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Poster: Diseases of Plants: Disease Detection & Diagnosis


Reporting the occurrence of Ralstonia based wilts of chillies in major vegetable growing areas of Punjab
A. HAMEED (1), S. Jameel (1), N. Liaqat (1), M. Ashfaq (2), R. Riaz (3), K. Riaz (1) (1) Department of Plant Pathology, University of Agriculture Faisalabad, Pakistan; (2) Department of Plant Pathology, PMAS-Arid Agriculture University Rawalpindi, Pakista

Ralstonia solanacearum (Rs), is one of the most severe pathogens of solanaceous crops with a very wide host range. Recently, a survey was conducted in districts of Punjab Province including Okara, Chiniot and Faisalabad to determine the incidence of bacterial wilt of chillies. The maximum disease incidence (58 %) was recorded in district Okara followed by Chiniot (43 %). The least disease incidence was found in district Faisalabad with 20 % occurrence. The samples were collected and after surface sterilization, placed on casamino acid-peptone-glucose-agar (CPG) medium. The colonies obtained on CPG medium were transferred on 2,3,5-triphenyltetrazolium chloride (TZC) medium. It was observed that the colonies on TZC were irregular, mucoid and white with pink centers. Out of all the isolates tested, 72% showed positive hypersensitive reaction (HR) with variable response. Only 40% of these HR positive isolates were confirmed as R. solanacearum through simple staining, streaming, KOH solubility, biochemical, pathogenicity and Plate Trapped Antigen-Enzyme Linked Immunosorbent Assay (PTA-ELISA) tests. Molecular confirmation of R. solanacearum was also done through genomic DNA using Rs-specific primers.