Lineages in Nectriaceae: re-evaluating the generic status of Ilyonectria and allied genera
Lombard, L. ; Merwe, N.A. Van Der; Groenewald, J.Z. ; Crous, P.W. - \ 2014
Phytopathologia Mediterranea 53 (2014)3. - ISSN 0031-9465 - p. 515 - 532.
black foot disease - cylindrocarpon-destructans - phylogenetic-relationships - multigene analysis - sp nov. - neonectria - rot - hypocreales - radicicola - grapevines
Genera with cylindrocarpon-like asexual morphs are important pathogens of various herbaceous and woody plant hosts globally. Recent multi-gene studies of this generic complex indicated that the genus Ilyonectria is paraphyletic. The present study was therefore initiated to re-evaluate the generic status of Ilyonectria and at the same time address some taxonomic irregularities in the genera Cylindrodendrum and Neonectria. Using multi-gene DNA data and morphological comparisons, the genus Dactylonectria is introduced with 10 new combinations, several of which were previously treated in Ilyonectria. Two new species, D. hordeicola and D. pinicola, are also described. Furthermore, one new combination is provided in the genus Cylindrodendrum, and three new combinations in the genus Neonectria, for species previously treated in the genera Acremonium, Cylindrocarpon, Nectria and Neonectria. The aquatic genus Heliscus is reduced to synonymy under Neonectria.
Ilyonectria palmarum sp. nov. causing dry basal stem rot of Arecaceae
Aiello, D. ; Guarnaccia, V. ; Vitale, A. ; Cirvilleri, G. ; Granata, G. ; Epifani, F. ; Perrone, G. ; Polizzi, G. ; Groenewald, J.Z. ; Crous, P.W. - \ 2014
European Journal of Plant Pathology 138 (2014)2. - ISSN 0929-1873 - p. 347 - 359.
black foot disease - 1st report - root-rot - cylindrocarpon-macrodidymum - phylogenetic trees - multigene analysis - united-states - trunk rot - grapevine - phytophthora
During surveys conducted in 2010–2013, a complete breakage or bending of the trunk and a dry basal stem rot were observed on containerised Brahea armata, B. edulis, Howea forsteriana and Trachycarpus princeps plants in different nurseries located in eastern Sicily (southern Italy). A cylindrocarpon-like species was consistently obtained from diseased palm tissues, while known pathogens of these hosts such as Ganoderma, Phytophthora and Thielaviopsis were not found associated with symptomatic tissues or isolated on standard or selective media. A total of 40 cylindrocarpon-like isolates were collected and characterised based on morphology and DNA phylogeny. Multigene analyses based on the ß-tubulin, histone H3, translation elongation factor 1-a, and the internal transcribed spacers (ITS1, 5.8S, ITS2) genes facilitated the identification of a new species, described here as Ilyonectria palmarum. The pathogenicity of one representative isolate collected from each palm species was tested on plants cultivated under nursery conditions and in a growth chamber. All isolates were pathogenic to B. armata, B. edulis, H. forsteriana, and T. princeps and symptoms identical to that observed in nurseries were reproduced. Dry basal stem rot and stem bending caused by Ilyonectria palmarum represents a potentially serious problem for nurseries cultivating containerised palms
Diaporthe: a genus of endophytic, saprobic and plant pathogenic fungi
Gomes, R.R. ; Glienke, C. ; Videira, S.I.R. ; Lombard, L. ; Groenewald, J.Z. ; Crous, P.W. - \ 2013
Persoonia 31 (2013). - ISSN 0031-5850 - p. 1 - 41.
