Maturation dates affecting the germinability of Lactuca serriola L. ACHENES collected from a natural population in the Negev desert highlands. Germination under constant temperatures

Abstract

The germination of achenes harvested from a natural plant population during summer 1989 was tested under constant temperatures in light or dark during the following growing seasons: winter and spring. Imbibition of achenes in constant temperatures in October 1989 showed the fastest germination in the achenes harvested in July, with a gradual significant decrease to the slowest germination in achenes harvested in September. The opposite was observed in the germination tests of March to May 1990: the germination of the July harvest was the slowest with a gradual significant increase to the fastest germination of achenes from the October harvest. Achenes imbibed in December 1989 or January 1990 showed intermediate behaviour in their germination.