Natural occurrence of episomal banana streak GF virus species infecting the GI-tagged banana cv. Virupakshi in India.

Abstract

Banana streak disease was identified as a new threat to banana cultivar Virupakshi (syn: Hill banana, AAB), registered under Geographical Indications (G.I. 124) in India. PCR and rolling circle amplification (RCA) of infected leaf samples revealed the presence of banana streak GF virus (BSGFV) as the causative agent of streak symptoms. RCA and sequence analysis identified an episomal BSGFV variant (BSGFV-IN; MW389538) along with the full-length BSGFV genome (BSGFV-IN1; PP134844). The shorter BSGFV-IN genome measured 6590 bp with a deletion of 673 bp, while the full-length BSGFV-IN1 genome was 7263 bp. Sequencing of the cloned fragments using MinION nanopore sequencer further confirmed these findings, with both isolates showing > 99% sequence similarity to the BSGFV (AY493509) from Ecuador. Interestingly, BSGFV-infected tissue-cultured (TC) plants exhibited variation in streak symptom expression under different climatic conditions. At lower temperatures (below 25 °C), typical streak symptoms were prevalent, whereas at higher temperatures, the symptoms completely remitted. This is the first documented report of the natural co-existence of a novel episomal BSGFV variant with a shorter genome, along with the full-length genome, associated with streak symptoms in cv. Virupakshi from India.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01546-w.