1) Male sterility and self-incompatibility are mechanisms used in hybrid seed production to reduce manual labor costs and increase yields. 2) Male sterility is caused by genetic or cytoplasmic factors and prevents pollen development, while self-incompatibility prevents self-pollination. 3) These mechanisms allow for the large-scale production of F1 hybrid seeds by using male sterile plants as the female parent and maintaining parent lines.

1. WELCOME
1

2. Role of breeder
2
• D - distinctness • U - uniformity
• S - stability
• V - variability

3. • New gene combination
• Heterosis
• Adopt to different climate
• Better chance for evolution
• Conserving some valuable genes
3
All these helps in…

4. Natural variations by
Spontaneous Mutation
Out crossing
Sexual reproduction in asexual plants
polyploidy breeding
MALE STERILITY
SELF INCOMPATIBILITY
4

5. opic :- MALE STERILITY AND
F INCOMPATIBILITY IN PLA

6. Why Male Sterility and Self
Incompatibility ? ? ?
• Reduce the cost of hybrid production.
• Production of large scale of F1 seeds.
• Avoid enormous manual work of emasculation and
pollination.
• Speed up the hybridisation programme.
• Commercial exploitation of hybrid vigour.
6

7. Male sterility in plants
7

8. Introduction :- pollens are absent or non functional.
First reported by
Koelreuter(1763)
8

9. Phenotypic expression of male sterility
(Kaul,1998)
stages of expression
• Absence, atrophy or malfunction of male sex organ.
• Lack of normal anther sac or anther tissues.
• Inability of the pollen to mature or to be released from
anther sac.
• Inability to develop normal microspores or pollen.
9

10. Structural male sterility
notypic expression is grouped into 3 cla
Sporogenous male sterility
Functional male sterility
10

11. Structural male sterility
Stamens absent, malformed, modified into floral parts.
11

12. Sporogenous male sterility
Normal stamen but abnormal microsporogenous tissue.
12

13. Functional male sterility
Pollen develop normally but function is impaired.
13

14. Genetic male sterility
Types of male sterility in plants
Cytoplasmic male sterility
Cytoplasmic genetic male sterility
Transgenic male sterility
Chemically induced male sterility
14

15. Genetic male sterility
• Governed by single recessive gene(ms ms).
• Also know as nuclear male sterility.
• Controlled by the action of specific gene(s) in the
nucleus.ms ms = male sterile (it is functionally a female
plant).
• Ms_ = male fertile (normal).
15

16. ms ms × Ms Ms
Ms ms
1Ms Ms, 2 Ms ms, 1 ms ms
(male fertile)
(male fertile)(male sterile)
male fertile male sterile
Inheritance of male sterility
16
⊕

17. Origin - majority of the ms allele arisen due to
spontaneous mutation and it can also be induced
artificially.
17

18. Site of action
Staminal initiation, stamen or anther development,
microsporangial differentiation, PMS formation, pre
meiotic events, tetrad formation , microspore liberation,
microspore development and maturation, pollen
liberation, anther sac dehiscence.
ms allele may act at more than one developmental stage
18

19. Types of genetic male sterility
Environment sensitive Environment in-sensitive
Photoperiod sensitive
Temperature sensitive (ex, 23.3°C - Paddy)
(ex, 13hrs 45 mins- paddy)
19

20. Utilisation
• These lines are used in hybrid seed production in crops
having seed as economic part.
• The progeny of ms ms × Ms ms are used as female
parent.
• Genotype of ms ms and Ms ms is homozygous except
for fertility(isogenic).
• ms ms line acts as A line (male sterile).
20

21. • Ms ms line acts as B line (maintainer line).
• The male fertile line in female line is identified and
removed before pollen shedding.
• This is done in seedling stage either due to the pleiotropic
effect of ms gene or due to the phenotypic effect of a
closely linked gene.
• For ex, in tomato ms line is closely linked with recessive
gene for anthocyanin production in vegetative part.
21

22. Maintenance of genetic male sterile line
• It is maintained by crossing the male sterile line with
heterozygous male fertile.
• 50% of the population is male fertile and other 50% is
male sterile.
• Half of the population are eliminated.
22

23. Cytoplasmic male sterility
• Male sterility is determined by cytoplasm.
• CMS is the result of mutation in the mitochondrial
genome.
rr
S
rr
F
male sterile male fertile
23

24. rr
S
rr
F
×
♂♀
rr
S
male sterile male fertile
male sterile
24

25. • Cytoplasmic male sterility is easily transferred to a given
strain by using that strain as the recurrent pollinator parent
in successive generations of back cross breeding.
25

26. rr
S
rr
F
male sterile male fertile×
♀ ♂
rr
SF1
A B
× rr
F
♂
rr
S
× rr
F
♂
F1 is sterile, 50%
nuclear genes is
from B
F1 BC1
repeated backcrosses26
75% of B genes

