scholarly journals Study of Phylogenetic Relationships Among Fusarium oxysporum f. sp. dianthi Isolates: Confirmation of Intrarace Diversity and Development of a Practical Tool for Simple Population Analyses

Plant Disease ◽  
2015 ◽  
Vol 99 (6) ◽  
pp. 780-787 ◽  
Author(s):  
M. C. Cañizares ◽  
C. Gómez-Lama ◽  
M. D. García-Pedrajas ◽  
E. Pérez-Artés

Fusarium wilt, caused by Fusarium oxysporum f. sp. dianthi, is the most important disease of carnation worldwide. Knowing the diversity of the F. oxysporum f. sp. dianthi population present in a carnation growing area is a key component of preventing dramatic losses in production. Sequence analyses of partial β-tubulin, translation elongation factor 1α genes, and the full-length ribosomal DNA intergenic spacer (IGS) were conducted to resolve phylogenetic relationships in a wide collection of Spanish F. oxysporum f. sp. dianthi isolates, along with some representatives from Italy. We found that, among the three different gene regions, the IGS sequence was the best choice to resolve phylogenetic relationships among F. oxysporum f. sp. dianthi isolates. The phylogenetic tree generated with the complete IGS region was the only one showing a clear clustering of isolates according to the molecular group (virulence grouping) and the vegetative compatibility group. In order to develop a more practical tool based on a shorter DNA sequence to quickly analyze diversity in F. oxysporum f. sp. dianthi populations, we examined IGS nucleotide alignments and identified a region of approximately 300 bp that accumulates enough “informative” changes to resolve intraspecific relationships and determine pathogenic variants in F. oxysporum f. sp. dianthi. Moreover, the “condensed” alignment of this short IGS region showing only the informative positions revealed the existence of virulence group-discriminating positions. In addition to clarifying the phylogenetic relationships among F. oxysporum f. sp. dianthi isolates of the recently described race groups by using multigene genealogies, we have developed simple tools for the phylogenetic analyses of F. oxysporum f. sp. dianthi populations and the determination of the molecular group of uncharacterized F. oxysporum f. sp. dianthi isolates.

Plant Disease ◽  
2020 ◽  
Vol 104 (6) ◽  
pp. 1811-1816
Author(s):  
Kelley R. Paugh ◽  
Thomas R. Gordon

Fusarium wilt of lettuce, caused by Fusarium oxysporum f. sp. lactucae, is now found in all major lettuce producing regions in California and Arizona. The population structure of F. oxysporum f. sp. lactucae in California and Arizona was characterized based on somatic compatibility and sequences of the translation elongation factor 1-α gene (EF-1α) and rDNA intergenic spacer region (IGS). In this study, 170 isolates were tested for somatic compatibility based on heterokaryon formation, using complementary nitrate nonutilizing (nit) mutants. Five subgroups (A to E) of somatic compatibility group 0300 were identified. Isolates associated with the same subgroup had a strong complementation reaction, whereas reactions between isolates of different subgroups were weak or delayed. An isolate from the first known infestation of Fusarium wilt of lettuce in California was associated with subgroup A, which predominated among isolates in our collection. Isolates representative of each subgroup were confirmed to be associated with race 1, based on the reaction of differential lettuce cultivars. It is possible that somatic compatibility subgroups B to E of F. oxysporum f. sp. lactucae were derived from subgroup A, as a consequence of somatic mutations affecting compatibility. If so, subgroups of F. oxysporum f. sp. lactucae may represent an intermediate step in divergence that will lead to clearly separable compatibility groups. Sequences of EF-1α and IGS were both identical for 58 isolates of F. oxysporum f. sp. lactucae that represented all somatic compatibility subgroups and locations from which isolates were obtained, indicating that subgroups were derived from the same clonal lineage (VCG 0300).


Plant Disease ◽  
2017 ◽  
Vol 101 (12) ◽  
pp. 2066-2072 ◽  
Author(s):  
A. M. Pastrana ◽  
S. C. Kirkpatrick ◽  
M. Kong ◽  
J. C. Broome ◽  
T. R. Gordon

Fusarium oxysporum has recently been identified as the cause of a wilt disease affecting blackberry in California and Mexico. Thirty-six isolates of F. oxysporum obtained from symptomatic blackberry plants in California and Mexico were comprised of nine distinct somatic compatibility groups (SCGs). Phylogenetic analysis of a concatenated data set, consisting of sequences of the translation elongation factor 1-α and β-tubulin genes and the intergenic spacer of the ribosomal DNA, identified nine three-locus sequence types, each of which corresponded to an SCG. Six SCGs were present only in California, two only in Mexico, and one in both California and Mexico. An isolate associated with the most common SCG in California was tested for pathogenicity on blueberry, raspberry, strawberry, and lettuce. All blueberry, raspberry, and lettuce plants that were inoculated remained healthy, but two of the five strawberry cultivars tested developed symptoms. The three strawberry cultivars that were resistant to the blackberry pathogen were also resistant to F. oxysporum f. sp. fragariae, the cause of Fusarium wilt of strawberry. We propose to designate strains of F. oxysporum that are pathogenic to blackberry as Fusarium oxysporum f. sp. mori forma specialis nov.


