scholarly journals Identification and Characterization of Verticillium longisporum Lineage A1/D1 from Brassica Crops in Manitoba, Canada

2020 ◽  
Vol 21 (10) ◽  
pp. 3499
Author(s):  
Zhongwei Zou ◽  
Vikram Bisht ◽  
W. G. Dilantha Fernando
Keyword(s):  
Small Subunit ◽  
Pathogenicity Test ◽  
Brassica Napus L ◽  
Gene Characterization ◽  
5.8S Rdna ◽  
Verticillium Longisporum ◽  
Brassica Crops ◽  
Small Subunit Rdna ◽  
Pcr Rflp

Verticillium stripe in canola (Brassica napus L.) caused by Verticillium longisporum was first reported in Manitoba in 2014. In this study, Brassica crops including canola, mustard (Brassica juncea) and radish (Raphanus sativus) with visible symptoms of Verticillium stripe were collected from Portage La Prairie, Manitoba, and the pathogens were isolated. Isolates from canola and radish were identified to V. longisporum, which produced longer conidia (7.92–12.00 µm) than Verticillium dahliae (4.32–7.04 µm). An isolate derived from mustard was characterized as V. dahliae. Molecular diagnostics with 18S rDNA, 5.8S rDNA and mating-type marker primers were used to confirm the identification of Verticillium isolates. PCR-RFLP of the mitochondrial small subunit rDNA and the cytochrome b gene were also employed to distinguish V. longisporum isolates from V. dahliae. The multi-gene characterization approach allowed for lineage determination, and V. longisporum isolates from canola and radish were in the A1/D1 group. Isolates of Verticillium longisporum from canola inoculated onto the canola cultivar ‘Westar’ caused symptoms of stem striping, stunting and short plants. Re-isolated fungal strains from infected stems were again inoculated onto canola plants, in order to confirm that V. longisporum was the causal agent of Verticillium stripe disease in the pathogenicity test.

scholarly journals Characterization of the marine propionate-degrading, sulfate-reducing bacterium Desulfofaba fastidiosa sp. nov. and reclassification of Desulfomusa hansenii as Desulfofaba hansenii comb. nov.

2004 ◽  
Vol 54 (2) ◽  
pp. 393-399 ◽  
Author(s):  
Lone Abildgaard ◽  
Niels Birger Ramsing ◽  
Kai Finster
Keyword(s):  
Small Subunit ◽  
Phenotypic Traits ◽  
Rrna Gene ◽  
Sulfate Reducing ◽  
Dissimilatory Sulfite Reductase ◽  
Small Subunit Rdna ◽  
Reductase Gene ◽  
Morphological And Physiological Traits ◽  
Dissimilatory Sulfite Reductase Gene

A rod-shaped, slightly curved sulfate reducer, designated strain P2T, was isolated from the sulfate–methane transition zone of a marine sediment. Cells were motile by means of a single polar flagellum. The strain reduced sulfate, thiosulfate and sulfite to sulfide and used propionate, lactate and 1-propanol as electron donors. Strain P2T also grew by fermentation of lactate. Propionate was oxidized incompletely to acetate and CO2. The DNA G+C content was 48·8mol%. Sequence analysis of the small-subunit rDNA and the dissimilatory sulfite reductase gene revealed that strain P2T was related to the genera Desulfonema, Desulfococcus, Desulfosarcina, ‘Desulfobotulus’, Desulfofaba, Desulfomusa and Desulfofrigus. These genera include incomplete as well as complete oxidizers of substrates. Strain P2T shared important morphological and physiological traits with Desulfofaba gelida and Desulfomusa hansenii, including the ability to oxidize propionate incompletely to acetate. The 16S rRNA gene similarities of P2T to Desulfofaba gelida and Desulfomusa hansenii were respectively 92·9 and 91·5%. Combining phenotypic and genotypic traits, we propose strain P2T to be a member of the genus Desulfofaba. The name Desulfofaba fastidiosa sp. nov. (type strain P2T=DSM 15249T=ATCC BAA-815T) is proposed, reflecting the limited number of substrates consumed by the strain. In addition, the reclassification of Desulfomusa hansenii as a member of the genus Desulfofaba, Desulfofaba hansenii comb. nov., is proposed. A common line of descent and a number of shared phenotypic traits support this reclassification.

