Six Species of Diaporthe Associated with Phomopsis Stem Canker of Sunflower in Southern Pampean Region of Argentina

Author(s):  
Andrés Zambelli ◽  
María F. Mancebo ◽  
María E. Bazzalo ◽  
Roberto J. Reid ◽  
María C. Sanchez ◽  
...  

A survey of 67 commercial fields in 19 locations was conducted in the southern Pampean region of Argentina for Phomopsis stem canker of sunflower (Helianthus annuus L.) between 2014 and 2019. A total of 210 plants having typical symptoms of Phomopsis stem canker were randomly sampled, and fungal isolation was performed. Of the 187 isolates of Diaporthe that were recovered, 94% of the isolates showed morphological characteristics similar to D. helianthi, 3% to D. gulyae, 1% to D. caulivora, 1% to D. sojae, 0.5% to D. kongii, and 0.5% to D. longicolla. Following morphological characterization, the identity of the six morpho-species was confirmed by phylogenetic analyses of β-tubulin, translation elongation factor 1-α, and internal transcribed spacer gene regions. Koch’s postulates were completed for the six fungi by inoculating one susceptible sunflower hybrid with one isolate each of the six species of Diaporthe using the stem-wound inoculation method. Seven days postinoculation, significant differences in disease severity were observed between the six isolates (P < 0.0001), with D. helianthi and D. gulyae isolates causing significantly greater disease severity. To our knowledge, this is the first report of D. kongii, D. longicolla, D. caulivora, and D. sojae associated with Phomopsis stem canker of sunflower in Argentina.

Plant Disease ◽  
2013 ◽  
Vol 97 (8) ◽  
pp. 1042-1050 ◽  
Author(s):  
Karina Elfar ◽  
René Torres ◽  
Gonzalo A. Díaz ◽  
Bernardo A. Latorre

Stem canker and dieback are important factors that limit the longevity and reduce the yield of blueberry (Vaccinium spp.) in Chile. In this study, species of Diaporthe associated with blueberry were isolated and identified. The internal transcribed spacer (ITS) regions of ribosomal DNA of 30 isolates and the translation elongation factor 1-α (EF1-α) of 14 isolates were sequenced, analyzed, and compared with their morphological and pathological characteristics. The molecular analysis of ITS sequences by alignment with those of ex-type strains deposited in GenBank and morphological characteristics allowed the identification of Diaporthe ambigua, D. australafricana, D. neotheicola, D. passiflorae, and Diaporthe sp. 1. However, morphology alone was insufficient to identify these species. The combined analysis of ITS and EF1-α gene sequences grouped the Chilean blueberry isolates in the same five groups obtained in the ITS analysis. Pathogenicity tests conducted with attached and detached blueberry shoots (<1 year old) and stems (1 to 2 years old) confirmed that isolates of these Diaporthe spp. were pathogenic. The symptoms were reproducible and consisted of necrotic reddish-brown cankers on blueberry shoots and stems. These isolates were capable of infecting blueberry fruit, causing a soft decay, suggesting that they were tissue nonspecific and were also pathogenic on shoots of apple, grapevine, and pear. D. australafricana was the most frequently isolated species and D. ambigua, D. australafricana, and D. passiflorae were highly virulent in shoots, stems, and fruit of blueberry. This study showed that at least four species of Diaporthe are primary pathogens, capable of causing stem canker symptoms on blueberry, and this is the first report of D. ambigua, D. neotheicola, and D. passiflorae attacking this host.


2020 ◽  
Vol 11 ◽  
Author(s):  
Indunil C. Senanayake ◽  
Jayarama D. Bhat ◽  
Ratchadawan Cheewangkoon ◽  
Ning Xie

A survey of bambusicolous fungi in Bijiashan Mountain Park, Shenzhen, Guangdong Province, China, revealed several Arthrinium-like taxa from dead sheaths, twigs, and clumps of Bambusa species. Phylogenetic relationships were investigated based on morphology and combined analyses of the internal transcribed spacer region (ITS), large subunit nuclear ribosomal DNA (LSU), beta tubulin (β-tubulin), and translation elongation factor 1-alpha (tef 1-α) gene sequences. Based on morphological characteristics and phylogenetic data, Arthrinium acutiapicum sp. nov. and Arthrinium pseudorasikravindrae sp. nov. are introduced herein with descriptions and illustrations. Additionally, two new locality records of Arthrinium bambusae and Arthrinium guizhouense are described and illustrated.


