Abstract

This study was conducted to understand the dynamics of microbial communities of soil microorganisms, and their distribution and abundance in the indigenous microorganisms (IMOs) manipulated from humus collected from the forest near the crop field. The soil microorganisms originated from humus and artificially cultured microbial-based soil amendments were characterized by molecular and biochemical analyses. The bacterial population (2 × 10⁶∼13 × 10⁶ CFU/g sample) was approximately 100-fold abundant than the fungal population (2 × 10⁴∼8 × 10⁴ CFU/g sample). The 16S rDNA and ITS sequence analyses showed that the bacterial and fungal communities in humus and IMOs were mainly composed of Bacillus and Pseudomonas, and Trichoderma and Aspergillus species, respectively. Some of the bacterial isolates from the humus and IMOs showed strong inhibitory activity against soil-borne pathogenic fungi Fusarium oxysporum and Sclerotinia sclerotiorum. These bacteria also showed the siderophore production activity as well as phosphate solubilizing activity, which are requisite traits for biological control of plant pathogenic fungi. These results suggest that humus and IMOs could be a useful resource for sustainable agriculture.

 抽象的

这项研究的目的是了解土壤微生物的微生物群落动态，以及它们在从农田附近森林收集的腐殖质中操纵的本地微生物（IMO）中的分布和丰度。通过分子和生化分析对源自腐殖质的土壤微生物和人工培养的基于微生物的土壤改良剂进行了表征。细菌种群（2 × 10 ⁶ ∼13 × 10 ⁶ CFU/g 样品）的丰度大约是真菌种群（2 × 10 ⁴ ∼8 × 10 ⁴ CFU/g 样品）的 100 倍。 16S rDNA和ITS序列分析表明，腐殖质和IMO中的细菌和真菌群落分别主要由芽孢杆菌和假单胞菌、木霉和曲霉组成。一些从腐殖质和 IMO 中分离出来的细菌对土传病原真菌尖孢镰刀菌和核盘菌表现出很强的抑制活性。这些细菌还表现出铁载体生产活性以及解磷活性，这是植物病原真菌生物防治的必要特征。这些结果表明腐殖质和 IMO 可能是可持续农业的有用资源。