Aurantioporthe cornigen. et comb. nov., an endophyte and pathogen ofCornus alternifolia

Abstract

Cryptodiaporthe corni is the causal agent of a destructive disease called golden canker, which affects Cornus alternifolia, known as the pagoda or alternate-leaved dogwood. Due to the association between Cr. corni and pagoda dogwood, we sought to determine whether this fungus was capable of living as an endophyte in pagoda dogwood and causing this disease. Forty asymptomatic stems of plants growing in nature were sampled from five sites across Minnesota. Cryptodiaporthe corni was present in more than half (62.5%) of the stems. Asymptomatic nursery material also was sampled, and the fungus was isolated from a small percentage (20%) of them. Inoculations carried out in the field and greenhouse suggested the endophytic isolates of Cr. corni were capable of causing disease. Asymptomatic stems of trees in the field inoculated with non-colonized (control) grain seed developed golden canker as frequently as those inoculated with grain seed colonized by Cr. corni, suggesting that the fungus was already present in these plants. In greenhouse pathogenicity trials an isolate of Cr. corni obtained from an asymptomatic stem was capable of causing golden canker disease, thus demonstrating causality, fulfilling Koch's postulates. The taxonomic placement of Cr. corni within Cryphonectriaceae was determined. Phylogenetic analysis of the ITS rDNA and β-tubulin gene regions, along with morphological characteristics, suggested Cr. corni is distinct from other genera within this family. Therefore, we propose a new genus, Aurantioporthe, as well as the new combination, A. corni, to accommodate this species within Cryphonectriaceae.

A new genus of Cryphonectriaceae isolated from Lagerstroemia speciosa in southern China

“…The fungus from L. speciosa had superficial to slightly immersed conidiomata, conidiomatal tissues of textura globulosa , orange conidiomata that were convex to globose in shape, non‐ostiolate, without necks and no paraphyses. These characters distinguished the fungus from other genera with orange conidiomata, including Amphilogia (Gryzenhout et al ., ), Aurantioporthe (Beier et al ., ), Aurantiosacculus (Crous et al ., ), Aurifilum (Begoude et al ., ), Cryphonectria (Gryzenhout et al ., ), Cryptometrion (Gryzenhout et al ., ), Endothia (Gryzenhout et al ., ), Filiocryphia (Cheewangkoon et al ., ), Holocryphia (Gryzenhout et al ., ), Immersiporthe (Chen et al ., ), Latruncellus (Vermeulen et al ., ), Microthia (Gryzenhout et al ., ), Rostraureum (Gryzenhout et al ., ) and Ursicollum (Gryzenhout et al ., ) in the Cryphonectriaceae.…”

Corticimorbus sinomyrti gen. et sp. nov. (Cryphonectriaceae) pathogenic to native Rhodomyrtus tomentosa (Myrtaceae) in South China

“…Conidiomata were black, conical without necks and lacked paraphyses. These characters distinguished the fungus from other genera in the Cryphonectriaceae (Cheewangkoon et al, 2009;Gryzenhout et al, 2009Gryzenhout et al, , 2010Begoude et al, 2010;Vermeulen et al, 2011;Crous et al, 2012a,b;Chen et al, 2013a,b;Crane & Burgess, 2013;Beier et al, 2015).…”

“…An HRc Axiocam digital camera with AXIOVISION v. 3.1 software (Carl Zeiss Ltd) was used to capture images and to obtain measurements. Characteristics of specimens were compared with those published for closely related genera/species in the Cryphonectriaceae (Cheewangkoon et al, 2009;Gryzenhout et al, 2009Gryzenhout et al, , 2010Begoude et al, 2010;Chen et al, 2011Chen et al, , 2013aVermeulen et al, 2011Vermeulen et al, , 2013aCrous et al, 2012a,b;Crane & Burgess, 2013;Beier et al, 2015). Results are presented as (minimum-) (mean À standard deviation) -(mean + standard deviation) (-maximum).…”

“…The family Cryphonectriaceae represents a group of fungi that includes some of the most important pathogens of trees (Gryzenhout et al, 2009). Twenty-one genera have been identified and described in this family, the majority of which include species that cause stem canker diseases on trees (Gryzenhout et al, 2009Begoude et al, 2010;Vermeulen et al, 2011;Chen et al, 2013a,b;Crane & Burgess, 2013;Beier et al, 2015). Exceptions are species of Aurantiosacculus, Chrysocrypta, Chrysofolia and Foliocryphia that cause leaf diseases (Cheewangkoon et al, 2009;Crous et al, 2012aCrous et al, ,b, 2015.…”

Novel Cryphonectriaceae from La Réunion and South Africa, and their pathogenicity on Eucalyptus

“…Those species include Cryphonectria parasitica, the causal agent of chestnut blight, which has devastated Castanea spp. (Fagaceae, Fagaceales) in Europe and North America, and the more recently discovered Aurantioporthe corni which causes a canker disease on Cornus alternifolia (Cornaceae, Cornales) in North America(Beier et al 2015). The two new species of Celoporthe found on T. grandifolia in La Réunion are the first fungi in this genus and family to have been recorded on that island.…”