scholarly journals First report of Didymosphaeria rubi-ulmifolii associated with canker and dieback of apple trees in southern Ethiopia

2021 ◽  
Vol 60 (2) ◽  
pp. 229-236
Author(s):  
Abraham YIRGU ◽  
Alemu GEZAHGNE ◽  
Tesfaye ALEMU ◽  
Minette HAVENGA ◽  
Lizel MOSTERT
Keyword(s):  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Internal Transcribed Spacers ◽  
Southern Ethiopia ◽  
Rrna Gene ◽  
Management Options ◽  
Apple Trees ◽  
First Report ◽  
Magnitude Distribution ◽  
5.8S Rrna Gene

Cultivation of apple trees in the highlands of Ethiopia began in 1955. In 2014, blistering of the bark due to cankers on the main stems mostly below the grafting points, followed by dieback and eventually death of apple trees, was observed in apple orchards in the Hadiya Zone in Ethiopia. This study aimed to identify the causal agent of canker and dieback symptoms on the apple trees. Symptomatic trunks from 20 trees (ten per cultivar) were sampled. Isolations were performed from ten trunks (five per cultivar). Fungus colonies with similar cultural features were obtained from all the samples, and the morphology of a representative isolate was characterized. Phylogenetic analyses of the concatenated internal transcribed spacers 1 and 2 and 5.8S rRNA gene, large subunit and actin gene regions confirmed the identity of two isolates as Didymosphaeria rubi-ulmifolii. Pathogenicity was confirmed for one isolate by inoculations of healthy branches of ‘Anna’ and ‘Dorsett Golden’ apple trees resulting in lesion formation, and subsequent re-isolation of the inoculated fungus. This study is the first report of D. rubi-ulmifolii associated with dieback of apple trees. This pathogen caused death of more than 26% of apple trees in one commercial orchard, and could cause severe losses for smallholder apple growers in Ethiopia. Future studies are required to assess the magnitude, distribution and management options of this economically important canker disease in Ethiopia.

Coleopuccinia in China and its relationship to Gymnosporangium

Phytotaxa ◽  
2018 ◽  
Vol 347 (3) ◽  
pp. 235 ◽  
Author(s):  
BIN CAO ◽  
SIQI TAO ◽  
CHENGMING TIAN ◽  
YINGMEI LIANG
Keyword(s):  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Rust Fungi ◽  
Internal Transcribed Spacers ◽  
Western China ◽  
Rrna Gene ◽  
Morphological Examination ◽  
Separate Genus ◽  
Lsu Rrna Gene ◽  
Lsu Rrna

The rust species Coleopuccinia sinensis was collected during an investigation of rust fungi in Tibet, a region in south-western China. Through morphological examination, we clarified that C. kunmingensis is a synonym of C. sinensis. Phylogenetic analyses using the combined loci of the internal transcribed spacers (ITS) and the partial large subunit (LSU) rRNA gene revealed that Coleopuccinia should be treated as a separate genus from Gymnosporangium.

scholarly journals Resolving Tiarosporella spp. allied to Botryosphaeriaceae and Phacidiaceae

Phytotaxa ◽  
2015 ◽  
Vol 202 (2) ◽  
pp. 73 ◽  
Author(s):  
PEDRO W. Crous ◽  
Michael M. Müller ◽  
Romina M. Sánchez ◽  
Lucrecia Giordano ◽  
M. Virginia Bianchinotti ◽  
...  
Keyword(s):  
South Africa ◽  
Ribosomal Rna ◽  
Plant Pathogens ◽  
Sequence Data ◽  
Large Subunit ◽  
Elongation Factor ◽  
Internal Transcribed Spacers ◽  
Rrna Gene ◽  
New Taxon ◽  
5.8S Rrna Gene

