Pestalotioid species associated with palm species from Southern China
YR Xiong, Ishara S. Manawasinghe, SSN Maharachchikumbura, Leilei Lu, ZY Dong, MM Xiang, Bingqian Xu
Abstract
Palm is the largest monocot group widely distributed in tropical and subtropical regions.The importance of palm species ranges from food sources to landscape.Therefore, the identification and characterization of pathogens associated with these hosts have economic and ecological significance.During surveys in 2020 to 2021, leaf spots on diseased Sabal mexicana and rotting tissues of Areca triandra, Arenga pinnata, Dypsis leptocheilos, Washingtonia robusta were collected from three cities in southwestern China.Fungal isolates were identified using morphological characterization and phylogenetic analysis based on the internal transcribed spacer (ITS) region of ribosomal DNA, beta-tubulin (tub2) gene and part of the translation elongation factor 1-alpha (tef 1-α).Six Neopestalotiopsis isolates and 22 Pestalotiopsis isolates were obtained.These isolates were further confirmed as two novel species described here as P. guangdongnsis and P. sabal; and three new host records N. formicidarum, P. diploclisae, P. kandelicola; and one unclassified Neopestalotiopsis sp.Pathogenicity assays were conducted on potted Sabal mexicana leaves for all isolated taxa.The results revealed that all species isolated from this study induced weak lesions on Sabal mexicana leaves.Pathogens were reisolated, and Koch's postulates were fulfilled.The results from this study will be an addition to micro-fungi associated with palm trees.Moreover, pathogenicity test results revealed the opportunistic nature of pestalotioid species on Sabal mexicana.These results will provide a basic platform to understand the pathogenic mechanisms and lifestyle of pestalotioid species in the future.