堆肥污泥对杨树幼苗主要抗逆生理动态变化的影响

Dynamic changes of main stress-resistance physiology in poplar seedlings exposed to composted sewage sludge

采用温室盆栽实验研究堆肥污泥对两个杨树品种[凌丰三号(Populus×euramaricanacl.‘Lingfeng 3’)和欧美杨108号(Populus×euramericana‘Guariento’)]幼苗叶片的超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性、过氧化物酶(POD)活性、脯氨酸(Pro)及丙二醛(MDA)含量在不同生长季(污泥施用后的4周、9周、16周和21周)动态变化的影响,分别设置低量污泥(15 t hm-2,LS)、中量污泥(30 t hm-2,MS)、高量污泥(60 t hm-2,HS)和对照(不施污泥,CK)4个处理。结果表明:施用堆肥污泥对2个杨树品种幼苗叶片的SOD、POD及CAT活性的影响在不同生长季均为显著,其中POD活性普遍有所降低,SOD活性基本呈现降低趋势,而CAT活性则因不同品种、污泥用量和生长季而异。施用堆肥污泥对两个品种叶片Pro含量的影响除了污泥施用前期(4周后)外,其他生长季均为显著。污泥对2个品种叶片的膜质过氧化的影响在不同生长季有所差异,在4周和21周后的影响均显著,而在9周和16周后的影响均不显著,并且在污泥施用前、中期(即4周和16周后),叶片的MDA含量基本呈现增加趋势,而在21周后MDA含量则普遍有所降低。由此说明,杨树幼苗对污泥施用有一个适应过程,但因品种和污泥用量而异。

A pot experiment in greenhouse was conducted to study the effects of composted sewage sludge （CSS） on the dynamic changes of superoxide dismutase activity （SOD）, hydrogen peroxide activity （CAT）, peroxidase activity （POD）, proline （Pro） content, and malondialdehyde （MDA） content in leaves of two varieties of poplar （Populus x euramaricanacl. ＇Lingfeng 3＇ and Populus x euramericana＇Guariento） in different growth seasons （4 weeks, 9 weeks, 16 weeks, and 21 weeks following CSS application）. Four treatments including low amount of sludge （15 t.hm2, LS）, medium amount of sludge （30 t.hm-2, MS）, high amount of sludge （60 t.hm-2, HS）, and control （no sewage sludge, CK）, were set in the experiment. The results showed that the application of CSS significantly affected the activities of SOD, POD and CAT in leaves of the two poplar varieties in different seasons. POD activity was generally decreased, SOD activity basically showed a lower change trend, and while CAT activity changes depended on the varieties, sewage sludge amount, and the growth season. Except the early stage following CSS application （after 4 weeks）, the application of CSS significantly affected the Pro content in leaves of the two varieties in other growth seasons. CSS had different impacts on membranous peroxidation in leaves of the two varieties in different growth seasons; after 4 and 21 weeks, it had significant effects, while the effects were not significant after 9 and 16 weeks. In addition, the MDA content in early and medium stages （after 4 weeks and 16 weeks） following CSS application were basically enhanced, while after application of 21 weeks the MDA content generally decreased. These results suggested that poplar seedlings may have a process of adaptation to CSS application, depending on the varieties and sludge dosages.