Diversite allozymique de peuplements de cypres naturels et introduits au Maroc : consequences pour la gestion des ressourcesAllozyme diversity of natural and introduced cypress stands in Morocco: consequences for management of genetic resources.

摘要

For the purpose of managing Cupressus atlantica natural genetic resources in Morocco, diversity among 9 provenances from 3 cypress species ( Cupressus atlantica and 2 introduced species: C. sempervirens and C. arizonica) was studied using seven enzymatic systems. Mean allele number per locus ( A) ranged from 2.0 in C. atlantica and C. arizonica to 1.7 in C. sempervirens. Genetic diversity was high (He = 0.29 in C. atlantica; 0.27 in C. sempervirens and 0.33 in C. arizonica) but heterozygote deficiencies were observed. C. atlantica provenances exhibited a low differentiation (GST = 0.013). The high interspecific differentiation (GST = 0.279) was due to the distance between the 2 Mediterranean cypresses ( C. atlantica and C. sempervirens) and the Arizonica cypress. Two enzymatic systems ( GOT et SOD) strictly differentiated these 2 origins and could be used for introgression monitoring. Advice for preserving and using C. atlantica genetic resources and for reducing the degradation of these natural stands are proposed.