Genetic identification of Pectobacteerium atrsopeticum and assessment of medicinal plant extracts as an ecofriendly approach to control blackleg disease of potato

Abstract

Potato (Solanum tuberosum L.) is a high value crop owing to its nutrient rich profile, consisting of significant quantities of carbohydrate, minerals, proteins and vitamins. It is an important food as well as cash crop implicating that losses in yield have dual impact on the society causing hungers and economic crisis at the same time. Phyto-pathogens including Pectobacterium atrosepticum (causing blackleg disease) are a major challenge for the potato growers across the globe. Devising an effective management strategy is crucial for achieving sustainable yields and ensuring food security. The study was primarily focused on detection, isolation and identification of pathogen using bio-chemical and genetic approaches, followed by estimation of antimicrobial activity of plant extracts. For this purpose pathogen was subjected to molecular characterization, the gapA gene based characterization confirmed isolate to be Pectobacterium atrosepticum which is widely associated pathogen with the blackleg disease. Genetic characterization has various benefits as it enables to understand pathogenic diversity and geographical distribution of pathogen which in turn can be used to understand factors enabling the prevalence of pathogen and passages associated with the dispersal and distribution of pathogen. Followed by genetic characterization, anti-microbial efficacy of plant extracts was evaluated as an alternative to traditional copper based pesticides which has toxic impact on environment and human health. For this, six plant extracts were evaluated at 3 different concentrations of 300 ppm, 500 ppm and 700 ppm, data was collected on 12 h regular interval for 36 h. The data analysis exhibited that Azadirachta indica (Neem), Mentha spicata (Mint), and Zingiber officinale (Ginger) are most effective in inhibiting bacterial growth. Assessment of concentration factor shows that antimicrobial activity is directly proportional to concentration of plant extract with 700 ppm extracts giving most effective response. Similarly the time factor also had a direct proportionality with growth inhibition activity. The experiment depict that plant extracts can be used as alternative for managing the blackleg disease and are an effective alternate to copper based pesticides.