Evidence of seed transmission of Banana bract mosaic virus in Musa synthetic diploid H-201, a possible threat to banana breeding

Abstract

Banana bract mosaic virus (BBrMV) is a serious constraint in Musa spp. and Musa textilis causing enormous economic losses to growers. The distribution of the virus in various parts of the seeds, flower and leaf tissues of seedlings from banana plants of a synthetic diploid, H-201, naturally infected in the field was determined by Plate-trapped antigen coating enzyme-linked immunosorbent assay (PTA-ELISA), reverse transcriptase (RT) polymerase chain reaction (RT-PCR), quantitative RT-PCR (qRT-PCR) analysis and sequencing. RT-PCR and qRT-PCR results revealed the presence of BBrMV in embryo, endosperm and seed coat of seeds from infected plants. Nucleotide sequencing of the RT-PCR amplicons confirmed the BBrMV infection in seed. Quantification of BBrMV in various parts of seed by qRT-PCR using SYBR Green chemistry revealed that the viral load was maximal in the endosperm followed by seed coat and embryo. In a seed growth test, thirteen seedlings, that were raised from embryos of infected seeds in vitro and twenty seedlings raised from infected seeds in pots, expressed typical symptoms of bract mosaic virus disease and were confirmed RT-PCR positive for the virus. This finding will have significant implications in banana breeding programmes.