al invernadero y mantenidas en una zona aislada libre de afidos.…”