Ongzi's SecretGarden: Banana Cultivars in SEA

Wednesday, 20 March 2019

Banana Cultivars in SEA

The first scientific term given to banana is Musa paradisiaca Linn., published in 1753 by Linnaeus in his book Species Plantarum.

Later, Linneaus published Musa sapientum Linn. in Systema Naturae in 1759 to describe a dessert banana which bear sweet fruits that are eaten fresh upon ripening.

To cope with the wealth in germplasm diversity in its center of origin, subsequent banana taxonomists applied such descriptive names as Musa nana Lour. for the Dwarf Cavendish, Musa rubra Firming. von Wall. for the Red banana, Musa corniculata Lour. for the horn plantain, and many others.

Cheesman (1948) recognized three groups of morphologically distinct cultivars. The first group shows predominantly the botanical characters of Musa acuminate while the second group of cultivars primarily exhibit the morphological features of Musa balbisiana. The third group possesses characteristics that combine the morphological characters of the two wild species and are considered as their natural hybrids.

Simmonds and Shepherd (1955) concluded that the edible bananas originated from two wild and seedy species, Musa acuminate Colla and Musa balbisiana Colla which are endemic to Southeast Asia.

According to rules of the International Code of Nomenclature for Cultivated Plants (ICNCP), hybrids can also be given a scientific name. However, the epithet must carry the prefix ‘x’ to indicate the hybrid nature of the species. In the case of hybrid banana cultivars, Musa x paradisiaca Linn. should be adopted as this binomial was

published ahead of Musa sapientum.

To cope with the problem, the authors agreed to adopt the three tiers system namely – species, genome group, and cultivar, in classifying bananas and identifying cultivar names and synonyms of the region.

The taxonomic scorecard suggested by Silayoi and Chomchalow (1987), was found very useful in segregating the numerous banana varieties into six genome groups.

Table 1 presents the 15 diagnostic characters used to differentiate Musa acuminata clones from Musa balbisiana cultivars and their hybrids. The cultivars are classified by inspecting the expression of each of the 15 characters shown in Figure 2 and assigning a score of 1 for each character that adheres closely with wild acuminata and 5 for characters with extreme balbisiana expression.

This scoring technique provides for a range of 15 (15 x 1) for wild acuminata and 75 (15 x 5) for wild balbisiana species. Intermediate expressions of the characters are assigned scores ranging from 2, 3, or 4 depending on intensity. The hybrid cultivars, therefore, should have total scores between 15 and 75. In actual practice, slight deviations are allowed.

Table 2 shows the six genome groups and the expected range of scores the cultivars under study will generate. Pure acuminata varieties should have scores between 15 to 25 while pure balbisiana cultivars should range between 70 to 75. The hybrids are expected to score between 26 to 69 points.

Table 3 presents the list of banana cultivar names and synonyms of Southeast Asia.