Banana is known to be one of the important fruit crops. It is also considered as food in many African countries. The present day cultivated bananas have evolved from two main species of Musa, namely, Musa acuminata and Musa balbisiana. Most of the classifications of the banana cultivars are made based on the morphological observations. Being a polyploid, parthenocarpic, vegetatively propagated crop, studies on karyomorphological aspects and breeding are rare.

In the present paper, an attempt was made to study the karyotypes of some Musa species and diploid cultivars to understand the karyology and homology of chromosomes. Basic cytological techniques like fuchsin staining and observations on chromosome number and karyomorphological studies were made. It was observed that there were differences among the Musa species and cultivars studied in the total chromosome length.

Banana is one of the oldest fruits of tropical countries. The fruit is part of the daily diet to more than 400 million people around the world and is also an important source of food (Oritz and Vuylsteke, 1996). Banana cultivars have evolved from two main species Musa acuminata and Musa balbisiana (Cheesman and Dodds, 1947; and Dodds and Simmonds, 1962) which belong to the section Eumusa. The diploid and triploid acuminata cultivars were taken by man to the native areas of balbisiana which resulted in natural hybridization and formation of hybrid progeny with the genomes: AB, AAB, ABB (Simmonds, 1962). Subsequent dispersal of edible bananas out of Asia would have been brought about by human intervention. Secondary diversification within the groups of cultivated bananas are the result of somatic mutations. It is necessary to understand its relationships and the homology in its hybrids. Cytological studies were made by earlier researchers reported variation in karyotype in different cells of same root section. Variability observed in number of different types of chromosomes was attributed to inversions and translocations by Chakravorti, 1951. Karyotype was observed to be symmetrical by Agrawal (1987 and 1988) in some cultivars of South India. He also reported cytological abnormalities and B chromosomes in M. rubra (Agrawal, 1983), a related species belonging to the section Rhodochlymus. Wild AA group accessions have been introduced to India through Myanmar and has contributed in the development of AB and highly diverse AAB and ABB group cultivars.

Only limited work was carried out in Musa karyomorphology of individual cultivars, species and subspecies though there are number of publications on in situ hybridization and flowcytometrical studies which reveal genomic constitution and ploidy level (Dolezel, 2004). Most of the available information is about the studies on chromosome pairing during meiosis (Shepherd, 1999). The present study aims at understanding the karyotype of some Musa species and cultivars of some AA genomic group.

Genetics & Evolution Journal, Parthenocarpic, Cytotaxonomical Studies, Cytogenetical Investigations, Karyomorphological Investigations, Karyotypic Formula, Median Centromere, Karyomorphological Data, Karyological Studies, Cytometric Analysis, Self-pollination Mechanism, Genome Analysis.