scholarly journals Pyricularia graminis-tritici sp. nov., a new Pyricularia species causing wheat blast

2016 ◽  
Author(s):  
V.L. Castroagudín ◽  
S.I. Moreira ◽  
D.A.S. Pereira ◽  
S.S. Moreira ◽  
P.C. Brunner ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Pyricularia Oryzae ◽  
Blast Disease ◽  
Sympatric Populations ◽  
Wheat Blast ◽  
Worldwide Distribution ◽  
Signal Grass ◽  
Morphological Differences ◽  
Urochloa Brizantha ◽  
Clade 1

AbstractAbstract Pyricularia oryzae is a species complex that causes blast disease on more than 50 species of poaceous plants. Pyricularia oryzae has a worldwide distribution as a rice (Oryza) pathogen and in the last 30 years emerged as an important wheat (Triticum) pathogen in southern Brazil. We conducted phylogenetic analyses using 10 housekeeping loci for 128 isolates of P. oryzae sampled from sympatric populations of grasses growing in or near wheat fields. Phylogenetic analyses grouped the isolates into three major clades. Clade 1 comprised isolates associated only with rice and corresponds to the previously described rice blast pathogen P. oryzae pathotype Oryza (PoO). Clade 2 comprised isolates associated almost exclusively with wheat and corresponds to the previously described wheat blast pathogen P. oryzae pathotype Triticum (PoT). Clade 3 contained isolates obtained from wheat as well as other Poaceae hosts. We found that Clade 3 is distinct from P. oryzae and represents a new species, Pyricularia graminis-tritici, (Pgt). No morphological differences were observed among these species, but a distinctive pathogenicity spectrum was observed. Pgt and PoT were pathogenic and highly aggressive on Triticum aestivum (wheat), Hordeum vulgare (barley), Urochloa brizantha (signal grass) and Avena sativa (oats). PoO was highly virulent on the original rice host (Oryza sativa), and also on wheat, barley, and oats, but not on signal grass. We conclude that blast disease on wheat and its associated Poaceae hosts in Brazil is caused by multiple Pyricularia species. Pyricularia graminis-tritici was recently found causing wheat blast in Bangladesh. This indicates that P. graminis-tritici represents a serious threat to wheat cultivation globally.

scholarly journals A Genomic Approach to Develop a New qPCR Test Enabling Detection of the Pyricularia oryzae Lineage Causing Wheat Blast

Plant Disease ◽  
2020 ◽  
Vol 104 (1) ◽  
pp. 60-70 ◽  
Author(s):  
Maud Thierry ◽  
Pierre Gladieux ◽  
Elisabeth Fournier ◽  
Didier Tharreau ◽  
Renaud Ioos
Keyword(s):  
Genomic Analysis ◽  
High Sensitivity ◽  
Fungal Species ◽  
Emerging Diseases ◽  
Pyricularia Oryzae ◽  
Blast Disease ◽  
South American ◽  
Analytical Sensitivity ◽  
Wheat Blast ◽  
Pcr Test

Rapid detection is key to managing emerging diseases because it allows their spread around the world to be monitored and limited. The first major wheat blast epidemics were reported in 1985 in the Brazilian state of Paraná. Following this outbreak, the disease quickly spread to neighboring regions and countries and, in 2016, the first report of wheat blast disease outside South America was released. This Asian outbreak was due to the trade of infected South American seed, demonstrating the importance of detection tests in order to avoid importing contaminated biological material into regions free from the pathogen. Genomic analysis has revealed that one particular lineage within the fungal species Pyricularia oryzae is associated with this disease: the Triticum lineage. A comparison of 81 Pyricularia genomes highlighted polymorphisms specific to the Triticum lineage, and this study developed a real-time PCR test targeting one of these polymorphisms. The test’s performance was then evaluated in order to measure its analytical specificity, analytical sensitivity, and robustness. The C17 quantitative PCR test detected isolates belonging to the Triticum lineage with high sensitivity, down to 13 plasmid copies or 1 pg of genomic DNA per reaction tube. The blast-based approach developed here to study P. oryzae can be transposed to other emerging diseases.

