Characterization of indigenous Musa species based on flow cytometric analysis of ploidy and nuclear DNA content

Ploidy and nuclear genome size variation were studied in Musa species indigenous to Malaysia i.e. Musa acuminata, Musa balbisiana, and Musa violascens. Flow cytometry was successfully used for ploidy estimation using DAPI and for nuclear DNA content where nuclei were stained with propidium iodide. No variation was observed in ploidy level, where as a large amount of variation in the genome size was observed among different Musa species analysed. Less variability was observed at the intraspecific level within the Musa acuminata. Similar genomic DNA content were observed in Musa acuminata ssp. malaccensis (Selangor type) and Musa acuminata ssp. siamea (Kedah type) samples. However, the highland banana Musa acuminata ssp. truncata (Cameron type) was significantly different from two forms. Larger variation was also observed between the species Musa balbisiana (547 Mbp), and Musa violascens (680 Mbp). The genome size of Musa violascens was significantly larger than the other two species although their chromosome numbers were higher (2n=22). Statistical and cluster analysis of data on genome size related in a grouping agreed well with the generally accepted taxonomic classification of Musa.