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Factors affecting distribution and abundance of Aspergillus section Nigri in vineyard soils from grapevine growing regions of Argentina
Author(s) -
Barberis Mauricio G,
Giaj Merlera Guillermo,
Reynoso Maria M,
Chulze Sofia N,
Torres Adriana M
Publication year - 2014
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.6647
Subject(s) - vineyard , ochratoxin a , aspergillus , biology , aspergillus niger , botany , mycotoxin , horticulture , food science
BACKGROUND Aspergillus species belonging to section Nigri are the main fungi responsible for ochratoxin ( OTA ) contamination in grapes and wine. These species live as saprophytes in the superficial layer of the vineyard soil. We evaluated the biodiversity of potentially ochratoxigenic strains of Aspergillus section Nigri isolated from vineyard soils from different grapevine growing regions of Argentina. The isolates were characterized by classical and molecular methods. A multiple correspondence analysis was performed to identify the overall correlation of the Aspergillus group distribution with environmental conditions, geographical characteristics and vineyard practices. RESULTS Aspergillus niger aggregate was the prevalent group (71%) and A. carbonarius made up only 2%. Species discrimination by species‐specific primers showed that in A. niger aggregate 89% were A. tubingensis ; 97% of the uniseriate were A. japonicus / A. aculeatus. Isolates belonging to these groups were unable to produce OTA . Our results clearly demonstrate a strong association between presence of A. carbonarius , high average temperatures and drip irrigation. Precipitation levels appear as a secondary factor, and altitude, vineyard age, predominant species, grape variety or total fungal count showed no association with A. carbonarius.CONCLUSION We demonstrated a low prevalence of ochratoxigenic species in vineyard soil from the grape‐growing regions of Argentina. © 2014 Society of Chemical Industry