DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 5-6/2023 str. 19 <-- 19 --> PDF |
(NW), cuticle thickness (CT), epidermis width (EW), epidermis thickness (ET), sclerenchyma width (SW), sclerenchyma thickness (ST), mesophiyll thickness (MT), resin canal number (CN), resin canal cell number (CCN), resin canal diameter (CD), central cylinder width (CW), central cylinder thickness (CCT), endodermis cell number (ECN), endodermis width (ENW) and endodermis thickness (ENT). Cross sections of a needle (20–25 µm) were taken by a freezing microtome using a small part of the needle plade. All sections were stained with hematoxylin and fast green for 30 min and mounted in entellan to create permanent slides (Vardar 1987). Well stained sections were examined with an Olympus BX51 light microscope (LM). Sixteen anatomical traits were measured (µm) using a BX51 LM equipped with the Bs200Pro analysis system software. All measurements and observations were checked at least three or four times from sections taken from selected specimens of examined populations. A raw data matrix generated by the measurements of sixteen traits was used for statistical analysis. Minimal and maximal values of characters were determined, and arithmetical means, standard deviation and variation coefficients were calculated and analysed for each population and elevation limits (Table 2, Table 3). Analysis of variance (ANOVA) was performed to determine the differences between populations and between trees within populations. The relationship between average values of anatomical traits and altitude were tested using Spearman’s coefficient (Sokal and Rohlf 2012). Multivariate statistical methods (cluster analysis and discriminant analysis) were used to identify structure of investigated populations. The cluster analysis resulted in a hierarchical tree, where the unweighted pair-group method with arithmetic mean (UPGMA) was used to join the clusters, and the Euclidean distance to define the distance between the studied populations. Principal component analysis was used to identify the best discriminating components and the best anatomical traits allowed the grouping of the investigated populations. Standardized data were used for the principal component analysis. The plot was constructed by two components (DF-1 and DF-2) showing analysed individuals (trees) and populations. The above statistical analyses were conducted using the SPSS Statistics 23.0 (Nie et al. 1975; IBM Corp 2015), SYNTAX 2000 (Podani 2001), and Past 3 (Hammer et al. 2001) statistical programs. RESULTS Rezultati Descriptive statistics of needle anatomical traits of the 64 trees belonging to eight natural Scots pine populations from Turkiye are given in Table 2. The highest mean values for NT, NW, EW, ET, MT, CW, CCT, ECN and ENT were observed in GE population (Figure 2). In contrast, the lowest mean values for NT, NW, ET, CCN, CW and CCT were observed in the EC and KT populations (Figure 2). Almost all measured needle anatomical traits correlated with each other at a statistically significant level. Using Spearman’s correlation coefficient (rs), a highly positive correlation was found between altitude and the mesophile thickness of (rs: 0.83). As a result of the ANOVA, significant differences in needle anatomical traits among the examined eight populations |