Morphological and molecular characterization of Aphelenchoides fujianensis n. sp. (Nematoda: Aphelenchoididae) from Pinus massoniana in China

Zootaxa ◽  
2010 ◽  
Vol 2509 (1) ◽  
pp. 39 ◽  
Author(s):  
KAN ZHUO ◽  
RUQIANG CUI ◽  
WEIMIN YE ◽  
MEI LUO ◽  
HONGHONG WANG ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Pinus Massoniana ◽  
Small Subunit ◽  
Mt Dna ◽  
Lateral Field ◽  
Small Subunit Rdna ◽  
Aphelenchoides Besseyi ◽  
Group 3 ◽  
Morphological And Molecular Characterization

Aphelenchoides fujianensis n. sp. is described and illustrated from a dead Pinus massoniana based on morphology and molecular analyses of the near-full-length small subunit rDNA gene and partial cytochrome oxidase subunit I of mitochondrial DNA. This new species belongs to the Group 3 of Aphelenchoides species sensu Shahina with star-shaped tail terminus and is characterised by a relatively long body (653–843 μ m in the male and 803–941 μ m in the female) and four lateral incisures in the lateral field. The male has relatively large spicules (24–30 μ m). The female has elongate postvulval uterine sac (extending ca 32–44% of vulva-anus distance), usually with sperms. Both male and female have star-shaped mucro. It is distinguished from other species by postvulval uterine sac length, a and c ratios, and spicule size and shape. Molecular analysis reveals that this species has unique 18S and mt-DNA sequences, and is closest to Aphelenchoides besseyi in dendrograms inferred using both markers. The identification codes of OEPP/EPPO for A. fujianensis n. sp. are: A1-B2-C1-D1/3-E1-F1/2.

scholarly journals Prokaryote diversity and taxonomy: current status and future challenges

2004 ◽  
Vol 359 (1444) ◽  
pp. 623-638 ◽  
Author(s):  
Aharon Oren
Keyword(s):  
Small Subunit ◽  
Current Status ◽  
Environmental Significance ◽  
Species Classification ◽  
Phenotypic Properties ◽  
Species Definition ◽  
Small Subunit Rdna ◽  
Future Challenges ◽  
Living Organisms

The prokaryotes are by far the most abundant organisms inhabiting planet Earth. They are also by far the most diverse, both metabolically and phylogenetically; they encompass the Bacteria and the Archaea, two out of the three major divisions of living organisms. The current prokaryote species classification is based on a combination of genomic and phenotypic properties. The recommended cut–off value of 70% DNA–DNA similarity to delineate species signifies an extremely broad species definition for the prokaryotes compared with the higher eukaryotes. The number of validly named species of prokaryotes is currently slightly more than 6200. However, on the basis of small–subunit rDNA characterization of whole communities and other approaches, the more exact number of species present can be inferred to be at least two orders of magnitude larger. Classic culturing methods based on colony formation on agar are generally unsatisfactory for the recovery of bacteria from the environment. Many of the most abundant prokaryotes in nature have not yet been brought into culture. Some of these may thrive by means of as yet unknown modes of energy generation. Several novel methods have recently enabled the isolation of some interesting organisms of environmental significance. A better coverage of the prokaryote diversity on Earth depends on such innovative approaches, combined with appropriate funding.

scholarly journals Genetic Characterization of Cryptosporidium cuniculus from Rabbits in Egypt

