Marker-assisted breeding of Musa balbisiana genitors devoid of infectious endogenous Banana streak virus sequences

Abstract

The authors wish to thank Frédéric Bakry and Léonidas Féréol for providing some doubled haploid lines and Guillaume Fort for technical help.This paper is dedicated to the memory of Jacky Ganry.Breeding new interspecific banana hybrid varieties relies on the use of Musa acuminata and M. balbisiana parents. Unfortunately, infectious alleles of endogenous Banana streak virus (eBSV) sequences are present in the genome of Musa balbisiana genitors. Upon activation by biotic and abiotic stresses, these infectious eBSVs lead to spontaneous infections by several species of Banana streak virus in interspecific hybrids harboring both Musa acuminata and M. balbisiana genomes. Here we provide evidence that seedy M. balbisiana diploids display diverse eBSV allelic combinations and that some eBSVs differ structurally from those previously reported. We also show that segregation of infectious and non-infectious eBSV alleles can be achieved in seedy M. balbisiana diploids through self-pollination or chromosome doubling of haploid lines. We report on the successful breeding of M. balbisiana diploid genitors devoid of all infectious eBSV alleles following self-pollination and on the potential of breeding additional M. balbisiana diploid genitors free of infectious eBSVs by crossing parents displaying complementary eBSV patterns. Our work paves the way to the safe use of M. balbisiana genitors for breeding banana interspecific hybrid varieties with no risk of activation of infectious eBSVs

Modifying Bananas: From Transgenics to Organics?

“…Further, genes from M. balbisiana are available for use in genetic modification, as there is no possibility of transferring BSV genes [48].…”

Assessment of Banana Streak MY virus-based infectious clone vectors in Musa ssp.

“…Genotypes that developed symptoms within 3 weeks of post-inoculation and immediately the cigar leaf and pseudostem were necrotic and plants died within 3 months of infection. including both infective and non-infective alleles (Umber et al 2016;Fort et al, 2017). Most AAB hybrids harbour either a non-infective allele which is highly rearranged, or are free from eBSVs, whereas ABB hybrids can retain allelic diversity similar to BB diploids Duroy et al 2016;Umber et al 2016;Fort et al, 2017).…”

“…including both infective and non-infective alleles (Umber et al 2016;Fort et al, 2017). Most AAB hybrids harbour either a non-infective allele which is highly rearranged, or are free from eBSVs, whereas ABB hybrids can retain allelic diversity similar to BB diploids Duroy et al 2016;Umber et al 2016;Fort et al, 2017). reported the complete absence of eBSIMV in the plantains from India, while…”

“…In the recent literature, it has been established that during self-pollination or chromosome doubling of haploid M. balbisiana, both infectious and non-infectious eBSVs alleles segregate. Therefore, through segregation of the alleles, it is possible to breed bananas lacking eBSVs through self-pollination or by cross pollination of parents displaying complementary eBSVs pattern (Umber et al, 2016).…”

“…The amount of BSMYV DNA in test samples was then calculated based on this standard curve, which was included in all qPCR runs. Based on these standard curves, the genotypes with no B-genome component were shown to have very low levels of amplification, which were essentially equivalent to background noise as seen in the non-template control samples Geering et al, 2001;Umber et al, 2016 …”