Evolutionary relationships of Slash Pine (Pinus elliottii) with its temperate and tropical relatives

Abstract

llozymes in bud tissue and monoterpene contents in xylem oleoresin of slash pine (Pinus elliottii) were analyzed from populations across the natural distribution, as well as those from other species in the AUSTRALES pines. Allozyme diversity measures of slash pine were similar to those found in other southern pines. The two slash pine varieties, the slower-growing south Florida variety (var. densa) and the more commercial ";typical"; variety (var. elliottii), were not separated in the cluster analysis of allozymes. Variation was continuous from south to north in Florida in slash pine, with no distinct transition between the two varieties. The monoterpene data also showed continuous variation between the two slash pine varieties. Expected heterozygosity declined from south to north, supporting the hypothesis that slash pine resided in a Pleistocene refugium in south Florida or the Caribbean, migrating northward at the close of the ice age. Allozyme frequencies as well as monoterpene compositions of slash pine and its AUSTRALES relatives showed a very close relationship between slash pine and Bahamian Caribbean pine (P. caribaea Morelet var bahamensis).


Southern African Forestry Journal No.190 2001: 73-78