scholarly journals High diversity of Diaporthe species associated with pear shoot canker in China

2020 ◽  
Vol 45 (1) ◽  
pp. 132-162 ◽  
Author(s):  
Y.S. Guo ◽  
P.W. Crous ◽  
Q. Bai ◽  
M. Fu ◽  
M.M. Yang ◽  
...  
Keyword(s):  
New Species ◽  
Phylogenetic Analyses ◽  
Geographical Location ◽  
Koch’S Postulates ◽  
Important Crop ◽  
Wide Range ◽  
Crop Diseases ◽  
High Degree ◽  
Koch's Postulates ◽  
High Diversity

Species of Diaporthe (syn. Phomopsis) are important endophytes, saprobes and pathogens, infecting a wide range of plants and resulting in important crop diseases. However, the species occurring on pear remain largely unresolved. In this study, a total of 453 Diaporthe isolates were obtained from branches of Pyrus plants (including P. bretschneideri, P. communis, P. pyrifolia and P. ussuriensis collected from 12 provinces in China) showing shoot canker symptoms. Phylogenetic analyses based on five loci (ITS, TEF, CAL, HIS, and TUB) coupled with morphology of 113 representative isolates revealed that 19 Diaporthe species were isolated, representing 13 known species (including D. caryae, D. cercidis, D. citrichinensis, D. eres, D. fusicola, D. ganjae, D. hongkongensis, D. padina, D. pescicola, D. sojae, D. taoicola, D. unshiuensis and D. velutina) and six new species described here as D. acuta, D. chongqingensis, D. fulvicolor, D. parvae, D. spinosa and D. zaobaisu. Although Koch's postulates confirmed all species to be pathogenic, a high degree of variation in aggressiveness was observed. Moreover, these species have a high diversity, plasticity, and prevalence related to the geographical location and pear species involved.

scholarly journals Loose Ends in the Cortinarius Phylogeny: Five New Myxotelamonoid Species Indicate a High Diversity of These Ectomycorrhizal Fungi with South American Nothofagaceae

Life ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 420
Author(s):  
María Eugenia Salgado Salomón ◽  
Carolina Barroetaveña ◽  
Tuula Niskanen ◽  
Kare Liimatainen ◽  
Matthew E. Smith ◽  
...  
Keyword(s):  
New Species ◽  
Current Knowledge ◽  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Global Scale ◽  
South American ◽  
Edible Fungi ◽  
Rdna Its ◽  
Morphological And Molecular Data ◽  
High Diversity

This paper is a contribution to the current knowledge of taxonomy, ecology and distribution of South American Cortinarius (Pers.) Gray. Cortinarius is among the most widely distributed and species-rich basidiomycete genera occurring with South American Nothofagaceae and species are found in many distinct habitats, including shrublands and forests. Due to their ectomycorrhizal role, Cortinarius species are critical for nutrient cycling in forests, especially at higher latitudes. Some species have also been reported as edible fungi with high nutritional quality. Our aim is to unravel the taxonomy of selected Cortinarius belonging to phlegmacioid and myxotelamonioid species based on morphological and molecular data. After widely sampling Cortinarius specimens in Patagonian Nothofagaceae forests and comparing them to reference collections (including holotypes), we propose five new species of Cortinarius in this work. Phylogenetic analyses of concatenated rDNA ITS-LSU and RPB1 sequences failed to place these new species into known Cortinarius sections or lineages. These findings highlight our knowledge gaps regarding the fungal diversity of South American Nothofagaceae forests. Due to the high diversity of endemic Patagonian taxa, it is clear that the South American Cortinarius diversity needs to be discovered and described in order to understand the evolutionary history of Cortinarius on a global scale.

scholarly journals Colletotrichum species associated with anthracnose of Pyrus spp. in China

