engleski

Secondary sexual dimorphism and cone phenotypic variability in two allopatric juniper species: Juniperus oxycedrus L. and J. deltoides R.P.Adams.

Juniperus oxycedrus L. and J. deltoides R.P.Adams are evergreen dioecious shrubs or small trees distributed in the western and eastern Mediterranean, respectively. Both species are widespread in their natural range and grow in xeric environments, on limestone or siliceous terrain, commonly affected by fires. Due to morphological similarities, J. deltoides was only recently delimited as a cryptic species from J. oxycedrus. In order to further investigate and analyze the distinctive characters of these two species, we studied needle and cone morphological traits . Since the needle morphology varies between male and female individuals in dioecious plants, we also examined morphological differences between sexes. The analyses included descriptive and multivariate statistical methods performed on data from six populations from the western and eastern Mediterranean region. The results showed that the needles of J. oxycedrus were slightly larger , longer, wider, and less variable than those of J. deltoides. The same trend was observed in cone morphology, where J. oxycedrus displayed higher values in all measured cone traits, confirming the morphological distinction between the two species. Furthermore, sexual dimorphism was detected in most of the measured needle traits, especially in J. oxycedrus, where needles of female individuals had higher values in seven of eight morphological traits. Although this study confirmed sexual dimorphism in terms of needle morphology, there was no consistent pattern of distribution between the two species. Our results demonstrate the high diversity within juniper species in arid and semiarid ecosystems of the Mediterranean region and open the field for further studies.

allopatric speciation ; cone morphology ; needle morphology ; phenotypic variability ; sexual dimorphism

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