Cotton breeding and various traits and mechanisms which act against drought

1. BREEDING FOR DROUGHT
TOLERANCE IN COTTON

2. Contents
1- Introduction
2- What is Drought?
3- Mechanism of
Drought Tolerance
4- Basis of Drought
Tolerance
5- Sources of Drought
Tolerance
6- Breeding Methods
7- Conclusion
8- Future Thrust

3. Introduction
 Genus Gossypium
 Common name Kapas
 Family Malvaceae
 Chromosome number (2n) 26, 52
 Cultivated species 4
Diploiad (2n=26)
Gossypium herbaceum
Gossypium arboreum
Tetraploid (2n=52)
Gossypium hirsutum
Gossypium barbadense
 Wild species 46

4. 1 2 3 4
Pakistan ranked 4th in the world with the production of 10.07
million cotton bales annually .
One cotton bale = 170 kg
(Pakistan Economic Survey, 2015-2016)

5. What is Drought?
Agricultural Drought
Physiological Drought
Hydrological Drought
Socio-economic Drought

7. (IPCC report, West Africa, 2011)

9. Mechanism of Drought Tolerance
• Drought susceptible variety perform well
under drought environment simply by
avoiding the drought period.
Drought
Escape
• The ability of plant to maintain favorable
internal water balance under moisture stress
is referred as drought avoidance.
Drought
Avoidance
• It refers to the ability of crop plants to
withstand at low tissue water content.
Drought
Tolerance
George Acquaah, Principles of Plant
Genetics & Breeding

10. Basis of Drought Tolerance.
Morphological Basis
Earliness
Early maturing varieties are ready for harvest before the onset of Drought.
Stomatal characters
Small sized
Less number per unit area
Rapid closing nature stomata
Adaxial stomata are more sensitive to water stress than abaxial stomata.
(Singh, 2004)

11. Leaf characters
Thick waxy cuticle
Small and thick leaves
Hairiness of leaves
(Singh et al., 2004)
Root characters
Root length and root density
Root to shot ratio
(Pace et al., 1999)
Growth habit
Indeterminate genotypes are suitable to Drought

12. Physiological Basis
• Higher rate of Photosynthesis.
• Lower rate of Transpiration.
• Higher leaf Turgidity.
(Hafeez et al., 2015), (Singh, 2004)

13. • Proline content
• Proline is an amino acid,
act as compatible solute
involved in cell osmotic
adjustment and protection
of cell components during
dehydration.
• (Zhang et al., 2009)
Biochemical
Basis

14. Sources of Drought Tolerance
Wild
Species
Land
Races
Cultivated
Varieties
Obsolete
Cultivars

15. Wild species
Diploid
(2n=26)
Gossypium harknessii
Gossypium aridum
Gossypium stocksii
Gossypium australe
Gossypium raimondii
Tetraploid
(2n=52)
Gossypium tomentosum
Gossypium darwinii
(Singh, 2004)

16. Land Races
Gossypium
hirsutum
Punctatum
Gossypium
arboreum
Sinense
Soudanense
Gossypium
harbaceum
Acerifolium
Persicum
Weightianum
(Singh, 2004)

17. Cultivated Varieties
149F, B-557, CIM-446 MNH-513
(Iqbal et al., 2011) (Shakoor et al., 2010)

18. Breeding Methods
Conventional
Introduction
Mass Selection
Pedigree Method
Backcross Method
Mutation Breeding
Non-
Conventional
Biotechnology

19. Conclusion
 Development of resistant varieties is most economical method for management of
drought.
 Biochemical, Physiological changes and structural modifications occur in resistant
plants which are responsible for drought resistance.
 Effectiveness of Breeding program is dependent on availability of germplasm,
efficient screening procedures, identification of adequate sources of resistance and
knowledge of inheritance.
 Traits related to drought tolerance are root length, root density, earliness, stomatal
conductance, small and thick leaves, photosynthesis rate, transpiration rate, Leaf
turgidity and proline accumulation.
 Wild species and Land races are good source of drought resistance.

20. Future Thrust
 Development of rapid and efficient screening method for drought resistance.
 Identification of new multiple resistance gene to incorporate resistance to drought.
 Research work is needed to transfer drought resistance traits from wild species to
cultivated species.
 Incorporation of gene through molecular breeding or marker assisted selection in
combination with conventional breeding methods.

21. References
Pakistan Economic Survey. 2015-2016. Govt. of Pakistan, Ministry of Finance,
Economic Advisor’s Wing, Islamabad.
Zhang, H., W. Liu, L. Wan, F. Li and L. Dai. 2010. Functional analyses of ethylene
response factor JERF3 with the aim of improving tolerance to drought and osmotic
stress in transgenic rice. Transgenic Res. 19: 809–818.
Singh, P. 2004. Cotton Breeding. 2nd Edi., Kalyani Publishers.New Delhi, India,
pp. 118.
Iqbal, K., F.M. Azhar, I.A. Khan and Ehsan-Ullah. 2011. Variability for drought
tolerance in cotton (Gossypium hirsutum) and its genetic basis. Int. J. Agric. Biol.,
13: 61–66.

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