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杨树人工林的连作障碍与土壤中的酚酸累积有密切关系.采用宏基因组测序技术研究I-107(Populus×euramericanna‘Neva’)欧美杨人工林连作与轮作土壤酚酸降解细菌群落特征及酚酸降解代谢的演变规律.供试土壤中共发现5种酚酸降解细菌,分别是假单胞菌(Pseudomonas sp.)、鲍氏不动杆菌(Acinetobacter baumannii)、皮氏罗尔斯顿菌(Ralstonia pickettii)、Acetobacteraceae bacterium AT-5844、多噬伯克霍尔德菌(Burkholderia multivorans).土壤酚酸降解细菌的丰度因人工林主伐更新轮作方式而异(P<0.05),表现为Ⅰ代林地>轮荒地>轮作花生地>Ⅱ代林地.杨树Ⅰ代林和Ⅱ代林土壤酚酸降解细菌的群落结构基本一致,总丰度Ⅱ代林较Ⅰ代林减少了9.69%,根际土壤中皮氏罗尔斯顿菌和Acetobacteraceae bacterium AT-5844丰度明显高于非根际土壤,根际效应明显;与杨树Ⅱ代林地相比,轮作花生地和轮荒地土壤中酚酸降解细菌总丰度分别增加了1.74%和8.27%.供试土壤中共发现6种酚酸降解关键酶,不同土壤中酚酸降解酶基因表达丰度存在显著差异(P<0.05),总体表现为Ⅰ代林地>Ⅱ代林地>轮作花生地>轮荒地,杨树Ⅱ代林地比Ⅰ代林地低11.18%,而轮作花生地和轮荒地分别又比杨树Ⅱ代林地低27.62%和19.90%,但轮作花生地和轮荒地中酚酸脱羧酶的基因表达丰度较杨树Ⅱ代林分别增加了73.33%和33.33%.因此,杨树人工林连作一代后,土壤中酚酸降解细菌的生长和代谢活性均受到了抑制;轮作可以改善连作对杨树人工林部分土壤酚酸降解细菌生长繁殖和代谢活动的影响.
Poplar × euramericanna’Neva ’Poplar × euramericanna’Neva’ Poplar × euramericanna’Neva ’Poplar × euramericanna’Neva’ Poplar × euramericanna’Neva ’Poplar × euramericanna’Neva’ Continuous-cropping and rotation Soil phenolic acid-degrading Bacterial community characteristics and Phenol acid degradation and metabolism of the evolution of soil were found in the total of five kinds of phenolic acid-degrading bacteria were Pseudomonas (Pseudomonas sp., Acinetobacter baumannii, Ralstonia pickettii and Acetobacteraceae bacterium AT-5844 and Burkholderia multivorans.The abundance of soil phenolic acid-degrading bacteria varied with plantation rotation and reforestation (P <0.05) Forestland> fallow land> perennial rotation> II generation of woodland.The community structure of phenolic acid-degrading bacteria in the poplarⅠandⅡgeneration forest soil was basically the same, the total abundanceⅡgeneration forest reduced 9.69% The abundance of AT-5844 in soil was significantly higher than that in non-rhizosphere soil, and the rhizosphere effect was obvious. Compared with the second generation of poplars, the phenolic acids degradation bacterial And the abundance increased by 1.74% and 8.27%, respectively. Six kinds of key enzymes of phenolic acid degradation were found in the soils, and there was a significant difference (P <0.05) in the gene expression abundance of phenolic degrading enzymes in different soils. > Ⅱ generation of woodland> rotation of peanut land> fallow land, and the second generation of poplars was 11.18% less than the first generation of woodland, while the rotation of peanut land and the rotation of wasteland were 27.62% and 19.90% lower than that of the second generation of poplar, respectively The gene expression abundance of phenolic decarboxylase increased by 73.33% and 33.33% in poplar and rotten habitat, respectively. Therefore, the growth and metabolic activity of phenolic acid-degrading bacteria Were restrained. Rotation could improve the effect of continuous cropping on the growth, reproduction and metabolism of phenolic acids-degrading bacteria in part of poplar plantations.