Loading...
 

Plantain subgroup


Plantain subgroup
Photo by Rony Swennen
Genome group: AAB
Subgroup: Plantain
Cultivars:

The Plantain subgroup refers to a set of more than 100 cultivars1 of cooking bananas that display a wide range of morphological variability. The triploid genome of these bananas, shorthanded AAB, denotes that they are hybrids of Musa acuminata and Musa balbisiana in a proportion of roughly two to one. Even though bananas originate from the Asia-Pacific region, the diversity of Plantains is highest in Africa, especially West and Central Africa. This diversity was created locally by farmers selecting and vegetatively propagating natural mutants derived from the maybe more than one cultivar introduced to the African continent. Archaelogical evidence in the form of phytoliths suggests that bananas were being grown in southern Cameroon during  the first millenium BC2. The Plantains grown in Latin America were introduced from Africa during the slave trade.

The term plantain is often used ambiguously to refer to all types of cooking bananas or to suggest that plantains are not bananas, as in the expression bananas and plantains3. In Spanish, plátano, from which is derived the term plantain, is often used to refer to all types of bananas.

Contents

Morphological characteristics

The cultivars in this subgroup display a wide range of morphological characters, from plants with a large bunch and male bud, to plants with only a few fruit and no male bud. As bunch weight decreases, the average fruit weight tends to increase.

The following traits, recorded on 55 cultivars from the Democratic Republic of Congo, have been proposed as being potentially characteristic of the subgroup4.

Pseudostem: Moderately waxy leaf sheaths; watery sap; suckers close to the mother plant and between ¼ and ¾ the height of the mother plant.

Petiole canal: Margins curved inward, winged and clasping the pseudostem; dry wing type; green petiole margin with a colour line along its edge; margin width ≤ 1cm.

Leaf: Shiny upper surface; dull lower surface; moderately waxy leaves; symmetric insertion point of the leaf blades on the petiole; rounded leaf blade base on both sides; intermediate leaf corrugation; large purple blotches on the leaves of the water suckers.

Peduncle: Slightly hairy.

Fruit: Pronounced ridges; hairless pedicel surface; slightly to not fused pedicels; high adherence of the peel (the fruits do not peel easily); persistent fruits (do not fall from hands at maturity); firm pulp texture.

A number of traits are used to distinguish cultivars: bunch orientation and density (very compact, compact and lax), the number of hands, size and shape of the fingers (straight, straight in the distal part, curved and S shapes), size of the pseudostem, presence or absence of the male bud, colour of the pseudostem (various shades of green, red, or violet), peel colour of immature fruit (various shades of green, red, yellow and brown).

Photo by Joseph Adheka
Photo by Joseph Adheka
Photo by Joseph Adheka
Photo by Joseph Adheka
Photo by Joseph Adheka
Photo by Joseph Adheka
Photo by Joseph Adheka
Photo by Joseph Adheka
Pendulous bunch orientation
Sub-horizontal bunch orientation
Horizontal bunch orientation
Erect bunch orientation

Clusters

French Plantain
Photo by Joseph Adheka
Photo by Joseph Adheka
French Horn Plantain
Photo by Richard Markham
Photo by Richard Markham
False Horn Plantain
Photo by Joseph Adheka
Photo by Joseph Adheka
Horn Plantain
Photo by Joseph Adheka
Photo by Joseph Adheka

Norman Simmonds recognized two types of Plantains distinguished by the presence of the male bud (French) or its absence/degeneration (Horn)5. Two types were later recognized: False Horn6 and French Horn1.

French

French Plantains have persistent bracts on the rachis and a large male bud. French plantains are commonly subdivided into size categories: giant, medium, small. The medium and small French types produce more suckers than the giant French types.

Since the height and girth of the pseudostem vary with the environmental conditions, the number of leaves produced from planting to flowering is used to determine the size class: giant (more than 40 leaves); medium (between 32 and 38 leaves); and small (less than 30 leaves)6. Most of the French Plantains are giant types characterized by large bunches that contain many hands and relatively small fruits. These cultivars have a long vegetative cycle and are susceptible to toppling in windy conditions.

French Plantains are called Plátano Hembra in Central America, Congo in Puerto Rico and banane blanche in the French West Indies6.

