Abstract
Berseem clover (Trifolium alexandrinum L.) is an important crop in semi-arid regions; its herbage and seed yields are often reduced by water stress. Our objectives were (i) to determine the effect of water stress, applied after a conditioning period, on water relations, proline accumulation and plant dry weight, and (ii) to investigate if some physiological responses differed in varieties of berseem. Five cultivars (Axi, Bigbee, Lilibeo, Sacromonte and Saniros) were grown in a controlled environment, and subjected to four irrigation treatments (T1, T2, T3 and T4 referring to plants irrigated to field capacity every 1, 2, 3 or 4 d, respectively) during a conditioning period (12 d). T1 treatment indicated the well-watered control, whereas T2, T3 and T4 treatments represented the conditioned plants. Leaf water potential (Ψ), osmotic potential (Ψπ), relative water content (RWC), gravimetric soil water content (GSWC) and leaf proline concentration were recorded during the conditioning period and a subsequent water deficit period (3 d) applied at early flowering growth stage. The conditioned plants subjected to subsequent water deficit maintained higher values of Ψ, Ψπ, RWC and GSWC, and lower values of leaf proline concentration. Reductions in parameter values were inversely related to the water stress severity that plants had previously experienced. At the end of the experiment, T1 showed 42%, 58% and 31% lower values for Ψ, Ψπ and RWC, respectively, than those of T4. Conditioned plants were also shorter and accumulated less leaf, stem and total dry weight. The conditioning treatments did not affect the relation between Ψ and Ψπ since conditioned plants show similar values of Ψπ as the control at the same Ψ value. Thus, drought acclimation in berseem clover contributed to water stress tolerance by the maintenance of tissue hydration. The berseem cultivars examined showed differences in plant growth parameters, but they were very similar for physiological responses to water deficit. The main genetic difference was recorded for turgor maintenance capacity.
Similar content being viewed by others
References
Barker D J, Caradus J R and McManus M T 1993 Physiological responses of white clover genotypes to water deficit. In Proc. 17th Int. Grassl. Congress, Vol. 1, 8-21 February 1993. pp. 67–68. Palmerston North, New Zealand.
Bates L S, Waldren R P and Teare I D 1973 Rapid determination of free proline for water-stress studies. Plant Soil. 39, 205–207.
Blum A and Ebercon A 1976 Genotypic responses in sorghum to drought stress. III. Free proline accumulation and drought resistance. Crop Sci. 16, 428–431.
Brown KW, Jordan WR and Thomas J C 1976 Water stress induced alterations of the stomatal response to decreases in leaf water potential. Physiol. Plant. 37, 1–5.
Cosgrove D J and Cleland R E 1983 Solutes in the free space of growing stem tissue. Plant Physiol. 72, 326–331.
Cutler J M and Rains D W 1978 Effects of water stress and hardening on the internal water relations and osmotic constituents of cotton leaves. Physiol. Plant. 42, 261–268.
Dale J E 1988 The control of leaf expansion. Ann. Rev. Plant Physiol. 39, 267–295.
Hanson A D 1980 Interpreting the metabolic responses of plants to water stress. HortScience 15, 623–629.
Hsiao T C 1973 Plant responses to water stress. Ann. Rev. Plant Physiol. 24, 519–570.
Iannucci A and Martiniello P 1998 Analysis of seed yield and yield components in four Mediterranean annual clovers. Field Crops Res. 55, 235–243.
Irigoyen J J, Emerich D W and Sánchez-Díaz M 1992 Water stress induced changes in concentrations of proline and total soluble sugars in nodulated alfalfa (Medicago sativa) plants. Physiol. Plant. 84, 55–60.
Johnson K L and Raguse C A 1985 Comparative effects of repeated cycles of water stress on growth and apparent dinitrogen fixation of Ladino and strawberry clovers. Crop Sci. 25, 299–306.
Joly R J and Zaerr J R 1987 Alteration of cell-wall water content and elasticity in Douglas-Fir during periods of water deficit. Plant Physiol. 83, 418–422.
Kimani P M, Benzioni A and Ventura M 1994 Genetic variation in pigeonpea (Cajanus cajan (L.) Mill sp.) in response to successive cycles of water stress. Plant Soil 158, 193–201.
Kramer P J 1983 Cell water relations. In Water Relations of Plants. Ed. PJ Kramer. pp 25–26. Academic Press, Oxford.
Levitt J 1972 Responses of plants to environmental stresses. Academic Press, New York.
Ludlow M M and Muchow R C 1990 A critical evaluation of traits for improving crop yield in water-limited environments. Adv. Agron. 43, 107–153.
Martiniello P and Ciola A 1995 Dry matter and seed yield of Mediterranean annual legume species. Agron. J. 87, 985–993.
Medrano H, Aguilo F and Socias F X 1992 Effect of drought on subterranean clover. 1. Leaf water relations of plants subjected to rapid or slowly-induced drought. Photosynthetica 27, 413–419.
Medrano H, Grau D and Tekle Z 1995 Osmotic potential changes in response to soil drying in subterranean clover leaves. In Proc. 2nd Stressnet Conference, 21-23 September 1995. pp. 149–154. Salsomaggiore, Italy.
Morgan J M 1980 Differences in adaptation to water stress within crop species. In Adaptation of Plants to Water and High Temperature Stress. Eds. NC Turner and PJ Kramer. pp 370–382. Wiley and Sons, New York.
Naidu B P, Aspinall D and Paleg L G 1992 Variability in prolineaccumulating ability of barley (Hordeum vulgare L.) cultivars induced by vapor pressure deficit. Plant Physiol. 98, 716–722.
Navari-Izzo F, Quartacci M F and Izzo R 1990 Water-stress induced changes in protein and free amino acids in field-grown maize and sunflower. Plant Physiol. Biochem. 28, 531–537.
Rhodes D 1987 Metabolic responses to stress. In The Biochemistry of Plants. Eds. PK Stumpf and J Priess. Vol. 12, pp 201–241. Academic Press, San Diego.
Singh T N, Aspinall D and Paleg L G 1972 Proline accumulation and varietal adaptability to drought in barley: a potential metabolic measure of drought resistance. Nature 236, 188–190.
Socias F X and Medrano H 1994 Drought acclimation in field growing subterraneum clover plants. Agronomie 2, 141–148.
Turner N C and Jones M M 1980 Turgor maintenance by osmotic adjustment: A review and evaluation. In Adaptation of Plants to Water and High Temperature Stress. Eds. NC Turner and PJ Kramer. pp 87–103. Wiley and Sons, New York.
Tyree M T and Jarvis P G 1982 Water in tissues and cells. In Encyclopedia of Plant Physiology, New Series, Vol. 12B. Eds.OL Lange, PS Nobel, CB Osmond and M Ziegler. pp 36–77. Springer-Verlag, Berlin.
Rights and permissions
About this article
Cite this article
Iannucci, A., Rascio, A., Russo, M. et al. Physiological responses to water stress following a conditioning period in berseem clover. Plant and Soil 223, 219–229 (2000). https://doi.org/10.1023/A:1004842927653
Issue Date:
DOI: https://doi.org/10.1023/A:1004842927653