The type species of the genus Tiarosporella, T. paludosa, is epitypified and confirmed as a member of the Botryosphaeriaceae. Based on morphology and DNA sequence data of the large subunit nuclear ribosomal RNA gene (LSU, 28S) and the internal transcribed spacers (ITS) and 5.8S rRNA gene of the nrDNA operon, the genus Tiarosporella is shown to be poly- and paraphyletic. A group of isolates morphologically similar to T. paludosa cluster to the Phacidiaceae (Phacidiales, Leotiomycetes) and we accommodated them in Darkera, a genus associated with needle diseases of conifers, with D. picea introduced as a novel taxon. This new taxon includes isolates occurring on needles of Picea spp. in Europe (Finland, Norway and Switzerland) and differs from D. parca according to a five-locus alignment consisting of ITS, LSU, partial 18S nuclear ribosomal RNA, translation elongation factor 1-alpha and beta-tubulin genes. Four novel genera are introduced for tiarosporella-like fungi, namely Eutiarosporella based on E. tritici on Triticum aestivum from South Africa, Marasasiomyces based on M. karoo on Eriocephalus sp. from South Africa, Mucoharknessia based on M. cortaderiae on Cortaderia selloana from Argentina, and Sakireeta based on S. madreeya on Aristida setacea from India. Together with the genus Botryobambusa, these genera represent a subclade in the Botryosphaeriaceae that is ecologically diverse, occurring on Poaceae, as well as woody hosts, including endophytes, saprobes, and plant pathogens.

scholarly journals Phylogeny and Synonymy of Gyrodinium heterostriatum comb. nov. (Dinophyceae), a Common Unarmored Dinoflagellate in the World Oceans [plus supplementary materials]

2020 ◽  
Vol 59 (2) ◽  
pp. 77-87
Author(s):  
Fernando Gómez ◽  
Luis F. Artigas ◽  
Rebecca J. Gast
Keyword(s):  
North Sea ◽  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Morphological Plasticity ◽  
Sister Group ◽  
Rrna Gene ◽  
Microbial World ◽  
The North ◽  
The North Sea ◽  
Environmental Sequences

The North Sea and the English Channel are regions with a long tradition of plankton studies, where the colony-forming haptophyte Phaeocystis globosa dominates the spring phytoplankton blooms. Among its predators, we investigated an abundant unarmored dinoflagellate (~3000 cells per liter) in the North Sea in May 2019. It has been reported in the literature as Gymnodinium heterostriatum or G. striatissimum, and often identified as Gyrodinium spirale. Phylogenetic analyses using the small-, large subunit- and Internal Transcriber Spacers of the ribosomal RNA (SSU-, LSU-, ITS rRNA) gene sequences indicate that our isolates clustered within the Gyrodinium clade. The new sequences formed a sister group with sequences of the freshwater taxon Gyrodinium helveticum, being one of the infrequent marine-freshwater transitions in the microbial world. This isolate is the first characterized member of a clade of numerous environmental sequences widely distributed from cold to tropical seas. This common and abundant taxon has received several names due to its morphological plasticity (changes of size and shape, often deformed after engulfing prey) and the difficulty in discerning surface striation. We conclude that the priority is for the species name Gymnodinium heterostriatum Kofoid & Swezy 1921, a new name that was proposed for Gymnodinium spirale var. obtusum sensu Dogiel 1906. The species Gyrodinium striatissimum (Hulburt 1957) Gert Hansen & Moestrup 2000 and Gymnodinium lucidum D. Ballantine in Parke & Dixon 1964 (=G. hyalinum M. Lebour 1925) are posterior synonyms. We propose Gyrodinium heterostriatum comb. nov. for Gymnodinium heterostriatum.

Spegazzinia camelliae sp. nov. (Didymosphaeriaceae, Pleosprales), a new endophytic fungus from northern Thailand

Phytotaxa ◽  
2021 ◽  
Vol 483 (2) ◽  
pp. 117-128
Author(s):  
NAKARIN SUWANNARACH ◽  
JATURONG KUMLA ◽  
SAISAMORN LUMYONG
Keyword(s):  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Elongation Factor ◽  
Small Subunit ◽  
Internal Transcribed Spacers ◽  
Nuclear Ribosomal Dna ◽  
Full Description ◽  
Translation Elongation ◽  
Spine Length ◽  
Elongation Factor 1 Alpha

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.

scholarly journals Two new asexual genera and six new asexual species in the family Microthyriaceae (Dothideomycetes, Ascomycota) from China