2015 ◽  
Vol 105 (4) ◽  
pp. 525-532 ◽  
Author(s):  
Kazunori Sasaki ◽  
Katsuya Nakahara ◽  
Shuhei Tanaka ◽  
Masayoshi Shigyo ◽  
Shin-ichi Ito

Fusarium oxysporum f. sp. cepae causes Fusarium basal rot in onion (common onion) and Fusarium wilt in Welsh onion. Although these diseases have been detected in various areas in Japan, knowledge about the genetic and pathogenic variability of F. oxysporum f. sp. cepae is very limited. In this study, F. oxysporum f. sp. cepae was isolated from onion and Welsh onion grown in 12 locations in Japan, and a total of 55 F. oxysporum f. sp. cepae isolates (27 from onion and 28 from Welsh onion) were characterized based on their rDNA intergenic spacer (IGS) and translation elongation factor-1α (EF-1α) nucleotide sequences, vegetative compatibility groups (VCGs), and the presence of the SIX (secreted in xylem) homologs. Phylogenetic analysis of IGS sequences showed that these isolates were grouped into eight clades (A to H), and 20 onion isolates belonging to clade H were monophyletic and assigned to the same VCG. All the IGS-clade H isolates possessed homologs of SIX3, SIX5, and SIX7. The SIX3 homolog was located on a 4 Mb-sized chromosome in the IGS-clade H isolates. Pathogenicity tests using onion seedlings showed that all the isolates with high virulence were in the IGS-clade H. These results suggest that F. oxysporum f. sp. cepae isolates belonging to the IGS-clade H are genetically and pathogenically different from those belonging to the other IGS clades.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12581
Author(s):  
Chunxia Wang ◽  
Hulei Zhang ◽  
Shenhai Wang ◽  
Shengfeng Mao

Leaf spot of Hosta ventricosa is a new disease in China. This disease seriously affects the ornamental value and greening function of H. ventricosa. Identification of the causal agent can prevent and control leaf spot in H. ventricosa and promote the healthy development of the H. ventricosa industry. Known incidents of leaf spot of H. ventricosa occurred in three places, and samples were collected. After the fungus were isolated, its pathogenicity was tested according to Koch’s postulates. Isolates ZE-1b and ZE-2b were identified as Fusarium oxysporum based on morphological features and multigene phylogenetic analyses of calmodulin (CMDA), RNA polymerase II subunit A (RPB1), RNA polymerase II second largest subunit (RPB2) and translation elongation factor 1-alpha (TEF1). These results provide a theoretical basis for the control of this disease of H. ventricosa.


2012 ◽  
Vol 25 (6) ◽  
pp. 418 ◽  
Author(s):  
Roy E. Halling ◽  
Mitchell Nuhn ◽  
Todd Osmundson ◽  
Nigel Fechner ◽  
James M. Trappe ◽  
...  

Harrya is described as a new genus of Boletaceae to accommodate Boletus chromapes, a pink-capped bolete with a finely scabrous stipe adorned with pink scabers, a chrome yellow base and a reddish-brown spore deposit. Phylogenetic analyses of large-subunit rDNA and translation elongation factor 1α confirmed Harrya as a unique generic lineage with two species, one of which is newly described (H. atriceps). Some Chinese taxa were recently placed in a separate genus, Zangia, supported by both morphology and molecular data. Multiple accessions from Queensland, Australia, support the synonymy of at least three species in a separate Australian clade in the new genus, Australopilus. The truffle-like Royoungia is also supported as a separate lineage in this clade of boletes. Even though it lacks stipe characters, it possesses the deep, bright yellow to orange pigments in the peridium. Additional collections from Zambia and Thailand represent independent lineages of uncertain phylogenetic placement in the Chromapes complex, but sampling is insufficient for formal description of new species. Specimens from Java referable to Tylopilus pernanus appear to be a sister group of the Harrya lineage.


Phytotaxa ◽  
2021 ◽  
Vol 508 (1) ◽  
Author(s):  
XU ZHANG ◽  
ZHI-QUN LIANG ◽  
SHUAI JIANG ◽  
CHANG XU ◽  
XIN-HUA FU ◽  
...  

Baorangia duplicatopora is described as a new species from Hainan Province, a tropical region of China. It is morphologically characterized by large to very large basidiomata with a dull rose red, rose pink to purplish red pileus, compound pores, pileus context near hymenophore and stipe context staining blue when injured, a red stipe, and cheilocystidia wider than those of other Baorangia species. Phylogenetic analyses of DNA sequences from part of the 28S gene, the nuc rDNA internal transcribed spacer (ITS) region, and part of the translation elongation factor 1-α gene (TEF1) also confirmed that B. duplicatopora forms an independent lineage within Baorangia. Detailed descriptions, color photographs of fresh basidiomata, and line drawings of microscopic features of the new species are presented. A key to species of Baorangia in the world is also provided.