2019 ◽  
Vol 42 (1) ◽  
pp. 1-35 ◽  
Author(s):  
M. Fu ◽  
P.W. Crous ◽  
Q. Bai ◽  
P.F. Zhang ◽  
J. Xiang ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Novel Species ◽  
Phylogenetic Analyses ◽  
Koch’S Postulates ◽  
Colletotrichum Species ◽  
Organ Specific ◽  
Pathogenicity Tests ◽  
Koch's Postulates

Colletotrichum species are plant pathogens, saprobes, and endophytes on a range of economically important hosts. However, the species occurring on pear remain largely unresolved. To determine the morphology, phylogeny and biology of Colletotrichum species associated with Pyrus plants, a total of 295 samples were collected from cultivated pear species (including P. pyrifolia, P. bretschneideri, and P. communis) from seven major pear-cultivation provinces in China. The pear leaves and fruits affected by anthracnose were sampled and subjected to fungus isolation, resulting in a total of 488 Colletotrichum isolates. Phylogenetic analyses based on six loci (ACT, TUB2, CAL, CHS-1, GAPDH, and ITS) coupled with morphology of 90 representative isolates revealed that they belong to 10 known Colletotrichum species, including C. aenigma, C. citricola, C. conoides, C. fioriniae, C. fructicola, C. gloeosporioides, C. karstii, C. plurivorum, C. siamense, C. wuxiense, and two novel species, described here as C. jinshuiense and C. pyrifoliae. Of these, C. fructicola was the most dominant, occurring on P. pyrifolia and P. bretschneideri in all surveyed provinces except in Shandong, where C. siamense was dominant. In contrast, only C. siamense and C. fioriniae were isolated from P. communis, with the former being dominant. In order to prove Koch's postulates, pathogenicity tests on pear leaves and fruits revealed a broad diversity in pathogenicity and aggressiveness among the species and isolates, of which C. citricola, C. jinshuiense, C. pyrifoliae, and C. conoides appeared to be organ-specific on either leaves or fruits. This study also represents the first reports of C. citricola, C. conoides, C. karstii, C. plurivorum, C. siamense, and C. wuxiense causing anthracnose on pear.

scholarly journals First Report of a Leaf Spot Disease of Tobacco Caused by Pseudomonas cichorii in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Dayu Lan ◽  
Fangling Shu ◽  
Yanhui Lu ◽  
Anfa Shou ◽  
Wei Lin ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Leaf Spot ◽  
Leaf Spot Disease ◽  
Pathogenicity Test ◽  
Pseudomonas Cichorii ◽  
Koch’S Postulates ◽  
First Report ◽  
Initial Symptoms ◽  
Wide Range ◽  
Koch's Postulates

Tobacco (Nicotiana tabacum L.), one of the chief commercial crops, is wildly cultivated worldwide. In June 2020 and 2021, an unknown bacterial leaf spot on tobacco was found in Hezhou and Hechi City, Guangxi, China. 30% of the tobacco were affected and the rate of diseased leaves reached about 10% in the field under high temperature and rainstorm. The disease mainly damaged the middle and top leaves of tobacco plants at vigorous growing stage. The initial symptoms were water-soaked spots on the frontal half of a leaf, and then expanded into circular to irregular spots with a yellow halo at the edge. The spots mostly appeared dark brown at high air humidity, while yellow brown at low humidity and exhibited a concentric pattern. In severe cases, the lesions coalesced and the whole leaf was densely covered with lesions, resulting in the loss of baking value. A bacterium was consistently isolated from diseased leaf tissues on nutrient agar (NA). Growth on NA was predominantly grayish white circular bacterial colonies with smooth margins, and the bacterium is rod-shaped, gram-negative and fluorescent on King’s B medium. Seven isolates (ND04A-ND04C and ZSXF02-ZSXF05) were selected for molecular identification and pathogenicity tests. Genomic DNA of the bacterium was extracted and the housekeeping gene of cts (encoding citrate synthase) was amplified with the primers cts-Fs/cts-Rs (forward primer cts-Fs: 5’-CCCGTCGAGCTGCCAATWCTGA-3’; reverse primer cts-Rs: 5’-ATCTCGCACGGSGTRTTGAACATC-3’) (Berge et al. 2014; Sarkar et al. 2004). 409-bp cts gene sequences were deposited in the GenBank database for seven isolates (accession no. OK105110-OK105116). Sequence of seven isolates shared 100% identity with several Pseudomonas cichorii strains within the GenBank database (accession no. KY940268 and KY940271), and the phylogenetic tree of cts genes of the seven isolates clustered with the phylogroup 11 of Pseudomonas syringae (accession no. KJ877799 and KJ878111), which was classified as P.cichorii. To satisfy Koch’s postulates, a pathogenicity test was tested by using a needle to dip a suspension of the bacterium (108 CFU/ml) and pricking three holes in the tobacco leaf. The control plants leaves were needled with sterile water. Each tobacco plant was inoculated with three leaves, and the test was repeated three times. All plants were placed in transparent plastic boxes and incubated in a greenhouse at 25 ± 3°C. The water-soaked spots appeared 24h after inoculation and quickly expanded through leaf veins. Three days after inoculation, all the inoculated leaves showed symptoms similar to those observed in the field. Control plants remained healthy. Only P. cichorii was successfully re-isolated from the lesions, confirming Koch’s postulates. Pseudomonas cichorii can infect eggplant, lettuce, tomatoand other crops, and has a wide range of hosts (Timilsina et al. 2017; Ullah et al. 2015). To our knowledge, this is the first report of P. cichorii causing leaf spot on tobacco in China.

