VARIATION IN CYANOGENESIS WITHIN AND AMONG POPULATIONS AND SPECIES OF TURNERA SERIES CANALIGERAE (TURNERACEAE)

Nine species of Turnera series Canaligerae, at three ploidal levels, were tested for cyanogenesis. Four of nine species (including both diploids and hexaploids) possessed cyanogenic plants. Tetraploids were never found to be cyanogenic. Variation for cyanogenesis occurred within three species. All acyanogenic plants investigated possess beta-glucosidases capable of hydrolysing exogenously supplied cyanogenic glycosides. Floral parts and seedling tissues are cyanogenic. Within-plant variation occurs and the intensity of cyanogenesis varies with leaf age.