Musa (genus)

''Musa'' is one of two or three genera in the family Musaceae. The genus includes flowering plants producing edible bananas and plantains. Around 70 species of ''Musa'' are known, with a broad variety of uses.

Though they grow as high as trees, banana and plantain plants are not woody and their apparent " stem" is made up of the bases of the huge leaf stalks. Thus, they are technically gigantic herbaceous plants.

''Musa'' species are used as food plants by the larvae of some Lepidoptera species, including the giant leopard moth and other ''Hypercompe'' species, including '' H. albescens'' (only recorded on ''Musa''), '' H. eridanus'', and '' H. icasia''.

Description

Banana plants represent some of the largest herbaceous plants existing in the present, with some reaching up to in height (59 feet (18 meters) in the case of '' Musa ingens''). The large herb is composed of a modified underground stem (rhizome), a false trunk of tightly rolled petioles, a network of roots, and a large flower spike. The false trunk is an aggregation of the basal portion of leaf sheathes; it is not until the plant is ready to flower that a true stem grows up through the sheath and droops back down towards the ground. At the end of this stem grows a peduncle (In the case of Musa ingens, being the second longest peduncle known, exceeded only by Agave salmiana with many female flowers protected by large purple-red bracts. The extension of the stem (this part called the rachis) continues growth downward where terminal male flowers grows. The leaves originate from a pseudostem and unroll to show a leaf blade with two lamina halves. The lamina can be as much as 22 feet (seven meters) in length in the case of '' Musa truncata'' of the Malay Peninsula). ''Musa'' reproduces by both sexual (seed) and asexual (suckers) processes, utilizing asexual means when producing sterile (non-seedy) fruits. Further qualities to distinguish ''Musa'' include spirally arranged leaves, fruits as berries, latex-producing cells present, Flowers with 5 connate tepals and 1 member of the inner whorl distinct, and petiole with one row of air channels.

Systematics and taxonomy

History

The genus ''Musa'' was first named by Carl Linnaeus in 1753. The name is a Latinization of the Arabic name for the fruit, ''mauz'' (موز). ''Mauz'' meaning ''Musa'' is discussed in the 11th-century Arabic encyclopedia ''The Canon of Medicine'', which was translated to Latin in medieval times and well known in Europe. ''Muz'' is also the Turkish, Persian, and Somali name for the fruit. Some sources assert that ''Musa'' is named for Antonius Musa, physician to the Emperor Augustus. According to Roger Blench, the ultimate origin of ''musa'' is in the Trans–New Guinea languages, whence they were borrowed into the Austronesian languages and across Asia, via the Dravidian languages of India, into Persian, Greek and Arabic as a ''Wanderwort'':

:

The word "banana" came to English from Spanish and Portuguese, which in turn apparently obtained it from a West African language (possibly Wolof).

From the time of Linnaeus until the 1940s, different types of edible bananas and plantains were given Linnaean binomial names, such as ''Musa cavendishii'', as if they were species. In fact, edible bananas have an extremely complicated origin involving hybridization, mutation, and finally selection by humans. Most edible bananas are seedless (parthenocarpic), hence sterile, so they are propagated vegetatively. The giving of species names to what are actually very complex, largely asexual, hybrids (mostly of two species of wild bananas, ''Musa acuminata'' and ''Musa balbisiana'') led to endless confusion in banana botany. In the 1940s and 1950s, it became clear to botanists that the cultivated bananas and plantains could not usefully be assigned Linnean binomials, but were better given cultivar names.

Sections

''Musa'' sectional systematics possesses a history dating back to 1887. In that year, M.P. Sagot published "Sur Le Genre Bananier", where the genus ''Musa'' was first formally classified. In this article, Sagot grouped the ''Musa'' species into three groups, although no section names were assigned to them. The grouping was based on morphological traits, establishing the trio as:
# Bananas with fleshy fruit;
# Ornamental bananas with upright inflorescences and bracts that were vibrantly colored; and
# Bananas that were giant in size.

