The article presents the results of examine the relationship of direct sprouting Triticum aestivum L. immature embryos in vitro and a temperature factor during their incubation in the dark and light. Immature embryos of 1,2–1,5 mm sizes from 7 spring bread wheat varieties have been used for callus induction. As a substrate Linsmayer-Skoog’s media (RM-64) containing 0,8% agar, 3,0% sucrose, 2,0 mg/l 2,4-D have been applied. The cultures were incubated in the dark. The effect of the explant incubation temperature on the direct sprouting of embryos was evaluated at different levels of the thermal factor: 26, 29, 32, 32 (14 days) → 26 °C. The part of the material was incubated in parallel at the light at the temperature 26 °C. It is shown that the physical factors such as light and temperature depress the explant direct sprouting on 67,3 and 86,0% respectively. The increase of the thermal factor from 26 to 32 °C reduces the rate of the wheat embryos pre-germination in 7.1 times. The best option is culturing explants for two weeks at 32 °C with the following decreasing temperature to 26 °C. The incubation of explants in the light leads to lower values of the feature in 3,1 times. A determining factor suppressing the sprouting rate of immature embryos is the incubation temperature. Its contribution to the total phenotypic variability is 38,4%.