Specifications of microsporogenesis of Larix sibirica Rupr. and Larix gmelinii Ledeb. in Eastern Siberia

The results of three-year study of male reproductive buds of Siberian larch (Larix sibirica Rupr.) and Gmelin larch (Larix gmelinii Ledeb.) growing at the territory of the Arboretum of the V. N. Sukachev Institute of Forest SB RAS (Krasnoyarsk) are presented. The results of the study revealed the transition of microsporocytes into a state of winter dormancy at the end of October; then, at the beginning of spring of the following year microsporogenesis resumes. Meiosis of Siberian larch is completed in early April with an effective temperature sum from 33 to 58°C. The meiosis of Gmelin larch is completed from 2 to 4 weeks earlier in average: in late February – beginning of March with an effective temperatures sum from 13 to 35°C. In 2024 the tetrad formation in Gmelin larch was observed on November 28th (effective temperatures sum is 13,4°C). The effect of temperature factor on the rate of microsporogenesis in larches is shown.