海水稻根际效应对滨海盐碱地土壤氨氧化微生物的影响  

Effects of Seawater Rice Rhizosphere Effect on Soil Ammonia-oxidizing Microorganisms in Coastal Saline-alkali Soil

作　　者：李高洋 黄永相[1,2] 吴伟健 陈艺杰 张伟健 罗舒文 李慧君 黄枫城 蔺中 甄珍 LI Gaoyang;HUANG Yongxiang;WU Weijian;CHEN Yijie;ZHANG Weijian;LUO Shuwen;LI Huijun;HUANG Fengcheng;LIN Zhong;ZHEN Zhen(College of Coastal Agricultural Sciences,Guangdong Ocean University,Zhanjiang,Guangdong 524088,China;South China Branch of National Saline-Alkali Tolerant Rice Technology Innovation Center,Zhanjiang,Guangdong 524088,China;Faculty of Chemistry and Environmental Science,Guangdong Ocean University,Zhanjiang,Guangdong 524088,China)

机构地区：[1]广东海洋大学滨海农业学院,广东湛江524088 [2]国家耐盐碱水稻技术创新中心华南中心,广东湛江524088 [3]广东海洋大学化学与环境学院,广东湛江524088

出　　处：《土壤学报》2023年第2期587-598,共12页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(41907033,41977125);广东省自然科学基金项目(2018A030307054)共同资助。

摘　　要：滨海盐碱地的特殊环境严重限制了土壤氮素转化和利用。微生物介导的水稻根际氨氧化过程是盐碱稻田土壤氮循环的关键过程,但限于研究盲点和技术不足,海水稻根际效应对滨海盐碱地土壤氨氧化微生物群落结构的影响仍少有报道。据此,本研究以“海稻86”为研究对象,分别设置低盐浓度(2 g·kg^(-1))和高盐浓度(6 g·kg^(-1))两组处理进行盆栽试验。结果显示:种植海水稻70 d后,高盐和低盐处理根际土壤的pH分别下降了0.82和0.70个单位,土壤有机质(SOM)含量下降了6.41和4.46 g·kg^(-1),腐殖质(HU)含量提高了5.76和4.45 g·kg^(-1),全氮(TN)含量减少0.46和0.37 g·kg^(-1),表明海水稻可通过降低盐碱地土壤pH,加速有机质分解转化,提高土壤氮循环速率。水稻根际作用可显著提高土壤微生物生物量碳(MBC)、微生物生物量氮(MBN)和微生物呼吸强度,并在种植第55天达到最高,在高盐处理中分别达到850.0 mg·kg^(-1)、72.2 mg·kg^(-1)和231.9 mg·kg^(-1)·d^(-1),低盐处理中达到546.1 mg·kg^(-1)、53.7 mg·kg^(-1)和171.2 mg·kg^(-1)·d^(-1),说明水稻根际作用对土壤微生物数量和活性的影响在55 d最强。海水稻根际效应对滨海盐碱地土壤氨氧化古菌(ammonia-oxidizing archaea,AOA)丰富度、多样性和丰度无显著影响,AOA优势菌为norank_c__environmental_samples_p__Crenarchaeota、unclassified_k__norank_d__Archaea和Nitrososphaera。海水稻根际效应显著提升了滨海盐碱地土壤氨氧化细菌(ammonia-oxidizing bacteria,AOB)丰富度和多样性,提高土壤AOB优势菌environmental_samples_f__Nitrosomonadaceae和Nitrosospira的丰度。相关性分析发现environmental_samples_f__Nitrosomonadaceae和Nitrosospira与土壤pH呈显著负相关,与腐殖质呈显著正相关。本研究结果表明种植海水稻可提高滨海盐碱地养分循环,并且在酸性土壤中耐盐碱水稻根系效应主要影响AOB的群落结构。【Objective】The special environment of coastal saline-alkali land restricts the transformation and utilization of soil nitrogen.Microorganisms in saline-alkali paddy environment mediate ammonia oxidation in rice rhizosphere in a key process of soil nitrogen cycling.However,due to research blindness and outdated technology,the effect of seawater rice rhizosphere effect on the microbial community structure of ammonia oxidation in coastal saline-alkali soil is rarely reported.【Method】In this study,the saline tolerant rice species‘Haidao 86’was used as the experimental material for the pot experiment.The pot experiment was conducted with low(2 g·kg^(-1))and high(6 g·kg^(-1))salt concentrations.Soil physicochemical properties and microbial biomass were measured and analyzed,and high-throughput sequencing of ammonia-oxidizing microorganisms was conducted to analyze the effects of different treatments of ammonia-oxidizing archaea(AOA)and ammonia-oxidizing bacteria(AOB)community structure in the rice rhizosphere.【Result】Results showed that after 70 days of rice growth,pH of rhizosphere soil decreased by 0.82 and 0.70,soil organic matter(SOM)content decreased by 6.41 g·kg^(-1)and 4.46 g·kg^(-1),humus(HU)content increased by 5.76 g·kg^(-1)and 4.45 g·kg^(-1),total nitrogen(TN)content decreased by 0.46 g·kg^(-1)and 0.37 g·kg^(-1)for low and high salt concentrations,respectively.Rice rhizosphere effect significantly increased soil microbial biomass carbon,microbial biomass nitrogen and microbial respiration intensity,reaching peak values on the 55th day of planting with 850.0 mg·kg^(-1),72.2 mg·kg^(-1)and 231.9 mg·kg^(-1)·d^(-1)for high salinity treatment and 546.1 mg·kg^(-1),53.7 mg·kg^(-1)and 171.2 mg·kg^(-1)·d^(-1)for low salinity treatment,respectively.The rhizosphere effect had no noticeable influence on the Chao1 index,Shannon index and Simpson index of AOA.At the genus level,the dominant bacteria of AOA were norank_c__environmental_samples_p__Crenarchaeota,unclassified_k__norank_d__Archae

关 键 词：海水稻 根际效应 氮循环 氨氧化细菌 氨氧化古菌 

分 类 号：S154[农业科学—土壤学]