Genetic male sterility (GMS) is a plant's inability to produce functional pollen grains, which is controlled by nuclear genes. There are several types of GMS including temperature sensitive (TGMS), photoperiod sensitive (PGMS), and transgenic GMS. TGMS and PGMS lines exhibit male sterility above or below certain temperature or photoperiod thresholds. Transgenic GMS uses foreign genes like Barnase/Barstar to induce sterility. GMS has been utilized for hybrid seed production in crops like rice, pigeonpea, tomato, and chilli by developing male sterile (A) and maintainer (B) lines. The XYZ system was also proposed for hybrid wheat production using alien chromosomes

1. GENETIC MALE STERILITY IN
CROP PLANTS AND THEIR
COMMERCIAL EXPLOITATION
ADITHYA P BALAKRISHNAN
04-AGRMA-01724-2018
M. Sc (Agri)
Dept. of Genetics and Plant Breeding
C. P. C. A, S. D. A. U

2. INTRODUCTION
Male Sterility :
Inability of a plant to produce functional male gametes or pollen
grains.
Kaul’s (1998) classification based on phenotypic expression:
1. Structural Male Sterility
2. Sporogenous Male Sterility
3. Functional Male Sterility

3. Capsicum annum

4. Types of Male Sterility
On the basis of genetic control mechanisms:
TGMS
1. Genetic Male Sterility (GMS) PGMS
TrGMS
2. Cytoplasmic Male Sterility (CMS)
3. Cytoplasmic - Genetic Male Sterility
4. Chemically Induced Male Sterility

5. Genetic Male Sterility (Nuclear male sterility)
 Controlled by nuclear factors and independent of cytoplasmic
influences.
 Usually, governed by a single recessive gene (ms).
Exception: Safflower
 Several different ‘ms’ genes act monogenically.
Eg: Maize – 70, Tomato – 64, Barley – 57 etc.
 Have two types of lines: A line (ms), B line (Maintainer line).

6. Sources of GMS / ‘ms’ Gene
 Spontaneous Mutation
(Upland Cotton, Barley, Rice, Sweet pea etc.)
 Induced Mutation
Interspecific Crosses
Crops Mutagens
Petunia, Tagetes erecta X ray
Tomato, Watermelon Gamma ray
Pepper, pea, Jowar Colchicine
Groundnut Ethidium Bromide
Barley Acetone

7. Site of action of ‘ms’ alleles:
 It is time, site, stage and sex-specific.
 ‘ms’ may affect the stages like staminal initiation, stamen or anther sac
development, micro sporangial differentiation, PMC formation, pre-
meiotic events, meiotic events, pollen maturation, liberation, etc.
Molecular mechanism of ‘ms’ alleles:
 Not clearly understood.

8. Inheritance of GMS

9. Maintenance of GMS

10. TYPES OF GMS:
1. Temperature sensitive GMS
 TGMS is heritable and regulated by temperature.
 Complete male sterility is achieved by a temperature above critical temperature.
 Normal fertility shown below the critical temperature.
Eg:- 23.3⁰ C for rice line Pei-Ai645
UPRI 95-140, UPRI 95-165 of rice (spontaneous mutation)
Stages sensitive to temperature: From formation of PMC’s to meiosis in rice.
 Used in China to develop hybrid rice.

11.  Eliminates need of B line for multiplication.
 No need of fertility restoration.
 TGMS is preferable to PGMS.
Line Origin Temperature range for
male fertility
Annong-1s Spontaneous mutation 27⁰C
Hennong S Hybridization < 29⁰C
5460S Irradiation < 29⁰C
SM-38 Spontaneous mutation < 22⁰C
SM-5 Spontaneous mutation < 22⁰C
JP-2 Spontaneous mutation < 26⁰C
JP-38S Spontaneous mutation > 30.5⁰C (Reverse ms)
TGMS lines from rice(indica)

