STUDY ON PHENOTYPIC CONVERSION, VIRULENCE AND BIOVAR EXPRESSION OF RALSTONIA SOLANACEARUMCAUSING POTATO WILT AND ITS MANAGEMENT

Abstract

ZINNAT KARIM Infected samples from different sources of inoculum viz. plant, soil, seed, weed, other crops, irrigation water etc. were collected from major potato growing districts of Bangladesh viz. Munshiganj, Chandpur, Tangail, Narayanganj, Jamalpur, Domar, Patuakhali, Rangpur, Bogra, Shariatpur, Meherpur, Joypurhat and Dinajpur to investigate the presence of R. solanacearum. Cross cut of plant samples showed bacterial ooze streaming in clear water and browning of the vascular bundle region of seed tuber were observed. Standard methods viz. Kelman’s tetrazolium chloride 0 C and 28 0 C temperature. Again, under the influence of temperature avirulent colony of R. solanacearum showed VBNC state at 10 0 C. In vitro and in vivo performance test with ten bioactive compounds against R. solanacearum were conducted as compared to control, bactericide and farmers practice to design an effective management tool. Propolis C and over 40±2 0 Key words: Bacterial wilt disease, Bangladesh, heterogeneity in virulence and biovar(s