MycoKeys ◽  
2021 ◽  
Vol 85 ◽  
pp. 1-30
Author(s):  
Min Qiao ◽  
Hua Zheng ◽  
Ji-Shu Guo ◽  
Rafael F. Castañeda-Ruiz ◽  
Jian-Ping Xu ◽  
...  
Keyword(s):  
New Taxa ◽  
Dna Sequences ◽  
Sequence Data ◽  
Southern China ◽  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Aquatic Hyphomycetes ◽  
Internal Transcribed Spacers ◽  
The Family

The family Microthyriaceae is represented by relatively few mycelial cultures and DNA sequences; as a result, the taxonomy and classification of this group of organisms remain poorly understood. During the investigation of the diversity of aquatic hyphomycetes from southern China, several isolates were collected. These isolates were cultured and sequenced and a BLAST search of its LSU sequences against data in GenBank revealed that the closest related taxa are in the genus Microthyrium. Phylogenetic analyses, based on the combined sequence data from the internal transcribed spacers (ITS) and the large subunit (LSU), revealed that these isolates represent eight new taxa in Microthyriaceae, including two new genera, Antidactylariagen. nov. and Isthmomycesgen. nov. and six new species, Antidactylaria minifimbriatasp. nov., Isthmomyces oxysporussp. nov., I. dissimilissp. nov., I. macrosporussp. nov., Triscelophorus anisopterioideussp. nov. and T. sinensissp. nov. These new taxa are described, illustrated for their morphologies and compared with similar taxa. In addition, two new combinations are proposed in this family.

scholarly journals First Report of a Leaf Blight Caused by Pyricularia pennisetigena on Cenchrus echinatus in Paraguay

Plant Disease ◽  
2021 ◽  
Author(s):  
Cinthia C. Cazal-Martínez ◽  
Yessica Magaliz Reyes Caballero ◽  
Alice Chávez ◽  
Pastor Enmanuel Pérez Estigarribia ◽  
Alcides Rojas ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Large Subunit ◽  
Fungal Species ◽  
Leaf Blight ◽  
Internal Transcribed Spacers ◽  
Conidial Suspension ◽  
Sterile Water ◽  
Potential Threat ◽  
First Report ◽  
Microscopic Features

The genus Pyricularia contains several fungal species known to cause diseases on plants in the Poaceae family (Klaubauf et al. 2014; Wang et al. 2019). While sampling for P. oryzae during March-2015 and April-2018, common weed Cenchrus echinatus L. was observed with leaf lesions in and around experimental wheat fields in the departments of Canindeyú and Itapúa. C. echinatus samples from both locations displayed similar leaf lesions, varying from small light brown pinpoint to elliptical brown lesions with greyish center. Symptomatic leaves were surface disinfested and cultured on potato dextrose agar (PDA) amended with 1% gentamicin at 25°C. Two monosporic isolates were obtained, one from Itapúa (ITCeh117) and the other from Canindeyú (YCeh55). The isolates were subsequently grown on oatmeal agar (OA) and PDA under a 12-h photoperiod at 25°C and evaluated after ten days for colony diameter, sporulation, macroscopic and microscopic features. Colonies on OA reached up to 4.8 cm diameter and were light grey, whereas colonies on PDA reached up to 5.3 cm diameter and were brown with grey centers, with cottony mycelium and broad white rims. Mycelium consisted of smooth, hyaline, branched, septate hyphae 4-4.5 µm diameter. Conidiophores were erect, straight or curved, unbranched, medium brown and smooth. Conidia were solitary, pyriform, pale brown, smooth, granular, 2-septate, 32-33 × 9-10 μm; truncated with protruding hilum and varied in length from 1.0 to 1.5 μm and diameters from 2.0 to 2.2 μm. Both isolates were similar and identified as Pyricularia pennisetigena, according to morphological and morphometric characteristics (Klaubauf et al. 2014). Subsequently, genomic DNA was extracted from each isolate using the primers described in Klaubauf et al. (2014) to amplify and sequence the internal transcribed spacers (ITS), partial large subunit (LSU), partial RNA polymerase II large subunit gene (RPB1), partial actin gene (ACT), and partial calmodulin gene (CAL). Sequences from each isolate (YCeh55/ITCeh117) were deposited in GenBank with the following submission ID for ITS: MN947521/MN947526, RPB1: MN984710/MN984715, LSU: MN944829/MN944834, ACT: MN917177/MN917182, and CAL: MN984688/MN984693. Phylogenetic analysis was conducted using the software Beast v1.10.4. The results obtained from the concatenated matrix of the five loci placed these isolates in the P. pennisetigena clade. To confirm pathogenicity, each isolate was adjusted to 5×104 conidia/ml of sterile water and C. echinatus plants were sprayed with the conidial suspension for isolate YCeh55, ITCeh117 or sterile water using an oilless airbrush sprayer until runoff. The three treatments were kept in the greenhouse at 25-28°C and about 75% relative humidity under natural daylight. Each treatment included three to five inoculated plants and 10 leaves were evaluated per treatment. Symptoms were observed 8-15 days after inoculation and were similar to those originally observed in the field for both isolates, whereas the control plants remained asymptomatic. P. pennisetigena was re-isolated from the inoculated leaves fulfilling Koch’s postulates. To our knowledge, this is the first report of leaf blight on C. echinatus caused by P. pennisetigena in Paraguay. The occurrence of P. pennisetigena in the region and its ability to infect economically important crops such as wheat and barley (Klaubauf et al. 2014; Reges et al., 2016, 2018) pose a potential threat to agriculture in Paraguay.