27. same procedure is repeated till F1BC6
at F1 BC6
rr
S
male sterile version of strain B
• >99% of the nuclear genes from strain B.
• maintained by crossing with male fertile strain B.
27

28. CMS line in some important vegetable crops
• Onion - CMS-S (alloplasmic)
CMS-T(mutant)
• Capsicum annum - mutant
28

29. Utilisation
• Used in hybrid production in certain ornamental or foliage
crop species having vegetative part as economic value.
29

30. cytoplasmic genetic male sterility
• For which a nuclear gene for restoring fertility in male
sterile is known.
• Restorer gene R is generally dominant.
• Also known as nucleo-plasmatic male sterility.
30

31. rr
S
× rr F rr
S
rr
S
× Rr
F/S
Rr
S
rr
S
× RR
F/S
Rr
S
rr
S
male sterile
male sterile
male sterile
male sterile
1 male sterile
male fertile
male fertile male fertile
male fertile 1 male fertile
Results from various matings
31

32. Utilisation
• It is extensively used in commercial hybrid seed production
many crops.
• Chilli male sterile line are MS1, MS2, MS3 and MS4.
• Onion - two independent systems; 1) Gene A, 2)Gene B
and C (complementary action)
32

33. A. Undesirable effects of the cytoplasm.
B. Unsatisfactory fertility restoration.
C. Unsatisfactory pollination.
D. Spontaneous reversion.
E. Modified genes.
F. Contribution of cytoplasm by sperm.
G. Environmental effects.
H. Non availability of suitable restorer gene.
Limitation of CGMS system
33

34. Transgenic male sterility
• Many transgene are shown to develop effective fertility
restoration systems.
• Barnase/Barstar system is a good example for this system
of Bacillus amyloliquefaciens.
34

35. Barnase-Bar/- × -/-
male sterile
phosphinotricin resistant
normal fertile
phosphinotricin sensitive
50% Barnase-Bar/-
male sterile
herbicide resistant
50% -/-
male fertile
herbicide sensitive
phosphinotricin spray (kill all fertile plants)
Barnase-Bar/- × Barstar/Barstar
male sterile male fertile(restorer line)
50% Barnase-Bar/Barstar
male fertile
(Barstar product inhibits Barnes RNase)
50% -/Barstar
male fertile
35

36. Chemically induced male sterility
• Many chemicals are know affect function of male
reproductive organs in plants.
• They are called by several names such as
male sterilant
male gametocides
pollen suppressant
pollenocides
androcides etc
36

37. • In 1985, McRae suggested the term chemical hybridising
agents (CHA’s).
• Induce non genetic male sterility.
• First report of this use by Moore and Naylor(1950) in
maize using Maleic Hydrazide (MH).
• In 1951, Laibach and Kribban reported α-NAA and β-IAA
increase the proportion of staminate flowers in cucumber.
37

38. Features of an ideal CHA
• Highly male and female selective.
• economical.
• Flexible time.
• should not be mutagenic.
• should not carried to F1.
• should cause 0% reduction in seed set.
• Eco friendly.
38

39. Important CHA’s used-
• Ethephon (ethrel)
• Mendok (FW450)
• Giberllic acid
• Maleic Hydrazide
• RH0007 (Hybrex)
• Shell

40. me important CHA’s used in vegetable breed
• Mendok(FW450) - chilli - affect female fertility, phytotoxin.
• Maleic Hydrazide - Onion - Phytotoxicity, flower
abscission.
40

41. hybrid seed production based on CHA’s
41
Advantages-
• Any line is used as male and female parent.
• Based on only 2 lines.
• No need to maintain restorer line.
• F2 is fully fertile.

42. Limitations
• Genotype, dose, and application stage specific.
• Chances for incomplete male sterility.
• Toxic to plants.
• Some may carry residues (ex, WL84811).
• Interfere with cell division (ex, RH531, RH532).
42

43. Self incompatibility in plants
43

44. • The prevention of fusion of fertile male and female gametes
after self pollination.
• Koelreuter first reported Self Incompatibility in mid 18th
century.
• The term was coined by Stout (1917).
• It is reported in more than 70 families of angiosperms.
44

45. Pollen grain fails to germinate on stigma
pollen tube fails to enter the stigma
slow growth of tube
embryo degenerate at early stage
SI can affect any of the stages above45

46. Classification of Self Incompatibility
(Lewis,1954)
Heteromorphic system Homomorphic system
Gametophytic control
Sporophytic control
46

47. Heteromorphic system
• Flowers of different incompatibility group are different in
morphology.
• Ex, in Primula there are 2 types of flowers, Pin and Thrum.
• Exhibit Distyly
Pin- long style and short stamen
Thrum - short style and long stamen
• compatible mating is between pin and thrum.
• It also reported in sweet potato and buckwheat.
• Tristyly is seen in Lythrum salicaria.
47