scholarly journals Recent Outbreak of Soybean Sudden Death Syndrome Caused by Fusarium virguliforme and F. tucumaniae in Argentina

Plant Disease ◽  
2004 ◽  
Vol 88 (9) ◽  
pp. 1044-1044 ◽  
Author(s):  
M. Scandiani ◽  
D. Ruberti ◽  
K. O'Donnell ◽  
T. Aoki ◽  
R. Pioli ◽  
...  
Keyword(s):  
United States ◽  
Phylogenetic Analyses ◽  
The United States ◽  
Positive Control ◽  
Koch’S Postulates ◽  
First Report ◽  
Molecular Phylogenetic ◽  
Soil Infestation ◽  
Pathogenicity Tests ◽  
Koch's Postulates

Sudden death syndrome (SDS) of soybean was detected initially in Argentina during 1991-1992 in the Pampas Region and 1992-1993 in the Northwest Region. The first report of the fulfillment of Koch's postulates of SDS caused by Fusarium solani f. sp. glycines in Argentina was published in 2003 (3). Subsequently, analyses have shown that F. solani f. sp. glycines represents several morphologically and phylogenetically distinct species, including F. tucumaniae in Argentina and F. virguliforme in the United States (1). Isolations were made from plants that exhibited typical SDS symptoms (interveinal foliar chlorosis and necrosis leading to defoliation of the leaflets but not the petioles) from fields in Santa Fe and Buenos Aires provinces in 2001, 2002, and 2003. To determine which species are responsible for SDS in Argentina, cultures of eight slow growing isolates that developed bluish pigmentation and produced abundant macroconidia in sporodochia on potato dextrose agar were subjected to morphological and molecular phylogenetic analyses and pathogenicity tests. Morphological analyses demonstrated that three of the isolates were F. virguliforme and five were F. tucumaniae. Isolates of F. tucumaniae produced long and narrow sporodochial conidia while F. virguliforme produced diagnostic comma-shaped conidia. Molecular phylogenetic analyses of DNA sequences from multiple loci confirmed morphology-based identifications and showed that the soybean SDS pathogen in the United States, F. virguliforme, was also present in Argentina. To our knowledge, this is the first report of F. virguliforme in Argentina and of this pathogen outside the United States. Five isolates of F. tucumaniae and three isolates of F. virguliforme were used for pathogenicity tests. F. virguliforme isolate 171 provided by J. Rupe (University of Arkansas, Fayetteville) was used as a positive control. Soybean cultivars Ripley, RA 702, Pioneer 9492RR, Spencer, and A-6445RG were inoculated with each of the isolates tested in a greenhouse assay using soil infestation and toothpick methods (2). All eight isolates produced typical foliar SDS symptoms 15 to 25 days after inoculation. Severity of foliar symptoms averaged 3.3 for F. virguliforme, 2.6 for F. tucumaniae, and 3.3 for the positive control using a disease severity scale in which 1 = no symptoms and 5 = severely infected or dead plants. Under these conditions, F. virguliforme appeared to be more virulent than F tucumaniae. Noninoculated plants remained symptomless. Koch's postulates were confirmed with soybean cultivars RA 702 and A6445RG. Isolates recovered from symptomatic plants inoculated by the soil infestation and toothpick methods were identical to those used to inoculate the plant. Strains were recovered at frequencies of 100 and 60% from plants inoculated by the toothpick and soil infestation methods, respectively. To our knowledge, this is the first report of the fulfillment of Koch's postulates for F. tucumaniae and F. virguliforme in Argentina. References: (1) T. Aoki et al. Mycologia 95:660, 2003. (2) K. W. Roy et al. Plant Dis. 81:1100, 1997 (3) M. Scandiani et al. Plant Dis. 87:447, 2003.

