Detection and in silico characterization of banana bunchy top virus in West Bengal, India: relevance to global genetic diversity and population structure.

Banana bunchy top disease is one of the major prevailing virus diseases associated with banana cultivation, spreading rapidly within a small scale of time. Till date there are only few extensive reports of completely sequenced isolates in India. A study was conducted to detect BBTV infection across 12 districts in West Bengal (WB) where extensive prevalence of the disease was ascertained. In silico characterization of the six genome components were accomplished which showed 84.90-99.86% similarity with other BBTV isolates reported worldwide. The phylogenetic analysis based upon DNA R and DNA S suggested formation of monophyletic cluster of majority of the WB isolates and its close association with Tripura, Manipur, Australia and Africa isolates indicating diversion from geographical differentiation. Dynamics of evolutionary pattern such as genetic diversity including Tajima's D test and Fu Li's Fs test, average number of nucleotide differences (K), Polymorphic sites (S); Fst distance; Mismatch distribution plot; Haplotype network, and selection pressure were performed based upon geographical distribution of the virus. Population genetics analysis of both Pacific Indian Ocean group and South East Asian group of the global BBTV population revealed low nucleotide diversity, high haplotype diversity, high gene flow within the group, and negative or purifying selection constraint indicating recent population expansion. Hence, this study portrays Indian subcontinent as the possible hotspot for rapid demographic expansion from a small virus population size, contributing valuable addition to the currently available information on BBTV worldwide.

Supplementary information: The online version contains supplementary material available at 10.1007/s13337-023-00815-0.