48. Distyly in Primula

49. Heterostyly in Brijal

50. Homomorphic system
• Most commonly found.
• No morphological difference among flowers.
• It is controlled by genotype of the plant on which it is produ
• SI is controlled by single complex locus S.
• More than one gene is involved in some cases.
50

51. Gametophytic system
• Described by East and Mangelsdorf in 1925 in Nicotiana
sandrae.
• Incompatibility reaction of pollen is determined by its own
genotype.
• This is because the biochemical substance involved in SI
reaction of the pollen is produced after meiosis.
51

52. Sporophytic system
• The Incompatibility reaction of pollen is governed by the
genotype of plant on which the pollen is produced.
• This type of SI was discovered by Huges and Babcock in
1950 in Cepris foetida.
• It is found in Raddish, Brassica crops etc.
52

53. Temporary suppression of Self
Incompatibility
Self- incompatibility is fully functional in the selfed progeny.
Such-fertility is known as pseudo fertility.

54. • Bud pollination - most practicable.
• Surgical techniques - removal of stigmatic surface.
• End-of-Season pollination - pollinating at end of flowering
season.
• High temperature - pistil upto 60°C.
• Increase CO2 concentration.
• High humidity.
• Salt spray - NaCl.
• Double pollination.
Some are Techniques. . . .

55. Elimination of Self Incompatibility
• In single gametophytic system, chromosome doubling can
be done.
• Isolation of self fertile mutations by irradiation.
• Self compatible allele can be transferred from other
varieties or related species.

56. male sterility and self incompatibility in hybr

57. Self Incompatibility
This system is confirmed in
• Kale (Thompson 1957)
• Radish (Simpson 1957)
• Broccoli (Samson 1957 and Odland 1962)
• Cabbage (Adamson 1965)
• Cauliflower (Hoser-Krauze 1979)

58. • Governed by single gene.
• Growth of incompatible pollen being arrested on the
stigma.
• It possess homomorphic sporadic self incompatibility.
• Inhibition of pollen germination at stigma surface.
• Pusa katki is having different S alleles: Sa, Sb, Sc, Sd.
• S allele is low expressive in heterozygous state.
Self Incompatibility in cauliflower

59. Steps in hybrid seed production
Selection of parent individually from an inbred population
but should be included with self incompatible line.
Ensures adequate cross compatible during F1 hybrid
production.
Once a suitable plant possessing the requisite sporophytic
SI is isolated and/or produce via plant breeding or other
means, it is maintained and multiplied via self pollination
as breeder or prebasic seed with at least one dominant
determinant being present in homozygous state.

60. Male sterility in chilli
• First reported by Martin and Grawford(1951) and Peterson
(1958).
• Nearly 20 genes of GMS is reported.
• Shifriss and Frankel named the first male sterile line as ms-
1 (spontaneous mutant).
• ms-2 from “California wonder”

61. According to morphological changes in
androecium, the male sterile mutant is
classified into 6 groups.
1. Androecium transformed into petaloid structure(ms-13)
2. shrivelled anthers devoid of pollen grains, including ms-l, ms
3. Anthers that are not reduced severely and contain a small am

62. 4. Shrunken anthers that release numerous aborted pollen grain
5. Anthers that appear to be normal, but pollen grains are sterile
6. Yellow anther lobes that are flattened laterally to give an app

63. Cytoplasmic male sterility (CMS):
• CMS in C. annuum was first studied by Peterson (1958).
• Showed that sterility was controlled by a major gene, ms.
• Daskalov (1974) identified a CMS mutant from the variety
‘Kalinkov 800/7’.
• Cytoplasmic male sterility has also been reported among
interspecific hybrids of C. baccatum and C. annuum.
• No adequate restorers have been found for this system.
• The presence of at least one dominant allele at both loci is
necessary to restore the pollen fertility in the plants with the
S cytoplasm.

65. Conclusion
• Hybrid technology offers tremendous potential for the much
needed second green revolution.
• Area expansion not possible thus need is to increase
production/unit area.
• Cost effective hybrid seed production (SI, MS) etc
65

66. Future prospects
• To fulfil the demand of vegetable in our country.
• To identify the stable SI and CMS lines.
• There is need to acquire deeper knowledge about these
two important mechanisms for developing location/
environment specific SI and MS lines
66

67. Reference
Singh, B.D, - Plant Breeding principles and Methods.
67
Vegetable Breeding
theory and practice.
Pradeep kumar T, Sadhan
kumar P G, Prasanna K P
-

68. 68
Presented by:-
Rakshith.M
Jr MSc Dept of CIB
COH, Mudigere