Variation in the tissue water relations of two sympatric Hawaiian Dubautia species and their natural hybrid
At one site of sympatry on the Island of Hawaii, Dubautia ciliolata and D. scabra are restricted to different lava flows, even though individuals of the two species may be found growing within a few meters of one another. Associated with this habitat difference is a difference in the tissue water deficits experienced by these two species. Midday water potentials in D. ciliolata are typically 0.4–0.5 MPa lower than in D. scabra.
These two species also exhibit significant differences in their tissue osmotic and elastic properties. Dubautia ciliolata exhibits a lower tissue osmotic potential at full hydration and a lower tissue elastic modulus near full hydration than D. scabra. As a result, high and positive tissue turgor pressures are maintained to significantly lower tissue water contents and water potentials in D. ciliolata than in D. scabra. These differences in tissue osmotic and elastic properties appear to have a marked influence on diurnal turgor maintenance. Thus, while diurnal water potentials in D. ciliolata are significantly lower than in D. scabra, the diurnal turgor pressures exhibited by these two species are very similar.
The natural hybrid between D. ciliolata and D. scabra exhibits intermediate tissue osmotic and elastic properties. This is evident, in particular, for the turgor dependence of the elastic modulus.
The degree of phenotypic variation in the tissue osmotic and elastic properties of D. ciliolata appears to be relatively limited. As a result, plants of D. ciliolata growing under both well-watered conditions in the glasshouse and under natural conditions in the field exhibit a large capacity for maintaining high turgor pressures as tissue water content decreases.
KeywordsWater Potential Elastic Property Natural Hybrid Turgor Pressure Tissue Water
Unable to display preview. Download preview PDF.
- Acevedo E, Ferres E, Hsiao TC, Henderson DW (1979) Diurnal growth trends, water potential, and osmotic adjustment of maize and sorghum leaves in the field. Plant Physiol 64:476–480Google Scholar
- Bradford KJ, Hsiao TC (1982) Physiological responses to moderate water stress. In: Lange OL, Nobel PS, Osmond CB, Ziegler H (eds) Encyclopedia of Plant Physiology (New Series) Vol 12B. Springer, Berlin, pp 263–324Google Scholar
- Bunce JA (1977) Leaf elongation in relation to leaf water potential in soybean. J Exp Bot 28:156–161Google Scholar
- Calkin HW, Pearcy RW (1984) Seasonal progressions of tissue and cell water relations parameters in evergreen and deciduous perennials. Plant Cell Env 7:347–352Google Scholar
- Carr GD, Kyhos DW (1981) Adaptive radiation in the Hawaiian silversword alliance (Compositae-Madiinae). I. Cytogenetics of spontaneous hybrids. Evolution 35:543–556Google Scholar
- Cutler JM, Shahan KW, Steponkus PL (1980) Alteration of the internal water relations of rice in response to drought hardening. Crop Sci 20:307–310Google Scholar
- Ehleringer J (1983) Ecophysiology of Amaranthus palmeri, a sonoran desert summer annual. Oecologia (Berlin) 57:107–112Google Scholar
- Henson IE, Mahalakshmi V, Bidinger FR, Alagarswamy G (1982) Osmotic adjustment to water stress in pearl millet (Pennisetum americanum (L.) Leeke) under field conditions. Plant Cell Env 5:147–154Google Scholar
- Hsiao TC, Acevedo E, Fereres E, Henderson DW (1976) Water stress, growth, and osmotic adjustment. Phil Trans R Soc Lond B 273:479–500Google Scholar
- Jones MM, Rawson HM (1979) Influence of rate of development of leaf water deficits upon photosynthesis, leaf conductance, water use efficiency, and osmotic potential in sorghum. Physiol Plant 45:103–111Google Scholar
