Morphological and phylogenetic analyses of an Elongisporangium species and two Globisporangium species (Peronosporales, Oomycota) from China

Introduction The species diversity and geographical distribution of Pythium sensu lato (s.l.) in China remain to be further supplemented and improved. In this study, three species formerly classified under Pythium s.l., Elongisporangium senticosum, Globisporangium monoclinum, G. oryzicola were new records from China. Methods Illustrated descriptions of the three new Chinese records are given based on their morphological observations and phylogenetic analysis inferred from the internal transcribed spacer region of the ribosomal RNA gene and mitochondrial cytochrome c oxidase subunit I gene. Results E. senticosum was found in Hainan and Guangdong Provinces, and it is characterized by having ovoid to ellipsoidal sporangia with conspicuous apical papilla, ornamented oogonia with acute spines, mostly monoclinous antheridia, and aplerotic oospores; G. monoclinum was collected from Xinjiang Uygur Autonomous Region, and it is distinguished by presence of hyphal swellings, absence of sporangia, smooth oogonia, mostly monoclinous antheridia, and subcircular, subclavate or fist-shaped antheridial cells; G. oryzicola was found in Jiangsu province, and it is characterized by having rarely presence of hyphal swellings, absence of sporangia, monoclinous or diclinous, sometimes hypogynous antheridia, and thin-walled oospores (0.8–1.1 µm). Discussion This study provides valuable insights into the distribution of oomycetes in China.