scholarly journals Global Diversity and Updated Phylogeny of Auricularia (Auriculariales, Basidiomycota)

2021 ◽  
Vol 7 (11) ◽  
pp. 933
Author(s):  
Fang Wu ◽  
Ablat Tohtirjap ◽  
Long-Fei Fan ◽  
Li-Wei Zhou ◽  
Renato L. M. Alvarenga ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Morphological Characters ◽  
Ecological Traits ◽  
Phylogenetic Relations ◽  
Worldwide Distribution ◽  
Medicinal Properties ◽  
Morphological Differences ◽  
North And South America ◽  
North And South ◽  
Molecular Characters

Auricularia has a worldwide distribution and is very important due to its edibility and medicinal properties. Morphological examinations and multi-gene phylogenetic analyses of 277 samples from 35 countries in Asia, Europe, North and South America, Africa, and Oceania were carried out. Phylogenetic analyses were based on ITS, nLSU, rpb1, and rpb2 sequences using methods of Maximum Likelihood and Bayesian Inference analyses. According to the morphological and/or molecular characters, 37 Auricularia species were identified. Ten new species, A. camposii and A. novozealandica in the A. cornea complex, A. australiana, A. conferta, A. lateralis, A. pilosa and A. sinodelicata in the A. delicata complex, A. africana, A. srilankensis, and A. submesenterica in the A. mesenterica complex, are described. The two known species A. pusio and A. tremellosa, respectively belonging to the A. mesenterica complex and the A. delicata complex, are redefined, while A. angiospermarum, belonging to the A. auricula-judae complex, is validated. The morphological characters, photos, ecological traits, hosts and geographical distributions of those 37 species are outlined and discussed. Morphological differences and phylogenetic relations of species in five Auricularia morphological complexes (the A. auricula-judae, the A. cornea, the A. delicata, the A. fuscosuccinea and the A. mesenterica complexes) are elaborated. Synopsis data on comparisons of species in the five complexes are provided. An identification key for the accepted 37 species is proposed.

scholarly journals Taxonomic and pathogenic diversity of the blast pathogen populations infecting wheat and grasses in Minas Gerais

2021 ◽  
Author(s):  
João Paulo Ascari ◽  
Emerson Medeiros Del Ponte
Keyword(s):  
Minas Gerais ◽  
Blast Disease ◽  
Host Specialization ◽  
Large Species ◽  
Wheat Blast ◽  
Minas Gerais State ◽  
Pcr Assays ◽  
Signal Grass ◽  
Pathogen Populations ◽  
Pathogenic Diversity

