Puccinia tuberosa Jing X. Ji & Kakish., sp. nov. (Fig. 1)

MycoBank No.: MB841349

Diagnosis: —Morphologically differs from P. allii complex and U. japonicus on Allium species by having smaller urediniospores with thicker walls. Phylogenetically distinct from Puccinia allii complex and Uromyces japonicus .

Type: — CHINA. Jilin Province: Changchun, uredinia on Allium tuberosum Rottler ex Spreng., October 2018, leg. Jing-Xin Ji (HMJAU8955, holotype, GenBank no. 28S: OK489427, ITS: OK489435) .

Etymology: —Named after species name of host plant.

Description: —Uredinia amphigenous, subepidermal, erumpent, pale yellow. Urediniospores ellipsoid to oval, 20–26.5 × 17.5–22.5 μm (av. 23.0 × 20.0 µm). Wall hyaline, echinulate, 2.0–4.0 μm thick, germ pores obscure.

Known host and distribution: —On Allium tuberosum, China, Philippines, Thailand (McTaggart et al. 2016).

In the phylogenetic analysis, U. japonicus on A. ochotense Prokh. and A. victorialis L. lies in a separate monophyletic clade from other rust species in the P. allii complex on Allium species (Fig. 2). However, U. japonicus should be transferred to Puccinia because it is phylogenetically included with a cluster of Puccinia species (McTaggart et al. 2016, Tanaka & Ono 2018). Although it is morphologically different from Puccinia species in having single-celled teliospores, it is common for rust fungi on Allium species to have a mixture of single-celled and 2-celled teliospores. Because P. japonica Dietel is preoccupied, we propose a new name, P. japonensis, as a replacement for U. japonicus .