Species delineation in the tree pathogen genusCeloporthe(Cryphonectriaceae) in southern Africa

Abstract

The genus Celoporthe was first described when C. dispersa was discovered in South Africa associated with dieback and cankers on trees in the Myrtales. Four additional species were recently described from Eucalyptus and Syzygium cumini in China as well as S. aromaticum and Eucalyptus in Indonesia. Inoculation trials have shown that all Celoporthe species, including those that have not been found on Eucalyptus species in nature, are pathogenic to Eucalyptus and they are thus potentially threatening to commercial Eucalyptus forestry. New isolates, morphologically similar to Celoporthe, have been collected from S. legatti in South Africa and S. guineense in Zambia. Multigene phylogenetic analyses based on DNA sequences of the ITS region, TEF1a gene and two areas of the b-tubulin gene revealed additional cryptic species in Celoporthe. Phylogenetic data were supported by morphological differences. These resulted in the description of two previously unknown species of Celoporthe, namely C. fontana and C. woodiana, for two of these cryptic groups, while the third group represented C. dispersa. These species all can readily infect Eucalyptus as well as several species of Syzygium, the latter of which are native to Africa.

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

“…To determine the phylogenetic placement of the isolates from R. tomentosa, sequences of the LSU gene region, as well as the sequence combination of 5.8S rDNA and the exon regions of the BT2 and BT1 (including partial exon 4, exon 5, partial exon 6 and partial exon 7) genes of all the previously described genera/species in the Cryphonectriaceae (Cheewangkoon et al, 2009;Gryzenhout et al, 2009Gryzenhout et al, , 2010Begoude et al, 2010;Vermeulen et al, 2011Vermeulen et al, , 2013aCrous et al, 2012a,b;Chen et al, 2013a,b;Crane & Burgess, 2013;Beier et al, 2015) were analysed together with sequences generated in this study. Prior to conducting the phylogenetic analyses for a combination of sequences for the 5.8S rDNA and the exon regions of the BT2 and BT1 genes, a partition homogeneity test (PHT) was performed in PAUP v. 4.0b10 (Swofford, 2003) to determine whether conflict existed between the two data sets (Farris et al, 1995;Huelsenbeck et al, 1996).…”

“…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).…”

Cryphonectriaceae associated with rust-infected Syzygium jambos in Hawaii

“…The ITS was amplified using primers ITS1 and ITS4 (White et al 1990), the BT1 using primers βt1a and βt1b (Glass and Donaldson 1995) and TEF1 using primers EF728F and EF986R (Carbone and Kohn 1999). The PCR reaction mixtures and thermal cycling conditions were the same as described previously for the ITS, BT1 (Chen et al 2011(Chen et al , 2013a and TEF1 gene regions (Vermeulen et al 2013).…”

“…The ITS, BT1 and TEF1 gene regions were analysed separately and in combination. This made it possible to determine the phylogenetic relationships amongst the isolates from Hawaii and all 10 previously described Celoporthe species (Nakabonge et al 2006;Chen et al 2011;Vermeulen et al 2013;Ali et al 2018;Wang et al 2018). A PHT was used to determine if conflict existed amongst the ITS, BT1 and TEF1 datasets (Farris et al 1995;Huelsenbeck et al 1996).…”

Figure 1 from: Roux J, Kamgan Nkuekam G, Marincowitz S, van der Merwe NA, Uchida J, Wingfield MJ, Chen SF (2020) Cryphonectriaceae associated with rust-infected Syzygium jambos in Hawaii. MycoKeys 76: 49-79. https://doi.org/10.3897/mycokeys.76.58406

“…For isolates that grouped in Celoporthe, based on ITS and BT1 gene sequences, TEF1 sequences were required to obtain accurate species-level identifications (Chen et al 2011;Vermeulen et al 2013). The ITS, BT1 and TEF1 gene regions were analysed separately and in combination.…”