Generative reproduction of Picea pungens Engelm. in the Voronezh urban environment: laboratory germination analysis from seed stratification

The prickly spruce (Picea pungens Engelm.) has broad prospects and high environmental potential for developing the conceptual foundations of Voronezh urban planning. In our experimental work, we investigated the germination rates of seeds depending on the pre-sowing treatment. We decided to test the stratification of cones with seeds in two versions: the classic method of "snowing" and natural stratification (collecting cones from trees at the end of March). The number of specimens of Picea pungens Engelm. from which cones were collected was 15, the age of the trees was 60 years, the number of cones was 50, the number of exfoliated seeds was 4000 pieces, 600 were used for germination (300 pieces each of spring and autumn harvest). A very significant coefficient of variation (r=0.99) appeared on certain and expected days of the experiments. The coefficient of determination varies slightly from R2 =0.94 (light-colored seeds) and R2 =0.97 (dark-colored seeds) in the batch of autumn seeds to R2 =0.98 (dark-colored seeds) and R2 =0.99 (light-colored) in the batch of spring seeds, with a value of p≤0.05. The standard deviation of autumn harvest seeds decreases to 18.7% with increasing germination day. Seeds from autumn cones have a low percentage of germination variability (V=39.6%). The variability of germination between dark-colored and light-colored batches of seeds of different harvest times is insignificant V=54.4% and V=56.5%, respectively.