Phytophthora asiatica

Name and publication

Phytophthora asiatica Rahman, Mukobata, Kageyama (2014)

Rahman MZ, Mukobata H, Suga H, and Kageyama K. 2014. Phytophthora asiatica sp. nov., a new species causing leaf and stem blight of kudzu in Japan. Mycol. Progress 13: 759–769.

Corresponding author: rahman@green.gifu-u.ac.jp

Nomenclature

from Rahman et al. (2014)

Mycobank

MB804495

Synonymy

= Phytophthora cinnamomi var. robiniae H.H.Ho var. nov. Mycotaxon. 82:392. 2002

= Phytophthora cinnamomi H.H.Ho, W.Y. Zhang, Z.R. Liang & Y. N. Yu Mycologia. 75:883. 1983

Etymology

named after the location of isolation of this pathogen, Asia

Typification

Type: JAPAN, collected from leaf and stem blight of kudzu (Pueraria lobata) in Toyama Prefecture, Kurobe city in 2005, collector H. Mukobata. Holotypus: Isolate NBRC H-13112 (frozen dry specimen) deposited at the Biological Resource Center - Culture Collection Division (NBRC)

Ex-type: Cultures NBRC 109140 and CBS 133347 (Toku-1)

Sequences for ex-type in original manuscript: Phytophthora asiatica Toku-1: ITS AB688422, LSU AB688587, TEF 1-α AB539557, β-tub AB539560, 60S/ L10 AB539554, HSP90 AB539563, tigA AB894380, COI AB688314, COXII AB894377

Ex-type in other collections

NBRC 109140 = CBS 133347 = Toku-1, P19977 (WPC), CPHST BL 124 (Abad), 61H3 (Yang)

Molecular identification

Voucher sequences for barcoding genes (ITS rDNA and COI) of the ex-type (see Molecular protocols page)

Phytophthora asiatica isolate CPHST BL 124 (= P19977 WPC) = ITS rDNA MG783378

Phytophthora asiatica isolate Toku-1 = COI AB688314

Selected specimen(s):

Phytophthora asiatica isolate CPHST BL 14 (=P16351 WPC) = ITS rDNA MG783379, COI MH136849

Sequences for ex-type in other sources
Position in ITS phylogenetic tree

Clade 7b

Morphological identification

adapted from Rahman et al. (2014)

Colonies and cardinal temperatures

Colony morphology on V8-A, PDA, and MEA with light stellate pattern. Minimum growth temperature 5°C, maximum 35°C, and optimum 28°C.

Conditions for growth and sporulation

Sporangia absent on solid media, but present in grass leaf blade water cultures.

Asexual phase

Sporangia nonpapillate, persistent, ellipsoid, obpyriform, obturbinate, or distorted (37–72 long x 16–33 μm wide), with internal (extended and nesting) and external proliferation, borne in simple and unbranched or simple sympodial sporangiophores. Hyphal swellings occasionally observed, when present catenulate lobate. Chlamydospores absent.

Sexual phase

Homothallic. Oogonia smooth, spherical, with average diameter of (18–55 μm). Antheridia amphigynous, rarely paragynous, regularly spherical or ovoid ellipsoid in shape. Oospores aplerotic, spherical, with average diameter of 15–43 μm.

Most typical characters

Phytophthora asiatica can be distinguished by the obturbinate, often distorted sporangia with internal and external proliferation and the shape of the catenulated hyphal swellings.

Additional specimen(s) evaluated

Phytophthora asiatica CPHST-BL 124 (Abad) = (P19977 World Phytophthora Collection – California, USA, duplicate of the ex-type CBS 133347).

Selected specimen CPHST-BL 14 (Abad) = P16351 WPC

Hosts and distribution

Distribution: Asia (China, Japan)
Substrate: leaf and stem
Disease note: leaf, petiole, and stem blight. The disease initially produced dark brown, irregular lesions on leaves, petioles, and stems. In advanced stages, the infected plant segments became dark and soft, leading to death of the plant.
Hosts: Peuraria lobata (kudzu)

Retrieved January 18, 2018 from U.S. National Fungus Collections Nomenclature Database.

Additional references and links

  also see Phytophthora cinnamomi robineae

Fact sheet author

Z. Gloria Abad, Ph.D., USDA-APHIS-PPQ-S&T Beltsville Laboratory, United States of America