Taxonomy, Phylogeny, and Life Cycle of Four Neophysopella Species on Meliosma myriantha and M. oldhamii in Korea

Abstract

The present study performed an in-depth investigation of rust diseases affecting Meliosma myriantha and Meliosma oldhamii trees (Sabiaceae) in Korea. The analysis identified four distinct species of the genus Neophysopella (Pucciniales) as the causal agents. Among these, N. hornotina was found to infect only M. oldhamii, whereas three Neophysopella species (N. meliosmae, N. meliosmae-myrianthae, and N. vitis) were parasitic on M. myriantha. To our knowledge, this is the first report of the former two species (N. hornotina and N. meliosmae) in Korea. In addition, we specified their alternate host plants for two heteroecious species (N. meliosmae-myrianthae and N. vitis) in Korea, completing the life cycles of the four rust species, and provided detailed morphological descriptions at each stage of their life cycles. Phylogenetic relationships of these rust species were uncovered using a comprehensive sample size, and we have constructed a phylogenetic tree for Neophysopella using the cytochrome c oxidase subunit III (cox3) gene sequences, demonstrating an effective approach for species delineation within this genus. The findings contribute to identifying and managing rust diseases affecting Meliosma species.