Effect of Terminal Water Stress on Grain Yield and Morpho-physiological Traits of Aegilops triuncialis Ecotypes

Document Type : Research Article

Authors

• Z Taghipour ¹
• R Asghary- zakaria ²

¹ Mohaghegh Ardabili University

² University of Mohaghegh Ardabili

10.22067/gsc.v17i3.70592

Abstract

Introduction
Drought stress is the most important and common environmental stress that annually bring huge damage to crops in the world and especially in Iran, which is considered as an arid and semi-arid country. Nowadays, most plants breeding plans for resistance against drought and preparing resistant species are to achieve favorable yield in arid environments and are based on recognizing morpho-physiological and biochemical traits and involved genes and transforming them to cultivars. There is a genetic diversity regarding resistance against aridity among Aegilops species that can be used to improve resistance against aridity in wheat during different stages of reproduction and plant growth.
Materials and Methods
This investigation was performed in green house of Agricultural Faculty in University of Mohaghegh Ardabili on 2011 in order to survey the effects of aridity stress and study the traits related to resistance in eight ecotypes of Aegilops triuncialis (ecotypes of Maku, Marand, Hashtrud, Namin, Hurand, Karaj, Meshkin and Ahar). The experiment was performed in three replications as factorial and based on completely randomized design. Different stages of irrigation including full irrigation as control, cutting of irrigation from booting (T1), (zadoks stage 45) and from 50% spike emergence (T2) (zadoks stage 55) to maturity were considered as water stress levels. Studied morphological traits include plant height (cm), plant dry weight (g), peduncle length (cm), spike length (cm), number of grains in spike, weight of grains per spike (g), 100 grain weight (g), spike dry weigh (g), root length and root mass. Chlorophyll content was measured by SPAD-502 machine. In order to measure fluorescence content of chlorophyll, OSI 30 machine of ADC Bioscietific Company and to measure stomatal conductance leaf porometer (SC-1 model) were used. Data analysis was performed by SAS ver.9.1 software and cutting was done in case of significant interactive effect. Mean comparison was done by Lsmeans test at probability level of 5%.
Results and Discussion
Water stress decreased all evaluated traits especially grain yield (89%). Water stress condition, by damaging photosynthesis system, reduced photochemical efficiency of PS II and chlorophyll index. Stomatal conductance rate reduced by 46% at booting stage and 55% at spike emergence and also decreased relative water content by 26% compared to normal circumstances. Although drought stress application in the experiment decreased grain yield in ecotypes compared to no stress conditions, some ecotypes like Hashtrud, Hurand and Maku could resist stress conditions and showed less grain yield decrease in comparison to the others. Ecotypes of Hashtrud, Marand, Meshkin could supply their necessary moisture from deep soil by increasing their root length. Ecotypes with higher ratio of Fv/Fm and less chlorophyll index decrease under stress condition could have less grain yield decrease. It seems that superiority of Hashtrud, Hurand and Maku ecotypes in stress conditions compared to other ecotypes could be due to these characteristics.
Conclusions
Terminal drought results in reduced growth period, length, peduncle length, main panicle length and also reduced grain yield. Drought stress by damaging photosynthesis system and decreased photosynthesis and chlorophyll and limiting photosynthesis allocations of grains under stress condition decreases their weight and finally their yield.

Keywords

• Drought stress
• Fluorescence chlorophyll
• grain yield
• stomatal conductance

20.1001.1.20081472.1398.17.3.5.7

---

References

1. Ahmadi, A., and Baker, D. A. 2001. The effect of water stress on grain filling processes in wheat. Journal Agriculture Science 136: 257-269.

2. Baalbaki, R., Hajj-Hassan, N., and Zurayk, R. 2006. Aegilops species from semiarid areas of Lebanon: Variation in quantitative attributes under water stress. Crop Science 46: 799-806.

3. Damania, A. B., Hakim, S., and Moualla, M. Y. 1992. Evaluation of variation in Triticum dicoccum for wheat improvement in stress environments. Hereditas 116: 163-166.

4. Dulai, S., Molnar, I., Pronay, J., Csernak, A., Tarnai, R., and Molnar-Lang, M. 2006. Effects of drought on photosynthetic parameters and heat stability of PSII in wheat and Aegilops species originating from dry habitats. Acta Biologica Szegediensis 50 (1-2): 11-17.

5. Flexas, L., and Medrano, H. 2002. Drought-inhibition of photosynthesis in C3 plant: Stomatal and non-stomatal limitation revisited. Annales Botanici Fennci 89: 183-189.

6. Gautam, P. P., Fritz Allan, K., Kirkham, M. B. K., and Gill, B. 2011. Response of Aegilops species to drought stress during reproductive stages of development. Fundamental for Life: Soil, Crop & Environmental Sciences. Internatinal Annual Meetings 16-19.

7. Gill, B. S., Friebe, B., Raupp, W. J., Wilson, D. L., Stan, C. T., Sears, R. G., Brown-Guedira, G. L., and Fritz, A. K. 2006. Wheat genetics resource center: the first 25 years. Advances in Agronomy 89: 73-136.