Phytotaxa ◽  
2021 ◽  
Vol 483 (2) ◽  
pp. 117-128
Author(s):  
NAKARIN SUWANNARACH ◽  
JATURONG KUMLA ◽  
SAISAMORN LUMYONG

A new endophytic ascomycete, described herein as Spegazzinia camelliae, was isolated from leaves of Camellia sinensis var. assamica collected from Nan Province, Thailand. This species is characterized by basauxic conidiophores and dark brown to blackish brown α and β conidia. It can be distinguished from previously described Spegazzinia species by the spine length of the α conidia and the size of the β conidia. Multi-gene phylogenetic analyses of the small subunit (SSU), large subunit (LSU) and internal transcribed spacers (ITS) of the nuclear ribosomal DNA (rDNA) and the translation elongation factor 1-alpha (tef1) genes also support S. camelliae is a distinct new species within Spegazzinia. A full description, color photographs, illustrations and a phylogenetic tree showing the position of S. camelliae are provided.


Phytotaxa ◽  
2019 ◽  
Vol 415 (4) ◽  
pp. 179-188
Author(s):  
XIANG-NYU CHEN ◽  
MING ZHANG ◽  
TAI-HUI LI ◽  
NIAN-KAI ZENG

Heimioporus sinensis, collected from tropical and subtropical areas of China, is introduced as a new species based on both morphological characters and molecular data. The species is characterized by the purplish red to deep magenta pileus, the reticulated stipe, the irregularly reticulate to reticulate-alveolate basidiospores 11.5–13.5 × 8–9.5 μm, and a trichodermal to intricately trichodermal pileipellis. Phylogenetic analyses based on the nuc 28S rDNA D1-D2 domains (28S) and the translation elongation factor 1-α gene (tef1-α) showed that H. sinensis is a distinct member of the genus Heimioporus in the subfamily Xerocomoideae.


2020 ◽  
Vol 44 (1) ◽  
pp. 206-239 ◽  
Author(s):  
Y.-F. Sun ◽  
D.H. Costa-Rezende ◽  
J.-H. Xing ◽  
J.-L. Zhou ◽  
B. Zhang ◽  
...  

Amauroderma s.lat. has been defined mainly by the morphological features of non-truncate and double-walled basidiospores with a distinctly ornamented endospore wall. In this work, taxonomic and phylogenetic studies on species of Amauroderma s.lat. are carried out by morphological examination together with ultrastructural observations, and molecular phylogenetic analyses of multiple loci including the internal transcribed spacer regions (ITS), the large subunit of nuclear ribosomal RNA gene (nLSU), the largest subunit of RNA polymerase II (RPB1) and the second largest subunit of RNA polymerase II (RPB2), the translation elongation factor 1-α gene (TEF) and the β-tubulin gene (TUB). The results demonstrate that species of Ganodermataceae formed ten clades. Species previously placed in Amauroderma s.lat. are divided into four clades: Amauroderma s.str., Foraminispora, Furtadoa and a new genus Sanguinoderma. The classification of Amauroderma s. lat. is thus revised, six new species are described and illustrated, and eight new combinations are proposed. SEM micrographs of basidiospores of Foraminispora and Sanguinoderma are provided, and the importance of SEM in delimitation of taxa in this study is briefly discussed. Keys to species of Amauroderma s.str., Foraminispora, Furtadoa, and Sanguinoderma are also provided.


Phytotaxa ◽  
2019 ◽  
Vol 425 (5) ◽  
pp. 259-268
Author(s):  
XIAO-XIAO FENG ◽  
JIA-JIE CHEN ◽  
GUO-RONG WANG ◽  
TING-TING CAO ◽  
YONG-LI ZHENG ◽  
...  

During an exploration of plant pathogens in vegetables occuring in Zhejiang province, China, a novel fungal species, was found. Three strains ZJUP0033-4, ZJUP0038-3 and ZJUP0132 were isolated from black round lesions in the stems and leaves of Amaranthus sp. Phylogenetic analyses based on sequences from four genes including rDNA internal transcribed spacer (ITS), translation elongation factor 1-α (EF1-α), histone (HIS) and β-tubulin (TUB) indicated that D. sinensis clustered in a distinct clade closely related to D. neoarctii, D. angelicae, D. subordinaria, D. arctii, D. cuppatea, D. lusitanicae, D. novem, D. infecunda, D. ganjae and D. manihotia. Morphologically, D. sinensis is distinguished by brown, scattered, globose pycnidia and ellipsoid alpha conidia with bi- to multiguttulate.


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