THE EFFECTS OF WATER STRESS ON MORPHOLOGICAL AND PHYSIOLOGICAL CHARACTERISTICS OF THE CEREALS

Öz

Water stress is the most important one of the several environmental factors affecting plants growth and development. The response of plants to stress depends on theirs genetic potential, stage of growth, morphology and yield potential and it causes important changes on morphological and physiological characteristics of the plants.

Root growth, root/shoot rate, the frequency of trichomes on leaf surfaces is increased, and a thick cuticle layer is formed by the effects of water stress on cereals. Transpiration, photosynthesis, protein synthesis, nitrate reduction activity and respiration decrease, abscisic acid (ABA) and ethylene production as a plant hormone, proline accumulation increase as a result of effect of water stress. Mechanisms such as stomatal closure or a reduction in leaf area, are effective in reducing water loss, but result in a loss in yield. Osmotic adjustment provides the potential for maintaining photosynthesis, as the water deficit increases.

Anahtar Kelimeler

• Water stress; cereals; morphological

TAHILLARDA SU STRESİNİN BİTKİ MORFOLOJİSİ VE FİZYOLOJİSİ ÜZERİNE ETKİLERİ

Öz

Su stresi, bitkilerin büyüme ve gelişmelerini etkileyen önemli çevre faktörlerinden birisidir. Bitkilerin su stresine karşı responsu, onların genetik potansiyeli, gelişme dönemi, morfolojisi ve verim potansiyeline bağlı olup, bitkilerin morfolojik ve fizyolojik yapılarında önemli değişmelere sebep olur.

Su stresinin etkisi ile tahıllarda kök gelişimi hızlanır, kökün gövdeye oranı artar. Su stresine karşı respons olarak bitkide yaprakların üzeri sık tüylerle kaplanır. Yaprakların üzerinde kalın kütiküla tabakası oluşur. Transprasyon ve fotosentez azalır. Bitki bünyesindeki hormonlardan absisik asit (ABA) ve etilen üretimi artar, protein metabolizması bozulur. Prolin birikimi artar, nitrat indirgenme aktivitesi ve solunum azalır. Stomaların kapanması ve yaprak alanında azalma, bitkiler tarafından su kaybının azaltılmasında önemli olan mekanizmalardır. Fakat, bu durum verimin azalmasına sebep olur. Osmotik düzenleme ise, artan su noksanlığına bağlı olarak, bitkilerde fotosentezin konulmasında bir potansiyel sağlar.

Anahtar Kelimeler

• Su stresi; tahıllar; morfoloji

Kaynakça

1. ACKERSON, RC. ve KRIEG, DR., 1977. Plant Physiology. 60: 850-53.
2. AEPLBAUM, A. and YANG. S.F., 1981. Biosynthesis of Stress Ethylene Induced by Water Deficit. Plant Physiol. 68: 594-596.
3. AKÇİN, A., 1990. Tarımsal Ekoloji. Ders Notları (Basılmamış). S. Ü.Ziraat Fakültesi, Konya.
4. AKÇİN, A., 1994. Bitki Büyüme ve Gelişmesine Etki Eden Hormonlar ve Etki Mekanizmaları. Yüksek Lisans Ders Notları (Basılmamış). S.Ü.Zir.Fak., Konya.
5. BARLOW, E.W.R.., MUNNS, N.S. and REISNER, A. H.1977. Water Potential,Growth and Polyribosome Content of The Stressed Wheat Apex. J.Exp.Bot. 28: 909-916.
6. BEGG, J.E. ve TURNER, N.C. 1976. Adv. Agron. 28:161-217.
7. BINGHAM, J., 1966. Varietal Respotise in Wheat to Water Supply in the Field and Male Sterilily Caused by A Period of Drought in a Glasshouse Experiment. Ann. Appt. Biol. 57: 365-377.
8. BLUM, A., MAYER, J. ve GOZLAND, G., 1983. Association Between Plant Production and The Some Physiologial Components of Drought Resistance in Wheat. Plant Cell Environ. 6:219- 225.

