Curvularia malina sp. nov. incites a new disease of warm-season turfgrasses in the southeastern United States

Abstract

A novel species of Curvularia was identified as a foliar pathogen of Cynodon dactylon (bermudagrass) and Zoysia matrella (zoysiagrass), two important warm-season turfgrasses in the southeastern United States. Field symptoms were conspicuous chocolate brown to black spots in turf of both species on golf course putting greens and fairways. Leaves of plants within these spots exhibited prominent, black eyespot lesions from which a darkly pigmented fungus was consistently isolated. The fungus produced gray- to black-olivaceous mycelium within 10 d on potato dextrose agar at 25 C but never produced conidia despite numerous attempts to induce them. Field symptoms were reproduced in inoculated plants of both grasses, and re-isolation of the pathogen from symptomatic tissues confirmed its pathogenicity in fulfillment of Koch's postulates. A phylogenetic analysis was performed using sequence markers of internal nuclear ribosomal transcribed spacer region (ITS), glyceralde-hyde-3-phosphate dehydrogenase (GPD1) and translation elongation factor 1-α (TEF 1). The concatenated phylogenetic tree showed strong support for a new species within Curvularia that is distinctly divergent from other Curvularia spp. Therefore, the darkly pigmented pathogen of warm-season turfgrasses is described and illustrated as a new species, Curvularia malina.

Etiology of soybean (Glycine max) leaf spot in Sinaloa, Mexico

“…Las secuencias se editaron en el software BioEdit versión 7.0.5.3 (Hall, 1999) y fueron comparadas contra otras secuencias depositadas en la base de datos del GenBank, utilizando el algoritmo BlastN. Las secuencias se alinearon junto con un set de 68 secuencias de referencia del género Curvularia y una secuencia de Bipolaris maydis como grupo externo (Madrid et al, 2014;Manamgoda et al, 2015;Tomaso-Peterson et al, 2016;Mehrabi-Koushki et al, 2018;Tan et al, 2018;Kiss et al, 2019), utilizando el alineador MUSCLE (Edgar, 2004) implementado en MegaX (Kumar et al, 2018). El análisis filogenético se realizó en MegaX, empleando el método de Máxima Verosimilitud y el modelo de Hasegawa-Kishino-Yano (HKY), con distribución gamma (cuatro categorías) y sitios invariables.…”

“…The sequences were aligned along with a set of 68 references sequences of the genus Curvularia and a sequence of Bipolaris maydis as an external group (Madrid et al, 2014;Manamgoda et al, 2015;Tomaso-Peterson et al, 2016;Mehrabi-Koushki et al, 2018;Tan et al, 2018;Kiss et al, 2019), using the MUSCLE aligner (Edgar, 2004) implemented in MegaX (Kumar et al, 2018). The phylogenetic analysis was carried out in MegaX, using the maximum likelihood method and the Hasegawa-Kishino-Yano (HKY) model, with a gamma distribution (four categories) and unvariable sites.…”

Ink Spot of Warm‐Season Golf Course Turfgrasses

“…The concatenated phylogenetic tree showed strong support for a new species within Curvularia that is distinctly divergent from other Curvularia and Bipolaris spp. (Tomaso‐Peterson et al, 2016). Curvularia malina is sterile—no sexual or asexual reproductive structures have been observed in axenic culture nor on infected plant material.…”

“…Curvularia malina has been characterized as sterile, despite attempts to induce sporulation on various media, environmental conditions, or infected plant material (Tomaso‐Peterson et al, 2016). Curvularia malina initially produces hyaline mycelium, and at 10 days, the colony develops a superficially light olive pigment; circular, suede‐like, radially grooved, and flat with an undulating margin (Fig.…”

“…The type strain of C. malina , FLS 26–2SS, is available through the Westerdijk Fungal Biodiversity (formerly Centraalbureau voor Schimmelcultures) culture collection, accessioned as CBS 131274. Confirmation of C. malina should be made using sequence data (Tomaso‐Peterson et al, 2016). Nucleotide sequence analysis using ITS, GPD1 , or TEF1 are sufficient to identify C. malina and differentiate from other Curvularia spp.…”