Variability of cones morphological features of Larix sibirica Ledeb. in the south of Siberia

Abstract

The results of the study of the intraspecific variability of the morphological traits of Siberian larch (Larix sibirica Ledeb.) cones in the south of Siberia (Tomsk Region, the Republics of Altai and Khakassia) are presented. Ecotypes (marsh, upland, forest-steppe, and steppe) and intraspecific forms, differentiated by the color of young female cones – red cone (f. rubriflora Szaf.), green cone (f. viridiflora Szaf.) and pink cone (f. rosea Szaf.) are considered. As a result of the study, a significant ecotopic variability of metric and qualitative traits of Siberian larch cones was established, caused by the heterogeneity of the ecological and geographical conditions of tree growth and probable interspecific hybridization. In the southern taiga subzone, in the process of hybridization with Sukachev’s larch (Larix sukaczewii Dylis), plantations of Siberian larch (marsh and upland ecotypes) were formed with a predominance (up to 95 %) of large-cone and large-scale trees promising for forest seed production. In the forest-steppe and steppe ecotopes of Altai and Khakassia, the proportion of trees with small cones increases (up to 37 %), and the polyvariance of Siberian larch cenopopulations in terms of the quality of cones increases. When evaluating the shape variability of Siberian larch, it was shown that trees of the red cone form produce larger cones (length, 30.1 ± 0.7 mm; width, 23.7 ± 0.7 mm) with a large number of smaller scales. The green cone form is characterized by smaller cones (length 28.8 ± 0.8 mm, width 22.3 ± 0.8 mm) with fewer larger scales. The pink cone form has intermediate values of the traits under consideration. The predominance of large cones in red cones may have an adaptive character, associated with the formation of a larger number of cones with large seeds. The identified features of the ecotopic and form differentiation of Siberian larch should be taken into account when carrying out silvicultural, breeding and silvicultural activities in the south of Siberia.

Keywords

• siberian larch
• polymorphism
• ecotypes
• intraspecific forms
• hybridization