presentation on the use of genetic male sterility in hybrid seed production of maize and millet.

1. Pir Mehr Ali Shah
Arid Agriculture University Rawalpindi
Department of Plant Breeding & Genetics
Supervisor: Dr. Fahad Masoud Wattoo
Presented By:
Muhammad Hassan Asadi
20-ARID-3018
PBG-506 Breeding Maize & Millet 1

2. Use of Genetic Male Sterility in Hybrid Seed
Development of Maize & Millet
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3. Genetic Male Sterility
Genetic Male
Sterility
Male reproductive development
is impaired due to underlying
genetic causes
Leads to the
malformation of male
gametes and/or pollen
Used to produce hybrid
seeds without pollens.
Ideal tool to accelerate
hybrid breeding.
Controlled by some
nuclear genes.
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4. Features
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Mainly governed by a monogenic, recessive gene but rarely
oligogenic, dominant.
A line:
• male sterile line
• used as a female parent
• homozygous recessive
B line:
• male fertile line
• used to maintain male sterility in A
(maintainer line).
• heterozygous dominant.
Consists of three types of lines:
R line:
• restorer line
• homozygous dominant

5. Inheritance Pattern
♀ mm (male sterile) X ♂ MM (male fertile)
F1 Mm (male fertile)
intercross of selfing
F2 mm Mm MM
25% homozygous sterile 50% heterozygous fertile 25% homozygous fertile
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6. Types
Temperature-sensitive
Genetic Male Sterility
(TGMS)
Photoperiod-sensitive
genetic male sterility
(PGMS)
Transgenic Genetic
Male Sterility
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7. Advantages & Disadvantages
Advantages Disadvantages
• Less stable due to GMS affected
by environmental factors like
temperature and day length
conditions.
• Increases production cost of
hybrid seed production because
50% of fertile plants are removed
yearly.
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• Fertility restoration in the hybrid
and crossing plans is relatively
easy.
• Use in both seed-propagated and
vegetative-propagated crops.
• Less area and labor because
maintain only two lines.
• Does not have undesirable
agronomic characteristics.

8. Utilization In Breeding Program
Eliminate emasculation in hybridization
Increase natural cross-pollination in self-pollinated crops
Facilitate commercial hybrid seed production
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9. Cytoplasmic Male Sterility
Line A Line B
X
R Line
X
Hybrid
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rr
s F
rr
s
rr
F or S
RR
F
Rr

10. GMS in Maize
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Identify parental
lines (P1, P2)
Introduce male
sterility in P1 line
Develop restorer
line (Rf) for male
sterility
Cross P1
(CMS/GMS) with
Rf Restorer Line
F1 Generation:
Male-Fertile
Hybrid (P1 x Rf)
Development
Identify Superior
F1 Hybrids
Conduct Hybrid
Vigor Testing
Produce Hybrid
Seeds
Commercialize
Hybrid Seed
Product

11. CMS in Maize
CMS-T (Texas) (Rogers and Edwardson,
1952)
CMS-C (Charrua) (Beckett, 1971)
CMS-S (USDA) (Jones,1957)
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12. CMS-T (Texas)
Discovered in the
1940s.
Used extensively
throughout the 1960s.
Highly stable under
all environmental
conditions.
Characterized by the
failure of anther
exertion and pollen
abortion.
Plants bearing the T
cytoplasm-
susceptible to race T
of the southern corn
leaf blight.
Widespread use of T-
cytoplasm for hybrid
corn production led to an
epidemic in 1970 with
the widespread rise of
Race T.
Toxin produced
by C.
heterostrophus =
T-toxin
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13. GMS in Millets
Millet crops use the
cytoplasmic-genetic
male sterility system
Caused by an interaction
of the sterility-inducing
factors in the cytoplasm
with the genetic factors
in the nucleus.
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14. Scheme CGMS in Millet
A X B
A X R
F1
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Male sterile parent line Maintainer line
Restorer line
Pollen (cross)
Pollen (cross)

15. Layout of Plot
Maintenance Field Hybrid Seed Production Field
isolation
1:1 A & B Rows 4:2 A & R Rows
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Harvest of B-line
gives B seed
Harvest of A-line
gives A seed
Harvest of A-line
gives hybrid seed
Harvest of R-line
gives R seed

16. Example of CMS Lines
A1
CMS
line in
pearl
millet
Tift
23A
CMS
line in
pearl
millet
ICMA
89111
CMS
line in
finger
millet
CMS-
1 lines
in
proso
millet
S
CMS
and A
CMS
in
foxtail
millet
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17. Conclusion
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In conclusion, genetic male sterility has revolutionized the
hybrid seed production of maize and millet. This technology
offers numerous advantages, including increased efficiency,
improved crop performance, simplified seed production
processes, and enhanced sustainability. By harnessing the
power of GMS, we can meet the ever-growing demand for
food and contribute to global food security in a more efficient
and environmentally friendly manner.

18. Thank you for your time and attention, and
I hope you have found this presentation
informative and engaging .
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