摘要
研究旨在筛选获得硒砂瓜根际促生菌,为硒砂瓜微生物肥料的开发利用提供土著菌种资源和理论基础。以宁夏地区特有经济作物硒砂瓜根际土壤为材料,采用稀释平板法分离土著细菌,对筛选到的50株菌进行溶磷、产铁载体、产吲哚乙酸(IAA)以及固氮能力评价,结合16S rDNA序列分析对优良促生菌进行鉴定,并选定9株优良促生菌,研究其对硒砂瓜幼苗的促生作用。结果显示,50株菌中有22株解磷菌株的溶磷量在7.12~64.54 mg·L^(-1)之间;有30株具有产铁载体能力的菌株,定量结果表明其中11株为高产铁载体菌株(A/A r<0.5);有18株具有分泌IAA能力的菌株,分泌量在3.70~58.94 mg·L^(-1)之间;有9株菌在阿须贝平板上经5次传代仍能正常生长,初步确定其具有固氮能力。筛选得到的20株优良促生菌分别隶属于芽孢杆菌属(Bacillus)、假单胞菌属(Pseudomonas)、肠杆菌属(Enterobacter)、不动杆菌属(Acinetobacter)、变形杆菌属(Proteus),其中6株菌兼具以上4种促生活性,11株菌兼具解磷、产铁载体、分泌IAA促生功能。接种促生菌后,对硒砂瓜幼苗的胚根、胚轴、鲜质量及干质量等指标均有促进作用。
The purpose of this study was to screen and obtain the rhizosphere growth-promoting bacteria of Selenium watermelon and provide native strain resources and theoretical basis for the development and utilization of Selenium watermelon microbial fertilizer.50 native strains were screened from the rhizosphere soil of the endemic commercial crop Selenium watermelon in Ningxia by dilution plate method.The ability to solubilize phosphorus,produce iron carrier,produce indole acetic acid(IAA)and fix nitrogen was evaluated.The excellent growth promoting bacteria were identified by 16S rDNA sequence analysis,and nine strains were selected to study their growth-promoting effects on Selenium watermelon seedlings.The results showed that the ability of 22 strains phosphorus solubilizing was 7.12~64.54 mg·L^(-1).Using Chrome Azurol S(CAS)plate method,30 strains were able to produce siderophores.The quantitative results showed that 11 strains were high siderophore-producing strains.Additionally,the capacities of 18 strains to secrete IAA were 3.70~58.94 mg·L^(-1).The qualitative results of Ashby’s nitrogen-free plate showed that 9 strains still grew normally after five generations,which was considered to have the ability of nitrogen fixation.The 20 excellent PGPR strains screened belong to Bacillus,Pseudomonas,Enterobacter,Acinetobacter and Proteus,respectivley.Among them,6 strains had the above four kinds of growth promoting activities,and 11 strains had the functions of phosphorus solubilizing,siderophore-producing and IAA secretion.Inoculation of growth promoting bacteria promoted the radicle,hypocotyl,fresh weight and dry weight of Selenium watermelon seedlings.
作者
朱滕滕
何学莲
勉小娟
马献
郑蕊
岳思君
苏建宇
ZHU Tengteng;HE Xuelian;MIAN Xiaojuan;MA Xian;ZHENG Rui;YUE Sijun;SU Jianyu(College of Life Sciences,Ningxia University,Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western China,Yinchuan,Ningxia 750021,China)
出处
《干旱地区农业研究》
CSCD
北大核心
2023年第2期221-229,共9页
Agricultural Research in the Arid Areas
基金
宁夏回族自治区自然科学基金项目(2020AAC03109)
宁夏回族自治区重点研发计划项目(2020BBF02004)。
关键词
根际促生菌
硒砂瓜
筛选
16S
rDNA鉴定
促生效应
plant growth-promoting rhizobacteria(PGPR)
Selenium watermelon
screening
16S rDNA identification
growth-promoting effect
