氮对小叶丁香生长及保护酶活性的影响

Effects of Nitrogen on Growth and Protective Enzyme Activity of Syringa microphylla Diels

为解决小叶丁香育苗中因土壤养分供应不足导致的生长势降低问题,试验研究了不同氮肥施用量对其生长和保护酶活性的影响规律,以期为育苗中科学合理施用氮肥提供理论依据。试验在田间条件下,设置4个氮肥施用量分别为0 g/株(N1,CK)、10 g/株(N2)、15 g/株(N3)、22.5 g/株(N4),3次重复。结果表明:N3枝条生长量比N1、N2提高了87.44%、49.11%;7~9月N3叶绿素分别比N2提高了4.82 mg/g、4.99 mg/g、4.05 mg/g,N4与N3之间无显著差异;5~9月,N3处理SOD活性分别比N2提高了16.58 U/g、12.05 U/g、21.54 U/g、27.14 U/g、37.19 U/g,7~9月差异显著,N4与N3之间无显著差异;N3处理POD活性在5、8、9月分别比N2提高了13.65 U/g、13.18 U/g、15.01 U/g,差异显著。结合本试验结果,小叶丁香育苗中氮肥施用量以15 g/株为宜。

In order to solve the problem of decreasing growth potential caused by insufficient soil nutrient supply in seedling breeding of Syringa microphylla Diels,the effects of different nitrogen application rates on growth and protective enzyme activities were studied to provide theoretical basis for rational application of nitrogen fertilizer in seedling breeding. The experiment was conducted in field conditions,with establishing 4 nitrogen fertilizer application amounts at 0 g/stock( N1,CK),10 g/stock( N2),15 g/stock( N3) and 22. 5 g/stock( N4),repeating for three times. The results showed that branch growth of N3 increased by 87. 44% and 49. 11% higher than N1 and N2. From July to September,Chlorophyll of N3 treatment increased by 4. 82 mg/g,4. 99 mg/g and 4. 05 mg/g higher than N2,there was no significant difference between N4 and N3. From May to September,SOD activity of N3 treatment increased by 16. 58 U/g,12. 05 U/g,21. 54 U/g,27. 14 U/g and 37. 19 U/g higher than N2,there was significant difference from July to September,and there was no significant difference between N4 and N3. POD activity of N3 treatment increased by 13. 65 U/g,13. 18 U/g and 15. 01 U/g higher than N2 in May,August and September separately,with significant difference. According to the test results,the optimum amount of nitrogen fertilizer was 15 g/stock in seedling breeding of Syringa microphylla Diels.