In 1893, five years after Sagot's article, J.G. Baker made the first formal designation of ''Musa'' sections. To do so, he named three subgenera which almost paralleled the sections that had been described by Sagot. These sections were:
# ''M''. subg. ''Physocaulis'' Baker: a group defined by a bract with many flowers, inedible fruits, and a bottle-shaped stem.
# ''M.'' subg. ''Rhodochlamys'' Baker: brightly-colored bracts with few flowers, usually inedible fruits, and cylindrical stems.
# ''M.'' subg. ''Eumusa'' Baker which possessed green, brown, or dull-violet bracts with many flowers, usually edible fruits, and cylindrical stems.

After this classification, 50 years passed without revision to the banana sections. In 1947, Cheeseman reclassified the taxon based on morphological features and chromosome number. This project proposed 4 sections:
# ''M''. sect. ''Eumusa'' Cheesman (2n = 2x = 22)
# ''M''. sect. ''Rhodochlamys'' (Baker) Cheesman (2n = 2x = 22)
# ''M''. sect. ''Australimusa'' Cheesman (2n = 2x = 20)
# ''M.'' sect. ''Callimusa'' Cheesman (2n = 2x = 20)

The addition of another ''Musa'' section came in 1976 in G.C.G. Ardent's "The wild bananas of Papua New Guinea". The added section, ''M''. sect. ''Ingentimusa'' Ardent, was based on a single species, ''Musa ingens''. This designation put the number of sections in ''Musa'' at five: ''Eumusa'', ''Rhodochlamys'', ''Callimusa'', ''Australimusa'', and ''Ingentimusa''.

In the 21st century, genomics have become cheaper, more efficient, and more accurate, and ''Musa'' genetic research has increased exponentially. Research was conducted around a diversity of genomic markers (cpDNA, nrDNA, rDNA, introns, various spacers, etc.). The results of many of these studies suggested that the five sections of ''Musa'' defined by morphology (and listed above) were not monophyletic.Häkkinen, Markku. "Reappraisal of Sectional Taxonomy in Musa (Musaceae)." Taxon, vol. 62, no. 4, 2013, pp. 809–813., doi:10.12705/624.3.

Based on the incorrect section grouping, Markku Häkkinen proposed another reclassification of the ''Musa'' sections in 2013. Using a multitude of genetic evidence and markers from other studies, Häkkinen suggested the reduction of five ''Musa'' sections into two: ''Musa'' and ''Callimusa''. Unlike sectional classifications of the past, this hypothesis was based on genetic markers rather than morphological features or chromosome number. The two groups were generally formed by the clustering of the previously defined groups:
*''Musa'' sect. ''Rhotochlamys'' and ''M''. sect. ''Eumusa''  became ''M.'' sect. ''Musa''
*''M''. sect. ''Ingetimusa'', ''M''. sect. ''Callimusa'' and ''M''. sect. ''Australimusa''  became ''M''. sect. ''Callimusa''

The advance of genomic analysis technologies and further data on the relatedness of ''Musa'' species, formulated Häkkinen's two sections and later corroborated them as correct subcategories for the genus. The history of ''Musa'' sections provides an example of genomics superseding morphological evidence and thus classifications.

Species

The World Checklist of Selected Plant Families accepts 68 species and two primary hybrids, , which are listed below. The assignment to sections is based on GRIN (where this gives the species), regrouped according to Wong et al.

Section ''Callimusa'' (incorporating ''Australimusa'')

and indicate known placement in the former sections ''Australimusa'' and ''Callimusa'', respectively.
* ''M.'' × ''alinsanaya'' R.V.Valmayor * ''M. azizii'' Häkkinen
* ''M. barioensis'' Häkkinen
* ''M. bauensis'' Häkkinen & Meekiong !-- Systematics and Biodiversity 2 (2): 169-173 -->
* ''M. beccarii'' N.W.Simmonds ref group=Note name=Note2/>
* ''M. boman'' Argent * ''M. borneensis'' Becc. * ''M. bukensis'' Argent
*'' M. velutina''
* ''M. campestris'' Becc. * ''M. coccinea'' Andrews – scarlet banana
* ''M. exotica'' R.V.Valmayor * ''M. fitzalanii'' F.Muell. – extinct
* ''M. gracilis'' Holttum * ''M. hirta'' Becc. * ''M. insularimontana'' Hayata * ''M. jackeyi'' W.Hill * ''M. johnsii'' Argent * ''M. lawitiensis'' Nasution & Supard. * ''M. lokok'' Geri & Ng
* ''M. lolodensis'' Cheesman * ''M. maclayi'' F.Muell. ex Mikl.-Maclay * ''M. monticola'' M.Hotta ex Argent * ''M. muluensis'' M.Hotta * ''M. paracoccinea'' A.Z.Liu & D.Z.Li * ''M. peekelii'' Lauterb. * ''M. salaccensis'' Zoll. ex Backer * ''M. textilis'' Née – Abacá
* ''M.'' × ''troglodytarum'' L. – the cultivated Fe'i bananas
* ''M. tuberculata'' M.Hotta * ''M. violascens'' Ridl. * ''M. viridis'' R.V.Valmayor et al.
* ''M. voonii'' Häkkinen