12. 2. Photoperiod sensitive GMS
 ‘ms’ gene expression affected by photoperiod provided temperature is within
critical range (eg:- 23-29⁰C in rice).
 Stages sensitive to PGMS: From differentiation of secondary rachis branches to
formation of PMC’s).
Line Origin Conditions for ms
Nongken 58S Spontaneous mutation Day-length <13.75 hrs
X 88 Hybridization Day-length <13 hrs
MG 201 EMS mutagenesis Day-length 12 hrs
PGMS lines of japonica rice

13. HYBRID RICE

14. 3. Transgenic GMS
 Induction of male sterility by incorporation of foreign genes into plants by r-
DNA technology.
Eg:- 1.) Barnase/Barstar system in Tobacco and Brassica napus (now
available in maize, cauliflower, tomato, wheat, chicory).
Barnase gene: from B. amyloliquifaciens & encodes an Rnase to degrade
tapetum cells, driven by TA29 promoter.
Barstar gene: from B. amyloliquifaciens & encodes a protein to inhibit Barnase
Rnase.
Barnase-bar: Male sterile, Phosphothricine resistant
Barstar/Barnase-bar: Male fertile

15. Barnase/barstar system

16. 2.) GM Mustard by Delhi University scientists
Developed by centre for genetic manipulation of crop plants Delhi University
Bar gene: From Streptomyces hygroscopicicus
30% yield advantage over check ‘Varuna’ (reported in bio-safety research level
field trials between 2014-15)
Varuna X Early Heera-2
DMH-11
(Dhara Mustard Hybrid)
(Barnase line) (Barstar line)

17. 3.) Antisense construct technology of Bcp1 gene in B. campestris
Bcp1 gene: Encodes protein essential for normal pollen development
It is not expressed in presence of antisense construct
driven by pollen specific LAT promoter.
Linked with hormone-inducer enhancer sequence.
Benefits: ms line is self-maintainable
Restorer line isn’t required
Used in hybrid seed production of B.oleraceae

18. Utilization of GMS in Plant Breeding
 Pigeon pea Hybrid ICPH 8 (ICPH 82008)
• First commercial hybrid in a pulse crop
• Developed in ICRISAT, Hyderabad particularly for central zone of
India.
ms Prabhat (DT) X ICPL 161
ICPH-8

19. Characteristics of ICPH-8:
High yield potential (41% over
control cultivar UPAS 120)
Vigorous growth
Matures in 115-135 days
Wide adaptation
Drought tolerance
 Other public sector hybrids by GMS:
ICPH-4, CoH 1, CoH 2, AKPH 4104, AKPH
2022

20.  XYZ System of Hybrid Seed Production in Wheat (Driscoll, 1972)
•The male sterility ‘ms’ gene is recessive and present on wheat chromosome.
• The corresponding male fertility gene ‘MS’ present on homologous chromosome derived
from related species (Rye) and it is linked with marker gene for “Hairy peduncle”.
• The lines X, Y and Z: Homozygous for male sterility factor
Contains 2, 1 and 0 doses of alien chromosomes respectively
• XYZ system’s practical application is still awaited.

21. XYZ system
• Z plant: Male sterile,
bears hybrid seed
• X and Y: For
production of female
parent of hybrid

22.  Tomato: GMS has been used for a limited extend for hybrid
production
 Chilli: Line ‘Ms12’ has GMS allele ms-509 (induced
mutagenesis) which is being used for hybrid seed production in
India, Korea and Hungary.
 Castor: Used for hybrid production in USA

23. Merits and Demerits of GMS
MERITS
 Used for hybrid seed production
in seed & vegetative propagated
crops.
Less labour and area
requirement
DEMERITS
 Less stable
50 percent plants are fertile
which have to remove every year
thereby increase in cost.

24. References
 B. D. Singh, (9th edition). (2013). Plant breeding principles and methods, 86-
93.
 Aligane, A. (2015). Male sterility systems in major field crops & their potential
role in crop improvement. Plant biology & biotechnology, (1). 6-25.
Pigeon pea hybrid ICPH 8 (ICPH 82008)- ICRISAT Plant material description
no.4 (1993)