Examples of cultivars: 'Obino l'Ewai' (Nigeria), 'Nendran' (India), 'Dominico' (Colombia)

French Horn and False Horn

The male bud of both French Horn and False Horn types degenerates at maturity. French Horn plantains have a high number of neutral flowers, whereas False Horn plantains retains only a few neutral flowers1. Both types have large fingers, but the bunch of French Horn plantains is dense. The plant size categories are also different. For example, a medium French Horn is taller than a medium False Horn.

Examples of French Horn cultivars: 'Batard' (Cameroon), 'Mbang Okon' (Nigeria)

Examples of False Horn cultivars: 'Agbagda' and 'Orishele' (Nigeria), 'Dominico-Harton' (Colombia)

Horn

Horn Plantains typically produce very few fruit spread over one to five hands (exceptionally eight to ten). The  rachis ends after the last hand. No male bud is produced.

Horn Plantains are called Plátano Macho in Central America.

Examples of cultivars: 'Ishitim' (Nigeria), 'Pisang Tandok' (Malaysia)

Since the French types are the only ones to have a complete inflorescence, they are believed to be at the origin of the other types. The degeneration process from French to Horn types is believed to have taken place in six phases7:
Phase 1: The basal male flowers experience an ‘ovary’ hypertrophy.
Phase 2: The male flowers (especially the basal ones) remain attached to the floral axis.
Phase 3: The total number of hands and flowers decreases, but the male bud persists to maturity.
Phase 4: The male bud is quickly exhausted. At  maturity about fourty hands, containing flowers with a half-reduced ovary, and sometimes developed as small bananas, are observed.
Phase 5: No trace of male bud. The last female hands also disappear. Some cultivars produce only on hand or even one monstrous banana.
Phase 6: The floral axis no longer bears fruits. Two or three very thick but very narrow bracts hang from the sterile glomerules.

Dwarfism

The Plaintain subgroup also has dwarf and semi-dwarf cultivars. Dwarfism is characterized by a lower leaf ratio (length/width) than the one measured on giant, medium and small types. The leaves of dwarf types are also more erect.

Agronomic performance

Plantains requires a warm and humid climate with no major oscillations. They will generally not survive a dry season that lasts more than 3 months and temperatures below 10ºC for more than a few nights. Exceptions are cultivars such as 'Vuhembe', which has been found growing at 2,172 m in North Kivu, the Democratic republic of Congo4.

Most Plantains exhibit strong apical dominance, which suppresses sucker growth until after bunch emergence. They then tend to remain small because of competition with each other.

The shallow and poorly ramified root system of Plantains also makes them susceptible to 'high mat', the tendency of the plant base to grow out of the soil.

References


1. Swennen, R. 1990. Limits of Morphotaxonomy : names and synonymes of plantains in Africa and elsewhere. p.172-210 In: Jarret, R. and Lusty, C. (eds.). Proceedings of Identification of Genetic Diversity in the genus Musa, Los Banos, Philippines, 1988/09/05-10. Identification of Genetic diversity in the genus Musa: Proceedings of an International Workshop. INIBAP, Montpellier, France.
2. Mbida, C.M., Van Neer, W., Doutrelepont, H. and Vrydaghs, L. 2000. Evidence for banana cultivation and animal husbandry during the first millennium BC in the forest of southern Cameroon. Journal of Archaeological Science 27:151-162.
3. Slippery uses of banana statistics, a blog post on the misuse of statistics and the habit of splitting bananas into bananas and plantains.
4. Adheka Giria, J. 2014. Contribution to the characterization and classification of the Congo basin African plantains (Musa AAB) in the Democratic Republic of Congo. PhD thesis. Department of Biotechnological Sciences, Faculty of Sciences, University of Kisangani.114 pp.
5. Simmonds, N.W. 1966. Bananas. 2 ed., Tropical Agricultural Series. Longman, New York (USA). 512p.
6. Tézenas du Montcel, H., De Langhe, E. and Swennen, R. 1983. Essai de classification des bananiers plantains (AAB). Fruits 38(6):461-474.

See also on this website

News and blogs related to Plantains:

Contributors to this page: Anne Vézina .
Page last modified on Friday, 10 October 2014 15:01:16 CEST by Anne Vézina.