Morphological differentiation of leaves in the relict tree Zelkova carpinifolia (Ulmaceae)

Abstract

Zelkova carpinifolia is a relict tree occurring in refugial zones of south-western Eurasia. The main aim of the study was the biometrical comparison of the leaf characteristics of the species sampled in three regions of Transcaucasia. We aimed to test the hypotheses that (1) leaves from vegetative (L) shoots would be larger and more variable than those from fertile (S) shoots, (2) the leaves from the same shoot type express geographic patterns of morphological differentiation, similar to pattern described for genetic markers and (3) to verify the systematic position of Z. hyrcana and Z. carpinifolia subsp. yomraensis. The plant material was collected from 5 populations of Z. carpinifolia, one of Z. hyrcana and one of Z. carpinifolia subsp. yomraensis. The total 1482 leaves, 713 from L-and 769 S-type were measured using 26 characters. Our results show very high level of differences between leaves from the L-and S-type of shoots. The majority of leaf characters did not reveal dependence neither on geographic latitude, longitude and altitude nor on the basic climatic data. The results of multivariate analyses of S leaves revealed three group of populations, namely from (1) Colchis, (2) eastern Caucasus (3) Talysh. Thus, our biometric analyses revealed similar pattern to the haplotypic differentiation of Z. carpinifolia detected using chloroplast markers described in the literature. We did not detected significant differences in the leaf characters between supposed Z. hyrcana and/or Z. carpinifolia subsp. yomraensis, when compared to Z. carpinifolia, thus not confirming their separate taxonomic status.

Taxonomic differentiation of Salix retusa agg. (Salicaceae) based on leaf characteristics

“…The leaf characteristics were chosen based on previous studies on the variation of S. herbacea L., S. reticulata L. and Dryas octopetala L. (Marcysiak, 2012a(Marcysiak, , 2012b(Marcysiak, , 2014 and from diagnoses of S. retusa group taxa (Pawłowski, 1956;Rechinger, 1957Rechinger, , 1974Dostál, 1989;Koblížek, 2006). The measurement procedure follows those described by Jasińska et al (2015) with implementation of WinFolia Pro 2003 (Regent Instruments Inc.) software.…”

Taxonomic relationships and population differentiation of the south-western Eurasian Zelkova species inferred in leaf morphology

“…The leaves were pressed, dried as herbarium material, and conserved in this state until measurement. Data on Z. carpinifolia from Jasińska et al (2015) were included in the analyses for comparison. In total, 3325 leaves from 361 individuals representing 20 populations were analyzed (Fig.…”

“…S1 for some details). Leaf characteristics were measured on scanned images, following the method described in Jasińska et al (2015). Measurements were performed on scanned images using WinFolia software (Regent Instrument).…”

“…The leaves of plants living in mesic regions are as a rule larger and have thinner epidermis and mesodermis layers, comparing to plants leaving in more xeric regions (Krüssmann, 1962;Lakusic et al, 2010;Zhong et al, 2014). The leaf blade length, width and shape, the number of marginal teeth and secondary veins are species specific, but influenced by their function and position on the vegetative versus reproductive shoots and position within tree crown (Mejnartowicz, 1972;Wójcicki, 1997;Wang et al, 2001;Jasińska et al, 2015). The leaf size and shape of specimens exposed to the animal browsing are different when compare to the leaves from undamaged specimens (Zieliński & Güner, 2000;Denk & Grimm, 2005;Kozlowski & Gratzfeld, 2013).…”

“…The species can be distinguished based on fruit and leaf characters (Quézel et al, 1993;Wang et al, 2001;Fu et al, 2003;Kozlowski & Gratzfeld, 2013). However, except for Z. carpinifolia (Jasińska et al, 2015), so far investigations and comparative analyses based on leaf morphometry have not yet been conducted. The Zelkova leaves from sterile/vegetative shoots have been usually described as different than those of fertile/fruiting twigs (Fig.…”