P-475 - Morphologically indistinguishable Neopestalotiopsis species are causing recent outbreaks in rubber and strawberry in the Philippines

Neopestalotiopsis is one of the Pestalotioids reclassified as a new genus in 2014 following the reconstruction of the Pestalotiopsis phylogeny. Fruit and foliar diseases caused by Neopestalotiopsis spp. have recently incurred yield losses in various crops worldwide including strawberry and rubber. In 2023, rubber trees in the southern regions of the Philippines were reported to have been severely damaged by N. clavispora. Interestingly, about the same period, similar foliar symptoms alongside fruit and crown rot were observed in strawberry, however, occurring in geographically distant northern island of the country. Here, morphological characteristics of the pathogen in strawberry were described. In addition, the phylogenetic relationship was determined between isolates of unrelated hosts and geographic origin. Isolates from strawberry exhibited Pestalotioid characteristics including undulated edge culture with acervuli and multicellular fusiform conidia. Phylogenetic analysis based on ITS, beta-tubulin, and calmodulin revealed all local isolates belonging to N. rosae, however, formed a branch distinct from those in China and U.S. Furthermore, in vitro fungicide sensitivity assay using tebuconazole showed varying EC50 ranging from 3.98 to 11.97 ug/mL. This is yet to be the first incidence of N. rosae to be reported in strawberry in the Philippines. Detection of Neopestalotiopsis spp. in different hosts from distant locations suggest prevalence of emerging Neopestalotiopsis spp. in the country, however, approaches for disease control may vary.