Brown spot of pear, an emerging disease in Argentina: identification and pathogenicity characterization of Argentinean Stemphylium vesicarium isolates

TEMPERINI, CAROLINA VIRGINIA; TUDELA, MARISA ANDREA ALUMINÉ; GIMENEZ, GUSTAVO NESTOR; DI MASI, SUSANA NOEMÍ; PARDO, ALEJANDRO GUILLERMO; POSE, GRACIELA NOEMÍ

EUROPEAN JOURNAL OF PLANT PATHOLOGY

SPRINGER

Lugar: Berlin; Año: 2022

0929-1873

Recently, a new plant disease was detected inthe rural area of the High Valley of Río Negro, in NorthernPatagonia, Argentina, called ?Brown Spot of Pear?(BSP), caused by Stemphylium vesicarium (teleomorph:Pleospora herbarum, syn. Pantoea allii) in its sexual andasexual stages which produces lesions on leaves andfruits. BSP has been reported previously in pear growingareas of Europe and Japan where research studies haveassessed the production of two host-specific toxins(HSTs) in culture filtrates of S. vesicarium (SV-I andSV-II toxin). The purpose of the present study was tocharacterize Stemphylium isolates from air and frombrown spot lesions on pear leaves and fruits grown inthis rural area, at a morphological, molecular and pathogeniclevel. The pathogen?s identity was determined asS. vesicarium and its aggressiveness and toxicity weredemonstrated through conidia and culture filtrate bioassaysshowing different degrees of pathogenicity.D?Anjou and Abate Fetel were the most susceptible pearcultivars to S. vesicarium isolates.