Effect of Calcium Carbonate on the Pathogenicity of Streptomyces scabies Causing Potato Scab and the Physiological Response of Potato Plants

Hesham, Engy; El-Samra, Ibrahim; Abdelkhalek, Ahmed; Behiry, Said I.

doi:10.21608/alexja.2025.382473.1140

Effect of Calcium Carbonate on the Pathogenicity of Streptomyces scabies Causing Potato Scab and the Physiological Response of Potato Plants

Document Type : Original Article

Authors

¹ Agricultural Botany Department, Faculty of Agriculture (Saba Basha), Alexandria University, Alexandria 21531, Egypt

² Plant Protection and Biomolecular Diagnosis Department, ALCRI, City of Scientific Research and Technological Applications, New Borg El Arab City 21934, Egypt

10.21608/alexja.2025.382473.1140

Abstract

Potato scab disease, caused by Streptomyces scabies, is a significant bacterial disease affecting potato production worldwide. This study investigated the effect of calcium carbonate (CaCO₃) on S. scabies pathogenicity and the physiological response of potato plants under greenhouse conditions. Potato plants (cv. Diamond) were grown in soil inoculated with S. scabies strain E21 with and without CaCO₃ (5 g/kg soil). Plant growth parameters, disease incidence and severity, and biochemical responses were evaluated. Results showed that CaCO₃ amendment increased disease severity from 31.15% to 45.35% and disease incidence from 91.68% to 100%, though not statistically significant. CaCO₃ treatment significantly increased tuber weight (107.5 g vs. 88.5 g) and root dry weight (1.05 g vs. 0.45 g) but decreased shoot dry weight and root length. Biochemical analyses revealed that CaCO₃ amendment enhanced antioxidant enzyme activities (SOD and CAT) while reducing H₂O₂, MDA, and phenolic compound levels at both 30 and 60 days after planting. These findings suggest that while CaCO₃ may increase disease severity by creating favorable conditions for S. scabies, it simultaneously enhances plant defense mechanisms, particularly the enzymatic antioxidant system. This study provides insights into the complex interactions between soil amendments, pathogen virulence, and plant physiological responses, with implications for integrated management of potato scab disease.

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