scholarly journals Morphological and phylogenetic analyses reveal three new species of Diaporthe from Yunnan, China

MycoKeys ◽  
2021 ◽  
Vol 78 ◽  
pp. 49-77
Author(s):  
Shengting Huang ◽  
Jiwen Xia ◽  
Xiuguo Zhang ◽  
WenXiu Sun
Keyword(s):  
New Species ◽  
Species Diversity ◽  
Yunnan Province ◽  
Plant Pathogens ◽  
Tropical Rainforest ◽  
Phylogenetic Analyses ◽  
Wide Range ◽  
High Species Diversity ◽  
Plant Hosts ◽  
Three New Species

Species of Diaporthe have often been reported as plant pathogens, endophytes or saprobes, commonly isolated from a wide range of plant hosts. Sixteen strains isolated from species of ten host genera in Yunnan Province, China, represented three new species of Diaporthe, D. chrysalidocarpi, D. machili and D. pometiae as well as five known species D. arecae, D. hongkongensis, D. middletonii, D. osmanthi and D. pandanicola. Morphological comparisons with known species and DNA-based phylogenies based on the analysis of a multigene (ITS, TUB, TEF, CAL and HIS) dataset support the establishment of the new species. This study reveals that a high species diversity of Diaporthe with wide host ranges occur in tropical rainforest in Yunnan Province, China.

scholarly journals Multilocus Phylogeography of the Tuber mesentericum Complex Unearths Three Highly Divergent Cryptic Species

2021 ◽  
Vol 7 (12) ◽  
pp. 1090
Author(s):  
Marco Leonardi ◽  
Daniele Salvi ◽  
Mirco Iotti ◽  
Gian Luigi Rana ◽  
Aurelia Paz-Conde ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Central Italy ◽  
Elongation Factor ◽  
Its Region ◽  
Wide Range ◽  
Volatile Organic ◽  
Phylogenetic Lineages ◽  
High Degree ◽  
Tuber Mesentericum ◽  
Elongation Factor 1

Tuber mesentericum is an edible European black truffle, apparently easy to recognize, but showing a high degree of genetic variability. In this study, we performed an integrative taxonomic assessment of the T. mesentericum complex, combining a multilocus phylogeographic approach with morphological analyses, and including authentic specimens of Vittadini, and Berkeley and Broome. We performed maximum likelihood phylogenetic analyses, based on single and concatenated gene datasets (ITS rDNA, β-tubulin, elongation factor 1-α), and including all available sequences from previous studies. Phylogenetic analyses consistently recovered three reciprocally monophyletic and well-supported clades: clade I, with a wide range across Europe; clade II, specimens collected mainly in the Iberian, Italian, and Balkan peninsulas; and clade III, specimens collected almost exclusively in central Italy. Genetic distance between clades ranged from 10.4% to 13.1% at the ITS region. We also designed new primer pairs specific for each phylogenetic lineage. Morphology of spores, asci, and peridium were investigated on specimens representing the three lineages. Macro- and micromorphological analyses of ascomata revealed only a few, but not diagnostic, differences between the three phylogenetic lineages, thus, confirming that they are morphologically cryptic. By studying authentic specimens of Vittadini, and Berkeley and Broome, it was possible to identify the three clades as T. mesentericum, Tuber bituminatum, and Tuber suave sp. nov., and to designate an epitype for T. mesentericum s.s. and a lectotype for T. bituminatum. Future investigations on volatile organic compound (VOC) composition are needed to define the aroma repertoires in this species complex.

