chromosom

1. Male Sterility :- Origin , Induction
and Application
Presented by…
Patel Hasti G.
Botany CBO -403
M.Sc. Sem 1
Department of Life Science
HNGU Patan

2. content
Introduction of Extra chromosomal
Inheritance
Male sterility :-
Introduction
Types of Male Sterility
Origin of Male Sterility
Induction of Male Sterility
Application of Male Sterility
Reference

3. Introduction of Extra Chromosomal
Inheritance
 Extra Chromosomal Inheritance is defined as non
mendelian inheritance, usually involving DNA in
replicating mitocondria and some other organelles of
cell.
 The genes that have been called cytoplasmic genes,
extra chromosomal genes, or extra nuclear genes are
located on a unique kind of chromosome inside
cytoplasmic organelle.
 Commonly defined as transmission through the
cytoplasm rather then the nucleus.

4. Male sterility
 Introduction
 Male sterility is the failure of plants to produce
functional anthers pollen or male gametes.
 Male sterility refers to either absence of pollen grain
or if present it is non functional.
 A male sterile plant can not pollinate other plants or
itself.
 Most of higher species are hermaphroditic and male
sterility is often considered as an accident of
development.

5. Types of Male Sterility
 There are two types of male sterile situations as follow:
1] Phenotypic Male sterility
 Structural male sterility
 Pollen Male sterility
 Functional Male sterility
2] Genotypic Male Sterility
 Genetic Male sterility
 Cytoplasmic Male Sterility
 Cytoplasmic Genetic Male Sterility

6. 1. Phenotypic Male sterility
 Structural Male Sterility: in which male flowers or
stamen are malformed and non functional or
completely absent.
 Pollen Sterility: in which male sterile individuals differ
from normal only in the absence or extreme scarcity of
functional pollen.
Functional Male Sterility: in which perfectly good and
viable pollen is trapped in indehiscent anther and thus
prevented from functioning.

7. 2. Genotypic Male Sterility
 There are three types of genotypic male sterility . It is
below:
A] Genetic Male sterility :
 It’s also called as nuclear male sterility.
 In this type of male sterility, the sterility is controlled
by a single nuclear gene which is recessive to fertility ,
so that the F1 progeny would be fertile and in F2
generation.
 The fertile and sterile individuals will be segregated I
the typical 3:1 ratio.

8. Genetic Male Sterility

9. B] Cytoplasmic Male Sterility
 The cytoplasm is the stuff
inside a cell wall in which
the cell nucleus floats
around in.
 When a plant sets seed,
some DNA from the mother
plants cytoplasm is carried
along.
 Cytoplasmic male sterility
is transmitted by this type
of DNA.
 If the mother cell was CMS,
the offspring will be also.

10. C] Cytoplacmic Genetic Male Sterility
 This is a CMS plant for
which exist genes this can
be introduced from
another plant which will
restore male sterility.
 This is great if you have
plant breeding facilities
and material to work with
but most of us farm scale
breeders probably don’t
have these resources.

11. Origin of Male Sterility
 Male Sterility individuals have arisen in nature under a
variety of circumstances that might perhaps be
considered as some of its regular sources.
 Frankal (1940) reported a rather high frequency of
male sterility occurring among the artificially inbred
populations of several species of Habe.
 Hayes et al. (1955) observed that a numbers of plants
with all maternal characteristics that have occurred in
the progeny tests of cross pollinated species, may have
resulted from apomictic reproduction.

12. Cont…
 Strasburger had originally put forth hypothesis that
male sterility may be a direct cause of the origin of
apomictic behaviour in some species.

13. Induction of Male Sterility
 Male sterility was determined in green house and field
grown wheat sprayed with 2- chloroethylphosphonic
acid.
 Plant treated with 500 ppm in pre-boot and boot stages
of development produced significantly fewer seeds per
spike compared with untreated spikes.
 Side effects were minimal except at higher
concentration in which poor spike emergence and plant
dwarfing were observed.

14. Application of Male Sterility
 Eliminate emasculation in hybridization.
 Increase natural cross pollination in self pollinated
species.
 Controlled pollination by maize plants.
 Facilitate commercial hybrid reproduction.

15. References
 Cell Biology, Genetics, Molecular Biology, Evolution
and Ecology
By Varma P S and Agarwal
 Male sterility in Flowering plants
By S K jain
 www.Male Sterility in Plants.com