Journal of Environmental Biology

Simulation of germination of pioneer species along an

experimental drought gradient

 

Mar?a A. P?rez-Fern?ndez^1,2, E. Calvo-Magro^3? and D. Ferrer-Cast?n⁴

¹Area de Ecolog?a, Universidad Pablo de Olavide, Carretera de Utrera, 41013 Sevilla, Spain

²Department of Environmental Biology, Curtin University, PO Box U1987 Perth WA 6845, Australia

³Area de Ecolog?a, Universidad de Extremadura, Avenida de Elvas s/n, 06071 Badajoz, Spain

⁴?rea de Ecolog?a, Universidad de Salamanca Campus Miguel de Unamuno, 37071, Salamanca, Spain

 

(Received: 20 November, 2004 ; Accepted: 26 July, 2005)

 

Abstract: The germination of ten plant species from the Iberian Peninsula was assessed along a water deficit gradient between -0.1652 (moist) and -0.4988 MPa (dry) of osmotic potential, created by addition of increasing concentrations of polyethylene glycol (PEG 6000) to distilled water in which plants were grown hydroponically. The level and rate of germination of Daucus carota and Thapsia villosa significantly decreased with decreasing Ψ. Seeds of Dactylis glomerata and Dittrichia viscosa had positive germination responses to low osmotic potentials; germination of Epilobium hirsutum was not affected by osmotic potential. Germination of Medicago arabica, Cynosurus cristatus, Cistus ladanifer and Cistus albidus, was no favored by the addition of polyethylene glycol (PEG). Germination of Foeniculum vulgare and Thapsia villosa was inhibited by PEG.

 

Key words: Drought tolerance, Generalized linear models, Germination, Osmotic potential, PEG.

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