The blast disease of Poaceae is caused by a large species complex, among which P. oryzae is composed of several host-specialized lineages. The Pyricularia oryzae Triticum pathotype (PoT) causes the blast disease in wheat, but is also capable of infecting other grasses, which may serve as an inoculum reservoir for epidemics in wheat. In Brazil, severe wheat blast epidemics are most common in the Cerrado region. The dominant hypothesis is that signal grass (Urochloa sp.) and other gramineous plants harbor the wheat blast pathogen, thus serving as a major reservoir of inoculum for epidemics in wheat. A two-year survey of the Pyricularia blast pathogens was conducted in both wheat and non-wheat areas as well as prior (February) and during (May) the wheat growing season in Minas Gerais. A total of 1,368 plant samples representative of 31 Poaceae species, including wheat, were collected and inspected for the presence of blast symptoms. During the isolations, 932 isolates were obtained, being one fourth obtained from gramineous plants. A subset of 572 isolates was selected for identification at the species level based on portions of the CH7-BAC9 gene sequences. Most of the isolates (n = 494) were P. oryzae, within which 68% were PoT and 32% non-PoT based on two PCR assays targeting (MoT3 and C17 PCR assays). The PoT lineage was found predominantly (97%) in wheat and rarely in the other hosts, even nearby wheat fields (2.1%), as well as at longer distances from wheat regions (0.1%). The blast pathogen population isolated from signal grass grouped in different clades from PoT, and therefore referred to Urochloa lineage (PoU). A series of cross-inoculation greenhouse experiments was conducted using wheat (cv. BRS Guamirim and BR 18-Terena) and signal grass (cv. Marandu) as host and 14 PoT and six PoU isolates as pathogen factor. In the first leaf-inoculation experiment, results showed a significant interaction between host and pathogen; PoT was strongly/weakly aggressive towards wheat/signal grass and PoU was strongly/weakly aggressive towards signal grass/wheat. In inoculated wheat heads, PoT was more aggressive (>91% infected spikelets) than PoU (52% infected spikelets). In a third experiment, four signal grass cultivars (Marandu, Basilisk, Piatã, and Xaraés) were inoculated with the same set of 20 isolates. Similarly, signal grass cultivars were generally more susceptible to PoU than PoT. Severity induced by PoU was twice (7.7% severity) as high as PoT (3.8%) and so was the number of conidia/leaf produced by PoU (47,500) and PoT (23,200). Two groups of signal grass cultivars were formed, the most susceptible composed of Marandu and Basilisk and the least susceptible composed of Piatã and Xaraés. Results of our study confirm the host-specialization and the shaping of the blast populations according to the host. We further suggest that grasses in general, especially signal grass, may not play a major role as an inoculum reservoir for PoT, as it harbors mainly the PoU population. However, due to the large extent of pasture-growing regions and cross-infection ability in wheat, signal grass may harbor amounts of PoT inoculum that are sufficient for initiating leaf and head blast epidemics in wheat blast in Minas Gerais state.

scholarly journals Chloroplast genome variation and phylogenetic relationships of Atractylodes species

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yiheng Wang ◽  
Sheng Wang ◽  
Yanlei Liu ◽  
Qingjun Yuan ◽  
Jiahui Sun ◽  
...  
Keyword(s):  
Chloroplast Genome ◽  
High Throughput Sequencing ◽  
Phylogenetic Analyses ◽  
Herbal Medicines ◽  
Structural Genomic ◽  
Protein Coding ◽  
Chloroplast Genomes ◽  
Original Plant ◽  
Morphological Differences ◽  
Rna Genes

Abstract Background Atractylodes DC is the basic original plant of the widely used herbal medicines “Baizhu” and “Cangzhu” and an endemic genus in East Asia. Species within the genus have minor morphological differences, and the universal DNA barcodes cannot clearly distinguish the systemic relationship or identify the species of the genus. In order to solve these question, we sequenced the chloroplast genomes of all species of Atractylodes using high-throughput sequencing. Results The results indicate that the chloroplast genome of Atractylodes has a typical quadripartite structure and ranges from 152,294 bp (A. carlinoides) to 153,261 bp (A. macrocephala) in size. The genome of all species contains 113 genes, including 79 protein-coding genes, 30 transfer RNA genes and four ribosomal RNA genes. Four hotspots, rpl22-rps19-rpl2, psbM-trnD, trnR-trnT(GGU), and trnT(UGU)-trnL, and a total of 42–47 simple sequence repeats (SSR) were identified as the most promising potentially variable makers for species delimitation and population genetic studies. Phylogenetic analyses of the whole chloroplast genomes indicate that Atractylodes is a clade within the tribe Cynareae; Atractylodes species form a monophyly that clearly reflects the relationship within the genus. Conclusions Our study included investigations of the sequences and structural genomic variations, phylogenetics and mutation dynamics of Atractylodes chloroplast genomes and will facilitate future studies in population genetics, taxonomy and species identification.

scholarly journals Bacillus Cyclic Lipopeptides Iturin and Fengycin Control Rice Blast Caused by Pyricularia oryzae in Potting and Acid Sulfate Soils by Direct Antagonism and Induced Systemic Resistance

