Intraspecific variability of seed quality and seedling development of Larix sibirica Ledeb. in a sowing experiment

Abstract

The results of a sowing experiment to assess the field germination of seeds, preservation and growth of seedlings of the Siberian larch Larix sibirica Ledeb., representing ecotypic (population) and form (individual) levels of intraspecific differentiation, are presented. The experiment was conducted for 4 years (2016–2019) at the experimental site of V. N. Sukachev Institute of Forest, Rus. Acad. Sci., Sib. Br., in Akademgorodok, the city of Krasnoyarsk for population and individual samples of the Siberian larch seeds from ecologically contrasting origins of Siberia – forest-swamp (Tomsk region), forest-steppe (Republic of Khakassia) and forest-tundra (Taimyr Dolgan-Nenets district of Krasnoyarsk territory). Field germination of seeds, dynamics of vertical annual growth of seedlings, their current and final safety were determined. It was found that the main features of intraspecific variability in the quality of the Siberian larch seeds appear in the first two years of the experiment. The Siberian larch seeds of different origin have different “strategy” of germination, determined by the habitat conditions of the parent stands. From the seeds of forest-tundra origin, single weakened seedlings were formed, which completely died in the first year of the experiment. Seeds of forest-swamp origin were characterized by a gradual increase in the number of seedlings and a higher safety of seedlings throughout the first year of growth, with a relatively smooth death over the following years. Seeds of forest-steppe origin in the first year of the experiment were characterized by accelerated germination and high initial growth of seedlings, but their final safety was low. Field seed germination, dynamics of seedling growth and their final preservation are characterized by significantly higher values in the typical form of the Siberian larch trees, compared with its intraspecific forms with features of cone morphology and habitus. The dynamics of growth and safety of seedlings correspond to the indicators of field and laboratory germination of seeds and their mass: the maximum values of these parameters were found in the origin of the Siberian larch from more optimal dry-steppe and forest-steppe ecotopes, as well as in the typical tree form.

Keywords

• siberian larch
• ecotypic and form differentiation
• field germination of seeds
• safety and growth of seedlings