Breeding of Fruit and Plantation Crops

Banana

• Botanical name: Musa sp.
• Family : Musaceae
• Chromosome number: n=112n = 22, 33 or 44 also exists
History of banana breeding

• Banana breeding was started in Trinidad, West Indies in 1922 and in Jamaica in 1924 (Shepherd, 1994). The driving force for this breeding programme was to develop improved Fusarium wilt (Fusarium oxysporum F.sp. Cubense) resistant banana for export trade. In 1960, both the programmes were combined under the Jamaica Banana Board. United Fruit Company also started a small breeding programme in Panama in 1920s. In India hybridization work was started at Central Banana Research Station, Adhuthurai, Tamil Nadu in 1949.


• Important banana growing states are Maharashtra, Karnataka, Kerala, Tamil Nadu, Andhra Pradesh, Orissa,Bihar, West Bengal and Assam . In recent days, in some districts of Uttar Pradesh, Harichal banana is cultivated on a commercial scale. In South India, other than its edible use, banana is extensively used in all auspicious occasions such as wedding, festivals and worshipping God. Banana is a good table fruit, besides, the cultivar Nendran is used for cooking. It is also used for preparation of chips.

Centre of diversity

• Edible banana is native to old world especially South East Asia (Simmonds,1962). Malayan area seems to be the primary centre of origin of cultivated banana (M.acuminata). M.acuminata, was probably introduced into India and Burma where M.balbisiana is a native species. Natural hybridization between these two species might have resulted in many hybrid progenies (AAB, ABB etc).

Genetic resources

Musa has about 50 species and this genus is divided into five sections:
a)Eumusa: Includes about 13-15 species of edible and wild banana. The chromosome number is 2n=22 in wild species and most of the cultivated varieties are having 2n=33 (2n=44 rarely) e.g. M.acuminata, M.balbisiana, M.basjoo etc.
b)Rhodochlamys: Mostly diploid, spread from India to Indonesia. Five to seven species are kept in this group. Parthenocarpy is absent in this group e.g. M.ornata, M.velutina.
c) Callimusa: This is of ornamental value and x=10 and 2n =20. It is found in Indo-China, Malaya and Borneo. Parthenocarpy is absent in this type. It includes about 5-6 species e.g. M.coccinea.
d) Australimusa: Like Callimusa it has x = 10 and 2n=20 chromosome. Species of this group is common in Queensland and Philippines. Important species of this group are M. textilis or manilahemp, M.maclavi etc.
e) Incertae sedis: It includes M.ingens (x=7, 2n=14) of New Guinea which grows to a height of over 10 m. This is the largest known herb. Another species in this group is M.beccarii (x=9, 2n=18) from North Borneo.



• Ensete is another genera of this family probably originated in Asia. Genus Ensete has 6-7 species of which E.ventricosa is reported to be grown in Ethiopia as a food crop. The most important Musa cultivars are almost sterile triploids (2n=3x=33) and also tetraploid and diploid banana cultivars have also local importance in Asia.
  


• All banana and plantain land races are farmers selection from intra and inter specific hybridization of two different species, M.acuminata Colta, donor of the A genome and M.balbisiana Colta, donor of the B genome. Simmonds and Shepherd (1955) reported scoring technique to indicate the relative contribution of the two wild species for the constitution of a given cultivar.
  


• Fifteen distinguishing characters between Musa acuminata and Musa balbisiana were identified by them. Score one was given for each character in which a cultivar agreed with Musa acuminata and score five was given for each character to which agreed with Musa balbisiana. Intermediate expressions of the characters were assigned score of 2, 3, or 4 depending on their intensity.

Taxonomic Scoring of banana based on distinguishing features

Characters	Musa acuminata	Musa balbisiana
Pseudostem colour	More or less heavily marked with black or brown blotches	Blotches slight or absent
Petiolar canal	Margin erect or spreading with scarious wings below, not clasping pseudostem	Margins not winged below, clasping pseudostem
Peduncle	Usually downy or hairy	Glabrous
Pedicel	Short	Long
Ovules	Two regular rows in each locule	Four irregular rows in each locule
Bract shoulder ratio	Usually high (ratio:0.28)	Usually low (ratio:0.30)
Bract curling	Bracts roll	Bracts lift but do not roll
Bract shape	Lanceolate or narrowly ovate tapering sharply from the shoulder Acute	Broadly ovate, not tapering sharply
Bract apex	Red dull purple or yellow Inside pink, dull purple	Obtuse
Bract color	Inside bract colour fades to yellow towards base	Inside bract colour continues to base
Bract scars	Prominent	Scarcely prominent
Free tepal of male flower	Variably corrugated below tip	Rarely corrugated
Male flower colour	Creamy white	Variably flushed with pink
Stigma colour	Orange or rich yellow	Cream, pale yellow or pale pink.


• At the botanical garden, Howrah, seeds of few banana species were collected from Chittagong and Madras (Roxburg, 1832). More number of genotypes of banana was also maintained at Central Banana Research Station, Aduthurai (Nayer, 1957). After that it was shifted to Horticulture college and research Institute, Tamil Nadu Agricultural University, Coimbatore. After the formation of National Research Centre on Banana (NRCB) in 1995, a wide germplasm collection including wild types are being maintained at this centre and intensive research programmes are being taken up on various problems related with banana. Presently, Tamil Nadu Agricultural University also maintaining 186 collections of germplasm.

Objectives of breeding

• To develop dwarf statured banana suitable for high density planting and to prevent damage from high wind velocity.
• Production of good quality fruits.
• Resistant to biotic and biotic stresses i.e. nematodes, panama wilt, bunchy top, sigatoka leaf spot, moko disease and pseudostem weevil etc.
• To develop varieties with wider agro-ecological adaptability.
• Development of male fertile parthenocarpic diploids with resistance to major diseases and pests.
• Developing longer finger size.
• Suitability for export.
• Good keeping quality.
Genome	Ploidy level	Score and nomenclature
Constitution AA AAA AAAA AB AAB ABB ABBB	2x 3x 4x 2x 3x 3x 4x	16-23 Matti,Anai komban 15-21 i)Gros Michel ii) Cavendish 15-20 Bodles Altafort (Synthetic hybrid of West Indies) 46-49 Ney Poovan, Kunnan 26-46 Champa, Rsathali 59-63 Kanchkela, Monthan 63-69 Klue Teparod