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.


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.


Phytotaxa ◽  
2020 ◽  
Vol 449 (2) ◽  
pp. 149-163
Author(s):  
DHANUSHKA N. WANASINGHE ◽  
PETER E. MORTIMER ◽  
CHANOKNED SENWANNA ◽  
RATCHADAWAN CHEEWANGKOON

During a survey of saprobic microfungi in Thailand, a dothideomycetous fungus was found on a dead twig of Delonix regia, on the Chiang Mai University campus. This fungus is characterized by fully immersed ascomata under a small blackened pseudoclypeus, pseudoparenchymatous peridium, cellular pseudoparaphyses, cylindrical-clavate asci with a distinct pedicel, overlapping 3–4-seriate, pale to dark brown, broadly fusoid, 7–9-transversally septate ascospores with a vertical septum in nearly all median cells. Multigene phylogenetic analyses, using partial sequences from the 28S nrRNA gene (LSU), 18S nrRNA gene (SSU), internal transcribed spacer regions and intervening 5.8S nrRNA gene (ITS) of the nrDNA operon and the translation elongation factor 1-alpha region (TEF) demonstrated a monophyletic affiliation of the new strain, accommodating the species of Phaeoseptum in the family Phaeoseptaceae. With further morphological and phylogenetic investigations, we justify the new fungus as a novel species, Phaeoseptum hydei in Phaeoseptaceae. Detailed descriptions and illustrations are provided for Phaeoseptum hydei and this novel species compared with the remaining species found in the genus. An updated checklist of microfungi recorded on Delonix regia from around the world is also provided.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11435
Author(s):  
Jessa P. Ata ◽  
Kelly S. Burns ◽  
Suzanne Marchetti ◽  
Isabel A. Munck ◽  
Ludwig Beenken ◽  
...  

Increasing prevalence of conifer needle pathogens globally have prompted further studies on pathogen identification and a better understanding of phylogenetic relationships among needle pathogens. Several Lophodermella species can be aggressive pathogens causing needle cast in natural pine forests in the USA and Europe. However, their relationships with other Rhytismataceae species have historically been based on similarities of only limited phenotypic characters. Currently, no molecular studies have been completed to elucidate their relationships with other Lophodermella needle pathogens. This study collected and sequenced three gene loci, namely: internal transcribed spacer, large ribosomal subunit, and translation elongation factor 1-alpha, from five Lophodermella needle pathogens from North America (L. arcuata, L. concolor, L. montivaga) and Europe (L. conjuncta and L. sulcigena) to distinguish phylogeny within Rhytismatacaeae, including Lophophacidium dooksii. Phylogenetic analyses of the three loci revealed that all but L. conjuncta that were sampled in this study consistently clustered in a well-supported clade within Rhytismataceae. The multi-gene phylogeny also confirmed consistent nesting of L. dooksii, a needle pathogen of Pinus strobus, within the clade. Potential synapomorphic characters such as ascomata position and ascospore shape for the distinct clade were also explored. Further, a rhytismataceous species on P. flexilis that was morphologically identified as L. arcuata was found to be unique based on the sequences at the three loci. This study suggests a potential wider range of host species within the genus and the need for genetic characterization of other Lophodermella and Lophophacidium species to provide a higher phylogenetic resolution.


Phytotaxa ◽  
2021 ◽  
Vol 529 (1) ◽  
pp. 43-56
Author(s):  
YING GAO ◽  
JUTAMART MONKAI ◽  
ELENI GENTEKAKI ◽  
GUANG-CONG REN ◽  
DHANUSHKA N. WANASINGHE ◽  
...  

