TY - JOUR
T1 - Characterization of Alternaria isolates from the infectoria species-group and a new taxon from Arrhenatherum, Pseudoalternaria arrhenatheria sp. nov
AU - Lawrence, Daniel P.
AU - Gannibal, Philipp B.
AU - Dugan, Frank M.
AU - Pryor, Barry M.
N1 - Funding Information:
The asexual lineages of Alternaria (alternata, alternantherae, porri, radicina, sonchi, and brassicicola species-groups) clustered phylogenetically distant to the sexual lineages of Alternaria (teleomorph Lewia) supporting the previously reported polyphyly of Alternaria. The alternata, alternantherae, porri, and brassicicola species-groups formed strongly supported clades (≥99%/1.0), whereas the radicina and sonchi species-groups were supported by moderate to strong support (77%/ 1.0 and 74%/1.0, respectively). A newly described group, the panax species-group, consisted of a strongly supported (99%/1.0) clade that contained A. panax and A. eryngii. The paraphyletic genus Ulocladium was weakly supported (70%/.95), but was strongly supported (90%/1.0) as belonging to the asexual Alternaria group. Isolate 564692-12FD clustered with A. rosae in a clade basal to the infectoria species-group and this position was strongly supported.
PY - 2014/5
Y1 - 2014/5
N2 - The infectoria species-group within the genus Alternaria was originally conceived by Simmons in 1993 and was based upon common morphological characteristics that included the development of conidial chains with primary, secondary, and tertiary branching resulting in substantial three-dimensional complexity. These characters can overlap to varying degrees with numerous taxa in another Alternaria group, the alternata species-group, making species-group differentiation difficult. However, members of the infectoria species-group are also distinguished from other small-spored Alternaria species based upon colony characteristics that typically include white or nearly white floccose colonies on DRYES medium and clumps of sporulation islands on low sugar media such as V8 agar, PCA, and weak PDA. In addition, the infectoria species-group contains representatives that are known to produce teleomorphs (Lewia), whereas the members of the alternata species-group and other Alternaria species-groups are strictly asexual. In this study, an assemblage of isolates recovered from varied hosts from the west coast of the United States were examined based upon morphological characters and compared to previously described members of the infectoria species-group. These isolates and members of the infectoria species-group typically produce arachnoid vegetative hyphae with multiple primary conidiophores, whereas other small-spored Alternaria species produce primary conidiophores predominately directly from the agar surface. Additionally, molecular phylogenetic analyses resolved these isolates and members of the infectoria species-group as distinctly nested amongst other sexual taxa in Allewia (Embellisia anamorph) and Macrospora (Nimbya anamorph) and phylogenetically distant to asexual lineages of Alternaria. One taxon among these isolates was novel and clustered with the asexual A. rosae in a distinct clade basal to all other members of the infectoria species-group. A new genus is proposed, Pseudoalternaria gen. nov. and a new taxon is described, Pseudoalternaria arrhenatheria sp. nov. Moreover, a second taxon is reclassified, Pseudoalternaria rosae comb. nov.
AB - The infectoria species-group within the genus Alternaria was originally conceived by Simmons in 1993 and was based upon common morphological characteristics that included the development of conidial chains with primary, secondary, and tertiary branching resulting in substantial three-dimensional complexity. These characters can overlap to varying degrees with numerous taxa in another Alternaria group, the alternata species-group, making species-group differentiation difficult. However, members of the infectoria species-group are also distinguished from other small-spored Alternaria species based upon colony characteristics that typically include white or nearly white floccose colonies on DRYES medium and clumps of sporulation islands on low sugar media such as V8 agar, PCA, and weak PDA. In addition, the infectoria species-group contains representatives that are known to produce teleomorphs (Lewia), whereas the members of the alternata species-group and other Alternaria species-groups are strictly asexual. In this study, an assemblage of isolates recovered from varied hosts from the west coast of the United States were examined based upon morphological characters and compared to previously described members of the infectoria species-group. These isolates and members of the infectoria species-group typically produce arachnoid vegetative hyphae with multiple primary conidiophores, whereas other small-spored Alternaria species produce primary conidiophores predominately directly from the agar surface. Additionally, molecular phylogenetic analyses resolved these isolates and members of the infectoria species-group as distinctly nested amongst other sexual taxa in Allewia (Embellisia anamorph) and Macrospora (Nimbya anamorph) and phylogenetically distant to asexual lineages of Alternaria. One taxon among these isolates was novel and clustered with the asexual A. rosae in a distinct clade basal to all other members of the infectoria species-group. A new genus is proposed, Pseudoalternaria gen. nov. and a new taxon is described, Pseudoalternaria arrhenatheria sp. nov. Moreover, a second taxon is reclassified, Pseudoalternaria rosae comb. nov.
KW - Alternaria
KW - Infectoria
KW - Pseudoalternaria
UR - http://www.scopus.com/inward/record.url?scp=84898549670&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84898549670&partnerID=8YFLogxK
U2 - 10.1007/s11557-013-0910-x
DO - 10.1007/s11557-013-0910-x
M3 - Article
AN - SCOPUS:84898549670
SN - 1617-416X
VL - 13
SP - 257
EP - 276
JO - Mycological Progress
JF - Mycological Progress
IS - 2
ER -