Katarzyna Marcysiak

Morphological differentiation supports the genetic pattern of the geographic structure of Juniperus thurifera (Cupressaceae)

Juniperus thurifera is an important component of woodland communities of dry sites within the West Mediterranean region and is characterised by a strongly disjunctive geographic range. Two subspecies were recognised, subsp. thurifera in Europe and subsp. africana in Africa. The aim of the study was the comparison of phenetic diversity to the pattern of AFLP geographic differentiation of the species described in the literature. The examination of phenetic diversity was based on the biometrical analysis of 17 populations using 12 morphological characters of cone and seed. The differences among populations were analysed using Student’s t test, analysis of discrimination, UPGMA agglomeration and hierarchical analysis of variance. The majority of morphological characters differentiated at a statistically significant level between populations and between J. thurifera subsp. thurifera and subsp. africana. Three groups of populations were detected using multivariate statistical analyses. The first, well separated, is subsp. africana, while the following two concern subsp. thurifera. The morphological differentiation of populations appeared similar to that described on the AFLP. The Gibraltar Straight appeared to be the most important barrier.

Variation of leaf shape of Salix herbacea in Europe

The morphology of Salix herbacea leaves was examined to find possible reasons for the observed intra-specific morphological variation. Seventeen samples were collected from the following regions: the Southern and Eastern Carpathians, the Northern Carpathians, the Alps: Eastern, Central and Western, the Pyrenees, Western Scandinavia, and Northern Scandinavia. The leaves were dried in an herbarium, scanned and measured. A total of 3,890 leaves from 503 individuals were statistically analyzed. The analyses were based on the shape-describing characters. A notable variation of shape characters of leaves of S. herbacea was found on different levels: intra- and inter-individual, between samples and between regions. The local environmental conditions did not affect the leaf shape much, but the regional climatic factors influenced them statistically significantly. The most important factor—the summer precipitation—was positively correlated with leaf elongation, while the mean wind velocity was negatively correlated with leaf elongation. The latter was also positively correlated with the tooth number. The hypothesis that glacial migrations and isolations of S. herbacea populations were responsible for the contemporary morphological differentiation of the species was not confirmed; however, some similarities between the biogeographical structures revealed in the previously published results of molecular analyses and in the present morphological study were also noticed.

Taxonomic and geographic differentiation of Juniperus phoenicea agg. based on cone, seed, and needle characteristics

The aim of this study was to examine the diversity of, and differentiation between, 41 natural populations representing Juniperus phoenicea complex within their geographic range using the morphological characteristics of cones, seeds, and sprouts with leaves. Seven populations of J. phoenicea s.s., 25 J. turbinata and nine J. canariensis, each represented by ∼20–30 individuals, were studied. The characteristics describing the size of cones and seeds and their proportions were different between J. phoenicea s.s., J. turbinata, and J. canariensis, and were useful in distinguishing between these three taxa. The populations of J. canariensis had a significantly higher percentage of trimerous cones, a higher number of cone scales, but a lower number of seeds, which were also larger than the seeds from other taxa. Juniperus phoenicea s.s., J. turbinata, and J. canariensis revealed a high level of multivariate differentiation, but there were no single characteristics which allowed one to distinguish between these alone. We detected significant differences between populations of J. turbinata from Europe and Africa, which supports the role of the Gibraltar Straight in the structuring of conifer species. Significant differences were also detected between European and Asiatic populations in several characters examined, indicating the important role of the Aegean Sea in the structuring of this taxon.