长期偏施氮肥对桑园土壤氨氧化微生物的影响  

Responses of soil ammonia-oxidizing microbes to different application years of nitrogen fertilizer in mulberry field

作　　者：于翠[1] 李欣[1] 朱志贤 董朝霞 莫荣利[1] 李勇[1] 邓文[1] 熊超[1] 胡兴明[1] YU Cui;LI Xin;ZHU Zhi-xian;DONG Zhao-xia;MO Rong-li;LI Yong;DENG Wen;XIONG Chao;HU Xing-ming(Industrial Crops Institute of Hubei Academy of Agricultural Sciences,Wuhan Hubei 430064)

机构地区：[1]湖北省农业科学院经济作物研究所,湖北武汉430064

出　　处：《中国土壤与肥料》2021年第3期35-44,共10页Soil and Fertilizer Sciences in China

基　　金：国家自然科学基金项目(31770660,31300518);现代农业产业技术体系建设专项(CARS-22)。

摘　　要：氮肥能够影响土壤氨氧化细菌(AOB)和氨氧化古菌(AOA)的丰度和种群结构。利用实时荧光定量PCR(RT-PCR)和变性梯度凝胶电泳(PCR-DGGE)技术研究不同氮肥施用年限(4年,4Y;17年,17Y;32年,32Y;0年,0Y)桑园土壤氨氧化微生物丰度及种群结构变化。结果发现,长期施用氮肥导致桑园土壤酸化,与4Y土壤相比,32Y土壤pH降低0.88。4Y处理土壤AOB amoA基因的拷贝数最高,而在32Y土壤中AOA amoA基因拷贝数最高。各处理AOB amoA基因拷贝数为每克干土6.46×10^(5)~8.32×10^(7),明显高于AOA amoA基因拷贝数每克干土1.70×10^(4)~1.20×10^(5)。AOB种群丰度与潜在硝化速率(PNR)呈显著正相关,而AOA种群丰度与土壤pH和PNR的相关性不显著,表明AOB在硝化作用中发挥更为重要的作用。DGGE条带分析表明,氮肥施用年限对AOB种群结构影响较大,而对AOA种群结构影响较小。结果表明,桑园中AOB种群在氮循环中占主导地位,并且长期施用氮肥对桑园土壤AOB丰度和种群结构影响较大,而对AOA影响最小。Nitrogen fertilizer can affect the abundance and composition of soil ammonia-oxidizing bacteria(AOB)and ammonia-oxidizing archaea(AOA).This study investigated the response of AOB and AOA to different application years(4 years,4Y;17 years,17Y;32 years,32Y;0 year,0Y)of nitrogen fertilizer using real-time polymerase chain reaction(RT-PCR)and denaturing gradient gel electrophoresis(PCR-DGGE).The results showed that long-term nitrogen fertilizer application resulted in soil acidification,and the pH was decreased by 0.88 in 32Y soil compared with 4Y soil.The 4Y soil had the highest copy numbers of AOB amoA genes among the treatments,whereas those of AOA amoA genes were found in 32Y soil.The bacterial amoA gene copy numbers ranging from 6.46×10^(5) to 8.32×10^(7)per gram of dry soil were significantly higher than those of archaeal amoA genes,ranging from 1.70×10^(4) to 1.20×10^(5) per gram of dry soil.The AOB population size was positively correlated with the potential nitrification rates(PNR),which indicated a potential role of AOB in nitrification.No significant correlations were observed among the population size of AOA,soil pH and PNR.DGGE patterns revealed that different application years of nitrogen fertilizer resulted in an obvious change of the AOB community composition,but not of AOA.These results suggest that long-term application of nitrogen fertilization had a significant impact on AOB abundance and composition,while minimal on AOA abundance in mulberry field soil.

关 键 词：氮肥 氨氧化微生物 种群结构和丰度 桑树 

分 类 号：S888.4[农业科学—特种经济动物饲养] S154.3[农业科学—畜牧兽医]