Effects of Isothermal Temperature Changing Treatment on Seed Germination of Pinus tabulaeformis Different temperatures have different effects on seed germination of Pinus tabulaeformis. The seed germination experiment is an experiment that must be done to calculate the seed germination rate. This is one of the important parameters of seed quality. Before the germination rate of seeds is measured, we first need to determine and analyze the 1000-seed weight of the seeds, the moisture content of the seeds, and the clarity of the seeds. The most commonly used instruments are the seed blower, the seed clarity analysis table, and the seeds. Counting instrument and seed suction bed instrument. These instruments are the most frequently used instruments for the identification of seed quality. These instruments provide very convenient services for quality inspection. Germination characteristics of Pinus tabulaeformis seedlings under constant temperature treatment: Germination tests showed that under specific temperature conditions, Pinus tabulaeformis seeds germinated at 2 to 3 days after pretreatment. At different temperatures of 15, 20, 25, 30, and 35°C, the seed germination rate and germination index of Pinus tabulaeformis were different. With the increase of temperature, the germination rate of seeds increased first and then decreased. The germination rate was the highest at 25°C, followed by 30°C. The germination rate was the highest at 30°C, followed by 25°C. The results showed that the optimum temperature for seed germination of Pinus tabulaeformis was 25°C and 30°C. The germination rate and germination index had no significant difference between the two treatments. When the temperature exceeded 35°C, the seed germination was inhibited. In the temperature range of 20~30°C, the germination rate of Pinus tabulaeformis seed could exceed 90%, and there was no significant difference, but the germination rate under 15°C and 35°C was significantly different (F=10.71, P< 0.05) Above 35°C, the mildew rate of the seed reached more than 40%. The seed germination indexes of Pinus tabulaeformis at 25, 30, 20, 15 and 35 °C were significantly different (F=15.98, P<0.05). The germination characteristics of Pinus tabulaeformis seedlings under variable temperature treatment: According to the germination test, the seed germination rate of Pinus tabulaeformis was the highest and the germination rate was the fastest under varying temperature treatment at 20°C/25°C; 15°C/25°C and 15°C/30°C variable temperature treatments. Under the conditions, the germination rate is lower and the germination rate is slower. There were significant differences in seed germination rate and germination index under different temperature treatments of 20°C/25°C and 15°C/25°C and 15°C/30°C (F=5.72, P<0.05, F=20.11, respectively). P<0. 05). In summary, it is known that an excessive temperature difference may inhibit the germination of Pinus tabulaeformis seeds. Pipe Fitting Elbow,Elbow Pipe Fitting Mould,Elbow Flexible Pipe Fittings,Elbow Pipe Fitting CHINA·SNGONG FLANGE MANUFACTURING CO., LTD. , https://www.sngong.com