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1.
Colletotrichum spp. are causal agents of anthracnose disease in chili fruits and other tropical crops. The disease is increasing in chili fruits in Thailand and significantly reduces fruit quality and fruit production. Forty-eight isolates of Colletotrichum spp. associated with chili anthracnose were collected from different areas of Thailand during 2010–2015. Based on morphological characteristic identification, 10 isolates were shown to belong to the C. gloeosporioides species complex, 24 isolates belong to the C. acutatum species complex and 14 isolates to C. capsici. For molecular identification, two primer sets, ITS1/ITS4 and ACT528/ACT738, were used for amplification of the internal transcribed spacer of rRNA gene (ITS1–5.8S–ITS2) and partial region actin gene (ACT), respectively. The phylogenetic analysis of individual and combined ITS region and actin nucleotide sequences identified the collected isolates into 4 species: C. gloeosporioides, C. siamense, C. acutatum and C. capsici. The pathogenicity test demonstrated that all four species were pathogenic on intact unwounded and healthy fruits. These results indicated that C. capsici, C. acutatum, C. gloeosporioides and C. siamense were the causal agents of chili anthracnose disease.  相似文献   

2.
Agarum clathratum, brown algae, play important ecological roles in marine ecosystem, but can cause secondary environment pollution when they pile up on the beach. In order to resolve the environment problem by A. clathratum, we focus to isolate and identify Penicillium because many species are well known to produce extracellular enzymes. A total of 32 Penicillium strains were isolated from A. clathratum samples that collected from 13 sites along the mid-east coast of Korea in summer. They were identified based on morphological characters and phylogenetic analysis using β-tubulin DNA sequences as well as a combined dataset of β-tubulin and calmodulin. A total of 32 strains were isolated and they were identified to 13 Penicillium species. The commonly isolated species were Penicillium citrinum, P. roseomaculatum, and Penicillium sp. Among 13 Penicillium species, four species – P. bilaiae, P. cremeogriseum, P. madriti, and P. roseomaculatum – have not been previously recorded in Korea. For these four new species records to Korea, we provide morphological characteristics of each strain.  相似文献   

3.
Mexico is one of the five largest producers of papaya worldwide, but losses caused by pathogens, mainly fungus, at the pre- and post-harvest stages are often more than 50% of the crop. Papaya anthracnose, caused by three different species of the Colletotrichum genus in Mexico, occupies a preponderant place in this problem. Although two of these species, C. gloeosporiodes and C. truncatum, have been characterized morphologically and genotypically, this has not occurred with C. magnum, the third species involved, about which there is very little information. Because of this, it is vital to know its genetic characterization, much more so considering that the studies carried out on the other two species reveal a wide genetic diversity, differences in pathogenicity and in the response to fungicides of the different strains characterized. In this work, Colletotrichum spp. isolates were collected at different papaya orchards in the south-southeast of Mexico. C. magnum isolates identified by species-specific primers were characterized by morphological and molecular approaches. Differences in colony characteristics resulted in five morphological groups. AP-PCR, DAMD and ISSR markers were found to be very efficient for revealing the interspecific variability of this species. The high genetic variability found in the accessions of C. magnum was linked to the geographical area where they were collected. Isolates from Chiapas State were the most variable, showing point mutations in the ITS1-ITS2 region. These results will enable a better phytosanitary management of anthracnose in papaya in this region of Mexico.  相似文献   

4.
In this contribution on the genus Cantharellus in Asia, C. subvaginatus is described from the Republic of Korea as a close relative to the Chinese C. vaginatus, which is here reported for the first time from India. Both species are here placed in Cantharellus subg. Cantharellus sect. Amethystini, together with the Indian C. pseudoformosus (syn.: C. umbonatus) and the Malayan C. subamethysteus. As such, Asia has suddenly become the continent with the highest diversity for Amethystini. Species delimitation in sect. Amethystini is molecularly supported by a combined phylogenetic analysis of rDNA sequences obtained for LSU and ITS and additionally suggests the existence of a still undescribed species in North America. Character variability is discussed for all known members of Amethystini, including atypical specimens of the North American C. lewisii that are morphologically more reminiscent of the South Korean C. subvaginatus.  相似文献   

5.
A new anthracnose disease of Atractylodes chinensis was observed in Liaoning province in China. The causal agent was isolated from diseased leaves. Based on morphology and ITS sequence data, it was identified as a Colletotrichum species belonging to the C. destructivum species complex. A multi-locus DNA sequence analysis (ITS, GAPDH, CHS-1, ACT, TUB2) revealed that the fungus represents a new species that is described here as C. atractylodicola sp. nov. Pathogenicity tests confirmed that the isolated species is the causal agent of the observed anthracnose symptoms on A. chinensis leaves.  相似文献   

