AUTHOR=Beránková Denisa , Čížková Jana , Majzlíková Gabriela , Doležalová Alžběta , Mduma Hassan , Brown Allan , Swennen Rony , Hřibová Eva 

TITLE=Striking variation in chromosome structure within Musa acuminata subspecies, diploid cultivars, and F1 diploid hybrids

JOURNAL=Frontiers in Plant Science

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1387055

DOI=10.3389/fpls.2024.1387055

ISSN=1664-462X

ABSTRACT=<p>The majority of cultivated bananas originated from inter- and intra(sub)specific crosses between two wild diploid species, <italic>Musa acuminata</italic> and <italic>Musa balbisiana</italic>. Hybridization and polyploidization events during the evolution of bananas led to the formation of clonally propagated cultivars characterized by a high level of genome heterozygosity and reduced fertility. The combination of low fertility in edible clones and differences in the chromosome structure among <italic>M. acuminata</italic> subspecies greatly hampers the breeding of improved banana cultivars. Using comparative oligo-painting, we investigated large chromosomal rearrangements in a set of wild <italic>M. acuminata</italic> subspecies and cultivars that originated from natural and human-made crosses. Additionally, we analyzed the chromosome structure of F1 progeny that resulted from crosses between Mchare bananas and the wild <italic>M. acuminata</italic> ‘Calcutta 4’ genotype. Analysis of chromosome structure within <italic>M. acuminata</italic> revealed the presence of a large number of chromosomal rearrangements showing a correlation with banana speciation. Chromosome painting of F1 hybrids was complemented by Illumina resequencing to identify the contribution of parental subgenomes to the diploid hybrid clones. The balanced presence of both parental genomes was revealed in all F1 hybrids, with the exception of one clone, which contained only Mchare-specific SNPs and thus most probably originated from an unreduced diploid gamete of Mchare.</p>