Take-all or nothing

TY - JOUR

T1 - Take-all or nothing

AU - Hernández-Restrepo, M.

AU - Groenewald, J.Z.

AU - Elliott, M.L.

AU - Canning, G.

AU - McMillan, V.E.

AU - Crous, P.W.

PY - 2016

Y1 - 2016

N2 - Take-all disease of Poaceae is caused by Gaeumannomyces graminis (Magnaporthaceae). Four varieties are recognised in G. graminis based on ascospore size, hyphopodial morphology and host preference. The aim of the present study was to clarify boundaries among species and varieties in Gaeumannomyces by combining morphology and multi-locus phylogenetic analyses based on partial gene sequences of ITS, LSU, tef1 and rpb1. Two new genera, Falciphoriella and Gaeumannomycella were subsequently introduced in Magnaporthaceae. The resulting phylogeny revealed several cryptic species previously overlooked within Gaeumannomyces. Isolates of Gaeumannomyces were distributed in four main clades, from which 19 species could be delimited, 12 of which were new to science. Our results show that the former varieties Gaeumannomyces graminis var. avenae and Gaeumannomyces graminis var. tritici represent species phylogenetically distinct from G. graminis, for which the new combinations G. avenae and G. tritici are introduced. Based on molecular data, morphology and host preferences, Gaeumannomyces graminis var. maydis is proposed as a synonym of G. radicicola. Furthermore, an epitype for Gaeumannomyces graminis var. avenae was designated to help stabilise the application of that name.

AB - Take-all disease of Poaceae is caused by Gaeumannomyces graminis (Magnaporthaceae). Four varieties are recognised in G. graminis based on ascospore size, hyphopodial morphology and host preference. The aim of the present study was to clarify boundaries among species and varieties in Gaeumannomyces by combining morphology and multi-locus phylogenetic analyses based on partial gene sequences of ITS, LSU, tef1 and rpb1. Two new genera, Falciphoriella and Gaeumannomycella were subsequently introduced in Magnaporthaceae. The resulting phylogeny revealed several cryptic species previously overlooked within Gaeumannomyces. Isolates of Gaeumannomyces were distributed in four main clades, from which 19 species could be delimited, 12 of which were new to science. Our results show that the former varieties Gaeumannomyces graminis var. avenae and Gaeumannomyces graminis var. tritici represent species phylogenetically distinct from G. graminis, for which the new combinations G. avenae and G. tritici are introduced. Based on molecular data, morphology and host preferences, Gaeumannomyces graminis var. maydis is proposed as a synonym of G. radicicola. Furthermore, an epitype for Gaeumannomyces graminis var. avenae was designated to help stabilise the application of that name.

KW - Cryptic species

KW - Gaeumannomyces graminis

KW - Magnaporthaceae

KW - Phylogeny

KW - Triticum

U2 - 10.1016/j.simyco.2016.06.002

DO - 10.1016/j.simyco.2016.06.002

M3 - Article

VL - 83

SP - 19

EP - 48

JO - Studies in Mycology

JF - Studies in Mycology

SN - 0166-0616

ER -