连作甜瓜土壤中酚酸类物质的变化规律和木霉菌降解作用研究

发布时间：2018-11-03 13:03

【摘要】：甜瓜(Cucumis sativus L.)又名香瓜,是我国东北地区重要的经济作物。近年来,我国东北地区甜瓜发展迅速,连作障碍日益突出,病虫害发生严重。甜瓜根系分泌物和植物病株残渣腐解是作物产生连作障碍的重要原因之一。本文通过高效液相色谱技术对甜瓜连作土壤中酚酸类物质进行检测,明确甜瓜连作土壤中酚酸类物质的组成以及变化规律,并从甜瓜病株土壤中筛选优势木霉菌种对酚酸类物质进行降解,为缓解甜瓜连作障碍提供科学依据。1.采用高效液相色谱技术,对盆栽模拟不同种植年限甜瓜土壤中酚酸物质的种类及其含量变化进行了分析鉴定。研究结果表明连作甜瓜土壤中对羟基苯甲酸、香草酸、丁香酸、香兰素、香豆酸、阿魏酸、苯甲酸随着连作年限的增加而增加,肉桂酸含量逐渐低,连作4年后8种酚酸物质的总量达257.94 mg·kg-1干土,显著高于未连作土壤;且随着盆栽模拟重茬种植年限的增加,甜瓜枯萎病等土传病害发生严重,植株生长受到抑制,坐果产量明显下降,连作障碍日趋严重。此外对东北三省18个地区的甜瓜土壤样品进行了分析鉴定,其中对羟基苯甲酸、香草酸等6种酚酸物质含量差异显著。2.筛选了东北地区甜瓜连作土壤中优势木霉菌种。本试验采集东北地区甜瓜连作土壤124份,筛选木霉菌菌株66株,占总数的53.23%;其中黑龙江地区分离到的木霉菌菌株31株,菌株数量和分离频率高于吉林和辽宁地区。经含有甜瓜根系分泌物的SA培养基中筛选出TQTH-03和TSY-02优势木霉菌株,对酚酸类物质具有较好的降解作用。3.建立了甜瓜连作土壤中的酚酸物质的降解体系,明确了木霉降解菌对甜瓜连作土壤中主要酚酸的降解作用。采用HPLC技术,通过外源施加孢子菌悬液、PD菌悬液和麦麸发酵物3种不同的接种方式测定木霉菌(T4、T23、TQTH-03、TSY-02)对甜瓜根际土壤中酚酸类物质的降解作用,结果表明木霉菌能够有效降解土壤中积累的酚酸物质,其中麦麸发酵物降解率可达到25%以上,降解效果最为显著;采用木霉菌(T4、T23、TQTH-03、TSY-02)无机盐发酵液、PD发酵液降解土壤样品,结果表明两种液体发酵液对甜瓜中主要酚酸物质的降解率多数高达20%以上,降解效果显著;利用木霉菌(T4、T23、TQTH-03、TSY-02)无机盐孢子悬浮混合液降解甜瓜土壤中主要的8种酚酸物质,用定量分析测得木霉菌均具有较好的降解作用,且高浓度时降解能力低,低浓度时降解率高。4.利用木霉菌和生物肥作为栽培基质进行了田间试验,为解决甜瓜连作障碍提供理论基础。实验结果表明,施加木霉菌处理的甜瓜发病率低于对照,利于增强甜瓜植株的生长抗病性,对连作障碍具有缓解作用。
[Abstract]:Melon (Cucumis sativus L.) Also known as cantaloupe, is an important cash crop in Northeast China. In recent years, muskmelon has developed rapidly in Northeast China. The root exudates of muskmelon and the residue decomposition of plant diseases are one of the important reasons of crop continuous cropping obstacle. In this paper, the phenolic acids in muskmelon continuous cropping soil were detected by high performance liquid chromatography (HPLC), and the composition and variation of phenolic acids in muskmelon continuous cropping soil were determined. In addition, the dominant Trichoderma species were selected from the soil of muskmelon to degrade phenolic acids, which provided scientific basis for alleviating the obstacle of continuous cropping of muskmelon. 1. High performance liquid chromatography (HPLC) was used to analyze and identify the phenolic acid species and their contents in the soil of cantaloupe. The results showed that the contents of p-hydroxybenzoic acid, vanillic acid, eugenic acid, vanillin, coumaric acid, ferulic acid and benzoic acid increased with the increase of continuous cropping time, but the content of cinnamic acid decreased gradually. After 4 years of continuous cropping, the total amount of 8 phenolic acids reached 257.94 mg kg-1 dry soil, which was significantly higher than that of non-continuous cropping soil. With the increase of planting years of simulated continuous cropping in pot plant, soil-borne diseases such as melon wilt occurred seriously, plant growth was inhibited, fruit yield decreased obviously, and continuous cropping obstacles became more and more serious. In addition, the soil samples of muskmelon in three provinces of Northeast China were analyzed and identified. The contents of 6 phenolic acids, such as p-hydroxybenzoic acid and vanillic acid, were significantly different. 2. The dominant Trichoderma species in continuous cropping soil of muskmelon in Northeast China were selected. In this experiment, 124 muskmelon continuous cropping soils were collected, 66 strains of Trichoderma strains were screened, accounting for 53.23% of the total, 31 strains of Trichoderma strains were isolated in Heilongjiang region, the number and frequency of isolation were higher than those in Jilin and Liaoning regions. TQTH-03 and TSY-02 dominant Trichoderma strains were screened from SA medium containing root exudates of muskmelon. The degradation system of phenolic acid in muskmelon continuous cropping soil was established, and the degradation effect of Trichoderma on the main phenolic acid in muskmelon continuous cropping soil was determined. The degradation of phenolic acids in muskmelon rhizosphere soil by Trichoderma (T4T23T23TQTH-03 TSY-02) was determined by three different inoculation methods with exogenous spore suspension, PD suspension and wheat bran fermentation. The results showed that Trichoderma could effectively degrade the phenolic acid accumulated in soil, and the degradation rate of wheat bran fermentation could reach more than 25%, and the degradation effect was the most remarkable. Soil samples were degraded by Trichoderma (T4T23T23TQTH-03TSY-02) inorganic salt fermentation broth and PD fermentation broth. The results showed that the degradation rate of the main phenolic acids in muskmelon was above 20%, and the degradation effect was remarkable. Trichoderma (T4T23TQTH-03TSY-02) inorganic salt spore suspension solution was used to degrade the main eight phenolic acids in muskmelon soil. The quantitative analysis showed that Trichoderma had a good degradation effect, and the degradation ability of Trichoderma was low at high concentration. The degradation rate is high at low concentration. 4. 4. The field experiments were carried out with Trichoderma and bio-fertilizer as cultivation substrates to provide a theoretical basis for solving the problems of continuous cropping of muskmelon. The results showed that the incidence of muskmelon treated with Trichoderma was lower than that of the control, which was beneficial to enhance the growth and disease resistance of muskmelon plants and alleviate the continuous cropping obstacle.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S652;S153

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