scholarly journals Morphological and phylogenetic analyses reveal a new genus and two new species of Tubakiaceae from China

MycoKeys ◽  
2021 ◽  
Vol 84 ◽  
pp. 185-201
Author(s):  
Zhaoxue Zhang ◽  
Taichang Mu ◽  
Shubin Liu ◽  
Rongyu Liu ◽  
Xiuguo Zhang ◽  
...  
Keyword(s):  
New Species ◽  
Plant Pathogens ◽  
New Genus ◽  
Phylogenetic Analyses ◽  
Morphological Characteristics ◽  
Wide Range ◽  
Two New Species ◽  
Plant Hosts ◽  
Quercus Palustris

Species of Tubakiaceae have often been reported as plant pathogens or endophytes, commonly isolated from a wide range of plant hosts. The isolated fungi were studied through a complete examination, based on multilocus phylogenies from combined datasets of ITS/LSU/rpb2 and ITS/tef1/tub2, in conjunction with morphological characteristics. Five strains isolated from Lithocarpus fohaiensis and Quercus palustris in China represented a new genus of Tubakiaceae, Obovoideisporodochium and three species, viz. Obovoideisporodochium lithocarpi sp. nov., Tubakia lushanensis sp. nov. and T. dryinoides.

scholarly journals Species Diversity of the Pleurostomatid Ciliate Genus Amphileptus (Ciliophora, Haptoria), With Notes on the Taxonomy and Molecular Phylogeny of Three Species

2021 ◽  
Vol 8 ◽  
Author(s):  
Lei Wu ◽  
Jiqiu Li ◽  
Alan Warren ◽  
Xiaofeng Lin
Keyword(s):  
Species Diversity ◽  
Sequence Data ◽  
Southern China ◽  
Phylogenetic Analyses ◽  
Phylogenetic Methods ◽  
Wide Range ◽  
Rdna Sequence Data ◽  
Molecular Phylogenetic ◽  
Intensive Sampling ◽  
High Diversity

Amphileptus is one of the largest genera of pleurostomatid ciliates and its species diversity has been reported in various habitats all over the world. In the present work, we review its biodiversity based on data with reliable morphological records. Our work confirms that there are 50 valid Amphileptus species, some of which have a wide range of salinity adaptability and diverse lifestyles. This genus has a high diversity in China but this might be because of the relatively intensive sampling. Phylogenetic analyses based on SSU rDNA sequence data verify the non-monophyly of the genus Amphileptus. Furthermore, two new and one poorly known Amphileptus species, namely A. shenzhenensis sp. n., A. cocous sp. n., and A. multinucleatusWang, 1934, from coastal habitats of southern China were investigated using morphological and molecular phylogenetic methods. These three species are highly similar based on their contractile vacuoles and macronuclear nodules. However, they can be discriminated by details of their living morphology and somatic kineties. We also propose two new combinations, Amphileptus polymicronuclei (Li, 1990) comb. n. (original combination Hemiophrys polymicronucleiLi, 1990) and Amphileptus salimicus (Burkovsky, 1970b) comb. n. (original combination Hemiophrys salimicaBurkovsky, 1970b).

scholarly journals Ophiocordyceps aphrophoridarum sp. nov., a new entomopathogenic species from Guizhou, China

