Responses of Pinus yunnanensis Seed Germination to Temperature, Light and GA₃

We investigated the effects of temperature, light, and GA₃ and their interactions on seed germination of Pinus yunnanensis, an endemic tree to southwest China. The results showed that: (1) The germination rate of P. yunnanensis seed was the highest at 20/5 ℃ and 25/10 ℃ (42% ± 0.30 and 40.25% ± 0.31, respectively), and too high (30/20 ℃) or too low (4 ℃) temperature was unfavorable for Pinus yunnanensis seeds germination. (2) Light had no significant effect on P. yunnanensis seed germination (P>0.05). The seeds of P. yunnanensis can germinate normally under light and dark conditions. (3) Soaking seeds with water could improve the seed germination of P. yunnanensis, but GA₃ had no significant effect on germination (P>0.05). (4) Due to the non-dormant nature of P. yunnanensis seeds, sowing in the early spring rainy season in Panxi region was beneficial for seedling establishment. In this paper, the response characteristics of seed germination to various environmental factors were investigated, aiming at understanding the germination characteristics of P. yunnanensis seeds, promoting scientific seed storage, and timely and appropriate seed sowing in afforestation projects, which had important significance for improving the survival rate of ecological restoration afforestation and the preservation rate of young forests in Southwest China.