Most cooking and several desert bananas are interspecific triploid hybrids between Musa acuminata (A genome) and M. balbisiana (B genome). To investigate the possibility of chromosome exchanges between these two species, Jeridi et al. develop a genomic in situ hybridization protocol suitable for analysing meiosis metaphase I from Musa pollen mother cells. They demonstrate that chromosome pairing between M. acuminata and M. balbisiana chromosomes is frequent in triploid interspecific hybrids, results that both provide new insight into cultivar evolution and have important implications for future breeding.
Diphasiastrum species have been assumed to produce homoploid hybrids whose reproductive competence is still a matter of debate. Using flow cytometry, Bennert et al. demonstrate that the three Central European primary hybrids are consistently homoploid. Their nuclear DNA amounts are invariable and intermediate between the parents; no indications for diploid backcrossing are found. Higher DNA amounts occur in three presumably triploid populations, which arose by a secondary hybridization event, probably involving unreduced diplospores formed by a diploid hybrid.