Quantitative real-time PCR of total bacteria from the DNA extracted from stored product mites reared on control and antibiotic treated diets.

<p>The numbers of copies were recalculated per one specimen, averages with respective standard deviations. The Dunnet significant differences from the control are marked by asterisk; CON - untreated control, AMP –ampicillin, NEO – neomycin, STR – streptomycin.</p

Venn’s diagram comparing the sequences in 16S rRNA library of the clones (A) and isolates (B) from mite on control and antibiotic treated diets.

<p>Venn’s diagram comparing the sequences in 16S rRNA library of the clones (A) and isolates (B) from mite on control and antibiotic treated diets.</p

The analyses of 16S rRNA libraries from isolates from stored product mites reared on antibiotic treated and control diets.

<p>Legend: Accession number of match in GENBANK for the most similar sequences of identified bacteria I (%) describes the similarity; A- ampicillin treated diet, C – control diet, N – neomycin treated diet, S – streptomycin treated diet (all 1 mgg⁻¹ of diet).</p><p>The analyses of 16S rRNA libraries from isolates from stored product mites reared on antibiotic treated and control diets.</p

The analyses of 16S rRNA libraries from the clones from stored product mites reared on control diets.

<p>The data from the three samples per treatment are presented altogether.</p><p>Legend: Accession number of match in GENBANK for the most similar sequences of identified bacteria I (%) describes the similarity; A– ampicillin treated diet, C – control diet, N – neomycin treated diet, S – streptomycin treated diet (all 1 mgg−1 of diet).</p><p>The analyses of 16S rRNA libraries from the clones from stored product mites reared on control diets.</p

The comparison of 16S rRNA sequences from isolated bacteria from of stored product mites (<i>Acarus siro</i>, <i>Lepidoglyphus destructor</i> and <i>Tyrophagus putrescentiae</i>) on control and antibiotic supplementation (1 mg g⁻¹ of diet) diets.

<p>The comparison of 16S rRNA sequences from isolated bacteria from of stored product mites (<i>Acarus siro</i>, <i>Lepidoglyphus destructor</i> and <i>Tyrophagus putrescentiae</i>) on control and antibiotic supplementation (1 mg g⁻¹ of diet) diets.</p

The comparison of cloned 16S rRNA sequences of stored product mites (<i>Acarus siro</i>, <i>Lepidoglyphus destructor</i> and <i>Tyrophagus putrescentiae</i>) on control and antibiotic supplementation (1 mg g⁻¹ of diet) diets.

<p>The comparison of cloned 16S rRNA sequences of stored product mites (<i>Acarus siro</i>, <i>Lepidoglyphus destructor</i> and <i>Tyrophagus putrescentiae</i>) on control and antibiotic supplementation (1 mg g⁻¹ of diet) diets.</p

Table S3. Common scab severity.

Table S3. Common scab severity

Table S6. T-RFLP profiles of actinobacterial communities in the bulk soil and potato tuberosphere at Zdirec site.

Table S6. T-RFLP profiles of actinobacterial communities in the bulk soil and potato tuberosphere at Zdirec site

Table S1. Chemical and biological properties of the bulk soil, potato tuberosphere and periderm at Vyklantice site.

Table S1. Chemical and biological properties of the bulk soil, potato tuberosphere and periderm at Vyklantice site

Determination of Factors Associated with Natural Soil Suppressivity to Potato Common Scab

<div><p>Common scab of potatoes is a disease, which is difficult to manage due to complex interactions of the pathogenic bacteria (<i>Streptomyces</i> 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 <i>txtB</i> 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 <i>txtB</i> gene copies in bulk soil, while at Vyklantice site it was associated with low <i>txtB</i> 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.</p></div