摘要
以内蒙古荒漠草原5种植物短花针茅(Stipa breviflora)、无芒隐子草(Cleistogenes songorica)、冷蒿(Artemisia frigida)、阿尔泰狗娃花(Heteropappus altaicus)和银灰旋花(Convolvulus ammannii)为研究对象,收集了5种植物根系12、24、48 h的分泌物,运用超高效液相色谱-四极杆飞行时间串联质谱法分析了其中的有机酸组分,并将检测到的4种有机酸组分回接到草原原位土壤中培养3周后,分析其对土壤中微生物与主要养分的影响。结果表明,短花针茅和阿尔泰狗娃花根分泌物中均检测到棕榈酸和油酸2种有机酸。无芒隐子草根分泌物中检出棕榈酸、油酸和邻苯二甲酸3种有机酸。银灰旋花根分泌物中检测到棕榈酸、油酸、邻苯二甲酸和琥珀酸4种有机酸。冷蒿根分泌物中仅检测到邻苯二甲酸1种。4种有机酸组分中,5、10、15μL·g−13种不同质量浓度的棕榈酸和油酸均可促进土壤细菌、真菌、放线菌及微生物总数显著增加,而且浓度越大其增加越显著。而3种不同浓度的邻苯二甲酸和琥珀酸对三大类群微生物的影响表现出不同的浓度效应。不同浓度的4种有机酸均可使土壤pH值显著下降,对土壤含水量无显著影响。棕榈酸、油酸和琥珀酸还可使土壤中有机碳、速效氮和速效磷的含量显著增加,而邻苯二甲酸使土壤有机碳和速效氮的含量显著降低,有效磷含量显著增加。棕榈酸和油酸能够显著改善植物根际土壤微环境。
In this study,we collected the roots of Stipa breviflora,Cleistogenes songorica,Artemisia frigida,Heteropappus altaicus and Convolvulus ammannii of the desert steppe in Inner Mongolia.Their root exudates of 12 hours,24 hours and 48 hours were collected respectively,and the organic acid components in the root exudates were analyzed by ultra-high-performance liquid chromatography-quadrupole rod time-of-flight tandem mass spectrometry.Then the four organic acid components were added to the soil and cultivated for three weeks,and their effects on the number of microorganisms and nutrients in the soil were analyzed.The results as follows,palmitic acid and oleic acid were detected in root exudates of S.breviflora and H.altaicus.Phthalate,oleic acid and palmitic acid were detected in root exudates of C.songorica.Succinic acid,palmitic acid,oleic acid and phthalic acid were detected in root exudates of C.ammannii.Only phthalate was detected in root exudates of A.frigida.Among the four organic acid components,at three different concentrations of 5,10 and 15μL·g−1,palmitic acid and oleic acid can significantly increase the numbers of bacteria,fungi,actinomycetes and the total number of microorganisms in the soil,and the greater their concentration,the more significant increase of microorganisms,numbers.The effects of different concentrations of phthalic acid and succinic acid on the three groups of microorganisms showed different concentration effects.The four organic acids at different concentrations could significantly reduce the soil pH,and all had no significant effect on soil water content.Palmitic acid,oleic acid,and succinic acid can also significantly increase the content of organic matter,available nitrogen and available phosphorus in the soil.Palmitic acid can significantly reduce soil organic carbon and available nitrogen,and significantly increase available phosphorus.Palmitic acid and oleic acid can significantly improve the microenvironment of plant rhizosphere soil.
作者
高雪峰
贾渊
GAO Xuefeng;JIA Yuan(College of Life Sciences and Technology,Inner Mongolia Normal University,Hohhot 010020,China)
出处
《生态环境学报》
CSCD
北大核心
2020年第10期1927-1934,共8页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(31660157)
内蒙古师范大学基金项目(2018YJRC042)。
关键词
荒漠草原
根分泌物
有机酸
土壤微生物
土壤养分
desert steppe
root exudate
organic acid
soil microorganism
soil nutrient