2021 ◽  
Vol 9 ◽  
Author(s):  
Yu Yang ◽  
Yuanpin Xiao ◽  
Gangjiang Yu ◽  
TingChi Wen ◽  
ChunYing Deng ◽  
...  
Keyword(s):  
New Species ◽  
Entomopathogenic Fungi ◽  
Related Species ◽  
Phylogenetic Analyses ◽  
Closely Related Species ◽  
Important Species ◽  
Wide Range ◽  
The Family ◽  
Molecular Phylogenetic ◽  
A New Species

Ophiocordyceps is the largest genus in the family Ophiocordicipitaceae, including many entomopathogenic species. In recent years, many species have been described in this genus, with a wide range of host insects. Entomopathogenic fungi include ecologically, economically and medicinally important species, but a large portion of their diversity remains to be discovered and described. In this study, a new species, Ophiocordyceps aphrophoridarum sp. nov, parasitising Aphrophoridae sp. (Hemiptera) is proposed from China, based on evidence from morphology and molecular phylogenetic analyses. This species is characterised by fibrous, pigmented stromata, cylindrical asci and filiform ascospores. Compared to its closest relative, O. tricentri, the new species has wider perithecia and longer asci. Molecular phylogenetic analyses of a multilocus dataset (consisting of SSU, ITS, LSU, TEF1, RPB1 and RPB2) confirm its placement in Ophiocordyceps. Ophiocordyceps aphrophoridarum is morphologically described and illustrated with colour photographs. Morphological comparisons with closely-related species are also presented in tabulated format.

scholarly journals Molecular phylogenetic analysis of a taxonomically unstable ranid from Sumatra, Indonesia, reveals a new genus with gastromyzophorous tadpoles and two new species

2018 ◽  
Vol 94 (1) ◽  
pp. 163-193 ◽  
Author(s):  
Umilaela Arifin ◽  
Utpal Smart ◽  
Stefan T. Hertwig ◽  
Eric N. Smith ◽  
Djoko T. Iskandar ◽  
...  
Keyword(s):  
New Species ◽  
New Genus ◽  
Phylogenetic Analyses ◽  
Taxonomic Status ◽  
Morphological Characters ◽  
12S Rrna ◽  
Molecular Evidence ◽  
Molecular Barcoding ◽  
Wide Range ◽  
Two New Species

The presence of an adhesive abdominal sucker (gastromyzophory) allows tadpoles of certain species of anurans to live in fast-flowing streams. Gastromyzophorous tadpoles are rare among anurans, known only in certain American bufonids and Asian ranids. To date,Huia sumatrana, which inhabits cascading streams, has been the only Sumatran ranid known to possess gastromyzophorous tadpoles. In the absence of thorough sampling and molecular barcoding of adults and larvae, it has remained to be confirmed whether other Sumatran ranid species living in similar habitats, i.e.,Chalcorana crassiovis, possesses this larval type. Moreover, the taxonomic status of this species has long been uncertain and its taxonomic position within the Ranidae, previously based exclusively on morphological characters, has remained unresolved. To study the diversity and relationships of these frogs and to establish the identity of newly collected gastromyzophorous tadpoles from Sumatra, we compared genetic sequences ofC. crassiovis-like taxa from a wide range of sites on Sumatra. We conducted bayesian and maximum likelihood phylogenetic analyses on a concatenated dataset of mitochondrial (12S rRNA, 16S rRNA, and tRNAval) and nuclear (RAG1 and TYR) gene fragments. Our analyses recoveredC. crassiovisto be related toClinotarsus,Huia, andMeristogenys. The DNA barcodes of the gastromyzophorous tadpoles matched adults from the same sites. Herein, we provide a re-description of adultC. crassiovisand propose “C. kampeni” as a synonym of this species. The molecular evidence, morphological features, and distribution suggest the presence of two related new species. The two new species andC. crassiovistogether represent a distinct phylogenetic clade possessing unique molecular and morphological synapomorphies, thus warranting a new genus.

Sign in / Sign up

Export Citation Format

Share Document