摘要
【目的】探究荧光假单胞菌(Pseudomonas fluorescens)的促生特性及其对桃树根区土壤环境和桃树生长的影响,明确荧光假单胞菌在桃树根系–土壤微生态系统中的作用机制,为荧光假单胞菌在桃园的应用提供理论依据。【方法】采用不同固体培养及液体发酵试验鉴定荧光假单胞菌的促生特性。以1年生盆栽毛桃[Prunus persica(L.)Batsch]实生苗为试材进行预备试验,确定了荧光假单胞菌悬液的适宜施用浓度为4×10^(8) CFU/mL。以2年生‘瑞光39/毛桃’[P.persica(L.)Batsch]嫁接苗为试材进行盆栽试验,试验设土施荧光假单胞菌悬液(4×10^(8) CFU/mL)(PF)和清水对照(CK)2个处理,在处理后1、2、4、6周,采集桃树根区土壤样品,测定荧光假单胞菌数量;在处理后40天采集根区土壤样品测定土壤微生物结构、酶活性、养分状况和pH。在处理后20、40天取植株样进行光合指标、生物量、根系生长发育的测定。【结果】1)荧光假单胞菌具有以下促生特性:吲哚-3-乙酸(IAA)产量为6.17 mg/L,溶无机磷和有机磷量分别为45.98和18.52 mg/L,产铁载体和具有解钾能力。2)与对照相比,PF处理提高了桃树嫁接苗根区土壤细菌和真菌群落的Chao 1和Shannon指数,其中土壤真菌群落的Chao 1和Shannon指数分别显著提高了28.5%和8.5%(P<0.05);改变了土壤微生物群落结构,其中土壤细菌变形菌门、酸杆菌门和放线菌门相对丰度分别提高了23.4%、8.6%和8.0%,拟杆菌门和厚壁菌门相对丰度分别降低了46.7%和35.7%。与CK相比,PF处理根区土壤pH降低了0.19,土壤速效磷、碱解氮、速效钾和有效态铁含量分别显著提高了42.3%、15.9%、39.5%和6.6%(P<0.05);土壤脲酶、蔗糖酶、碱性磷酸酶和过氧化氢酶活性分别显著提高了4.3%、37.6%、34.2%和40.2%(P<0.05);根系表面积和体积分别显著提高了67.3%和21.3%(P<0.05),增加了侧根数量。与CK相比,PF处理显著提高了桃树叶片的净光合速率,叶片和根系的全氮、全磷和全钾含量,并使桃树叶片的全铁含量提高了26.0%,使桃树株高、地下部和地上部干重分别显著提高了14.8%、19.3%和19.9%(P<0.05)。【结论】荧光假单胞菌具有产IAA和铁载体,溶解无机磷和有机磷,降解难溶性钾的促生特性。土壤施用荧光假单胞菌悬液可以显著改善根区土壤环境,增加土壤微生物群落多样性,改变土壤微生物群落结构,降低土壤pH,提高土壤养分含量和土壤酶活性,从而促进桃树嫁接苗侧根的形成和生长,提高叶片净光合速率和养分含量,进而促进桃树生长。
【Objectives】We studied the growth-promoting characteristics of Pseudomonas fluorescens,and the growth promoting effect of P.fluorescens from soil microecosystem,to provide theoretical basis for the application of microbials for sustainable orcharding.【Methods】The growth-promoting characteristics of P.fluorescens were identified using different solid culture media and liquid fermentation.A pilot pot experiment was carried out using one-year-old potted peach seedlings,and the suitable concentration of P.fluorescens suspension was found to be 4×10^(8) CFU/mL.Then,a pot experiment was carried out using grafted seedlings of 2-year old‘Ruiguang39/Prunus’[P.persica(L.)Batsch]as experimental material,with 4×10^(8) CFU/mL of P.fluorescens suspension as the treatment(PF),and no P.fluorescens(CK)as the control.On the 7th,14th,28th,and 42nd days of treatment,soil samples around root zone of peach seedlings were collected for the determination of microbial structure,enzyme activity,nutrient content,and pH.On the 20th and 40th days of treatment,shoot and root samples were collected for the determination of root growth,shoot nutrient content,leaves photosynthetic characteristics and plant growth of peach.【Results】1)P.fluorescens was proven having the following growth-promoting characteristics:producing 6.17 mg/L of indole-3-acetic acid(IAA),dissolving inorganic and organic P of 45.98 and 18.52 mg/L,respectively,and the capacity of producing siderophores and releasing slowly-available K.2)Compared with CK,PF treatment increased the Chao 1 and Shannon index of bacteria and fungus communities,and the increment in the Chao 1 and Shannon index of fungus community were as high as 28.5%and 8.5%(P<0.05);PF treatment altered the soil microbial community structure.The relative abundance of Proteobacteria,Actinobacteria,and Acidobacteria were increased,while Bacteroidetes population was reduced.The relative abundance of Ascomycota and Basidiomycetes were decreased,while that of Moridomycetes was increased.The soil pH was decreased by 0.19,available P,N,K and Fe content in PF treatment was significantly increased by 42.3%,15.9%,39.5%and 6.6%(P<0.05),and the activities of soil urease,sucrase,phosphatase and catalase were improved by 4.3%,37.6%,34.2%and 40.2%(P<0.05),compared to the soil of CK.PF application significantly increased root surface area and volume by 67.3%and 21.3%(P<0.05),and increased the lateral root number.PF treatment significantly increased the net photosynthesis,the contents of total NPK in leaves and roots,and the content of total iron in leaves of peach by 26.0%,thus,significantly increasing the plant height,above-and below ground dry weight by 14.8%,19.3%and 19.9%(P<0.05).【Conclusions】P.fluorescens has certain growth-promoting characteristics of IAA and siderophores production,degradation of inorganic phosphorus,organic phosphorus and insoluble potassium.Soil application of P.fluorescens suspension increases soil microbial community diversity,alters soil microbial community structure,reduces soil pH,increases peach rhizospheric soil nutrient content and soil enzyme activities.P.fluorescens increases the lateral root number,improves the root architecture,increases the photosynthetic rate,thus increasing the nutrient content and the biomass,thereby promoting the growth of peach.
作者
杨晓帆
梁家慧
于文英
吴雪莲
李艳艳
肖元松
彭福田
YANG Xiao-fan;LIANG Jia-hui;YU Wen-ying;WU Xue-lian;LI Yan-yan;XIAO Yuan-song;PENG Fu-tian(College of Horticulture Science and Engineering,Shandong Agricultural University/State Key Laboratory of Crop Biology,Tai’an,Shandong 271018,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2022年第8期1494-1508,共15页
Journal of Plant Nutrition and Fertilizers
基金
国家重点研发计划资助(2020YFD1000203)
国家桃产业技术体系(CARS-30-2-02)
山东省农业良种工程(2020LZGC007)。
关键词
荧光假单胞菌
桃树
促生作用
土壤理化性状
土壤微生物
Pseudomonas fluorescens
peach
growth-promotion effect
soil physical and chemical properties
soil microorganism