Molecular Relationships of Fungi Within theFusarium redolens-F. hostaeClade

Abstract

The evolutionary relationships of fungi in the Fusarium redolens-F. hostae clade were investigated by constructing nuclear and mitochondrial gene genealogies for 37 isolates representing the known genetic and pathogenic diversity of this lineage, together with 15 isolates from putative sister groups that include the Gibberella fujikuroi and F. oxysporum species complexes and related species. Included in the analyses were 29 isolates of F. redolens from Asparagus, Convallaria, Dianthus, Fritillaria, Hebe, Helleborus, Hordeum, Linum, Pisum, Pseudotsuga, and Zea spp., and from soil. Isolates of F. hostae analyzed included two reference isolates from Hosta spp. and six isolates from Hyacinthus spp. that originally were classified as F. oxysporum f. sp. hyacinthi. DNA sequences from a portion of the nuclear translation elongation factor 1alpha (EF-1alpha) gene and the mitochondrial small subunit (mtSSU) ribosomal RNA (rRNA) were analyzed individually and as a combined data set based on results of the nonparametric Wilcoxon signed ranks Templeton combinability test. Maximum parsimony analysis of the combined data set identified the F. redolens-F. hostae clade as a sister group to a phylogenetically diverse clade in which the G. fujikuroi species complex formed the most basal lineage. Also included in this latter clade were two unnamed Fusarium spp. that are morphologically similar to F. oxysporum and putative sister taxa comprising the F. oxysporum complex and a F. nisikadoi-F. miscanthi clade. Phylogenetic diversity in F. redolens was small; all isolates were represented by only three EF-1alpha and two mtSSU rDNA haplotypes. Both the isolates of F. redolens f. sp. asparagi and those of F. redolens f. sp. dianthi were nearly evenly distributed in the combined molecular phylogeny between the two major subclades within F. redolens.

Fusarium burgessii sp. nov. representing a novel lineage in the genus Fusarium

“…The advent of inexpensive sequencing technology now allows the phylogenetic reassessment of these variable isolates. Phylogenetic based techniques have been used to differentiate, for example, F. foetens (Schroers et al 2004), F. hostae ) and F. redolens (Baayen et al 2001) and reassess many recently described species e.g. F. brevicantenulatum (Amata et al 2010).…”

“…F. brevicantenulatum (Amata et al 2010). Many have morphological affinities with F. oxysporum but with intermediate morphological characters that contradicted their placement in F. oxysporum sensu stricto (Baayen et al 2001;Geiser et al 2001). Despite the utility and routine application of molecular data, morphological and physiological characters remain essential for robust species delineation as such characters can be used to assign biological meaning to phylogenetic sub-clustering (Leslie et al 2001).…”

Occurrence of Fusarium wilt in Japan caused by Fusarium oxysporum f. sp. tanaceti.

“…oxysporum と同定した (Matuo and Motohashi, 1967;Booth, 1971;Matuo et al, 1975;Gerlach and Nirenberg, 1982;松尾 ほ か，1982;有江ほか，1986;有江，1988;Nirenberg and O'Donnell, 1998;Schroers et al, 2004) Booth, 1971;松尾 ほか，1982;Kistler, 1997;Baayen et al, 2000Baayen et al, , 2001) ．日本のキク科植物における F. oxysporum の分化 型の記録はゴボウ萎凋病菌の F. oxysporum f. sp. arctii (Matuo et al, 1975) ，レタス(チシャ)萎凋病菌の F. oxysporum f. sp.…”

Breeding resistance in strawberry cultivars for Fusarium oxysporum f. sp. fragariae

“…Identification and knowledge of the variations within the subgroups of the forma specialis is vital for breeding for resistant strawberry cultivars. To get an indication of the genetic relationships within or between populations of F. oxysporum, vegetative compatibility groups (VCG), volatiles produced, and molecular techniques have been used (Correll et al, 1986;O'Donnell et al, 1998;White et al, 1990;Moore et al, 1991;Baayen et al, 2001;Martinez-Culebras et al, 2002;Zhou and Everts, 2006).…”

“…The decision to use the EF-1α and mtSSU gene regions in this study was based on the common use and results obtained from studies of genetic similarities among formae speciales of F. oxysporum (O'Donnell et al, 1998;White et al, 1990;Baayen et al, 2001;Skovgaard et al, 2001;O'Donnell et al, 2004;Bogale et al, 2006;Rahjoo et al 2008;Fourie et al, 2009). Although relationships within Fof were clearly defined by EF-1α analysis and suggest more divergent evolution of EF-1α sequences in different isolates of Fof, the few sequence differences revealed from mtSSU analysis was generally insufficient to resolve interspecific and intraspecific genetic variation among the Fof isolates.…”