Identification and distribution of species of Neofusicoccum that cause blueberry stem blight in Chile

ABSTRACT

Stem blight is a destructive woody disease of blueberry (Vaccinium corymbosum) caused by several species of the family Botryosphaeriaceae. A field survey was conducted in the mayor blueberry production area of Chile, comprising latitudes 32°49ʹS to 40°55ʹS, to determine the occurrence and distribution of Botryosphaeriaceae in the region. Together, a multilocus analysis, morphological characterization, and phytopathogenicity testing were used to identify 51 Neofusicoccum isolates belonging to N. nonquaesitum (28 strains), N. parvum (22 strains), and N. australe (1 strain). Of these, N. parvum and N. nonquaesitum were the most commonly found, with N. parvum most frequent from latitude 37°40ʹS to the north and N. nonquaesitum predominantly located from the same latitude toward the south. Morphological traits of the isolates were consistent with the species identified by molecular techniques, despite the overlapping of conidial size of some isolates among species. Pathogenicity trials showed that the three species were pathogenic to blueberry plants and revealed that N. parvum and N. nonquaesitum were the most aggressive species, although variability in virulence was observed among isolates of N. parvum and N. nonquaesitum.

KEYWORDS:

• Blueberry stem canker
• Botryosphaeriaceae
• dieback
• pathogen

DISCLOSURE STATEMENT

No conflict of interest was reported by the author(s).

SUPPLEMENTARY MATERIAL

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00275514.2023.2180976

Additional information

Funding

This research was funded by Núcleos de Investigación grant code 502953-70 of the Institute of Agricultural Research (INIA), Chile. The authors also acknowledge the FONDEQUIP Program from the Chilean National Agency for Research and Development (ANID) (grant: EQM200205) for funding a platform of equipment for the preservation of microbial genetic resources.