9. BOYER, J.S., 1970. Leaf Enlargement and Metabolic Rates in Corn, Soybean and Sunflower at Various Leaf Water Potentials. Plant Physiol. 46; 233-235.
10. DHINDSA, D.R. and CLELAND, R.E., 1975. Water Stress and Protein Synthesis II. Interaction Between Water Stress, Hydrostatic Pressure and Abscisic Acid on The Pattern of Protein Synthesis in Avena Coleoptiles. Plant Physiol. 55: 1899-1905.
11. DUNCAN, D.R. and WIDHOLM, J.M., 1987. Prolin Accumulation and Its Implication in Cold Tolerance of Regenerable Maize Callus. Plant Physiology. 83: 703-708.
12. FRANK, AB., POWER, J.F. and WILLIS, W.O., 1973. Effect of Temparature and Plant Water Stress on Photosynthesis Diffussion Resistance and Leaf Water Potential in Spring Wheat. Argon. J. 65: 777-780.
13. GAFF, D.F., 1980.Protoplasmic Tolerance of Extreme Water Stress. P. 207-230. In N.C. Turner and P.J. Kramer (ed.) Adaptation of Plants to Water and High Temperature Stress. John Wiley and Sons, New York.
14. GARDNER, P.C., PEARCE, R.B. ve MITCHELL, R.L. 1965. Physiology of Crop Plants. Iowa State University Press.
15. GORDON, L.K., ALEKSEEVA, V.Y., BICHURINA, GOLUBEV, A.I.,KASIHAPOVA, L.A.,CHERNYSH, O. O. and GERASIMOV, N.N., 1975 Changes of Respiratory Metabolism and Cell Ultrastructure in Roots of Wheat During Dehydration Soviet Plant Physial. (Engl. Transl) 22:804-808.
16. GÜRSOY, A.T. ve TURAN, Z.M., 1991. Kuraklığın Bitki Morfolojisi ve Fizyolojisi Üzerine Etkileri. Uludağ Univ. Zir. Fak. Derg.. 8; 189-199. Bursa.
17. GUSTA, L.V., BURKE, M.J. and KAPOOR, A. C., 1975. Determination of Unfrozen Water in Winter Cereals. Plant Phv. 56:707-709.
18. HSIAO, T.C. and BRADFORD, K..J.,1983. Physiological Consequences of Cellular Water Deficits. Limitations
19. to Efficient Water Use in Crop Production. P. 227-258. American Society of Agronomy. Inc. Wiskonsin. U.S.A.
20. HSIAO, T.C., 1973. Plant Responses to Water Stress. Ann. Rev. Plant Physiol. 24: 519-570.
21. JOHNSON, R.R., FREY, N.M. ve MOSS, d.n., 1974. Effect of Water Stress on Photosynthesis And Transpiration of Flag Leaves And Spikes of Barley and Wheat. Crop Sci. 14: 728-731.
22. LAWLOR, D.W., 1979. Effects of Water and Heat Stress on Carbon Metabolism of Plants With C3 and C4 Photosynthesis P.304-326. In. H. Mussel and R.C.Staples (ed.) Stress Physiology in Crop Plants. John Wiley and Sons, New York.
23. LEVITT, J., 1980. Responses of Plants to Enviromental Stress es. Academic Press. Inc (London) LID, pp. 607.
24. MAYORAL, M.L., ATSMON, D., SHIMSHI, D. and GROMET-ELHANON, Z., 1981. Effect of Water Stress on Enzyme Activities in Wheat and Related Wild Species. Carboxylase Activity, Electron Transport and Photophoshory in Isalated Chloroplasts. Aust. J.Plant Physiol 8.385-393.
25. McMICHAEL, B.L., JORDON, W.R. and POWELL, R.D., 1972. An Effect of Water Stress on Ethylene Production by Intact Cotton Petioles Plant Physiol. 49: 658-660.
