Intraspecific variability of the Siberian larch Larix sibirica Ledeb. seed scales

The results of the study of morphological features variability of the Siberian larch seed scales are presented in the paper. Variation of seed scales size, forms of flat and scale edge ofithave been analyzed. Population analysis has been carried out on the phenotypic races and, depending on growing conditions. Four races of the Siberian larch have been investigated. The populations from highlands and low mountains sites of every race have been studied. Samples of seed scales have been selected from thirty trees on each plot. The length and widthof the seed scale, the form index of scaleand the edge form ofseed scale have been considered. The classification of trees on tight scale, wide scale and intermediate forms have been carried out in accordance with the index form of seed scales. The geographic variation analysis of seed scales sizes showed the differentiation of features between races, and, depending on growing conditions. The trees with small scales dominate in larch populations of Baikal race of this species. The largest seed scales have been found in the trees of Sayan race populations in the Kuznetsky Alatau low mountains sites. Polymorphism in the form of seed scale and form its edge has been detected in the studied larch populations. The dominance of «wide scale» and «intermediate» forms trees have been observed in the northern populations (the polar race). The «intermediate» form trees on type flat seed scale predominate in populations of the Sayan race. The most variability of seed scale forms have been found in populations of the Altai and Sayan races. Increased occurrence of wide scale form in the upper mountain belt have been found in both races (more than 50 %). In contrast, more than 50 % of the trees that have cones of tight scale form have been revealed in populations of the Baikal Olkhon Island at altitude of 500 meters above sea level