The Geography of Phytochemical Races

162 3 After the Ice
discussed. Those workers observed no geographic patterning among populations in
a study of nine enzymes encoded by 16 loci.
3.3 Europe
3.3.1 Pinus halepensis (Pinaceae)
The three examples from Europe all involve species of pine, the fi rst of which is
the Aleppo pine, Pinus halepensis Mill. The Aleppo pine enjoys a natural range that
extends from Spain and Morocco in the west to Jordan in the east and from Israel in
the south to the Rhone Valley in France (Nahal, 1962; Jalas and Suominen, 1973).
Variation in this taxon has been studied using a variety of approaches, which provides
an opportunity to examine its past from several points of view. An early division
of the species into three geographical groups, “Oriental,” “Occidental,” and
“North African”, was based upon palynological data (Nahal, 1962). Differences in
needle anatomy and morphology were shown by Calamassi (1986) to be correlated
with latitude, longitude, and altitude. Schiller et al. (1986) found that isozyme data
led to the division of the species into two major groups, eastern and western Mediterranean.
Further resolution of the main western group into four races was based
upon allele frequencies and genetic distances. A study of cortical monoterpenes
led Shiller and Grundwald (1987b) to distinguish three groups, Greek, western
European, and North African. Baradat et al. (1995) studied the terpene chemistry
of more extensive collections and concluded that the variation observed did not
conform to any straightforward pattern of migration and could well refl ect a degree
of human intervention.
A recent study of chemical variation in Aleppo pine involves the work of
Kaundun et al. (1998a, b) on needle fl avonoids. In this study, 215 trees from nine
populations were sampled. Six of these originated from experimental gardens;
three were collected from nature (two from France, one from Algeria). Countries
of origin were: Morocco, Tunisia, Algeria, Spain, France, Italy, and Greece. Plant
material was extracted and the extracts subjected to HPLC analysis which allowed
identifi cation of procyanidin, identifi ed as cyanidin [278], and prodelphinidin,
identifi ed as delphinidin [279], kaempferol [280], quercetin [281], isorhamnetin
[282], myricetin [283], larycitrin [284], and syringetin [285] (see Fig. 3.11 for
structures). Differences between trees sampled in nature and those grown in experimental
gardens were signifi cant, but fl avonoid differences between trees grown
in the gardens were minimal. Of the eight compounds identifi ed in this study,
only myricetin showed signifi cant quantitative differences among the populations.
Cluster analysis pointed to the existence of three major geographical groups: (1)
Greece; (2) North African/Western European (populations from Tunisia, Morocco
and Spain); and (3) Southern European (populations from France and Italy). This
grouping refl ected a decrease in the myricetin level as one went from highest