Endophytic fungi in blueberry cultivars, in three production areas of Argentina

Blueberries develop a shallow and fibrous root system, with sparse root hairs, normally colonized by mycorrhizal fungi. The presence of endophytic fungi in blueberry roots has been studied mainly in the area of origin of each species. The aims of the present study were to determine the occurrence of endophytic fungi in the roots of southern highbush blueberry (SHB) cultivars, in the three most important blueberry production areas of Argentina, and identify them. Soil samples with blueberry rootlets were obtained and endophytic fungi were isolated from them. Some of them by classical taxonomy identification, and, when this was not possible, PCR amplified material were sequenced (Macrogen laboratory), DNA fragments were analyzed with the Basic Local Alignment Search Tool (BLAST) and identified, through GenBank. Blueberry roots were found to be colonized by a large number of fungal genera, which varied greatly among locations and cultivars. Some of the endophytic fungi identified have pathogenic function, others are only plant hosts, and some of them have mycorrhizal function as is the case of genus Oidiodendron where we found O. maius and O. echinulatum. We may conclude that SHB is associated with local ericoid fungi, some of which are mycorrhizal and some dark septate endophytes, which, in most cases, do not match with those found in production regions of their native area, but same of them are important to promote blueberry growth.