中文摘要：

盆栽试验以黄瓜为主栽作物,分蘖洋葱为套作作物,研究了套作不同化感潜力分蘖洋葱对黄瓜生长及土壤微环境的影响.结果表明：与化感潜力强的分蘖洋葱套作,黄瓜根际土壤电导率降低、pH值提高;根际土壤过氧化氢酶和转化酶活性提高,过氧化物酶活性降低;根际土壤细菌丰富度增加.DGGE条带测序显示,黄瓜根际土壤细菌大多与不可培养的细菌种属具有较高的同源性,共有条带的测序比对推测为放线菌纲和变形菌纲,差异条带的测序比对推测为变形菌纲和酸杆菌纲,红螺旋菌目、酸杆菌属只出现在与化感潜力弱的分蘖洋葱套作的黄瓜根际土壤中.相关分析表明,土壤脲酶与黄瓜幼苗株高、全株干质量、叶面积、DGGE条带数呈显著正相关.综上,与化感潜力强的分蘖洋葱套作,可为黄瓜生长创造良好的根际微环境,显著促进黄瓜幼苗生长.

英文摘要：

A pot experiment was conducted to study the effects of intercropping various Chinese onion cultivars of different allelopathic potential on the cucumber growth and rhizospheric soil environment. When intercropped with high allelopathic Chinese onion cultivars, the EC value and peroxidase activity of cucumber rhizospheric soil decreased, while the pH value, invertase and catalase activities, and bacterial community diversity increased. The cloning and sequencing results indicated that most DGGE bands amplified from cucumber rhizospheric soil samples showed a high homology to uncultured bacterial species. The common bands were affiliated with Actinobacteria and Proteobacteria, and the differential bacteria bands were affiliated with Proteobacteria and Anaerolineaceae. Rhodospirillales and Acidobacteria were only found in the cucumber rhizospheric soil intercropped with low allelopathic Chinese onion cultivars. Correlation analysis showed that there were significant positive correlations between rhizospheric soil urease activity and cucumber seedlings height, total dry biomass, leaf area, and DGGE band number. It was suggested that intercropping high allelopathic Chinese onion cultivars could establish a good rhizospheric soil micro-environment for cucumber growth, and promote the growth of cucumber seedlings markedly.