2021 ◽  
Vol 9 (7) ◽  
pp. 1441
Author(s):  
Van Bach Lam ◽  
Thibault Meyer ◽  
Anthony Arguelles Arias ◽  
Marc Ongena ◽  
Feyisara Eyiwumi Oni ◽  
...  
Keyword(s):  
Rice Blast ◽  
Induced Systemic Resistance ◽  
Pyricularia Oryzae ◽  
Blast Disease ◽  
Systemic Resistance ◽  
Acid Sulfate Soils ◽  
Acid Sulfate ◽  
Wide Range ◽  
Bacillus Spp ◽  
Sulfate Soils

Rice monoculture in acid sulfate soils (ASSs) is affected by a wide range of abiotic and biotic constraints, including rice blast caused by Pyricularia oryzae. To progress towards a more sustainable agriculture, our research aimed to screen the biocontrol potential of indigenous Bacillus spp. against blast disease by triggering induced systemic resistance (ISR) via root application and direct antagonism. Strains belonging to the B. altitudinis and B. velezensis group could protect rice against blast disease by ISR. UPLC–MS and marker gene replacement methods were used to detect cyclic lipopeptide (CLiP) production and construct CLiPs deficient mutants of B. velezensis, respectively. Here we show that the CLiPs fengycin and iturin are both needed to elicit ISR against rice blast in potting soil and ASS conditions. The CLiPs surfactin, iturin and fengycin completely suppressed P. oryzae spore germination resulting in disease severity reduction when co-applied on rice leaves. In vitro microscopic assays revealed that iturin and fengycin inhibited the mycelial growth of the fungus P. oryzae, while surfactin had no effect. The capacity of indigenous Bacillus spp. to reduce rice blast by direct and indirect antagonism in ASS conditions provides an opportunity to explore their usage for rice blast control in the field.

Morphology and phylogeny of Halamphora yongxingensis sp. nov. (Bacillariophyta), a new marine benthic diatom isolated from Yongxing Island, South China Sea

Phytotaxa ◽  
2015 ◽  
Vol 195 (1) ◽  
pp. 53 ◽  
Author(s):  
Hai-ying Jiang ◽  
Chao-qun Hu ◽  
Hai-peng Yang ◽  
Lv-ping Zhang ◽  
Peng-fei Peng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
South China Sea ◽  
South China ◽  
18S Rdna ◽  
Phylogenetic Analyses ◽  
Light And Electron Microscopy ◽  
Benthic Diatom ◽  
Rbcl Gene ◽  
China Sea ◽  
Morphological Differences

Halamphora yongxingensis sp. nov., a marine benthic diatom isolated from an intertidal reef around the Yongxing Island, South China Sea (16° 58’ 43.3” N, 112° 14’ 41.7” E), is described in this study on the basis of light and electron microscopy. This diatom is also compared with related taxa such as Halamphora subturgida (Hustedt) Levkov and Amphora subtropica Wachnicka & Gaiser. In addition, phylogenetic analyses based on 18S rDNA and rbcL gene were also conducted. The results revealed that H. yongxingensis was clustered into the Halamphora clade, closely related to Halamphora montana (Krasske) Levkov. We discuss morphological differences between H. yongxingensis and H. montana.

scholarly journals Studying of Cultural Properties of Pyricularia oryzae Cav. Strains in the South of Russia

2021 ◽  
Vol 12 (1) ◽  
pp. 21-28
Author(s):  
Dmitry Nartymov ◽  
Evgeny Kharitonov ◽  
Elena Dubina ◽  
Sergey Garkusha ◽  
Margarita Ruban ◽  
...  
Keyword(s):  
Pyricularia Oryzae ◽  
Blast Disease ◽  
The South ◽  
Directional Growth ◽  
Rice Plants ◽  
Affected Plant ◽  
Cultural Traits ◽  
Plant Form ◽  
Using Data

