The Banana Plant: Morphology, Propagation and Breeding

www.iita.orgA member of CGIAR consortium
The Banana Plant: Morphology,
Propagation and Breeding
Training on Increasing the Capacity of Research Technicians in Breeding. IITA-Ibadan, Nigeria.
July 27-August 14, 2015.
Amah Delphine, IITA Nigeria

Plan
1. Introduction
2. Classification
3. Growth cycle
4. Morphology
• Pseudostem and foliage
• Inflorescence
• Flowers
• Bunch
5. Propagation
6. Breeding
7. References and further reading

Introduction
• Bananas are giant perennial herb mostly cultivated for their fruits.
– Perennial: new stems (suckers) continuously grow from the base of the mother plant to
replace the aerial stems which die off.
– Herb: no woody components and aerial parts dies once bunch is harvested.
• Fruits may be eaten raw, steamed, roasted, fried or processed into flour.
• They contribute to food and income security to millions of people especially in the
tropics.
• FAO estimates for world production in 2013 is about 145 Mt.

Classification
• ‘Bananas’ refers to all members of the genus Musa comprising
wild and edible types e.g. plantains (a well-defined group of
starchy bananas).
• Monocots belonging to the Eumusa section of the genus Musa
(several species), family Musaceae, and order Zingiberales.
• Inter- and intra- specific hybrids from two ancestral species M.
acuminata colla (A genome) and M. balbisiana colla (B
genome) 2n=2x=22 chromosomes.
• Edible bananas of Eumusa have 22, 33, or 44 sets of
chromosomes corresponding to diploids, triploids and
tetraploids respectively. Ploidy is important for classifying
hybrids from breeding programs.

Question
Name a popular banana in your country,
mention its form(s) of consumption and
describe how you will identify it.

Classification
• Form of consumption: desert, cooking
and beer types
• Genomic composition:
– AAA desert, highland beer and cooking
bananas
– AAB plantains and desert bananas
– ABB cooking bananas
– AA wild and edible types
– BB wild types
AAA-EAHBABB AAA BB wild
AA
AAB

Classification
• Height of pseudostem:
– Giant (≥3m, >40 leaves), Medium (2.1-2.9m, 32-40 leaves), Small
(≤2m, <32 foliage leaves)
• Inflorescence type (plantains):
– French, False horn, Horn
French HornFalse horn

Growth Cycle
Vegetative phase - leaf emergence
Two phases of development; Vegetative and reproductive phase

Growth Cycle
Reproductive phase - bunch emergence

Morphology (rhizome)
Rhizome (or corm) - true stem of the plant, has extremely short
internodes covered by closely packed leaf scars, differentiated into
central cylinder and cortex, ground tissue is starchy parenchyma.
It is a storage organ sustaining growth of the bunch, and
developing suckers. The terminal growing point (meristem) is a
flattened dome from which leaves are formed and later becomes
the inflorescence. The root system is adventitious and mostly
confined to the upper 40cm of the soil. Roots originate in groups of
3-4 from the corm as primary roots branching off to secondary and
then tertiary roots.
It is important for the rhizome
to remain completely below
the surface of the soil. A
phenomenon known as high
mat arises when the rhizome
is ‘climbing out’ of the soil
resulting to plant instability
and yield decline due to
exposure of roots.

Morphology (suckers)
Suckers - lateral outgrowths from vegetative buds
found on the rhizome opposite the leaf base.
Propagation is by suckers and four different types
of suckers are distinguished;
Peeper - small sucker which has just emerged
through the soil
Sword sucker - narrow leaves and a broad rhizome
base; ideal type of planting material
Water sucker - broad leaves, smaller rhizome and
weaker connection to mother plant; not ideal as
planting material.
Maiden sucker - full grown sucker bearing foliage
leaves
Several suckers are produced on the rhizome and
the whole unit or clump is known as a mat. When
a sucker is planted and the first bunch is harvested
this is known as the plant crop. After harvest, the
mother plant is cut down and a follower or
daughter sucker is selected to produce the second
harvest: first ratoon, the third harvest: second
ratoon and so on. Water sucker
Peeper
Sword
sucker
Maiden sucker

Morphology (Pseudostem and foliage)
Pseudostem - looks like a stem or a trunk, formed by overlapping
leaf sheaths, serves as a vascular connection between leaves, roots
and fruits. Pseudostem height, aspect and colour are used to
distinguish between varieties.
The distal end of the elongating leaf contracts into a narrow
petiole which continues into the leaf becoming the mid rib. The
mid rib divides the blade into two lamina halves with pinnately
arranged parallel leaf veins. The lamina develops inside the
pseudostem as a rolled cylinder (cigar leaf) and unfolds after
emergence. Older leaves senesce and die and new leaves emerge
every 7-10 days. The final leaf to emerge is a smaller flag leaf
which curves to protect the emerging inflorescence.
Scale leaves are first produced from the central meristem of developing suckers
followed by narrow sword leaves and then broad leaves with wider laminae
and finally full-sized leaves by 6 months.