Section ''Ingentimusa''

* ''M. ingens'' N.W.Simmonds

Section ''Musa'' (incorporating ''Rhodochlamys'')

* ''M. acuminata'' Colla – wild seeded banana, one of the two main ancestors of modern edible banana cultivars
** ''M. acuminata'' subsp. ''zebrina'' ''M. sumatrana''/small> – blood banana
* ''M. aurantiaca'' G.Mann ex Baker
* ''M. balbisiana'' Colla – wild seeded banana, one of the two main ancestors of modern edible banana cultivars
* ''M. banksii'' F.Muell.
* ''M. basjoo'' Siebold & Zucc. ex Iinuma – Japanese fiber banana, hardy banana
* ''M. cheesmanii'' N.W.Simmonds
* ''M. chunii'' Häkkinen
* ''M. griersonii'' Noltie
* ''M. itinerans'' Cheesman
* ''M. laterita'' Cheesman
* ''M. mannii'' H.Wendl. ex Baker
* ''M. nagensium'' Prain
* ''M. ochracea'' K.Sheph.
* ''M. ornata'' Roxb.
* ''Musa'' × ''paradisiaca'' L. = ''M. acuminata'' × ''M. balbisiana'' – many of the cultivated edible bananas
* ''M. rosea'' Baker
* ''M. rubinea'' Häkkinen & C.H.Teo
* ''M. rubra'' Wall. ex Kurz
* ''M. sanguinea'' Hook.f.
* ''M. schizocarpa'' N.W.Simmonds
* ''M. siamensis'' Häkkinen & Rich.H.Wallace
* ''M. sikkimensis'' Kurz
* ''M. thomsonii'' (King ex Baker) A.M.Cowan & Cowan
* ''M. truncata'' Ridl.
* ''M. velutina'' H.Wendl. & Drude – pink banana
* ''M. yunnanensis'' Häkkinen & H.Wang – Yunnan banana, wild forest banana
* ''M. zaifui'' Häkkinen & H.Wang

Section undetermined or unknown

* ''M. arfakiana'' Argent
* ''M. arunachalensis'' A.Joe, Sreejith & M.Sabu
* ''M. celebica'' Warb. ex K.Schum.
* ''M. juwiniana'' Meekiong
* ''M. kattuvazhana'' K.C.Jacob
* ''M. lanceolata'' Warb. ex K.Schum.
* ''M. lutea'' R.V.Valmayor et al.
* ''M. sakaiana'' Meekiong et al.
* ''M. shankarii'' Subba Rao & Kumari
* ''M. splendida'' A.Chev.
* ''M. tonkinensis'' R.V.Valmayor et al.
* ''M. yamiensis'' C.L.Yeh & J.H.Chen

Formerly placed here

*'' Ensete davyae'' (Stapf) Cheesman (as ''M. davyae'' Stapf)
*''Ensete gilletii'' (De Wild.) Cheesman (as ''M. gilletii'' De Wild. or ''M. martretiana'' A.Chev.)
*''Ensete glaucum'' (Roxb.) Cheesman (as ''M. glauca'' Roxb.)
*''Ensete lasiocarpum'' (Franch.) Cheesman (as ''M. lasiocarpa'' Franch.) – also placed in a separate genus as ''Musella lasiocarpa'' (Franch.) C.Y.Wu ex H.W.Li
*'' Ensete livingstoniana'' (J. Kirk) Cheesman (as ''M. livingstoniana'' J.Kirk)
*''Ensete perrieri'' (Stapf) Cheesman (as ''M. perrieri'' Claverie)
*''Ensete superbum'' (Roxb.) Cheesman (as ''M. superba'' Roxb.)
*''Ensete ventricosum'' (Welw.) Cheesman (as ''M. arnoldiana'' De Wild., ''M. ensete'' J.F.Gmel. or ''M. ventricosum'' (Welw.) Cheesman)
*''Heliconia bihai'' (L.) L. (as ''M. bihai'' L.)