- Jones MM, Turner NC (1980) Osmotic adjustment in expanding and fully expanded leaves of sunflower in response to water deficits. Aust J Plant Physiol 7:181–192Google Scholar
- Jones MM, Turner NC, Osmond CB (1981) Mechanisms of drought resistance. In: Paleg LG, Aspinall D (eds) The Physiology and Biochemistry of Drought Resistance in Plants. Academic Press, New York, pp 15–37Google Scholar
- Ludlow MM (1980) Adaptive significance of stomatal responses to water stress. In: Turner NC, Kramer PJ (eds) Adaptation of Plants to Water and High Temperature Stress. John Wiley & Sons, New York, pp 123–138Google Scholar
- Melkonian J, Wolfe J, Steponkus PL (1982) Determination of the volumetric modulus of elasticity of wheat leaves by pressure-volume relations and the effect of drought conditioning. Crop Sci 22:116–123Google Scholar
- Monson RK, Smith SD (1982) Seasonal water potential components of sonoran Desert plants. Ecology 63:113–123Google Scholar
- Osonubi O, Davies WJ (1981) Root growth and water relations of oak and birch seedlings. Oecologia (Berlin) 51:343–350Google Scholar
- Parker WC, Pallardy SG, Hinckley TM, Teskey RO (1982) Seasonal changes in tissue water relations of three woody species of the Quercus-Carya forest type. Ecology 63:1259–1267Google Scholar
- Passioura JB (1982) Water in the soil-plant-atmosphere continuum. In: Lange OL, Nobel PS, Osmond CB, Ziegler H (eds) Encyclopedia of Plant Physiology (New Series) Vol 12B. Springer, Berlin, pp 5–33Google Scholar
- Richter H (1976) The water status in the plant — experimental evidence. In: Lange OL, Kappen L, Schulze E-D (eds) Water and Plant Life. Springer, Berlin, pp 42–58Google Scholar
- Roberts SW, Strain BR, Knoerr KR (1980) Seasonal patterns of leaf water relations in four co-occurring forest tree species: parameters from pressure-volume curves. Oecologia (Berlin) 46:330–337Google Scholar
- Schulze E-D, Hall AE (1982) Stomatal responses, water loss, and CO2 assimilation rates of plants in contrasting environments. In: Lange OL, Nobel PS, Osmond CB, Ziegler H (eds) Encyclopedia of Plant Physiology (New Series) Vol 12B. Springer, Berlin, pp 181–230Google Scholar
- Takami S, Turner NC, Rawson HM (1981) Leaf expansion of four sunflower (Helianthus annuus L.) cultivars in relation to water deficits. I. Patterns durint plant development. Plant Cell Env 4:399–407Google Scholar
- Takami S, Turner NC, Rawson HM (1982) Leaf expansion of four sunflower (Helianthus annuus L.) cultivars in relation to water deficits. II. Diurnal patterns during stress and recovery. Plant Cell Env 5:279–286Google Scholar
- Turner NC, Jones MM (1980) Turgor maintenance by osmotic adjustment: a review and evaluation. In: Turner NC, Kramer PJ (eds) Adaptation of Plants to Water and High Temperature Stress. John Wiley & Sons, New York, pp 87–103Google Scholar
- Turner NC, Begg JE, Tonnet ML (1978) Osmotic adjustment of sorghum and sunflower crops in response to water deficits and its influence on the water potential at which stomata close. Aust J Plant Physiol 5:597–608Google Scholar
- Tyree MT, Jarvis PG (1982) Water in tissues and cells. In: Lange OL, Nobel PS, Osmond CB, Ziegler H (eds) Encyclopedia of Plant Physiology (New Series) Vol 12B. Springer, Berlin, pp 35–77Google Scholar
- Wilson JR, Ludlow MM (1983) Time trends for change in osmotic adjustment and water relations of leaves of Cenchrus ciliaris during and after water stress. Aust J Plant Physiol 10:15–24Google Scholar
- Wilson JR, Ludlow MM, Fisher MJ, Schulze E-D (1980) Adaptation to water stress of the leaf water relations of four tropical forage species. Aust J Plant Physiol 7:207–220Google Scholar
- Zimmermann U (1978) Physics of turgor- and osmoregulation. Ann Rev Plant Physiol 29:121–148Google Scholar