Effect of temperature and daylength on morphogenesis of Scytosiphon lomentaria (Scytosiphonales, Phaeophyta) from eastern Canada

Abstract

The morphogenetic responses to temperature and photoperiod of plants from Nova Scotia, Canada belonging to the Scytosiphon lomentaria complex were evaluated. Formation of erect thalli by clonal isolates of S. lomentaria var. complanatus was controlled by temperature, and independent of daylength. All plants formed uprights at 0.degree. C .**GRAPHIC**. 5.degree.C .**GRAPHIC**. and 10.degree.C (16:8h, .**GRAPHIC**. and .**GRAPHIC**. only few did so at 15.degree. C (16:8h and .**GRAPHIC**. and none at 20.degree.C (16:8h and .**GRAPHIC**. In contrast, uprights of S. lomentaria var. lomentaria were formed in response to short daylength (10.degree. C).