scholarly journals First Report of Colletotrichum acutatum Causing a Leaf Spot on Myrica cerifera in Florida

Plant Disease ◽  
2006 ◽  
Vol 90 (9) ◽  
pp. 1263-1263 ◽  
Author(s):  
S. J. Mackenzie ◽  
L. M. Takahashi ◽  
J. C. Mertely ◽  
T. E. Seijo ◽  
N. A. Peres
Keyword(s):  
Colletotrichum Acutatum ◽  
Rrna Gene ◽  
Single Spore ◽  
Myrica Cerifera ◽  
First Report ◽  
Central Florida ◽  
Potted Plants ◽  
5.8S Rrna Gene ◽  
Young Leaves ◽  
Plastic Bag

Wax myrtle (Morella cerifera (synonym Myrica cerifera) (L.) Small) is a native tree used in Florida landscapes. In the summer of 2005 and spring of 2006, small necrotic spots were observed on young leaves in two commercial nurseries in central Florida. Lesions were dark brown-to-black and eventually coalesced to form large, irregular necrotic areas. Leaves with large lesions abscised prematurely, defoliating the entire plant. Conidia formed on acervuli were observed on the surface of the largest lesions and were tentatively identified as a Colletotrichum sp. Isolations from the edges of lesions were made on potato dextrose agar (PDA) after surface disinfestation of leaf pieces in 0.6% NaOCl for 30 sec. Red chromogenic colonies developed after 5 days of incubation at 24°C. Colonies produced hyaline, oblong conidia with pointed ends averaging 14 × 4 μm and were identified as Colletotrichum acutatum J.H. Simmonds (1). The sequence from internal transcribed spacer regions 1 and 2 and the 5.8s rRNA gene of the rDNA repeat for an isolate (GenBank Accession No. DQ839609) was 100% identical to sequence from the same region of 36 C. acutatum isolates in the NCBI database. These isolates came from at least 16 different hosts, including seven ornamental hosts. There were three isolates from blueberry among the matches (Accession Nos. AB219029, AJ301911, and AJ301905), and the rDNA sequence was also identical to the sequence obtained in our laboratory for a chromogenic C. acutatum isolate from blueberry. Three single-spore isolates were tested for pathogenicity on potted plants in the greenhouse. Two young shoots were spray inoculated with a suspension (1 × 106 conidia/ml) of each isolate. Shoots were covered with a plastic bag for 24 h and maintained at 26.5°C. Two shoots were sprayed with sterile water as a control and similarly covered. All isolates produced brown spots on the youngest leaves 3 to 5 days after inoculation; no symptoms developed on control shoots. The fungus was reisolated from all inoculated shoots. To our knowledge, this is the first report of C. acutatum on wax myrtle in Florida. The disease has a potential to spread and become a significant problem for the cultivation of this species in ornamental nurseries in Florida. Reference: (1) J. H. Simmonds. Qld. J. Agric. Anim. Sci. 22:437, 1965.

Sign in / Sign up

Export Citation Format

Share Document