Isolation and structural identification of a germination inhibitor in fire-recruiters from the california chaparral

A role for inhibitors as regulators of seed dormancy in fire-dependent annu als and their nondormant (fire-independent) congeners was examined in the f amily Hydrophyllaceae. From seeds of the fire-dependent species, Emmenanthe penduliflora, Phacelia minor, P. brachyloba, and P. grandiflora. extracts were obtained that were found to be largely self-inhibitory and potent inhi bitors of seed germination in nondormant congeners. Lower activity was dete cted in the fire-independent species, P. tanacetifolia and P campanularia. The inhibitory activity was associated with the new sucrose ester, 6-O-lino leyl-alpha -D-glucopyranosyl-beta -D-fructofuranoside.