internal transcribed spacer - south-africa - species concepts - sp-nov - coelomycete phomopsis - foeniculum-vulgare - multigene analysis - north-america - ribosomal dna - twig dieback
Diaporthe (Phomopsis) species have often been reported as plant pathogens, non-pathogenic endophytes or saprobes, commonly isolated from a wide range of hosts. The primary aim of the present study was to resolve the taxonomy and phylogeny of a large collection of Diaporthe species occurring on diverse hosts, either as pathogens, saprobes, or as harmless endophytes. In the present study we investigated 243 isolates using multilocus DNA sequence data. Analyses of the rDNA internal transcribed spacer (ITS1, 5.8S, ITS2) region, and partial translation elongation factor 1-alpha (TEF1), beta-tubulin (TUB), histone H3 (HIS) and calmodulin (CAL) genes resolved 95 clades. Fifteen new species are described, namely Diaporthe arengae, D. brasiliensis, D. endophytica, D. hongkongensis, D. inconspicua, D. infecunda, D. mayteni, D. neoarctii, D. oxe, D. paranensis, D. pseudomangiferae, D. pseudophoenicicola, D. raonikayaporum, D. schini and D. terebinthifolii. A further 14 new combinations are introduced in Diaporthe, and D. anacardii is epitypified. Although species of Diaporthe have in the past chiefly been distinguished based on host association, results of this study confirm several taxa to have wide host ranges, suggesting that they move freely among hosts, frequently co-colonising diseased or dead tissue. In contrast, some plant pathogenic and endophytic taxa appear to be strictly host specific. Given this diverse ecological behaviour among members of Diaporthe, future species descriptions lacking molecular data (at least ITS and HIS or TUB) should be strongly discouraged.
Ilyonectria black foot rot associated with Proteaceae
Lombard, L. ; Bezuidenhout, C.M. ; Crous, P.W. - \ 2013
Australasian Plant Pathology 42 (2013)3. - ISSN 0815-3191 - p. 337 - 349.
cylindrocarpon-destructans - phylogenetic analysis - multigene analysis - fusarium - disease - grapevine - radicicola - pathogens - cultivars - africa
Proteaceae is an important component of the South African cut flower industry. Propagation of these woody plants using vegetative cuttings is, however, hampered by fungal infections initiated in the nursery. Recently black foot rot disease symptoms were observed on vegetative cuttings of Protea and Leucospermum in a fynbos nursery near Stanford, Western Cape Province, South Africa. Isolations from symptomatic plant material revealed several isolates of Ilyonectria, which were identified as I. macrodidyma, I. torresensis and four novel taxa described here as I. capensis, I. leucospermi, I. protearum and I. vredehoekensis. Species were characterised based on DNA phylogenetic inference and morphological comparisons. Furthermore, pathogenicity tests were conducted, which confirmed all six Ilyonectria species capable of causing black foot rot of Proteaceae. Other than the novel plant pathogenic species described here, this study also represents the first report of black foot rot disease associated with the cultivation of Proteaceae cut flowers.
Virulence and cross-infection potential of Ilyonectria species to grapevine
Cabral, A. ; Rego, C. ; Crous, P.W. ; Oliveira, H. - \ 2012
Phytopathologia Mediterranea 51 (2012)2. - ISSN 0031-9465 - p. 340 - 354.
black foot disease - cylindrocarpon-liriodendri - multigene analysis - c. macrodidymum - sp nov. - decline - spain
Black foot is an important disease of grapevines, affecting vines in nurseries as well as in young plantations. In recent years the disease has increased in incidence and severity throughout the world. Black foot is associated with at least two Campylocarpon and 12 Ilyonectria species, most of which have only recently been described. The recognition of previously unknown species, together with published reports of variability in virulence between and within species identified as I. macrodidyma and I. liriodendri, underlined the need to compare the virulence of isolates from these complexes. A further objective of this work was to determine the cross-infection potential of isolates of these species from other hosts to grapevine. Results from this study revealed recently described species such as I. lusitanica, I. estremocensis and I. europaea to be more virulent to grapevine than the species previously accepted as the main causal agents of black foot, such as I. liriodendri and I. macrodidyma. Furthermore, these results also provided support for isolates obtained from non-grapevine hosts to be as virulent to grapevines as isolates obtained from grapevine, underlying the cross-infection potential of these pathogens.