Data from: Determination of factors associated with natural soil suppressivity to potato common scab

Common scab of potatoes is a disease, which is difficult to manage due to complex interactions of the pathogenic bacteria (Streptomyces spp.) with soil, microbial community and potato plants. In Bohemian-Moravian Highlands in the Czech Republic two sites (Vyklantice and Zdirec) were selected for a study of common scab disease suppressivity. At both sites, a field with low disease severity occurs next to one with high severity and the situation was regularly observed over four decades although all four fields undergo a crop rotation. In the four fields, quantities of bacteria, actinobacteria and the gene txtB from the biosynthetic gene cluster of thaxtomin, the main pathogenicity factor of common scab, were analyzed by real-time PCR. Microbial community structure was compared by terminal fragment length polymorphism analysis. Soil and potato periderm were characterized by contents of carbon, nitrogen, phosporus, sulphur, calcium, magnesium, and iron. Quality of organic matter was assessed by high performance liquid chromatography of soil extracts. The study demonstrated that the suppressive character of the fields is locally specific. At Zdirec, the suppressivity was associated with low txtB gene copies in bulk soil, while at Vyklantice site it was associated with low txtB gene copies in the tuberosphere. The differences were discussed with respect to the effect of abiotic conditions at Zdirec and interaction between potato plant and soil microbial community at Vyklantice. Soil pH, Ca soil content or cation concentrations, although different were not in the range to predict the disease severity. Low severity of common scab was associated with low content of soil C, N, C/N, Ca and Fe suggesting that oligotrophic conditions may be favorable to common scab suppression.

马铃薯普通疮痂病是一种防控难度较高的土传病害，其防控难点在于病原菌链霉菌属（Streptomyces spp.）与土壤、微生物群落及马铃薯植株之间存在复杂的互作关系。在捷克共和国波希米亚-摩拉维亚高地，研究人员选取了两个试验位点（Vyklantice与Zdirec），以探究马铃薯普通疮痂病的抑病特性。两个位点均各设有一块低病害严重度田块与一块高病害严重度田块，尽管四块试验田均实施了作物轮作制度，但这种病害严重程度的差异已被持续观测了四十年。研究人员通过实时荧光定量PCR（real-time PCR）分析了四块试验田中的细菌、放线菌数量，以及作为马铃薯普通疮痂病主要致病因子的毒素菌素（thaxtomin）生物合成基因簇中的txtB基因拷贝数；通过末端片段长度多态性分析（terminal fragment length polymorphism analysis）比较了各试验田的微生物群落结构。同时，研究人员测定了土壤与马铃薯周皮中的碳、氮、磷、硫、钙、镁、铁元素含量，并通过高效液相色谱法（high performance liquid chromatography）对土壤提取物进行检测以评估有机质品质。本研究证实，试验田的抑病特性具有位点特异性：在Zdirec位点，抑病性与原状土壤中较低的txtB基因拷贝数相关；而在Vyklantice位点，抑病性则与块茎际土壤中较低的txtB基因拷贝数相关。研究人员针对Zdirec位点的非生物条件效应，以及Vyklantice位点的马铃薯植株与土壤微生物群落间的互作效应，对上述差异展开了讨论。尽管土壤pH值、土壤钙含量或阳离子浓度存在差异，但这些指标均无法用于预测病害严重程度。马铃薯普通疮痂病的低发生程度与土壤中较低的碳、氮、碳氮比、钙及铁含量显著相关，这表明贫营养条件可能有利于马铃薯普通疮痂病的抑病防控。