Plant Reproduction
System
PLANT REPRODUCTION SYSTEM
 The
reproduction mechanism of a
particular plant species or the way
it reproduces determines
its
genetic characteristics
the breeding approach.
1. SEXUAL REPRODUCTION
Using sex organs to form
next generation / to produce
seeds.

1. SEXUAL REPRODUCTION (CONT.)
Important steps:
1.
2.
3.
Production of gametes (gametogenesis)
Pollination – Transfer of pollen from
anther (male organ) to the stigma
(female organ).
Fertilization – The union of male and
female gametes to produce new
genotypes.
POLLINATION
 Transfer
of pollen from anther
(male organ) to the stigma
(female organ).

Two kinds of pollination,
 Self
pollination
 Cross pollination
SELF POLLINATION
Transfer
of pollen from
anther to stigma of the
same flower / plant
SELF POLLINATION
Natural
mechanisms that
encourages self pollination:
1.

Cleistogamy
Pollination happens when
flower is still closed.
Example: Rice
SELF POLLINATION (CONT.)
2.


Stigma protected by
anther
Anthesis and pollination
occur instantaneously
once the flower blooms.
Many pollen are
produced, covering the
stigma, hence
preventing pollination by
pollen from outside.
Example: lime, tomato
and chilli
Chilli flower
SELF POLLINATION (CONT.)
3. Stigma and anther
protected by other parts of
flower.
 Male (stamen) and
female (pistil) organs
covered by keel, i.e. two
fused petals.

Example: Leguminosae
family, sub-family
Papilionoideae.
CROSS POLLINATION
Transfer
of pollen from
anther to stigma of flower of
different plant.
CROSS POLLINATION(CONT.)
 Natural
mechanisms to
promote cross pollination:
1.
Dieocious
Male
and female flowers are
formed on different plants.
 Have male and female
plants.

Example: Papaya, salak
Male salak flower
Female salak flower
CROSS POLLINATION(CONT.)
2. Monoecious
 Male
and female
flowers are in
separate positions
on the same plant
but mature at
slightly different
times.

Example: Oil palm, corn
and rubber.
CROSS POLLINATION(CONT.)
3. Dichogamy
Anther and stigma from
hemaphrodite flower or
flower of monoecious
plant mature at different
times.
Protogyne
Stigma (female flower)
matures before anther (male
flower).
Example: Potato, cassava
and cashew.

Protogyne:
Potato flower
CROSS POLLINATION(CONT.)
3. Dichogamy (cont.)
Protandry
Anther (male flower)
matures before stigma
(female flower).
Example: Starfruit and
rubber.

Protandry: Starfruit
flower
CROSS POLLINATION(CONT.)
4. Self-incompatibility
Pollens are unable to fertilize
ovule (female gamete) of the
same flower/plant due to
genetic factor (self
incompatibility gene)
Example: Potato, passion fruit and
starfruit.
CROSS
POLLINATION(CONT.)
In some species, there are more than
one mechanism to promote cross
pollination:
1. Rubber and corn: monoecious and
protandry.
2. Potato, Sweet potato: Selfincompatibility and protogyne
3. Starfruit & passion fruit: Selfincompatibility and protandry

METHODS TO DETERMINE
MODES OF POLLINATION
1. Identify flower formation system.
2. Isolate plants.
No fruit/seed  cross pollinated
Fruit set/seed set  self pollinated and
possibly cross pollinated
3. Selfing.
To observe the effects of inbreeding.
Present  cross pollinated.
Absent / minimal  self pollinated.
2. ASEXUAL REPRODUCTION

Does not involve sex or union
of male and female gametes.
Mechanisms:1. Vegetative reproduction
2. Apomixis
VEGETATIVE REPRODUCTION
o
o
o
o
o
o
Stem/branch/root cuttings 
e.g. cassava
Grafting  e.g. rubber,
rambutan & durian
Rhizome  e.g. tumeric &
ginger
Stolon  e.g. grass
Tuber  e.g. potato & sweet
potato
Tiller  e.g. pineapple ,
sugarcane & banana
APOMIXIS
Formation
of seeds without
union of gametes, i.e.
fertilization.
APOMIXIS (CONT.)

Apogamy – Embryo formation from synergids or
antipodals
APOMIXIS (CONT.)

Apospory Embryo develops
from somatic cell such as
nucellus and integument.

Diplospory Embryo develops
from megasporocyte.

Adventitious embryo Embryo
develops directly from nucellus
and integument cells without
involving embryo sac cells.

Parthenogenesis Embryo
develops from unfertilized eggs.
APOMIXIS (CONT.)
Obligate apomixis
1.


Apomixis reproduction
is the main method of
reproduction.
Example: mangosteen
2. Facultative
apomixis
 Both apomixis and
sexual reproduction
occur.
 Example: Guinea
grass (Panicum
maximum), Citrus
sp.
CHARACTERISTICS OF CROSS
POLLINATED, SELF POLLINATED AND
ASEXUAL PLANTS
Characteristic
Cross
pollinated
Self pollinated Asexual
Population
Heterogeneous
Homogeneous
Homogeneous
Genotype
Heterozygous
Homozygous
Heterozygous
Gamete
Different
Similar
Different
Progeny
Different &
heterozygous
Similar &
homozygous
Similar &
heterozygous
Inbreeding
depression
Present
Absent
Present
Incompatibility Present
Absent
Present