【作者】 张洪；

【导师】 龚国淑；

【作者基本信息】 四川农业大学 ， 植物病理学， 2008， 硕士

【摘要】 本文采用稀释平板法对采自横断山北部高山区35个土样进行了分离与计数,分析了细菌数量与土壤质地、海拔高度、土地利用方式和土层深度等因子的关系。根据土壤细菌的数量、种群研究了该地区土壤细菌的物种多样性,并分析了该区域土壤细菌在拮抗病原菌和解磷解钾方面的潜在能力。研究结果表明,横断山北部高山区土壤中细菌数量比较丰富,平均数量达1.03×10⁷±8.57×10⁶ cfu·g^-1干土,不同样点的表层土壤细菌数量存在较大的差异,表层土壤细菌数量最高和最低之间相差了100多倍,而在深层土壤细菌数量最高与最低之间只相差10多倍。0～20cm表层土样表现为松林口(2.05×10⁷±1.8×10⁷ cfu·g^-1干土)＞雀儿山(1.01×10⁷±3.38×10⁶ cfu·g^-1干土)＞折多山(7.03×10⁶±5.23×10⁶ cfu·g^-1干土);粘壤土(1.79×10⁷±3.11×10⁷cfu·g^-1干土)＞粉砂质粘壤土（1.32×10⁷±1.01×10⁷cfu·g^-干土）＞粉砂质壤土(8.8×10⁶±8.80×10⁶cfu·g^-1干土)＞砂质壤土(7.34×10⁶±6.62×10⁶cfu·g^-1干土)＞壤土(4.23×10⁶±4.23×10⁶ cfu·g^-1干土);林地(1.65×10⁷±2.56×10⁷cfu·g^-1干土)＞草地(4.56×10⁶±4.00×10⁶ cfu·g^-1干土)＞灌丛林地(4.22×10⁶±3.66×10⁶ cfu·g^-1干土);土壤深度增加,细菌数量减少。同一样点,受海拔高度影响细菌数量呈现减少的趋势,但影响程度却不大。经分离共获得668株土壤细菌,鉴定为15个属,其中包括芽孢杆菌9个种。表层土壤分布范围较广的细菌为有纤维素单胞菌（Cellulomonas spp.）、脂肪杆菌（Pimelobacter spp.）、微球菌（Micrococcus spp.）、芽孢杆菌（Bacillus spp.）、土壤单胞菌（Agromonas spp.）和葡萄杆菌（Gluconobacter spp.）,其分离频率分别为54.29%、60%、51.43%、100%、54.29%和28.57%。此外,芽孢杆菌中蜡状芽孢杆菌（B.cereus）和球形芽孢杆菌（B.spaericus）分布较广泛,分离频率分别为80.0%和51.43%。不同区域,细菌优势类群均以芽孢杆菌（Bacillus spp.）和脂肪杆菌（Pimelobacter spp.）数量居多;壤土和砂质壤土均以脂肪杆菌数量最多,粉砂质壤土、粉砂质粘壤土和粘壤土均以芽孢杆菌数量最多;林地、草地和灌丛林地的芽孢杆菌数量占绝对优势。横断山北部高山区土壤细菌的物种丰富度、物种多样性指数、均匀度指数、优势度指数均各不相同,它们的值分别是7.3714±4.7035、1.0144±0.4575、0.3746±0.1689和0.4955±0.2249。不同样点土壤细菌的物种多样性指数、均匀度指数、优势度指数都各不相同,同样的物种丰富度,其物种多样性指数之间可能存在较大的差异;即使是物种丰富度相同的样点也有着不相同的物种多样性指数、均匀度指数和优势度指数。203株细菌中具有抑制立枯丝核菌的菌株共25株,占供试菌株总数的11.90%;37株对禾谷镰孢菌有抑制作用,占供试菌株总数的17.62%;6株菌株发酵液同时对两种病原菌抑制率达到50%以上。具有抑制作用的菌株大多为芽孢杆菌。18株对无机磷具有一定的分解能力,大部分为芽孢杆菌属和脂肪杆菌属,17对有机磷具有一定的分解能力,大部分为节杆菌属。没有菌株具有明显的解钾能力。更多还原

