Comparison between Pathogenic <i>Streptomyces scabies</i> Isolates of Common Scab Disease

Abstract

Streptomyces scabies (Thaxter) causes destructive and serious damages to many vegetable field crops, including potato. Fourteen pure isolates were obtained from naturally diseased potato tubers showing symptoms of common scab disease, collected from different localities of Sohag governorate, Egypt. All tested isolates were identified as S. scabies (Stc) according to morphological and biochemical tests. Isolate Stc 10 exhibited the highest activity of polyphenoloxidase enzyme, followed by isolate Stc 11, while isolate Stc 2 produced the lowest activity of this enzyme. Concerning the peroxidase activity, the isolates varied in their production; Stc 11 exhibited the highest activity enzyme, followed by isolate Stc 2, whereas isolate Stc 10 produced the lowest activity of enzyme. In regard with Tyrosine Amonnia Lyase (TAL) activity, isolate Stc 2 exhibited the highest activity, followed by isolate Stc 10, whereas isolate Stc 11 exhibited the lowest activity. Agarose gel electrophoresis of the PCR amplification products revealed a band representing the expected 279 bp DNA fragment in each DNA extracted from the highly pathogenic isolates Stc 10 and 11. The results demonstrated that PCR amplification of the nec1 gene could be used as a reliable marker for detecting pathogenic Streptomyces isolates on potato tubers.

Efficacy of Some Biocontrol Agents Against Streptomyces scabiei the Causative of Common Scab Disease in Potatoes

“…While the second method of evaluation the effect of biological treatments was at 48 hours after inoculation with the pathogen, and it will be referred to as (After Inoculation time). The disease index was determined at 90 days after planting (Hosny et al 2016). Percentage of disease reduction was evaluated according to Hussein et al (2019).…”

“…Streptomyces scabiei the casual pathogen of common scab, S. acidiscabies the causal pathogen of netted scab and S. turgidiscabies is the bacterial species of russet scab (Kers et. al., 2005;Hosny et al, 2016 andAbd El-Hafez andAbd El-Rahman 2019). Truper and De'clari (1997) actually used Streptomyces scabiei (ex Thaxter) Truper and De'clari, instead of Streptomyces scabies (Lambert and Loria 1989) due to a grammatical rule outlined in Rule 12c of the international code of bacterial nomenclature.…”

Variability and genetic diversity among Streptomyces scabiei infected potato cultivars with common scab from Egypt

“…Potato is being infected with many fungal, bacterial, viral and nematodes pathogens. Among these diseases, potatoes common scab considered as an important disease infecting potato and cause a serious loss in potato quality (Hosny et al, 2016). Potato scabs caused by many species of Streptomyces e.g.…”