26. MILBORROW, B.V., 1974. The Chemistry and Physiology of Abscisic Acid. Annu. Rev. Plant Physiol. 25: 259-307.
27. MORGAN, J.M., 1980. Osmotic Adjustment in The Spikelets and Leaves of Wheat. J.Exp.Bot. 31: 655/665.
28. MUNNS, R., BRADY, C.J. and BARLONV, EAV.R., 1979. Solute Accumulation in The Apex and Leaves of Wheat During Water Stress. Aust.J. Plant Physiol. 6: 379- 389.
29. PALEG, L.G. and ASPINALL, D., 1981. Physiology and Biochemistry of Drought Resistance in Plants. Academic Press, New York.
30. PEARCY, R.W., BERRY, J.A. and FORK, D. C., 1977. The Effects of Growth Temperature on The Thermal Stability of The Photosynthetic Apparatus of Atriplex Lentiformis (Torr.). Plant Physilo. 59: 873-878.
31. PHELOUNG, P. and BARLOW, E.W.R., 1981. Respiration and Carbonhydrate Accumulation in Water. Stressed Wheat Apex. J.Exp.Bot. 32:921-931.
32. QUARRIE, S.A. ve JONES, H.G., 1977. Effect of Abscisic Acid and Water Stress on Development and Morfology of Wheat. J.Exp. Bot. 28; 192-203.
33. QUARRIE, S. A., 1980. Genotypic Differences in Leaf Water Potential Abscisic Acid and Prolin Concentrations in Spring Wheat During Drought Stress. Ann. Bot. 46: 383-394.
34. QUATTAR, S., JONES, R.J. ve CROOKSON, R.K., 1987. Effect of Water Deficit During Grain Filling on the Pattern of Maize Kernel Growth and Development, Crop Science, 27(4): 617-846.
35. SADE, B., 1992. Tahıl Yetiştirme Fizyolojisi. Yüksek Lisans Ders Notlan (Basılmamış).S.Ü.Zir.Fak., Konya.
36. SAINI, H.S. ve ASPINAL, D., 1981. Effect of Water Deficit on Sporogenesis in Wheat (Triticum aestivum) Ann. Bot. 48: 623-644.
37. SHIMSHI, D., MAYORAL, M.L. ve ATSMON, D., 1982. Responses to Stress in Wheat and Related Wild Species Crop Sci. 22: 123-128.
38. STENVART, C.R. and HANSON, AD., 1980. Prolin Accumulation as a Metabolic Response to Water Stress, p. 173-189. INC C. Turner and P.J. Kramer (ed.) Adaptation of Plants to Water and High Temperature Stress. John Wiley and Sons. New York.
39. SUNG, F.J.M. and KRIEG, D.R., 1979.Relative Sensitivity of Photosynthetic Assimilation and Translocation of14 Carbon to Wtare Stress. Plant Physiol.. 64: 852-56.
40. TAL, M. and IMBER, D., 1974. Abnormal Stomatal Behaviour and Hormanal Imbalance in Flacca, a Wilty Mutant of Tomato: Effect of Abscisic Acid and Auxin on Stomatal Behaviour und Peroxidase Activity. J.Exp.Bot. 25: 51-60.
41. TURNER, N.C., 1979. Drought Resistance and Adaption to Water Deficits in Crop Plants. In Stress Physiology in Crop Plants. p. 343-372.
42. WALTON, D.C., 1980. Biochemistry and Physiology of Abscisic acid. Ann.Rev.Planl Physiol.31:453-489.
43. WARDLAW, I.FA., 1971. The Early Stages of Grain Development in Wheat: Response to Water Stress in a Single Variety. Aust.J. Biol.Sci. 24:1047-1055.
44. WRIGHT, S.T.C., 1977. The Relationship Between Leaf Water Potential and The Levels of Absisic Acid and Ethylene in Excised Wheat Leaves. Plantal, 134: 183-189.