Puccinia caricis-rafaensis 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 : 248-250

C16: Puccinia caricis-rafaensis Jing X. Ji, Zhuang Li, Y. Li & Kakish. sp. nov. ( Fig. 19 )

MycoBank No: MB 838302.

Diagnosis: —This species is morphologically similar and phylogenetically close to P. moiwensis , but has distinct lineage, and also has a more round-shape of urediniospores and smaller teliospores.

Typus: — CHINA, Jilin Province, Changchun, Jingyue Forest Park , uredinia and telia on Carex sp. , 1 October 2018, M. Kakishima & J. X. Ji, HMJAU 8798 , Holotype . CHINA, Jilin Province, Jilin, Lafa Mountain , Spermogonia and aecia on Urtica laetevirens Maxim. , 30 July 2015, M. Kakishima & J. X. Ji, HMJAU 8530 , Epitype .

Etymology: —Named after uredinial and telial host genera and locality name, Lafa, where the spermogonial and aecial stages were collected.

Description: — Spermogonia amphigenous, honey-yellow, grouped, subepidermal, flask-shaped, type 4 of Cummins & Hiratsuka (2003). Aecia is mostly hypophyllous, sometimes in large groups, spreading along veins, yellow, cupulate with peridia, Aecidium - type. Peridial cells firmly conjunct, cubic to polygonal, hyaline. Aeciospores catenulate, globose to subglobose, angular, 12.5–17.0 × 12.5–15.5 µm (av. 15.0 × 14.0 µm); walls hyaline, 0.7–1.1 µm (av. 0.8 µm) thick, densely verrucose with big glanules. Uredinia hypophyllous, scattered, minute, deep reddish-brown to blackish brown, covered by epidermis but eventually erumpent. Urediniospores globose or subglobose, 21.5–24.5 × 19.0–24.0 µm (av. 23.0 × 21.5 µm); walls brown, echinulate, 1.2–1.9 µm (av. 1.5 µm), germ pores 2, equatorial; pedicels sometimes persistent. Telia hypophyllous, blackish brown, compact, rounded to broadly elliptic, erumpent. Teliospores broadly clavate, ellipsoid, mostly rounded at apices, constricted at the septa, attenuate at the bases, 33.5– 43.0 × 13.5–17.5 µm (av. 39.0 × 16.0 µm); walls chestnut-brown, 0.6–1.0 µm (av. 0.8 µm) thick at sides, 7.0–12.0 µm (av. 10.0 µm) at apices; pedicels persistent, hyaline to pale brown, thin-walled, 10.0–24.0 µm (av. 17.0 µm) long.

Additional specimens examined from northeastern CHINA: — Jilin Province, Changchun , uredinia and telia on Carex sp. , 16 September 2017, HMJAU 8796 , 8914 , 1 October 2018, HMJAU 8797 .

Hosts and distribution in northeastern CHINA ( Fig. 1 ):—Spermogonia and aecia on Urtica laetevirens (Urticaceae) (B). Uredinia and telia on Carex sp. (A).

Note: —This species is phylogenetically close to P. moiwensis , but morphologically different in the shape of the urediniospores, the size of the teliospores, and the structure of the uredinia. Uredinial sori of this species are opened soon after maturation, but those of P. moiwensis are covered by the host epidermis. Pedicels attached to the urediniospores are long and persistent in this species, but those of P. moiwensis are deciduous. This species is suspected to have a heteroecious life cycle, alternating between Urtica and Carex in limited localities in the study area.

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 19. Puccinia caricis-rafaensis on Urtica laetevirens (A–G) and Carex sp. (H–J). A. Plants producing spermogonia and aecia on the leaf surface in the field. B. Aecia on the lower leaf surface. C. Vertical section of a spermogonium. D. Vertical section of an aecium surrounded with peridia. E. Aeciospores. F. An aecium observed under SEM. G. Aeciospores with granules on the surface observed under SEM. H. Urediniospores. I. Vertical section of a uredinium. J. Vertical section of a telium. Scale bars: C, J = 30 μm, D = 50 μm, E, H, I = 20 μm, F = 100 μm, G = 5 μm.