Puccinia caricis-ribicola Jing X. Ji, Zhuang Li, Y. Li & Kakish., 2022

Ji, Jingxin, Li, Zhuang, Li, Yu & Kakishima, Makoto, 2022, Phylogenetic approach for identification and life cycles of Puccinia (Pucciniaceae) species on Carex (Cyperaceae) from northeastern China, Phytotaxa 542 (3), pp. 221-255 : 235-236

C4: Puccinia caricis-ribicola Jing X. Ji, Zhuang Li, Y. Li & Kakish. sp. nov. ( Fig. 7 ) MycoBank No: MB 838296

Diagnosis: —This species is characterized by the relatively small-sized teliospores among species having spermogonia and aecia on Ribes . It is also phylogenetically close to P. caricina DC. on Ribes (sometimes reported as P. caricis Rebent. ), but has a distinct lineage from P. caricina .

Typus: — CHINA, Jilin Province, Baishan City, Lushuihe , telia on Carex dispalata Boott ex A. Gray , 3 September 2018, M. Kakishima & J. X. Ji, HMJAU 8871 , Holotype . CHINA, Heilongjiang Province, Wuchang City, Fenix Forest Park , spermogonia and aecia on Ribes mandshuricum (Maxim.) Kom. , 15 June 2019, M. Kakishima & J. X. Ji, HMJAU 8873 , Epitype .

Etymology: —Named after host plant genera associated with different life-cycle stages.

Description:— Spermogonia mostly epiphyllous, surrounded by greenish yellow lesions, densely grouped, honey-yellow, subepidermal, flask-shaped, type 4 of Cummins & Hiratsuka (2003). Aecia mostly hypophyllous, grouped, pale yellow, cupulate with long peridia, Aecidium - type. Peridial cells firmly conjunct, cubic to polygonal, hyaline. Aeciospores catenulate, globose to subglobose, angular, 14.5–17.5 ×12.0–15.5 µm (av. 16.0 × 14.0 µm); walls hyaline, 0.4–0.8 µm (av. 0.6 µm) thick, densely verrucose with big granules. Immature uredinia rarely found. Telia hypophyllous, black, exposed. Teliospores pedicellate, cylindrical or oblong-clavate, mostly rounded at the apices, moderately constricted at the septa, rounded and attenuate at the bases, 37.5–56.0 × 13.5–20.5 µm (av. 44.5 × 17.5 µm); walls chestnut-brown, 0.7–1.1 µm (av. 0.8 µm) thick at sides, thicker and darker at the apices, 4.7–11.5 µm (av. 8.5 µm); pedicels persistent, pale yellow or hyaline, 17.5–49.5 µm (av. 30.5 µm) long.

Additional specimens examined from northeastern CHINA:— Jilin Province, West of Changbai Mountain , telia on Carex dispalata , 1 September 2018, HMJAU 8869 , 8872 . Jilin Province, North of Changbai Mountain , telia on C. dispalata 3 September 2018, HMJAU 8870 . Jilin Province, North of Changbai Mountain , telia on C. latisquarnea Kom. , 16 September 2013, HMJAU 8944 .

Hosts and distribution in northeastern CHINA ( Fig. 1 ):— Spermogonia and aecia on Ribes mandshuricum (Grossulariaceae) (C). Telia on Carex dispalata (D); C. latisquarnea (D).

Note: —Species of Ribes have been reported as the spermogonial and aecial host plant of P. caricina or P. caricis , but species delimitation and host plant range of these species are different according to available references ( Arthur 1934, Ito 1950, Gäumann 1959, Wilson & Henderson 1966, Hiratsuka et al. 1992, Zhuang et al. 1998, Azbukina 2005, 2015, Termorshuizen & Swertz 2011). Their morphology and host plants are quite variable and therefore, should be taxonomically reconsidered. Puccinia caricis-ribcola is described as an independent species to avoid taxonomic confusion from P. caricina or P. caricis . Puccinia pringhsheimiana Kleb. (= P. caricina ) has been reported from northern Asia as a species having spermogonia and aecia on Ribes ( Ito 1950, Gäumann 1959), but its teliospore size is longer than that of this species. Teliospores of this species are also morphologically similar to P. yokotensis Miura reported from Japan and Russian Far East ( Ito 1950, Hiratsuka et al. 1992, Azbukina 2005, 2015), but its teliospore size is slightly shorter than that of this species.

Figures

FIGURE 1. Collection areas in northeastern China. A. Changchun area in Jilin Province. B. Jilin area in Jilin Province. C. Mountanious area in southern Heilongjiang Province. D. Area around Changbai Mountains in Jilin Province. E. Baicheng area in western Jilin Province. F. Yanbian area in eastern Jilin Province. G. Tonghua area in southeastern Jilin Province.

FIGURE 7. Puccinia caricis-ribicola on Ribes mandshuricum (A–C) and Carex dispalata (D–F). A. Vertical section of a spermogonium. B. Vertical section of an aecium surrounded with peridia. C. Aeciospores. D. Plants producing telia on the leaf surface in the field. E. Telia on the lower leaf surface. F. Vertical section of a telium. Scale bars: A, C, F = 20 μm, B = 30 μm.