作 者 ：张树生,杨兴明,茆泽圣,黄启为,徐阳春,沈其荣
期 刊 ：生态学报 2007年 27卷 5期 页码：1809~1817
关键词：黄瓜(Cucumis sativus)；灭菌土；连作障碍；土壤微生物区系；PCR-DGGE；
Keywords:cucumber (Cucumis sativus), sterilized soil, obstacle of continuous mono-cropping, soil microflora, PCR-DGGE,
摘 要 ：采用盆栽试验的方法，对黄瓜的生长状况、抗病相关酶及土壤微生物区系特征进行了测定。结果表明：连作土灭菌能在较大程度上改善黄瓜的生长，灭菌土上生长的黄瓜的叶绿素含量、株高、叶面积和鲜重均大于连作土，但随氨基酸肥料（AAF）施用量的增加，灭菌土与连作土之间的差异变小。黄瓜叶片的SOD和POD活性在不施用AAF条件下灭菌土显著高于连作土，然而随着AAF施用量的增加，活性则相反。CAT活性及可溶性蛋白含量灭菌土所有处理均极显著高于相对应的连作土，MDA含量则显著低于相对应的连作土。灭菌土的细菌、真菌数量分别比连作土增加1.89~3.03倍和6.96~2.43倍，放线菌的增加幅度相对较小，真菌/细菌比值也显著提高。随AAF施用量的增加，连作土中的黄瓜枯萎病的致病菌（尖孢镰刀菌）减少，而灭菌土的所有处理均未分离到。土壤细菌的PCR-DGGE图谱分析表明，灭菌土DGGE图谱带明显比连作土增加，土壤间带谱的相似性降低，土壤微生物多样性指数增加。灭菌土上的黄瓜未见枯萎病发生，而连作土的黄瓜发病率达31.25%~68.75%。
Abstract:Pot experiments were carried out to investigate effect of sterilization and application of amino acid fertilizer on growth of cucumber plants and soil microflora in a continuous mono-cropping soil. The soil which had been planted with continuous mono-cropping cucumber for 4 seasonal crops and had a severe continuous obstacle, was used in the experiment. The experiments had 6 treatments with 8 replicates for each treatment, including CK (Non-sterilized soil with no application of amino acid fertilizer), 0.5% AAF (Non-sterilized soil with the addition of 0.5% amino acid fertilizer based on soil dry weight), 1.0% AAF (Non-sterilized soil with the addition of 1.0% amino acid fertilizer based on soil dry weight)，S-CK (Sterilized soil with no application of amino acid fertilizer), S-0.5% AAF (Sterilized soil with the addition of 0.5% amino acid fertilizer based on soil dry weight) and S-1.0% AAF (Sterilized soil with the addition of 1.0% amino acid fertilizer based on soil dry weight). Uniform cucumber seedlings with two cotyledons were transplanted to pots (0.5 L, 400 g soil) at March 7, 2006, and harvested at May 10, 2006. The results obtained are listed as follows. Soil sterilization could improve growth of cucumber plants to greater extent, and, for example, SPAD value, plant height, leaf area and fresh weight of cucumber plants grown in sterilized soil were significantly higher than those in non-sterilized soil. The differences of cucumber growth between the sterilized soil and non-sterilized soil decreased with increase of AAF application, showing that the application of AAF could solve some problems coming from continuous mono-cropping system. SOD and POD activities in the leaves of cucumber plants grown in sterilized soil were higher than CK, but their activities became lower with increase of AAF application. CAT activities and soluble protein contents of all treatments in sterilized soil were significantly higher than those in non-sterilized soil while MDAs were significantly lower. The number of bacteria and fungi in sterilized soil was increased by 1.89-3.03 folds and 6.96-2.43 folds, respectively, compared with those in non-sterilized soil and the ratio of fungi to bacteria was significantly increased. In addition, Actinomycetes were slightly enhanced. The analyses of PCR-DGGE profiles showed that the number of bands on the lanes of DGGE profiles in sterilized soil was more than those in non-sterilized soil, with low similarities of DGGE profiles, and the diversities of soil microorganism in sterilized soil were increased compared to those in non-sterilized soil. The incidence of Fusarium wilt of cucumber plants grown in non-sterilized soil was up to 31.2%-68.8%, but no incidence in sterilized soil.