Banana florL biology

1. FLORAL BIOLOGY OF
BANANA
Presenters
Deekshith.J
Deekshitha.M,E
Deepthishree.T,P
Devika.T,N
Dharithri Mahesh.P
Dia Rodrigues

2. • Botanical name: Musa sp.
• Family : Musaceae
• Chromosome number: n=11
• 2n = 22, 33 or 44 also exists
• Origin: South -east Asia

3. • The banana is a tree-like perennial herb
• It is an herb because it does not have
woody tissues and the fruit-bearing stem
dies down after the growing season
• It is a perennial because suckers, shoots
arising from lateral buds on the rhizome,
take over and develop into fruit-bearing
stems

4. • Trunk is not a woody stem but a pseudostem, a compact assemblage
of overlapping and spirally arranged leaf sheaths
• The ‘true’ stem is made up of three parts: the underground rhizome,
the aerial stem to which are attached the leaves, and the peduncle to
which is attached the inflorescence
• The stem starts on the rhizome’s apical meristem, grows inside the
pseudostem, and ends in the male bud.

6. AA Group
• Kadali (Poovan Kadali, Vella Kadali, Ambala Kadali)
• Plant is slender, bunch weight 6-10kg
• Fruits are small, stout, dark green, turn yellow on
ripening
• Sweet with excellent flavor
• Cultivated in southern districts of Kerala and Tamil
Nadu, used for worshiping.

7. AB group
• Ney poovan (Yalakki, Safed Velchi, Ney Kadali,
Vadakkan Kadali)
• Cultivated commercially in Karnataka & Kerala
• Intercrop in coconut and arecanut plantations
• Fruits are medium sized, pseudo stem slender
and yellowish with reddish petiole margin
• Flesh is firm, sweet, fragrant, average bunch
weighs 10-12kgs
• Resistant to leaf spot, Panama wilt

8. AAA group
a)Dwarf Cavendish: Pachabale, Basarai, Grant Governor, Morris,
Mauritius.
One of the most important variety of India
Average bunch weigh 15-25kg.
Plant is dwarf, Suitable for high density planting and wind prone
tracts.
Cavendish sub group

9. • Harichal, Peddapacha, Bombay
green
• Semi tall budsport of dwarf Cavendish
• Better keeping quality than dwarf
Cavendish.
• Average bunch weight 20-25kg.
• Resistant to panama wilt.
b)Robusta

10. C. Grand Naine(G9)
• Tall mutant of dwarf Cavendish
• Average bunch weight 25-30kg.
• It requires propping
• Cavendish group (all 3 var.)
susceptible to leaf spot diseases.

11. Red banana of sub group
• Chenkadali, Lalkela, Agniswar, Chandrabale
• It thrives well in humid tropics and at higher
altitudes
• Color of the pseudo stem, petiole, midrib and
fruit peel is purplish red
• Fruits large with characteristic aroma, average
bunch weight is 18-22kgs
• Highly susceptible to bunchy top, fusarium wilt
and nematodes
• Sensitive to winds because height is >15 feet
A)Red banana

12. • Pseudostem is greenish yellow
• Fruit turns golden yellow on ripening
• Peel is thick, flesh firm, sweet with
pleasant aroma
Rajbale

13. AAB group
• Mysore poovan/champa
• Plant is tall, vigorous and hardy.
• Fruits are small to medium think peeled,
pulp cream coloured with sub acidic taste.
• Resistant to panama wilt.
A)Mysore sub group

14. B)Silk sub group
• Eg: Rasthali (Rasabale, Amruthpani,
Sankel, Silk fig)
• It is the choice table variety and
priced high in the market
• It can be easily identified by the
yellowish green stem with brownish
patches
• Reddish margins of the petiole and
the leaf sheath

15. • Fruit is medium sized, thin
peeled, ivory yellow in colour,
flesh firm, sweet with pleasant
apple flavor.
• Average bunch weight is 12kg
• It is a long duration variety
• Highly susceptible to Fusarium
wilt/Panama wilt

16. C)Pome sub group
• Hill banana (Virupaxi, Marabale, ladan, valla
vazhai, Sirumalai)
• Elite banana of South India preferred for its
fruits having good keeping quality, unique
aroma and taste.
• It a tall, sturdy plant
• Fruits are having thick peel
• AV. Bunch weight 10-12kg

17. D)Plantain sub group
• Nendran
• It is a dual purpose cultivar of Kerala
• The fruit is longer and thicker with good
keeping quality average bunch weight 10-
15kg
• Suitable for chips making
• Susceptible to bunchy top and bract mosaic
virus

18. ABB group
• (Bontha, Madhuranga bale, Ponthan,
Balinga)
• It is a leading culinary or cooking cultivar
of India
• Plant is hardy, drought tolerant, tall, robust
and light gr
• Average bunch 10-15kg
• Resistant to panama wilt, Black Sigatoka
and bunchy top diseases
A)Monthan

19. B)Karpooravalli
• Pey kunnan
• It is a table variety commercially
cultivated in Tamil Nadu
• Av. Bunch weight 25-30kg
• Good keeping quality
• Suitable for juice & wine making

20. Ex: Saba
It is an important cooking cultivar of Philippines
AAAA group
Ex: Bolds Alta forte
ABBB
Ex: Klue Teparod
BBB group

21. Inflorescence
• The inflorescence is branched spadix.
• The flowers are protected by large, brightly coloured, spirally
arranged, boat shaped bracts called spathes.
• When the flowers open, the spathes roll back and finally fall off.
• The flowers are polygamous i.e. staminate flowers, pistillate flowers
and bisexual flowers are present in the same plant.
• The male flowers lie within the upper bracts, the female flowers
within the lower bracts and the bisexual flowers within the middle
bracts.