【Abstract】 43 soil samples of 35 plots,located by GPS（Global Position System）,were collected from the regions of northern alp of Hengduan Mountains of Qinghai-Xizang Plateau.Quantities of bacteria were determined with the dilution plate technique.The soil bacteria were identified and the correlations between the quantities of bacteria and some factors which including area,agrotype,land-use type, altitude and soil depth were analyzed by using the software of DPS.According to the quantities, communities and their distribution,the bacteria diversity was also studied.Potential which could antagonize to pathogen,solubilize phosphate and potassic-compound was also analyzed.The result showed that the average quantity of bacteria was about 1.03×10⁷±8.57×10⁶ cfu·g^-1 dry soil in the regions of northern alp of Hengduan Mountains.In the same depth and different regions,the quantity of bacteria in the highest sample is 100 times as many as it in the lowest sample.Bacteria quantities from high to low were as follows:in different regions,Songlinkou (2.05×10⁷±1.80×10⁷ cfu·g^-1 dry soil)＞Que’er Mountain(1.01×10⁷±3.38×10⁷ cfu·g^-1 dry soil)＞Zheduo Mountain(7.03×10⁶±5.23×10⁶ cfu·g^-1 dry soil).In different soil textures,clay Ioam(1.79×10⁷±3.11×10⁷ cfu·g^-1 dry soil)＞heavy clayey soil(1.32×10⁷±1.01×10⁷ cfu·g^-1 dry soil)＞powder sandy loam (8.8×10⁶±8.80×10⁶ cfu·g^-1 dry soil)＞sand loam(7.34×10⁶±6.62×10⁶ cfu·g^-1 dry soil)＞loam soil(4.23×10⁶±4.23×10⁶ cfu·g^-1 dry soil);In different land utilization way,forest land(1.65×10⁷±.56×10⁷ cfu·g^-1 dry soil)＞grass land(4.56×10⁶±4.00×10⁶ cfu·g^-1 dry soil)＞brush forest land(4.22×10⁶±3.66×10⁶ cfu·g^-1 dry soil).At the same plot,there were more bacteria in upper（0～20cm） than in deepersoil layers（20～40cm）.Bacteria quantity was changed with altitude,but the degree of the impact is not great.A total of 668 bacteria isolates were collected from the soil in the northern alp regions of Hengduan Mountains.15 bacteria genera were identified.Among these genera,Cellulomonas spp.,Pimelobacter spp., Micrococcus spp.,Bacillus spp.,Agromonas spp.and Gluconobacter spp.,were isolated more frequently at 54.29%,60.00%,51.43%,100.00%,54.29%and 28.57%.In addition,B.cereus and B.spaericus was also bacillus of main population,and its isolation frequency were 80.0%and 51.43%,respectively.In different regions,the genera of main population were Bacillus spp.and Pimelobacter spp.,In loam soil and sand loam,the genera of main population were Pimelobacter spp..In powder sandy loam,powder sandy loam and clay loam,the genera of main population were Bacillus spp..In different land utilization way,the quantity of bacillus is highest than other bacteria genera.The abundance（S）,Shannon-wiener’s diversity（H′）,Pielou’s evenness（E） and dominance index（D） were 7.3714±4.7035、1.0144±0.4575、0.3746±0.1689和0.4955±0.2249,respectively.In different location,the abundance（S）,Shannon-wiener’s diversity（H′）,Pielou’s evenness（E） and dominance index（D） were different.Even if,in the same abundance（S）n,The Shannon-wiener’s diversity（H′）, Pielou’s evenness（E） and dominance index（D） were different.Among 203 isolates,there were 25 isolates had obvious antagonistic effects against Rhizoctonia solani and 37 isolates had obvious antagonistic effects against Fusarium graminearum.In addition, there were 10 isolates against the two plant pathogens,and the percent inhibition of 6 isolates metabolites were more than 50%.There were 18 isolates which mainly belong to Bacillus spp.and Pimelobacter spp.were abiophosphate-solubilizing bacteria,and 17 isolates which mainly belong to Arthrobacter spp.solubilized organic-phosphate.更多还原