Morphology (Inflorescence)
• inflorescence is a complex spike with a stout
peduncle on which flowers are arranged in
nodal clusters.
• each node comprises two rows of flowers
subtended by a bract which protects the
young flowers.
• flowers are predominantly unisexual, the
plant monoecious and dichogamous
• proximal nodes bear female flowers (about
5-18)
• distal nodes contain male flowers tightly
enclosed in bracts which form a conical
structure (male bud).
• hermaphrodite, or neutral flowers, may be
present on the rachis (stalk between the
female flowers and the male bud).
• peduncle elongates as flowers open in
sequence.

Question
What do you understand by
- monoecious?
- dichogamous?
Is selfing possible in banana?

Morphology (flowers)
Male flowers have a
smaller ovary, slender
style, 5 stamens with long
anthers that may or may
not produce pollen.
Female flowers have an inferior elongated
trilocular ovary with 3 fused carpels bearing
6 petal (5 free and 1 fused) surrounding a
thick style and non-functional staminodes
Ovaries of female flowers later become the
fruit or finger.
Female flower Male flower

Morphology (bunch)
• The ovaries of the female flowers develop into
seedless fruits by pathenocarpy.
• Aborted ovules are seen as small brown flecks in
centre of fruit.
• Nodal clusters of rows of female flowers is the
hand and individual fruits developed from female
flower is the finger.
• Number of hands per bunch and fingers per hand
is determined at flower initiation by the no. of
female flowers produced influenced by; genome
group, crop cycle, temperature, plant vigour, level
of management.
• Bunch position, appearance and shape are used to
distinguish varieties.
• Weight of bunch is taken at harvest to determine
yield.
• Other post-harvest traits – no. of hands, finger
length, finger circumference, peel/pulp ratio, pulp
color/texture, dry matter content, nutrient
content.

Question
What are the major constraints to
increased banana production?

Propagation principle
• A well developed plantain plant
has a corm with clumps of
meristems of different ages and
stages of development.
• Beside the main apical meristem,
there are several lateral
meristems found opposite the
bases of the leaf sheaths
• When the apical meristem is
destroyed lateral buds develop
from lateral meristems on corms.
• Principle employed for
macropropagation and field
decapitation techniques for clean
planting material production

Micropropagation
Sword suckers Explant preparation
Shoot tip initiation
Establishment and proliferation
Multiple bud formationRooted plantlets
Shoot tip culture

Micropropagation
Micropropagation
• Over 1000 plantlets from a single
plant in a year
• Disease-free planting material
• Uniform planting material;
synchronized harvests
• Faster field establishment with
higher yields
• Planting material can be obtained all
year round
Conventional propagation
• Only 5-10 suckers from single plant
in a year
• Often infected planting material
• Non-uniform planting material;
staggered harvests
• Slower field establishment with
lower yields
• Limited availability of planting
material

Nematode
Weevil
PestsDiseases
Biotic Constraints
Black Sigatoka
Bunchy top disease

Breeding objectives
- Taste and consumer acceptability
- High and stable yields
- Disease and pest resistance (black sigatoka, nematode,
weevil)
- Short stature
- Earliness

Breeding bottlenecks
- Low reproductive fertility
- Parthenocarpy
- Triploidy
- Slow propagation
- Large space requirement (6m2/plant)
- Long generation time (about 2 years from
seed to seed)

Breeding scheme
3x landrace X 2x wild or improved
4x hybrid X 2x wild or improved
3x secondary triploid
2x doubling
(oryzalin)
Several black Sigatoka resistant PITA and BITA hybrids
developed and are being distributed for testing.

Breeding PITAs
•
3x landrace
OL
2x wild
PL
3x landrace
BT 2x wild
C4
4x hybrid
1658-4
(PITA 7)
2x hybrid
2829-62
3x hybrid – 23688-2
(PITA 21)

Pollination - bagging
Male parentFemale parent

Pollination
male flowers
female flowers
7.30-10.30am

Question
Why do we pollinate at 7.30 – 10.30 am?

Ripening and seed extraction

Embryo culture
embryo extraction
embryo germination
bud proliferationroot development
acclimatization

Evaluation
Source: Pillay & Tenkouano 2011

References and further reading
1. IPGRI-INIBAP/CIRAD Descriptors for banana (Musa spp.)
1996.
2. Pillay M. and Tenkouano A. eds. Banana breeding: progress
and challenges. CRC Press, 2011.
3. Robinson J. C. and Galán Saúco V. Bananas and plantains.
Vol. 19. Cabi, 2010.
4. Swennen R. Plantain cultivation under West Africa
conditions: A reference manual. IITA, 1990.
5. Swennen R. and Ortiz R. Morphology and growth of
plantain and banana. IITA, 1997.

Thank you.

The Banana Plant: Morphology, Propagation and Breeding

Empfohlen

Empfohlen

Weitere ähnliche Inhalte

Was ist angesagt?

Was ist angesagt? (20)

Andere mochten auch

Andere mochten auch (20)

Ähnlich wie The Banana Plant: Morphology, Propagation and Breeding

Ähnlich wie The Banana Plant: Morphology, Propagation and Breeding (20)

Mehr von International Institute of Tropical Agriculture

Mehr von International Institute of Tropical Agriculture (20)

Kürzlich hochgeladen

Kürzlich hochgeladen (20)

The Banana Plant: Morphology, Propagation and Breeding