Ceratocystis fimbriata on kiwifruit (Actinidia spp.) in Brazil

Abstract

Ceratocystis fimbriata causes wilt and death of plants in several important crops and native vegetation in Brazil. Ceratocystis wilt was recently found to be causing substantial mortality in kiwifruit (Actinidia deliciosa and A. chinensis) in the Farroupilha region of Rio Grande do Sul. The aim of this study was to describe the symptomatology of the new disease and characterise isolates of C. fimbriata obtained from kiwifruit plants. Affected plants showed substantial discoloration of the woody xylem and wilt-type symptoms of the foliage, with eventual death of the whole plant. Phylogenetic analysis of ITS rDNA of 39 isolates from kiwifruit identified five haplotypes, which were placed in the Latin American clade of C. fimbriata. The ITS haplotypes were morphologically similar to isolates of C. fimbriata from other hosts in Brazil. Eight isolates of four ITS haplotypes varied somewhat in aggressiveness to three kiwifruit cultivars (Monty, Hayward and Elmwood), but all isolates were pathogenic and all three cultivars were susceptible.