Mycology (2019) 10, 243-249

Hung K. Doan and R. Michael Davis (2019)
Pythiogeton manoomin, a new species causing root and basal stalk rot of wild rice in the United States
Mycology 10 (4), 243-249
Abstract: A new species of Pythiogeton isolated from wild rice exhibiting rot and dieback of roots and stalks in California is described. Pythiogeton manoomin sp. nov. is characterized by coenocytic hyphae, club-like appressorium, and terminal or intercalary sporangia, which are often a short distance from the end of supporting hyphae. The protoplasm is discharged through a discharge tube into an elongate transient vesicle, which soon disappears, leaving the naked protoplasm to differentiate into reniform zoospores. Pythiogeton manoomin also produces thick-walled pigmented chlamydospores, not found in other Pythiogeton species. In greenhouse trials, Pg. manoomin did not infect economically important crops such as rice, bean, chard, corn, carrot, lettuce, oat, radish, sweet pepper, tomato, or wheat. Phylogenetic analysis based on ITS data supports the conclusion that this organism is a new species that is most closely related to Pg. ramosum. In this paper, we describe morphological characteristics, temperature–growth relationships, pathogenicity, and phylogenetic relationships that support the description of this taxon as a new species, Pythiogeton manoomin sp. nov.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article
Database assignments for author(s): R. Michael Davis

Research topic(s) for pests/diseases/weeds:
identification/taxonomy

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Pythiogeton manoomin	Wild rice (Zizania)	U.S.A. (SW)