Identification and Molecular Characterization of Mung Bean Yellow Mosaic Virus in French Bean through Coat Protein Gene

Background: French bean (Phaseolus vulgaris L.), is one of the important legume vegetables grown in India. The disease mung bean yellow mosaic virus (MYMV) limits successful production of beans. MYMV has become an epidemic in bean growing regions, particularly in the tropical and subtropical countries. In summer, the disease is more serious and widely distributed and reported in various countries. The current study is aimed at identification of MYMV and molecular characterization of mung bean yellow mosaic virus in French bean. This study will be helpful for early detection of the virus, so that better preventive measures can be taken to control MYMV.Methods: The investigations were conducted during 2016-2017, all the agro climatic zones of Karnataka province were surveyed. The coat protein (CP) gene of MYMV was amplified using gene specific primer with DNA isolated from MYMV infected leaves samples in french bean. Polymerase chain reaction products were Sequenced and analysed using a bioinformatic tool. Result: The CP gene decrypt sequences analysis revealed that the identity and similarity in global alignment for all the obtained sequences ranging from 80.8 to 95.3% with reference to MYMV, whereas for horse gram yellow mosaic virus (HYMV) it ranges from 90.4 to 99.1%. Two distinct yellow mosaic viruses infecting french bean (MYMV and HYMV) were identified and it was observed that there exists considerable genetic variation among these species. Present work showed that the CP region is efficient enough to provide a simple, rapid and reliable method for early detection of MYMV infections in french bean, which would help to develop proper management strategies to control these viruses.

Genome Sequence and Phylogeny of a Bean Yellow Mosaic Virus Isolate Obtained from a 14-Year-Old Australian Lentil Sample

Using RNA strand-specific sequencing followed by de novo assembly, a Bean yellow mosaic virus (BYMV) genome was obtained from a lentil sample (Aus14BY) collected in Victoria, Australia, in 2005. When compared with 51 BYMV genomes, it closely resembled the Western Australian isolate PN83A (Lupinus angustifolius), with 98.4% nucleotide identity.

Affection of Gladiolus plants with Bean Yellow Mosaic Virus, Cucumber Mosaic Virus and Tobacco Ringspot Virus in some Northern and Central regions of Ukraine

Gladioli can be affected with 15 species of viruses, which cause significant economic losses to both floriculture and agriculture. The most prevalent and harmful for gladioli are Bean yellow mosaic virus (BYMV) and Cucumber mosaic virus (CMV), circulating on the territory of Ukraine on vegetable, legume and other crops, and also Tobacco ringspot virus (TRSV), which is included into the List of regulated pests of Ukraine and is the subject to strict control. The aim of the work was to conduct testing of gladiolus plants for the presence of viral infection symptoms and to test them for the affection with the most widespread and dangerous viruses, namely: BYMV, CMV, TRSV. Visual diagnostics, enzyme-linked immunosorbent assay in DAS-ELISA modification, transmission electron microscopy method and statistical data analysis were used in this research. The results of the studies showed absence of TRSV in all tested samples. For the first time in Ukraine, it has been established that gladioli are infected by Bean yellow mosaic virus. Its circulation on gladioli has been registered in Poltava, Kyiv and Sumy regions. Gladioli were also found to be affected by CMV or mixed infection of these pathogens. Gladioli infection by BYMV and CMV in Kyiv region is 88.2% and 93.8%, in Poltava – 69.2% and 55.5%, in Sumy – 66.6% and 0%, respectively. Typical symptoms on gladiolus plants caused by CMV and BYMV isolates are leaf chlorotic stripes and flower color break, less often – spotting on the leaves and plant stunting. It has been revealed that affection of gladioli by CMV and BYMV can be asymptomatic. The diversity, nature and course of viral infections in gladioli demonstrate the relevance of further research and their monitoring in Ukraine.