2. MALE STERILITY
• It refers to a condition in which pollen is
either absent or nonfunctional in
flowering plants
• First reported in flowering plants by
Koelreuter in 1763
• It prevent autogamy and promote
allogamy
3. FEATURES OF MALE STERILITY
• Important outbreeding device
• Lead to heterozygousity
• Reduce homozygousity
• Due to action of cytoplasmic gene and
nuclear gene
• Caused due to pollen or anther abortion
4. Classification of male sterility
Kaul (1988) classified male sterility in three
major groups
1. Phenotypic male sterility
2. Genotypic male sterility
Genetic male sterility
Cytoplasmic male sterility
Cytoplasmic genetic male sterility
3. Chemical male sterility
5. PHYNOTYPIC CLASS OF STERILITY
• POLLEN STERILITY
Extreme scarcity of functional pollen grains
• STRUCTURAL MALE STERILITY
In which male flower or stamen are
malformed and nonfunctional
• FUNCTIONAL MALE STERILITY
In which perfectly good and viable pollen is
trapped in indehiscent anther and prevented
from functioning
6. GENETIC MALE STERILITY
• POLLEN sterility caused by nuclear
genes
• Mostly governed by single recessive
gene (ms) but dominant gene
governing male sterility(safflower)
• ORIGION: spontaneous mutation or
both chemical and physical mutagens
• In this system seed parent (msms)
maintainer(MSms) and
pollinator(MSMS)are used
7.
8. CYTOLOGICAL CHANGE
• Breakdown in microsporogenesis can
occur at a number of pre or post
meiotic stage
• The abnormalities can involve
aberration during the process of
meiosis, in the formation of tetrad,
during release of tetrad,
9. Types of Genetic Male Sterility
• ENVIROMENNT INSENSTIVE
• ENVIROMENT SENSTIVE
• TGMS(thermo genetic male sterility)
• Sterility at high particular temperature
• PGMS(photo genetic male sterility)
• Sterility obtained in long day condition
10. Merits & Demerits
• Used for production of
hybrid seed in both seed
and vegetative
propagated species.
• Require less labor and
area.
• Less stable as it become
fertile at low
temperature.
• 50% plants are fertile
which have to be
removed every year
which increase the cost of
hybrid
11. CYTOPLASMIC MALE STERILITY
• Determined by the cytoplasmic gene
• Result of mutation in mitochondrial genome (mt
DNA)which lead to mitochondrial dysfunction
• F1 seed produced only male sterile plant because
their cytoplasm come from female gamete only.
• CMS is maternally inherited
• A mitochondrial gene disrupt pollen development
• Male fertile line (maintainer B line)used to
maintain the male sterile line(A line)
12.
13. Merits & Demerits
• Highly stable and is not
influenced by
environmental condition
like temperature and day
length.
• Require less area.
• Not use where seed is
the economic product
• Used only in asexually
propagated species
14. CYTOPLASMIC GENETIC MALE
STERILITY
• Pollen sterility controlled by both
cytoplasmic and nuclear gene
• The fertility restorer gene R dominant
• It include A, B, R ,line which are male
sterile, male fertile, and restorer line
respectfully
• It is used in commercial production of
hybrid seed in maize, rice, bajra, wheat
,sunflower
15.
16. Merits & Demerits
• Widely used for hybrid
seed production in both
seed and vegetative
propagated species
• Highly stable and
reliable
• Not affected by
environment factors
• It require more area and
labor
• Some time CGMS line
have inferior agronomic
performance
17. CHEMICAL INDUCED MALE
STERILITY(CHA)
• Many chemicals effect function of male reproductive
organ in plants Gametocides
• CHA
• It can be done when different hormones such as
NAA, IAA ,are sprayed on plants .
• Some of the male .gametocides
used are ,sodium methyl arsenate, gibberellin,
maleic hydrazide
18. USED IN CROP IMPROVMENT
Genetic male sterility can be used for the
development of commercial hybrid seed
and vegetative propagated crops and fruit
set crops EX_ sunflower, tomato ,wheat,
maize, watermelon
Cytoplasmic male sterility is useful for the
development of hybrid of ornamental
plants EX-onion, cabbage, sorghum
Cytoplasmic genetic male sterility is
useful for the commercial production of
hybrid EX-sunflower, bajra, rice, wheat,