Cultivated bananas

A number of distinct groups of plants bearing edible fruit have been developed from species of ''Musa''. In English, fruits which are sweet and used for dessert are usually called "bananas", whereas starchier varieties used for cooking are called "plantains", but these terms do not have any botanical significance. By far the largest and now the most widely distributed group of cultivated bananas is derived from section ''Musa'', particularly and , either alone or in various hybrid combinations. The next but much smaller group is derived from members of section ''Callimusa'' (previously classified as ''Australimusa'') and is restricted in importance to Polynesia. Of even more restricted importance are small groups of hybrids from Papua New Guinea; a group from section ''Musa'' to which '' Musa schizocarpa'' has also contributed, and a group of hybrids between section ''Musa'' and section ''Callimusa''.

Banana and plantains are the fourth most produced food globally surpassed only by the staple crops of rice, wheat and maize.

Properties

Plants of the ''Musa'' spp. including roots, flowers and fruits have been used in the folk medicine cultures of Africa, Asia, India and the Americas. Modern studies examining the properties of the fruits have found diversity of bioactive compounds among genotypes compared with commercially grown cultivars.

Section ''Musa'' cultivars

When the Linnaean binomial system was abandoned for cultivated bananas, an alternate genome-based system for the nomenclature of edible bananas in section ''Musa'' was devised. Thus, the plant previously known by the "species" name ''Musa cavendishii'' became ''Musa'' (AAA Group) 'Dwarf Cavendish'. The "new" name shows clearly that 'Dwarf Cavendish' is a triploid, with three sets of chromosomes, all derived from ''Musa acuminata'', which is designated by the letter "A". When ''Musa balbisiana'' is involved, the letter "B" is used to denote its genome. Thus, the cultivar 'Rajapuri' may be called ''Musa'' (AAB Group) 'Rajapuri'. 'Rajapuri' is also a triploid, expected to have two sets of chromosomes from ''Musa acuminata'' and one from ''Musa balbisiana''. In the genome of edible bananas from section ''Musa'', combinations such as AA, BB, ABB, BBB and even AAAB can be found.

Fe'i-type cultivars

No such nomenclature system has been developed for the group of edible bananas derived from section ''Callimusa''. This group is known generally as the "Fe'i" or "Fehi" bananas, and numerous cultivars are found in the South Pacific region. They are very distinctive plants with upright fruit bunches, featuring in three of Paul Gauguin's paintings. The flesh can be cooked before eating and is bright orange, with a high level of beta carotene. Fe'i bananas are no longer very important for food, as imported foods have grown in popularity, although some have ritual significance. Investigations are under way to use the Fe'i karat bananas (the name derives from " carrot" due to the intense orange-yellow color of the fruit) in prevention of childhood blindness in Pohnpei. Fe'i bananas probably derive mainly from ''Musa maclayi'', although their origins are not as well understood as the section ''Musa'' bananas. Cultivars can be formally named, as e.g. ''Musa'' (Fe'i Group) 'Utafun'.

Other uses

In addition to the edible fruits, the flowers can be eaten cooked, and the heart of the plant (like heart of palm) can be eaten raw or cooked. Additionally, the rootstocks and leaf sheaths of some species can be cooked and eaten.

See also

*''Ensete'' (false bananas); for more information about ''Musella'', also see ''Musella lasiocarpa''
*True plantains

Notes

References

Further reading

* Hedrick, U.P. (ed.) (1919):
Sturtevant's Edible Plants of the World
'. J.B. Lyon Co., Albany.
* Nelson, S.C.; Ploetz, R.C. & Kepler, A.K. (2006)
''Musa'' species (banana and plantain)

*

External links

Musapedia, page on Musa wild species

Musapedia, page on Musa sections

Musapedia, page on the diversity of banana cultivars





Musarama, banana image bank
*

{{DEFAULTSORT:Musa (Genus)

Zingiberales genera
Musaceae