During a survey of saprobic microfungi in Southwest China, a coelomycetous fungus was found on dead twigs of Jasminum nudiflorum in Kunming, Yunnan Province. Based on a detailed morphological characterization coupled with multi-locus phylogenetic analyses, the fungus was identified as a new species in the genus Dothidea. Phylogenetic analyses using a combined matrix consisting of internal transcribed spacer (ITS), large subunit rRNA (LSU), small subunit rRNA (SSU), beta tubulin (tub2) and translation elongation factor-1 alpha (tef1-α) confirmed its placement in Dothideaceae and revealed a sister relationship to Dothidea eucalypti. The new species is characterized by pycnidial conidiomata, ampulliform or doliiform conidiogenous cells as well as aseptate, subglobose to ovoid, hyaline to pale-brown conidia. Comprehensive descriptions and illustrations are provided. Morphological characteristics of asexual morph taxa in Dothideaceae are also summarized and discussed.


Phytotaxa ◽  
2021 ◽  
Vol 512 (1) ◽  
Author(s):  
XIANGFU LIU ◽  
SAOWALUCK TIBPROMMA ◽  
FAN ZHANG ◽  
JIANCHU XU ◽  
K.W.T. CHETHANA ◽  
...  

In this paper we describe a new species of cave fungus belonging to Sporocadaceae (Amphisphaeriales), collected from Gem Cave, Fumin County, Yunnan Province, China. Initial morphological observations confirmed that our fungal collection is a pestalotioid species. Phylogenetic analyses of combined internal transcribed spacer (ITS), β-tubulin (TUB) and translation elongation factor 1-alpha (TEF1α) gene sequence dataset confirmed that our fungus forms an independent branch within Neopestalotiopsis. Thus, we describe our fungus as a new species of Neopestalotiopsis based on both morphology and multigene phylogeny. This is the first-ever report of Neopestalotiopsis from a cave habitat. A full description, micrographs and a phylogenetic tree showing the placement of the new species are provided.


Plant Disease ◽  
2014 ◽  
Vol 98 (5) ◽  
pp. 636-652 ◽  
Author(s):  
ShuaiFei Chen ◽  
David P. Morgan ◽  
Janine K. Hasey ◽  
Kathleen Anderson ◽  
Themis J. Michailides

Species of family Botryosphaeriaceae and genus Diaporthe (anamorph: genus Phomopsis, family Diaporthaceae) were reported and caused diseases on various fruit and nut trees in California. In the last several years, diseases on English walnut (Juglans regia) caused by species of Botryosphaeriaceae and Diaporthe were observed frequently in California. Disease symptoms include stem canker; shoot canker and blight; twig, leaf, and fruit blight; and necrotic leaf lesions. Isolates of the pathogen were collected from English walnut in 13 counties in California. The aims of this study were to identify these isolates and to test their pathogenicity to English walnut cultivars. In total, 159 California isolates were identified based on comparisons of DNA sequence data of the internal transcribed spacer, translation elongation factor 1-α, and β-tubulin gene regions, and combined with the morphological features of the cultures and conidia. Research results revealed that isolates represent 10 species of Botryosphaeriaceae and two species of Diaporthe. These species include Botryosphaeria dothidea, Diplodia mutila, D. seriata, Dothiorella iberica, Lasiodiplodia citricola, Neofusicoccum mediterraneum, N. nonquaesitum, N. parvum, N. vitifusiforme, Neoscytalidium dimidiatum, Diaporthe neotheicola, and D. rhusicola. Pathogenicity on three English walnut cultivars (‘Chandler’, ‘Tulare’, and ‘Vina’) using a mycelium plug inoculation method revealed that all these species are pathogenic to all the tested cultivars, with L. citricola and N. parvum being the most pathogenic species, followed by N. mediterraneum, N. dimidiatum, and B. dothidea. Chandler was more tolerant to infection than Tulare and Vina. Results in this study determined that multiple numbers of the Botryosphaeriaceae fungi and two Diaporthe spp. cause cankers and blights of English walnut and vary in their virulence from highly to slightly virulent, respectively.


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