Photoinhibition of white clover seed germination at low water potential.

Autor: Niedźwiedź-Siegień, Irena, Lewak, Stanislaw
Předmět:
Zdroj: Physiologia Plantarum; May89, Vol. 76 Issue 1, p53-56, 4p
Abstrakt: Photosensitivity of germination of white clover (Trifolium repens L. cv. Podkowa) seeds was studied under water deficit (low water potential) conditions at 25°C. The seeds showed negative photoblastism, which was most pronounced at ‐0.03 MPa polyethylene glycol solution. Inhibition was observed at two different wavelength bands with maxima at 660 nm (R) and around 730 nm (FR). Red light acted identically to white light (maximum inhibition ca 50%). The effect of far‐red illumination was less inhibitory (20–30%). The photoresponse required long illuminations (3 h exposures); saturation level was at 0.1 W m−2, independently of the light quality. White clover seed germination showed no reversibility of the effects of R and FR light. Prolonged illumination with R and FR increased the inhibition, and intermittent illumination had a higher effect than a continuous one. It was concluded that the photoinhibition of germination of seeds of Trifolium repens involves a reaction dependent on the rate of phytochrome interconversion, a property that is characteristic for the high irradiance reaction. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index