23. Flowers
Male flower
• Male banana flowers have a slender style and stigma, and well-developed
anthers, which in wild species usually contain pollen. In edible bananas, the
amount of pollen is reduced or absent
• Together, the anther and the filament form a stamen. A male banana
flower typically has five stamens. Collectively the stamens form the
androecium (from the Greek andr-, meaning man, and oikios, meaning
house).
• The style, stigma and male parts of the banana flower are enveloped
within a tubular structure formed by fusion of five petal-like tepals, with a
sixth tepal remaining free.
• The male flowers are contained in the male bud, in which they are
arranged in clusters called hands. Each hand is enfolded by a bract that lifts
when the flowers have finished developing. Male flowers usually fall to the
ground a short time after flowering.

24. • Female flowers
• Female banana flowers have a massive style and stigma, and stamens
which are usually reduced to staminodes that do not produce pollen.
Sometimes the male organs are absent.
• The enlarged basal portion which contains the ovules is called the ovary
(from the Latin’s ovum, meaning egg).
• Together, the ovary, style and stigma make up the pistil, also called a
carpel. In a banana flower, three pistils fuse producing a tri-pistillate ovary,
style and stigma.
• The collective term for the parts of the flower that produce ovules and
ultimately develop into the fruit and seeds is gynoecium (from the Greek
gyne, meaning women’s, and oikos, meaning house)
• Each flower is connected to a cushion of tissue on the peduncle by the
pedicel.
• The female flowers reach anthesis (the period during which a flower is fully
open and functional) before the male flowers.

27. • Hermaphrodite flowers
• In some wild species, the basal fruit-forming flowers have a functional
gynoecium and androecium, and can self-fertilise before bract
opening if the stigma and anthers are aligned. These flowers are
called hermaphrodite or perfect
• The ability to self-fertilize is significant because it reduces
hybridization and as such contribute to genetic isolation.
• Norman Simmonds noted that the occurrence of basal female
flowers with male fertility may have adaptive significance at the edges
of a species’ range as it would bias seed set towards selfing if
populations of plants were distant from one another.

28. • Other types of flowers
• In some edible bananas, there may be flowers at the point of
transition from the basal female to the distal male portion of the
inflorescence that do not produce fruit and have a small ovary,
although it is larger than in male flowers.
• These flowers may retain some features of fruit-forming flowers, such
as remaining attached to the peduncle.
• Such flowers are called neuter or intermediate.
• They are also described in some wild species, where they can be
neuter or functionally male.

29. Pollination
• The flowers provide the structure for sexual reproduction, which
occurs when pollen produced by the anther of a male flower fertilises
the ovule in a female flower to produce a viable embryo.
•
• First, pollen needs to be transferred to the stigma. Since the female
flowers open before the male flowers on the same inflorescence,
more than one inflorescence, and a pollinator to collect and deliver
the pollen, are essential.

30. • Second, once on the stigma, the pollen grains need to be ‘recognised’
in order to germinate. The tube emerging from a germinated pollen
grain responds to chemical signals that guide it down the canal in the
centre of the style to reach one of the three locules where ovules are
located. Further guidance is needed to get a pollen tube to an
available ovule to form a viable embryo.
•
• The fertilised ovule containing the viable embryo develops into a
seed. This in turn stimulates pulp development around the seeds in
the ovary, resulting in a seed-bearing banana fruit. In a wild species a
fruit might contain up to 300 seeds.

31. Pollinators
• Pollinators
• The nature of the banana inflorescence is that female flowers are
separated in space and time from male flowers. In this case,
pollinators are essential for seed production.
•
• Since the tepals are not colourful and nectar is abundant, the main
pollinators are bats and birds.22 Banana flowers are visited by
numerous species of insects and some animals but these are not
involved in pollination.

32. • Parthenocarpic bananas
• In edible bananas, sexual reproduction is rarely successful, with very
few if any seeds produced as a consequence of pollination. This
failure is multifaceted, due to a greater or lesser extent to a lack of
viable pollen, disruption of the pollen pathway through the
gynoecium in the female flower and a lack of viable ovules.
•
• Instead, the fruit of edible bananas develop through vegetative
parthenocarpy, with the pulp developing autonomously from tissues
on the ovary wall of the female flower without the need for
pollination.

33. • Female flower
• Female banana flowers have a massive style and stigma, and stamens
which are usually reduced to staminodes that do not produce pollen.
Sometimes the male organs are absent.
•
• The enlarged basal portion which contains the ovules is called the ovary
(from the Latin’s ovum, meaning egg).
•
• Together, the ovary, style and stigma make up the pistil, also called a
carpel. In a banana flower, three pistils fuse producing a tri-pistillate ovary,
style and stigma.