GENETIC DIVERSITY AMONG COASTAL AND ANDEAN NATURAL-POPULATIONS OF ARAUCARIA-ARAUCANA KOCH,(MOLINA),K

Proportional composition of foliar epicuticular wax alkanes was analyz ed for 40 individuals from 4 natural populations of Araucaria araucana in the Andes and the coastal Nahuelbuta mountains of Chile, using gas -liquid chromatography. A total of 17 long-chain alkanes were detected and identified, ranging in carbon chain length from C-21 to C-37. Maj or alkanes were the C-29, C-31 and C-33 homologues, Multivariate analy ses (principal components analysis, canonical discriminant analysis an d a phenogram based on cluster analysis of Nei's genetic distances) in dicated a greater differentiation between west-side Andean populations than between Andean and the coastal Nahuelbuta population. The popula tion differentiation was consistent with an hypothesis for genetic ada ptation to more arid conditions by biosynthesis of a greater proportio n of long-chain alkanes. Intrapopulation variation was relatively high , even in the isolated coastal population suggesting the viability of this species in the face of environmental change. No evidence was foun d to support racial differentiation within Araucaria araucana. (C) 199 8 Elsevier Science Ltd. All rights reserved.