Biochemical characterization of Streptomyces isolates associated with scab of Potato in Punjab Singh Hardeep Sabhikhi, Singh Mandeep Hunjan*, Singh Parminder Tak Department of Plant Pathology, Punjab Agricultural University, Ludhiana-141004, Punjab *Corresponding author: niceshweta22@gmail.com
Online published on 3 February, 2021. Abstract Scab of potato is caused by physiologically distinct species of Streptomyces in different geographic regions of the world. Different strains of this pathogen show considerable variation in their phenotypic and genotypic characteristics. During the current study, disease survey of key potato growing regions of northern India revealed that scab was widely present in potato fields, but in relatively low severity (1–7.9%). Kufri Pukhraj, a widely grown variety of potato in the region, had a mean disease severity of 7.3 per cent, whereas, a less grown variety Lady Rosetta had the highest disease severity (10.5%). One hundred and seven isolates of Streptomyces spp. were categorized into four groups, each having distinct substrate utilization patterns and antibiotic sensitivity. More than 97 per cent of the isolates produced melanin and most of them were pathogenic on potato, whereas, few isolates that did not produce melanoid pigment were non-pathogenic. Multiple antibiotic resistance was observed in the test isolates, with 14 of them tolerating two or more antibiotics. Three of the isolates viz., Strep101, Strep114 & Strep157 could tolerate three antibiotics and three isolates viz., Strep127, Strep154 & Strep178 could tolerate four antibiotics. Top Keywords Biochemical characterization, Common scab, Disease occurrence, Potato, Streptomyces. Top |