Variation in needles anatomy of Picea omorika(Pinaceae) plants belonging to different gene pools in natural populations on Tara Mt. in Serbia

Abstract

Picea omorika (Serbian spruce) is a stenoendemic species whose current distribution range is restricted to refugial habitats in W Serbia and E Bosnia and Herzegovina. We analyzed variability in the anatomical structure of needles in populations from Tara Mt. which had previously been found to belong to two gene pools characterized by different history and levels of genetic diversity. Needle anatomy was investigated on transverse, sagittal and longitudinal sections and 28 characters were measured. Descriptive statistics, one-way and two-way ANOVA, principal component analysis (PCA), canonical discriminant analysis (CDA) and cluster analysis (UPGMA) were performed to describe the overall anatomical variability and relationships between individuals from three populations. We found that plants originating from different gene pools showed significant anatomical differences. The main differences between the populations were related to needle thickness and width, dimensions of the mesophyll, vascular bundle and endodermis, volume and number of the intercellular spaces and dimensions of resin ducts.