Phylotype analysis of Ralstonia solanacearum strains causing potato bacterial wilt in Karnataka in India

Abstract

Potato is one of the important cash crop of Karnataka (India) farmers and there is a tremendous scope to increase the area and productivity of this crop in the state. However, this crop is badly affected by bacterial wilt disease caused by Ralstonia solanacearum especially in Hassan, Chikmagalur and Bengaluru districts. During Kharif 2011 season, a total of fifteen bacterial strains were recovered from stem pieces of wilting potato plants collected from potato growing regions of Hassan and Chikmagalur districts in Karnataka. Total genomic DNA was extracted and the identity of all the fifteen strains was confirmed as R. solanacearum as expected single 280-bp fragment resulted in all the isolates following polymerase chain reaction (PCR) amplification using the R. solanacearum specific universal primer pair 759/760. A phylotype specific multiplex PCR revealed that all the bacterial strains belonged to phylotype I of R. solanacearum which correspond to race 1 of the pathogen.