Randomly amplified polymorphic DNA analysis of Xylella fastidiosa Pierce's disease and oak leaf scorch pathotypes

Abstract

Randomly amplified polymorphic DNA analysis was conducted with 14 primers to 17 strains of Xylella fastidiosa. There was a high degree of similarity among the seven Pierce's disease (PD) strains (S(xy) > 0.93) and the seven oak leaf scorch (OLS) strains (S(xy) > 0.96). However, the two groups were different, with a similarity index of 0.67, confirming the presence of a PD DNA cluster and suggesting the presence of a new OLS cluster. The control plum leaf scald strains (two strains) together with the periwinkle wilt strain had a much smaller similarity index (0.44) compared with the PD and OLS clusters.