GENETIC DIFFERENTIATION AMONG AND WITHIN NATURAL AND PLANTED CUPRESSUS SEMPERVIRENS L. EASTERN MEDITERRANEAN POPULATIONS

The aim of the study was to extend our knowledge of the geographic pat terns of genetic variation of Cupressus sempervirens L., and to try to relate the earliest plantations of C. sempervirens in Israel to its u ltimate seed origins. Seeds of 22 populations, most of them of C. semp ervirens var. horizontalis, were used for the analysis of the genetic diversity within and among East Mediterranean populations. Bulk seed l ots from 13 populations, and single-tree seed collections, representin g about 30 trees from each of the populations from Cyprus, Syria and T urkey, and from 267 trees from 20 Israeli plantations were available. Horizontal starch gel electrophoresis was used to resolve allele patte rns in 22 loci encoding 13 enzyme systems. The mean number of alleles per locus was 1.7; the over all percentage of polymorphic loci was 41. 7% (S.E.+/-1.1). The over all mean observed heterozygosity and the exp ected heterozygosity, i.e., genetic diversity within populations - wer e 0.149 (S.E.+/-0.021) and 0.181 (S.E.+/-0.03), respectively; and the over all mean total genetic diversity among the natural populations wa s 0.192 (S.E.+/-0.032). The fixation indices, F-it, F-is F-st and G(st ) for each polymorphic locus, over all the populations, are 0.180, 0.3 33, 0.187 and 0.049, respectively. The phylogenetic tree enabled us to define three main groups: a north-eastern Mediterranean group which i ncludes the populations from central Mediterranean Turkey, Syria and I ran; a low-altitude east Aegean group which includes the populations o f Kos, 2 Turkish population on the shores of the Aegean Sea together w ith populations on the island of Samos; a third group which includes p opulations from Crete, Cyprus, Rhodes, Jordan and plantations in Israe l. The results imply that plantations of Cupressus sempervirens in Isr ael probably originated from seed material imported from Crete, Cyprus , Rhodes and Jordan.