Diversity of Ilyonectria species in a young vineyard affected by black foot disease

Abstract

Fungi of the Ilyonectria genus are the main causal agents of black foot disease of grapevine. These pathogens cause necrosis in the basal end of the rootstock, leading to the early decline and the death of vines in nurseries and young vineyards. In the present study a collection of isolates of the genus Ilyonectria obtained from a vineyard located in the Alentejo region, Portugal, was characterised. This vineyard was established with planting material originating from three different nurseries. To assess the inter- and intra-specific variability among isolates, morphological, cultural and biomolecular characteristics were evaluated. Morpho-cultural and molecular data (RAPD and ISSR markers and histone H3 nucleotide sequence) identified I. estremocensis, I. europaea, I. liriodendri, I. macrodidyma, I. torresensis, I. vitis and “Cylindrocarpon” pauciseptatum. Ilyonectria torresensis was the most common species found in the survey, representing more than 50% of the isolates.