6.
Species in Plectosphaerella are well known as pathogens of several plant species causing fruit, root and collar rot and collapse. In an investigation of endophytic fungi associated with cucurbit plants in China, we isolated 77 strains belonging to the genus Plectosphaerella. To identify the isolated strains, we collected the type or reference strains of all currently accepted species in Plectosphaerella except P. oratosquillae and conducted a phylogenetic analysis. Phylogenetic analysis of the partial 28S rDNA sequences showed that all species in Plectosphaerella were located in one clade of Plectosphaerellaceae. Based on multi-locus phylogenetic analysis of the ITS, CaM, EF1, TUB and morphological characteristics, all species in Plectosphaerella were well separated. Three endophytic strains from stems of Cucurbita moschata, Citrullus lanatus and Cucumis melo from North China were assigned to a new species described as P. sinensis in this paper. The new species differs morphologically from other Plectosphaerella species by irregular chlamydospores, and the dimensions of phialides and conidia. The other endophytic strains from several cucurbit plants were identified as P. cucumerina.  相似文献   

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During a study on the biodiversity of yeasts and yeast-like ascomycetes from wild plants in Iran, four strains of yeast-like filamentous fungi were isolated from a healthy plant of Euphorbia polycaulis in the Qom Province, Iran (IR. of). All four strains formed small hyaline one-celled conidia from integrated conidiogenous cells directly on hyphae and sometimes on discrete phialides, as well as by microcyclic conidiation. Two strains additionally produced conidia in conidiomata that open by rupture. The internal transcribed spacer (ITS) sequences suggested the placement of these strains in the genera Collophorina (Leotiomycetes) and Coniochaeta (Sordariomycetes), respectively. Blast search results on NCBI GenBank and phylogenetic analyses of ITS, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the translation elongation factor 1α (EF-1α) sequences, and the nuclear large subunit ribosomal gene (LSU), partial actin (ACT), and β-tubulin (TUB) sequences, respectively, revealed the isolates to belong to three new species, that are described here as Collophorina euphorbiae, Coniochaeta iranica, and C. euphorbiae. All three species are characterised by morphological, physiological, and molecular data.  相似文献   

10.
The hybrid origin of Miscanthus purpurascens has previously been proposed, primarily because of its intermediate morphology. In this study, phylogenies based on the DNA sequences from the internal transcribed spacer region of nuclear ribosomal DNA (nrDNA ITS), on the DNA sequences of the trnL intron and trnL-F intergenic spacer of chloroplast DNA, and on amplified fragment length polymorphism (AFLP) fingerprinting confirm that M. purpurascens originated through homoploid hybridization between M. sinensis and M. sacchariflorus. Two different types of ITS sequences were identified from almost all plants of M. purpurascens. One type was found to be closely related to M. sinensis and the other to M. sacchariflorus. Miscanthus purpurascens was found to possess many M. sinensis- and M. sacchariflorus-specific AFLP bands but no band specific to itself. Clustering with the Unweighted Pair Group Method with Arithmetic Mean and principal coordinate analysis based on the AFLP data also demonstrated that M. purpurascens is an approximate intermediate of the two species. In addition, M. purpurascens has the plastid genome of M. sinensis or M. sacchariflorus, suggesting that either species could be its maternal parent. All specimens of M. purpurascens and its coexisting parental species are identified as diploids (2n = 2x = 38). Possible mechanisms of natural hybridization, hybrid status, chloroplast DNA recombination, and evolutionary implications of this hybridization are also discussed.  相似文献   

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Authentic identification of fish species is essential for conserving them as a valuable genetic resource in our environment. DNA barcoding of living beings has become an important and ultimate tool for establishing their molecular identity. Among cyprinids, Barilius is an important genus having nearly 23 species in Indian region whose morphological identification is often difficult due to minute differences in their features. Five species collected from Indian waters and primarily identified as Opsarius bakeri (syn. Barilius bakeri), B. gatensis, B. vagra, B. bendelisis and B. ngawa were authenticated by their DNA barcoding based on mitochondrial COI gene sequences. Five individuals of each species were taken for barcode preparation by COI gene sequencing which yielded one barcode for B. ngawa, two barcodes each for O. bakeri, B. gatensis, B. bendelisis and three barcodes for B. vagra. The order of inter and intra-specific variation was estimated to know a preliminary status of variation prevailing in these cold stream fish species significant for evolution and conservation of these valued species of our ichthyofauna. Average variation within genera was found to be 13.6% with intra-specific variation ranging from 0.0% (B. ngawa) to 0.6% (B. gatensis). These distance data are in the same order found by various researchers globally using COI barcode sequences in different fish species. Phylogenetic relatedness among Barilius species and some other cyprinids validate their status of individual species as established by conventional taxonomy.  相似文献   

