The importance of controlled temperature during the four-days co-cultivation period was evaluated under the most physiologically relevant conditions for Agrobacterium tumefaciens-mediated transformation of tobacco (Ni...The importance of controlled temperature during the four-days co-cultivation period was evaluated under the most physiologically relevant conditions for Agrobacterium tumefaciens-mediated transformation of tobacco (Nicotiana tabacum L. cv. Xanthi (nn, Smith)) leaf disks. We compared the effect of temperatures ranging from 15°C, 18°C, 20°C, 22°C to 25°C on the stable expression of β-glucuronidase (GUS) activity of 14 days old hygromycin-selected leaf disks, and on the increase in the fresh weight yield of 28 days old kanamycin-selected calli. The highest average of GUS activity was obtained at 20°C among the five temperatures tested although the difference between the 18°C and 20°C treatment was not statistically significant. The GUS activity at 15°C was statistically lower than those at 18°C and 20°C. The GUS activity in 22°C treatment was an intermediate between the highest (18/20°C) and second highest averages (15°C), and was not statistically significantly different. The lowest average of GUS activity was observed at 25°C. The highest increase in the plate average of fresh weight yield was obtained at 20°C among the five temperature tested. The 20°C treatment was statistically significantly better than the 15°C and 18°C treatments. The 20°C co-cultivation treatment resulted in the higher FW yield than 22°C and 25°C even though the differences were not statistically significant. In conclusion, low co-cultivation temperature at 20°C resulted in the reproducible maximum increase in both the fresh weight yield and stable expression of GUS activity after transformation of tobacco leaf disks.展开更多
[Objective] This study aimed to investigate the effects of different fertilizer levels on lodging and yield of rice. [Method] A total of four treatments were designed and applied with 6, 9, 12 and 15 kg of nitrogen fe...[Objective] This study aimed to investigate the effects of different fertilizer levels on lodging and yield of rice. [Method] A total of four treatments were designed and applied with 6, 9, 12 and 15 kg of nitrogen fertilizer, respectively. After seedling transplanting, the biological characteristics of rice at different growth stages in each treatment and the biological and economic characteristics of rice after lodging were determined for statistical analysis. [Result] Application with 15 kg of nitrogen fertilizer had significant promotion effect on the increase of rice yield; compared with the control (6 kg of nitrogen fertilizer), rice yield in three experimental treatments (9, 12 and 15 kg of nitrogen fertilizer, respectively) increased by 50.74%, 89.11% and 94.48%, respectively; lodging-resistance mechanical strengths of the three experimental treatments were 103.97%, 132.01% and 89.83% of the control, respectively; rice lodging resistance of treatment C (12 kg of nitrogen fertilizer) was the strongest, with the highest yield. [Conclusion] This study provides reference data and technical support for the rational fertilization of rice production.展开更多
文摘The importance of controlled temperature during the four-days co-cultivation period was evaluated under the most physiologically relevant conditions for Agrobacterium tumefaciens-mediated transformation of tobacco (Nicotiana tabacum L. cv. Xanthi (nn, Smith)) leaf disks. We compared the effect of temperatures ranging from 15°C, 18°C, 20°C, 22°C to 25°C on the stable expression of β-glucuronidase (GUS) activity of 14 days old hygromycin-selected leaf disks, and on the increase in the fresh weight yield of 28 days old kanamycin-selected calli. The highest average of GUS activity was obtained at 20°C among the five temperatures tested although the difference between the 18°C and 20°C treatment was not statistically significant. The GUS activity at 15°C was statistically lower than those at 18°C and 20°C. The GUS activity in 22°C treatment was an intermediate between the highest (18/20°C) and second highest averages (15°C), and was not statistically significantly different. The lowest average of GUS activity was observed at 25°C. The highest increase in the plate average of fresh weight yield was obtained at 20°C among the five temperature tested. The 20°C treatment was statistically significantly better than the 15°C and 18°C treatments. The 20°C co-cultivation treatment resulted in the higher FW yield than 22°C and 25°C even though the differences were not statistically significant. In conclusion, low co-cultivation temperature at 20°C resulted in the reproducible maximum increase in both the fresh weight yield and stable expression of GUS activity after transformation of tobacco leaf disks.
文摘[Objective] This study aimed to investigate the effects of different fertilizer levels on lodging and yield of rice. [Method] A total of four treatments were designed and applied with 6, 9, 12 and 15 kg of nitrogen fertilizer, respectively. After seedling transplanting, the biological characteristics of rice at different growth stages in each treatment and the biological and economic characteristics of rice after lodging were determined for statistical analysis. [Result] Application with 15 kg of nitrogen fertilizer had significant promotion effect on the increase of rice yield; compared with the control (6 kg of nitrogen fertilizer), rice yield in three experimental treatments (9, 12 and 15 kg of nitrogen fertilizer, respectively) increased by 50.74%, 89.11% and 94.48%, respectively; lodging-resistance mechanical strengths of the three experimental treatments were 103.97%, 132.01% and 89.83% of the control, respectively; rice lodging resistance of treatment C (12 kg of nitrogen fertilizer) was the strongest, with the highest yield. [Conclusion] This study provides reference data and technical support for the rational fertilization of rice production.
