Phragmidium zhouquensis Y. M. Liang & T. Yang, 2015

Yang, Ting, Chang, Wei, Cao, Bin, Tian, Cheng-Ming, Zhao, Long & Liang, Ying-Mei, 2015, Two new Phragmidium species identified on Rosa plants native to China, Phytotaxa 217 (2), pp. 182-190 : 185-186

publication ID

https://doi.org/ 10.11646/phytotaxa.217.2.8

persistent identifier

https://treatment.plazi.org/id/038E87AF-FFA2-7C47-FF5F-0E592CF4FE6A

treatment provided by

Felipe

scientific name

Phragmidium zhouquensis Y. M. Liang & T. Yang
status

sp. nov.

Phragmidium zhouquensis Y. M. Liang & T. Yang , sp. nov. ( Fig. 1 View FIGURE 1 )

MycoBank no.:—MB811453

Etymology:— Zhouquensis, referring to the location of the collection of this species.

Diagnosis:—Telia hypophyllous, dark brown, teliospores 67–103 × 32–39 μm, (3–)6–8(–9)-celled, yellowish brown, apical papilla 3.5–6 μm, verrucose, 2–3 germ pores in each cell, pedicels 80–160 × 14–24 μm.

Type:— CHINA, Gansu Province, Zhouqu County, on Rosa omeiensis Rolfe ( Rosaceae ), 20 August 2014, coll. Y. M. Liang & B. Cao (Holotype: BJFC-R01516; Paratype: BJFC-R01529).

Spermogonia, aecia, and uredinia unknown.

Telia produced on the abaxial leaf, scattered or loosely grouped, minute, 0.5–2.5 mm, pulverulent, dark brown, leaf colour turns rose-red to aubergine at the position of the sorus ( Figs 1A, 1B View FIGURE 1 ); teliospores ellipsoid-oblong to cylindrical, 67–103 × 32–39 μm, 3–9-celled, mostly 6–8-celled, the uppermost cell longer than the others, rounded at both ends, often somewhat attenuate at the apex, wall 2–5 μm thick, yellowish brown ( Figs 1E, 1F View FIGURE 1 ), with coarse and nearly hyaline verrucae on the spore surface ( Figs 1C, 1D View FIGURE 1 ), apical papilla conical, pale-coloured or hyaline with dense tubercles, 3.5–6 μm long, not constricted at the septa, with 2–3 germ pores in each cell ( Fig. 1E View FIGURE 1 ); pedicels 80–160 μm long, persistent, upper part colourless or pale brown, lower part with coarse surface and yellowish content, slightly swollen, gradually become lanceolate, approximately 14–24 wide at the broadest diameter ( Figs 1D, 1E View FIGURE 1 ).

Notes:— Phragmidium primarily parasitise Potentilla , Rubus , and Rosa , and rust species do not overlap among these three host genera. Of the 11 Phragmidium species reported on Rosa in China, four species colonise Rosa omeiensis , including Ph. mucronatum , Ph. robustum , Ph. rosae-omeiensis , and Ph. tuberculatum ( Table 2). Phragmidium zhouquensis differed from Ph. mucronatum primarily by the dark brown telia ( Figs 1A, 1B View FIGURE 1 ) and short papilla with lengths up to 6 μm ( Figs 1D, E View FIGURE 1 ), whereas Ph. mucronatum telia were black and teliospores with papillae at the top had lengths up to 17 μm ( Wei 1988, Zhuang et al. 2012). Phragmidium robustum was characterized by wider and more robust teliospores (50–106 × 35–48 μm), mostly 5–6-celled, with longer pedicels of 70–190 μm ( Zhuang & Wei 2009, Zhuang et al. 2012); these features can be used to distinguish it from the present species. The new species Ph. zhouquensis could be distinguished from Ph. rosae-omeiensis by its verrucose teliospores ( Fig. 1D View FIGURE 1 ); by contrast, the surface of Ph. rosae-omeiensis teliospores was smooth. The common species, Ph. tuberculatum , can be distinguished from Ph. zhouquensis according to its 1–8-celled (mostly 6-celled) teliospores bearing long papillae (7–23 μm) at the spore apices; the papillae of Ph. zhouquensis were 3.5–6 μm long ( Figs 1D, 1E View FIGURE 1 ) ( Wei 1988, Zhuang et al. 2012).

Phragmidium zhouquensis can be distinguished from other morphologically closely-related Rosa species as follows. Phragmidium fusiforme View in CoL is one of the most widespread Phragmidium species in the northern hemisphere; it is characterized by multiple-celled (mostly greater than 10-celled) and fusiform teliospore with long papilla up to 15 μm at the spore apex, which is obviously different from that of the present species ( Wei 1988, Hiratsuka et al. 1992, Wahyuno 2001, Zhuang et al. 2012). Phragmidium zhouquensis also differed from Ph. montivagum View in CoL by the dark brown telia ( Figs 1A, 1B View FIGURE 1 ) with ellipsoid-oblong to cylindrical teliospores and lanceolate pedicels ( Figs 1D, 1E View FIGURE 1 ), whereas the latter species had black telia aggregated by fusiform or subclavate teliospores with hygroscopic and bulbous pedicels.

Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF