Phylogenetic relationships in Neonectria species having Cylindrocarpon anamorphs inferred from mitochondrial ribosomal DNA sequences

Mitochondrial small subunit (mtSSU) rDNA sequences elucidated phylogenetic relationships in Neonectria Wollenw. (anamorphs = Cylindrocarpon Wollenw.; Ascomycetes, Hypocreales). Twelve isolates representing seven species in fi ve taxonomically informal groups of Neonectria were subjected to phylogenet ic analysis. Fusarium inflexum R. Schneid. (teleomorph: Gibberella) and Nec tria cinnabarina (Fr.) Fr. (= Nectria s.str.) were outgroups. All of the Ne onectria species formed a strongly supported clade with respect to the outg roups, indicating a single ascomycete genus for the holomorphs of Cylindroc arpon. Within the Neonectria clade there were three well-supported subclade s that only partially corresponded to phenotype-defined groups. DNA sequenc e divergence among the twelve Neonectria isolates, 2.3-7.4%, was sufficient to resolve them. The results suggest that the mtSSU rDNA region is appropr iate for phylogenetic analysis of Neonectria and Cylindrocarpon. The follow ing new combinations are proposed: Neonectria coronata, Neonectria discopho ra, Neonectria neomacrospora, Neonectria radicicola, Neonectria rugulosa, N eonectria veuillotiana.