Effect of heat stress on zea mays

1. Student Name : Maryam Noor
Registration Number : 2018-ag-3563
Supervisor : Dr. Muhammad Ahsan
Department : Botany
University of Agriculture Faisalabad
1

2. Effects of Heat Stress on Zea Mays
2

3. Topic Outline
o Introduction
o Stresses
o Effects of heat stress
o Tolerance
o References
3

4. Introduction of maize
o Zea mays
o Family : Poaceae
o Sub-family : panicoideae
o Queen of cereals
o chromosomes no 20 and 32,000 genes
o C4 crop
o Monoecious plant, 5% self-pollination and 95% cross-
pollination
o Two growth stages
4

5. Conti
o United State the largest producer of maize with production of 4096190
thousand million tons and Mexico yields 765545 thousand million tons
(FAO, 2012).
o Maize covers an area of nearly 1334 thousand hectares with an
average production of 6130 thousand tones and per hectare harvest is
4.60 tones in Pakistan (Govt. of Pakistan, 2017).
o It gives 0.5% to GDP (Govt of Pakistan., 2017)
o High nutritional value
o Used as foodstuff of humans and fodder of animals
5

6. Stresses
o Two types, biotic and abiotic stress
o Heat stress is the rise in temperature beyond a threshold level for
a period of time sufficient to cause irreversible damage to plant
growth and development.
o Reproductive stage is more sensitive
o Average optimum temperature 30-34°C
o Increase in temp by 2°C reduces yield by 13%
o At growth 8-10 °C , above 30 °C damaged cell division , 38 °C
Grain filling , pollen viability at 33 °C.
6

7. Effects
It effects on
o Growth and Development
o Morphological level
o Cellular level
o Molecular and Genetic level
o Physiological and Biochemical level
o Anatomical level
Akbar (2009)
7

8. Morphological level
o Reduction in cell size
o Stunted growth
o Sunburn on leaves
o Reduction in Turgor
Pressure
o Less grain yield
Lizso (2016)
8

9. Cellular level
o Direct injuries
o Indirect injuries
o Enzyme inactivation
o Loss of membrane integrity
9

10. Molecular and
Genetic level
o Cell membrane
thermostability
o Change genetics of
plant
o Hormonal changes
o Accumulation of
compatible Osmolytes
o Production of ROS
10

11. Physiological and
Biochemical
o Stomatal closure
o High transpiration
o Less respiration
o Less photosynthesis
o Opened flowers
abortion during
reproduction
Jhanska (2010)
11

12. Anatomical
level
o Protein activity loses
o Enzymes inactivation
o Leaf tissues died
o Lowers amount of
ATP production
o Lowers level of CO2
inside plant
12

13. Summary of effects of Heat stress on Zea mays
o Inhibition of seed germination
o Reduction of plant growth
o Improper development
o Alteration in photosynthesis
o Alteration in phenology
o Loss in dry matter
o Yield reduction
o Reduction of crop quality
13

14. Tolerance Mechanisms 14

15. Achievements for Heat Stress
o 57 experiment on 7760 genotypes for the screening of maize for
heat stress
o CAH151 9.2 ton per hec
o CAH153 8.9 ton per hec
o Rampur Hybrid-10 8.79 ton
o Rampur Hybrid-8 9.18 ton
o 900M Gold 8.4 ton
o 30V92 8.3 ton
15

16. References
o Akbar M. Saleem M. Ashraf M. Y. Husain A. Azhar F. M. Ahmad R. (2009)
Combining ability studies for physiological and grain yield traits in maize at two
temperature regimes. Pakistan Journal of Botany, 41(4): 1817-1829.
o FAO STAT. Food and Agriculture organization. 2013.
o Janska, A.; Marsik, P.; Zelenkova, S.; Ovesna, J. Cold stress and acclimation:
What is important for metabolic adjustment? Plant Biol. 2010, 12, 395–405.
o Lizaso, J.I., Rodríguez, L., Ruiz-Ramos, M., Gabaldón-Leal, C., Oliveira, J.A.,
Lorite, I.J., 2016. Improving CSM-IXIM maize model in DSSAT to simulated the
impact of elevated temperatures. In: International Crop Modelling Symposium
iCropM, 15–17 March 2016, Berlin, Germany.
16