8. Gooding, M. J., Ellis, R. H., Shewry, P. R., and Schofield, J. D. 2003. Effects of restricted water availability and increased temperature on grain filling, drying and quality of water wheat. Journal of Cereal Science 37: 295-309.

9. Innes, P., Hoogendoorn, J., and Blackwell, R. D. 1985. Effects of difference in date of early emergence and height on yield of winter Wheat. Journal of Agricultural Science 105: 543-549.

10. Ji, X., Shiran, B., Wan, J., Lewis, D. C., Jenkins, C. L. D., Condon, A. G., Richards, R. A., and Dolferus, R. 2010. Importance of pre-anthesis anther sink strength for maintenance of grain number during reproductive stage water stress in wheat. Plant Cell and Environment 33: 926-942.

11. Liu, J. X., Liao, D. Q., Oane, R., Estenor, L., Yang, X. E., Li, Z. C., and Bennett, J. 2006. Genetic variation in the sensitivity of anther dehiscence to drought stress in rice. Field Crops Research 97: 87-100.

12. Liu, H. S., Li, F. M., and Xu, H. 2004. Deficiency of water can enhance root respiration rate of drought-sensitive but not drought-tolerance spring wheat. Agricultural water management 64 (1): 41-48.

13. Mitra, J. 2001. Genetics and genetic improvement of drought resistance in crop plant. Current Science 80: 758-763.

14. Moaveni, P., and Pazoki, A. 2010. Investigation of proline changes, cytoplasmic membrane stability, yield and root length in four wheat cultivars under drought stress conditions. Plant and ecosystem 6 (21): 59-72. (in Persian).

15. Molnar, I., Gaspar, L., Sarvari, E., Dulai, S., Hoffmann, B., Molnar-Lang, M., and Galiba, G. 2004. Physiological and morphological responses to water stress in Aegilops biuncialis and Triticum aestivum genotypes with differing tolerance to drought. Functional Plant Biology 31: 1149-1159.

16. Paknejad, F., Majidi heravan, E., Noor mohammadi, Qh., Siyadat, A., and Vazan, S. 2007. Effects of drought stress on chlorophyll fluorescence parameters, chlorophyll content and grain yield of wheat cultivars American Journal of Biochemistry and Biotechnology 5 (4): 162-169.

17. Pierre, C. S., Petersona, J., Rossa, A., Ohma, J., Verhoerena, M., Larsona, M., and Hoefera, B. 2008. White wheat grain quality changes with genotype, nitrogen fertilization, and water stress. Journal of Agronomy Science 100 (2): 414-420.

18. Rampino, P., Pataleo, S., Gerardi, C., Mita, G., and Perrotta, C. 2006. Drought stress response in wheat: Physiological and molecular analysis of resistant and sensitive genotypes. Plant Cell and Environment 29 (12): 2143-2152.

19. Riaz, R., and Chowdhry, M. A. 2003. Genetic analysis of some economic traits of wheat under drought condition. Australian Journal of Plant Science 2 (10): 790-796.

20. Royo, C., Aparicio, N., Blanco, R., and Villegas, D. 2004. Leaf and green area development of durum wheat genotypes grown under Mediterranean conditions. European Journal of Agronomy 69: 231-233.

21. Royo, C., Alvaro, F., Martos, V., Ramdani, A., Isidro, J., Villegas, D., and Garcia del Mortel, L. F. 2006. Genetic changes in durum wheat yield components and associated traits in Italian and Spanish varieties during the 20th century. Euphytica 155: 259-270.

22. Sabagh pour, S. H. 2003. Mechanism of plant tolerance. Journal of Dry and Saeson Dry 13: 21-32. (in Persian).

23. Safaee chaeekar, S., Rabiee, B., Sami zaheh, H., and Esfahani, M. 2008. Evaluation of tolerance to terminal drought stress in rice (Oryza sativa L.) genotypes. Iranian Journal of Crop Sciences 9 (4): 315-331. (in Persian).

24. Schlemmer. M. R., Francis, D. D., Shanahan, J. F., and Schepers, J. S. 2005. Remotely measuring chlorophyll content in corn leaves with differing nitrogen levels and relative water content. Agronomy Journal 97: 106-112.

25. Van Slageren, M. W. 1994. Wild wheats: a monograph of Aegilops L. and Amblyopyrum (jaub. and Spach) Eig (poaceae). Wageningen Agricultural University. Wageningen, the Netherland pp: 94-107.

26. Wang, G., Miyashita, N. T., and Tsunewaki, K. 1997. Plasmon analysis of Triticum (wheat) and Aegilops: PCR-single-strand conformational polymorphism (PCR-SSCR) analyses of organellar DNAs. Proceeding of National Academy Sciences of the USA 94: 570-577.

27. Zhang, J., and Davies, W. J. 1989. Abscisic acid produced in dehydrating roots may Enable the plant to measure the water status of the soil. Plant, Cell and Environment 12 (1): 73-81.

28. Wade, L. J., Kamoshita, A., Yamauchi, A., and Azhiri-Sigari, T. 2000. Genotypic variation in response of lowland rice to drought and rewatering. I. Growth and water use. Plant Production Science 3 (2): 173-179.