Effects of Microwave Radiation and Seed Soaking on Seed Viability and Germination of Pinus armandii

In order to understand the effects of different levels with which treatment combinations (TCs) of the 2 factors of microwave radiation and clear water on water absorption and viability of seeds, involved germination rate of seed kernel. And the effects of microwave radiation combined with clear water and GA₃ seed soaking on germination rate of seeds for Pinus armandii. The L₉(3⁴) orthogonal design was applied to implement the experiments. The results show that the seed viability, water absorption rates of seed, kernel and seed shell for the TCs of microwave radiation and water soaking were 75.3%–88.0% (94.7% of the control), 6.63%–10.44%, 15.00%–23.80% and 0.98%–4.87%, respectively, and with significant differences in seed and kernel water absorption between the TCs (P < 0.01). The dominant factor affecting viability was the interaction between microwave radiation and water soaking time, and the water absorption of seeds and kernels was affected by the soaking time of seeds in clear water; the germination rates of seeds with and without viability measured (TTC method) were 4.0%–22.8% and 52.7%–90.0%, respectively, and those of the control were 4.7% and 60.0%. Microwave radiation was the dominant factor affecting the germination rate. Nursery germination rates of seeds radiated with microwave combined seeds soaked with water and GA₃ were 56.0%–71.6% (56.0% of the control), with the interaction between water and GA₃ soaked seeds was the dominant factor affecting the germination rate. The combination of microwave radiation and soaking seeds in water reduced seed viability. When the seeds were soaked in water for 8 hours, the water absorption of the seeds basically reached saturation. Soaking seeds in microwave radiation for 10 s, and clear water for 8 h after 0.05 g/L GA₃ solution could improve the germination rate of P. armandii seeds, which could be applied to production practice.