This article presents the results of the development of a methodology for describing the main morphological and cultural traits of the Pyricularia oryzae Cav. strains widespread in the south of Russia. At the same time, the types of traits are identified and listed, which make it possible to unambiguously determine the uniqueness and variety of the pathogen. The relationships and patterns established using cluster and statistical analysis make it possible to identify the conditions for the development of a pathogen that determine its predominant forms. Thus, research shows that leaf forms of P. oryzae strains isolated from rice plants with leaf form of blast disease have an equally directional growth pattern of a colony with a felt structure, and strains isolated from neck-affected plant form often produce a zone of a colony with a clumpy structure. The classification of cultural traits will make it possible to obtain scientifically grounded and comparable data that can be used in the analysis of the interaction of P. oryzae strains with rice plants on various varieties and in various agro-technological conditions in order to improve and rationalize agricultural activities. The study opens up the possibility of using data in breeding, making it possible to identify forms of a pathogen that infect certain varieties.

A new species of Cyrtodactylus (Squamata: Gekkonidae) from Ninh Thuan Province, southern Vietnam

Zootaxa ◽  
2021 ◽  
Vol 4999 (1) ◽  
pp. 58-76
Author(s):  
Quyen Hanh Do ◽  
TRUNG MY PHUNG ◽  
HANH THI NGO ◽  
MINH DUC LE ◽  
THOMAS ZIEGLER ◽  
...  
Keyword(s):  
New Species ◽  
Phylogenetic Analyses ◽  
Coi Gene ◽  
Unique Combination ◽  
Mitochondrial Coi ◽  
Southern Vietnam ◽  
Mitochondrial Coi Gene ◽  
Morphological Differences ◽  
Dorsal Pattern ◽  
A New Species

A new species of the Cyrtodactylus irregularis group is described from Ninh Thuan Province, southern Vietnam based on molecular divergence and morphological differences. Cyrtodactylus orlovi sp. nov. is distinguished from the remaining Indochinese bent-toed geckos by having the unique combination of the following characters: size medium (SVL 61.0–77.7 mm); dorsal tubercles in 16–20 irregular rows; 36–39 ventral scale rows; precloacal pores absent in females, 5 or 6 in males, in a continuous row; femoral pores absent; 3–8 enlarged femoral scales; postcloacal spurs 1 or 2; lamellae under toe IV 16–19; a continuous neckband; a highly irregular transverse banded dorsal pattern; the absence of transversely enlarged median subcaudal scales. In phylogenetic analyses, the new species was revealed to be the sister taxon to a clade consisting of Cyrtodactylus cattienensis and the most recently described species from Vietnam, C. chungi, with 12.1–12.4% and 11.7 % pairwise genetic divergence from the two species, respectively, based on a fragment of the mitochondrial COI gene.  

A new species of Psammophis (Serpentes: Psammophiidae) from the Turpan Basin in northwest China

Zootaxa ◽  
2021 ◽  
Vol 4974 (1) ◽  
pp. 116-134
Author(s):  
MINLI CHEN ◽  
JINLONG LIU ◽  
BO CAI ◽  
JUN LI ◽  
NA WU ◽  
...  
Keyword(s):  
New Species ◽  
Phylogenetic Analyses ◽  
Northwest China ◽  
Genetic Differences ◽  
Cytb Gene ◽  
Turpan Basin ◽  
Morphological Differences ◽  
A New Species

An adult sand snake specimen was collected during a herpetofaunal survey conducted in the Turpan Basin in northwest China. Phylogenetic analyses revealed that this specimen, along with other snake sloughs and skins collected from different localities in the Turpan Basin formed a clade that is sister to Psammophis lineolatus. This taxon exhibited substantial divergence from its congeners (P. lineolatus and P. condanarus) with uncorrelated p-distances ranging from 11.9 ± 0.9% to 15.8 ± 1.6% for the ND4 gene and from 10.2 ± 0.8% to 13.8 ± 1.1% for the Cytb gene. Given the genetic differences along with morphological differences, we describe the specimen from the Turpan Basin as Psammophis turpanensis sp. nov. We provide detailed morphological descriptions, and compare this specimen with five Asian sand snakes and the Afro-Asian Sand Snake, P. schokari. In addition, we provide brief comments on the biogeography of Psammophis in China. 

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