Ploidy determination of <i>Musa</i> germplasm using morphological descriptors and chloroplast count in pairs of stomatal guard cells

Abstract

Musa species comprise different ploidy natures with most cultivated species being triploid. This results in its sterility and limits improvement. This work was aimed at determining the ploidy nature of Musa accessions from identified Musa germplasm, using cost-effective procedures. Accessions from Musa germplasm of Ebonyi State University, Abakaliki were assessed. To classify their genomes, twenty-six morphological descriptors of both qualitative and quantitative traits were employed. Chloroplast density in pairs of stomatal guard cells of the accessions was also determined. Morphological description showed that germplasm were variants of banana and plantain with 54.55 % of accessions classified as diploid, while 45.45 % were triploid. The chloroplast count showed significant difference at p ≤ 0.05 with chloroplast number which ranged from 9 to 18. ‘Efol red’ had mode and mean of 9 and 9.45 ± 0.61, respectively, while Calcutta 4 and PITA 14 had mode of 16, with a mean of 16.70 ± 0.92 for PITA 14. The chloroplast count grouped 18.18 % accessions as tetraploid, 72.73 % as triploid and 9.09 % as diploid. Although morphological characterisation is ideally the first method to adopt while classifying variants, chloroplast characterisation has brought better clarity since its influence by the environment is limited.