Botryosphariaceae species associated with stem canker, die-back and fruit rot on apple in Uruguay

Abstract

Botryosphaeriaceae species are pathogens of apple and many other woody hosts worldwide. In this study, 34 apple orchards belonging to 22 farmers located in the south of Uruguay, the main apple production region, were surveyed. Stem canker, die-back and fruit rot were consistently observed, the most serious damage being due to cankers. From the 91 Botryosphaeriaceae isolates obtained, eight species belonging to the genera Botryosphaeria, Diplodia, Neofusicoccum and Lasiodiplodia were identified by means of phenotypic characteristics and phylogenetic analysis of the ITS region and the TEF-1α gene. The predominant species was Botryosphaeria dothidea (56) and the second most important was Diplodia seriata (16). Other species found were Neofusicoccum parvum (8), D. intermedia (5), N. luteum (3), D. pseudoseriata (1), N. australe (1) and Lasiodiplodia theobromae (1). D. pseudoseriata and L. theobromae were associated with apple for the first time. Most of the eight species were isolated from both stem and fruit and were distributed throughout the apple-producing region. Isolates of all species were able to cause typical symptoms in stems and fruits of apple when inoculated, but the most severe symptoms were caused by L. theobromae, N. parvum and N. luteum.