Polymorphism for Cyanogenesis in Lotus australis Andr. Populations at Greenough Front Flats, Western Australia

Abstract

In populations of Lotus australis growing on a sand dune system south of Geraldton: Western Australia, the seedling stage was polymorphic at the coastal and inland sites, both populations containing about 15% of acyanogenic phenotypes.

All but 2% of these acyanogenic seedlings were developmentally flexible and in moist productive conditions eventually metabolized both glucoside and enzyme. This developmental inhibition of glucoside and enzyme may be a response to severe soil moisture stress, salt stress or trampling by sheep. All the adult plants were cyanogenic (under natural conditions) on the coastal dunes but the inland dunes retained a relatively high proportion (12%) of acyanogenic individuals.