14.
Chili pepper (Capsicum annum L.) is an important economic crop that is severely destroyed by the filamentous oomycete Phytophthora capsici. Little is known about this pathogen in key chili pepper farms in Punjab province, Pakistan. We investigated the genetic diversity of P. capsici strains using standard taxonomic and molecular tools, and characterized their colony growth patterns as well as their disease severity on chili pepper plants under the greenhouse conditions. Phylogenetic analysis based on ribosomal DNA (rDNA), β-tubulin and translation elongation factor 1α loci revealed divergent evolution in the population structure of P. capsici isolates. The mean oospore diameter of mating type A1 isolates was greater than that of mating type A2 isolates. We provide first evidence of an uneven distribution of highly virulent mating type A1 and A2 of P. capsici that are insensitive to mefenoxam, pyrimorph, dimethomorph, and azoxystrobin fungicides, and represent a risk factor that could ease outpacing the current P. capsici management strategies.  相似文献   

15.
In our study, seventy specimens from Brazilian herbaria, as well as from NY and PDD, identified as Morganella, were analyzed. They included the paratype of M. mexicana and holotypes of M. arenicola, M. albostipitata, M. compacta, M. nuda, M. rimosa. Specimens were studied morphologically and used for DNA extraction and amplification of ITS and LSU nuclear ribosomal DNA. New sequences were obtained and compared with homologous sequences from GenBank. As a result of these analyses, a new species and six new combinations are proposed. Morphological review and discussion are provided for the species from Brazil.  相似文献   

16.
Two new species of Metarhizium, M. bibionidarum and M. purpureogenum are described from Japan. Metarhizium bibionidarum is the phylogenetic sister species of M. pemphigi and a member of the M. flavoviride species complex. It is distinguished morphologically from M. pemphigi by its larger conidia. The species is based on a collection of an infected March fly larva (Diptera: Bibionidae) but is also known to occur on fruit beetle (Coleoptera: Scarabaeidae) encountered in France. Metarhizium purpureogenum was isolated from soil by plating and insect baiting methods and represents a unique phylogenetic lineage placed outside the M. anisopliae and M. flavoviride species complexes. Three isolates of M. purpureogenum excreted a distinctive red-purple pigment into agar medium when co-cultured with M. robertsii or Aspergillus oryzae.  相似文献   

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Carex lucorum currently comprises two morphologically similar varieties. We revise the taxonomy of C. lucorum, and map the distribution of the taxa. Based on multivariate analyses and analyses of variance of measured characters, allopatry, and previous studies revealing differences in achene micromorphology, chromosome differences, and flavonoid chemistry, we elevate C. lucorum var. austrolucorum to species status as C. austrolucorum. We provide an identification key to C. lucorum and its closest relatives.  相似文献   

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Cymbopogon

is an important member of grass family Poaceae, cultivated for essential oils which have greater medicinal and industrial value. Taxonomic identification of Cymbopogon species is determined mainly by morphological markers, odour of essential oils and concentration of bioactive compounds present in the oil matrices which are highly influenced by environment. Authenticated molecular marker based taxonomical identification is also lacking in the genus; hence effort was made to evaluate potential DNA barcode loci in six commercially important Cymbopogon species for their individual discrimination and authentication at the species level. Four widely used DNA barcoding regions viz., ITS 1 & ITS 2 spacers, matK, psbA-trnH and rbcL were taken for the study. Gene sequences of the same or related genera of the concerned loci were mined from NCBI domain and primers were designed and validated for barcode loci amplification. Out of the four loci studied, sequences from matK and ITS spacer loci revealed 0.46% and 5.64% nucleotide sequence diversity, respectively whereas the other two loci i.e., psbA-trnH and rbcL showed 100% sequence homology. The newly developed primers can be used for barcode loci amplification in the genus Cymbopogon. The identified Single Nucleotide Polymorphisms from the studied sequences may be used as barcodes for the six Cymbopogon species. The information generated can also be utilized for barcode development of the genus by including more number of Cymbopgon species in future.
  相似文献   

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