Effect of temperature, light, seed weight and GA3 on the germination of Verbascum bithynicum, Verbascum wiedemannianum and Salvia dicroantha

Abstract

S. dicroantha, (Stapf in Denkseehr) Verbascum bithynicum and V. wiedemannianum are (Bioss.) endemic and medicinal potential plants disturbed in Turkey. V. wiedemannianum is different from the other Verbascum species in red-dark purple flowers and as a threated plant. Seed germination strategies of these species were studied with the aim of producing appropriate germination protocols for use ex situ conservation. The optimum temperature for seed germination of S. dicroantha, V. bithynicum and V. wiedemannianum was 20°C and darkness. The seeds of V. bithynicum and V. wiedemannianum incubated in darkness showed higher germination percentages than the seeds incubated with a 16:8 h photoperiod or continuous light, but the effect of application of darkness,photoperiod (16:8 h) or continuous light on the germination percentage of the seeds of S. dicroantha was not significant. In the case of S. dicroantha, seed weight significantly affected germination percentage, but not significant in the case of V. bithynicum and V. wiedemannianum. Exogenous GA3 (20, 100, 200 mg L-1) was comletely prevented germination the seeds of these species. © 2007 Asian Network for Scientific Information.