XVI International Botanical Congess
We have tested genetic adaptation in cuticular hydrocarbons in three related taxa (Austrocedrus chilensis, Fitzroya cupressoides, Pigerodendron uviferum, Cupressaceae), that form a continuum over 2500 km in southern Chile and Argentina. Mean carbon numbers decreased and alkane dispersion increased among species with increasing latitude, correlated with decreasing mean annual temperature and increasing precipitation. Intraspecific variation in A. chilensis resolved into three groups (mediterranean Chile, Patagonian steppe, Valdivian rainforest). P. uviferum separated into northern and southern groups. Both species differences and intraspecific variation provide evidence for genetic adaptation in alkane profiles to climatic conditions.