Effects of Different Temperature Treatments on Seed Germination and Physiological Metabolism of Pyrus calleryana

With the seeds of Pyrus calleryana as panicle materials, different temperatures were applied to determine the germination on seed of P. calleryana, including 10 ℃, 15 ℃, 20 ℃, 25 ℃, and 30 ℃. The seed germination rate was recorded at different temperatures, and the change in nutrient content and enzyme activity were measured during the germination process at 10 ℃, 15 ℃, and 25 ℃, so as to analyze the effect of different temperatures on seed germination and physiologic metabolism of P. calleryana. It was revealed that the seed germination rate of P. calleryana was the highest at 15 ℃, reaching 96.67%; with a germination index of 14.16, and the germination process took the shortest time. What's more, the consumption of nutrients was the largest, and the metabolic enzyme activity was the strongest at 15 ℃.; At 20 ℃, the percentage of germination was the second highest at 87%, and the germination index was the highest at 16.82, indicating that the seed began to germinate earliest; At 10 ℃, the seed percentage rate of P. calleryana was less than 50% , and the metabolic consumption rate and enzyme activity of seeds were lower than those at 15 ℃; At 25 ℃, the percentage of germination was less than 20%, and the physiological metabolic process of seeds was slow.; At 30 ℃, the seeds didn't germinate. Therefore, 15 ℃～20 ℃ is more suitable for the germination of P. calleryana.