THE EXTENT AND STRUCTURE OF GENETIC-VARIATION IN THE MACROZAMIA-PAULI-GUILIELMI COMPLEX (ZAMIACEAE)

Allozyme variation in 12 enzyme systems coded by 17 loci was investiga ted in six populations of Macrozamia, including two populations of M. parcifolia, three populations of M. pauliguilielmi and one population of nrl. crassifolia from Queensland (Australia) in order to measure th e levels of genetic variation. This was required to establish whether the allozyme data supports recent taxonomic treatment. Seven loci were found to be monomorphic. All species were genetically depauperate, wi th low levels of genetic diversity (P = 17.6-35.3%, A = 1.2-1.4, H-e = 0.02-0.11) compared with two (only) existing reports, and plants in g eneral. Genetic differentiation among populations was high (G(ST) = 0. 47). UPGMA cluster analysis using Nei unbiased genetic distance showed M. parcifolia and M. pauli-guilielmi to be more similar genetically t o each other than either is to M. crassifolia. This is concordant with groupings based on morphological characters, thus supporting the obje ctives of the investigation. (C) 1998 Elsevier Science Ltd. All rights reserved.