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 775
Author(s):  
Doaa Naguib ◽  
Dawn M. Roellig ◽  
Nagah Arafat ◽  
Lihua Xiao
Keyword(s):  
Rflp Analysis ◽  
Small Subunit ◽  
Rrna Gene ◽  
Small Subunit Rrna ◽  
Genetic Characteristics ◽  
Glycoprotein Gene ◽  
Cryptosporidium Spp ◽  
Small Subunit Rrna Gene ◽  
Pcr Rflp

Rabbits are increasingly farmed in Egypt for meat. They are, however, known reservoirs of infectious pathogens. Currently, no information is available on the genetic characteristics of Cryptosporidium spp. in rabbits in Egypt. To understand the prevalence and genetic identity of Cryptosporidium spp. in these animals, 235 fecal samples were collected from rabbits of different ages on nine farms in El-Dakahlia, El-Gharbia, and Damietta Provinces, Egypt during the period from July 2015 to April 2016. PCR-RFLP analysis of the small subunit rRNA gene was used to detect and genotype Cryptosporidium spp. The overall detection rate was 11.9% (28/235). All 28 samples were identified as Cryptosporidium cuniculus. The 16 samples successfully subtyped by the sequence analysis of the partial 60 kDa glycoprotein gene belonged to two subtypes, VbA19 (n = 1) and VbA33 (n = 15). As C. cuniculus is increasingly recognized as a cause of human cryptosporidiosis, Cryptosporidium spp. in rabbits from Egypt have zoonotic potential.

Novel contributions to the peritrich family Vaginicolidae (Protista: Ciliophora), with morphological and phylogenetic analyses of poorly known species of Pyxicola, Cothurnia and Vaginicola

2019 ◽  
Vol 187 (1) ◽  
pp. 1-30 ◽  
Author(s):  
Borong Lu ◽  
Lifang Li ◽  
Xiaozhong Hu ◽  
Daode Ji ◽  
Khaled A S Al-Rasheid ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Small Subunit ◽  
Its2 Region ◽  
5.8S Rdna ◽  
Small Subunit Rdna ◽  
Distinct Lineage ◽  
Large Subunit Rdna ◽  
First Time

Abstract The classification of loricate peritrich ciliates is difficult because of an accumulation of several taxonomic problems. In the present work, three poorly described vaginicolids, Pyxicola pusilla, Cothurnia ceramicola and Vaginicola tincta, were isolated from the surface of two freshwater/marine algae in China. In our study, the ciliature of Pyxicola and Vaginicola is revealed for the first time, demonstrating the taxonomic value of infundibular polykineties. The small subunit rDNA, ITS1-5.8S rDNA-ITS2 region and large subunit rDNA of the above species were sequenced for the first time. Phylogenetic analyses based on these genes indicated that Pyxicola and Cothurnia are closely related. The present study suggested that the loricate species probably represent a distinct lineage in peritrich evolution and both genera Cothurnia and Thuricola are monophyletic. Pyxicola pusilla, Cothurnia ceramicola and Vaginicola tincta are recircumscribed.

Theileria parva ribosomal internal transcribed spacer sequences exhibit extensive polymorphism and mosaic evolution: application to the characterization of parasites from cattle and buffalo

Parasitology ◽  
1999 ◽  
Vol 118 (6) ◽  
pp. 541-551 ◽  
Author(s):  
N. E. COLLINS ◽  
B. A. ALLSOPP
Keyword(s):  
Genetic Recombination ◽  
Large Subunit ◽  
Small Subunit ◽  
Internal Transcribed Spacers ◽  
Rrna Genes ◽  
Gene Pools ◽  
Theileria Parva ◽  
Causative Agents ◽  
Internal Transcribed Spacer Sequences

We sequenced the rRNA genes and internal transcribed spacers (ITS) of several Theileria parva isolates in an attempt to distinguish between the causative agents of East coast fever and Corridor disease. The small subunit (SSU) and large subunit (LSU) rRNA genes from a cloned T. p. lawrencei parasite were sequenced; the former was identical to that of T. p. parva Muguga, and there were minor heterogeneities in the latter. The 5·8S gene sequences of 11 T. parva isolates were identical, but major differences were found in the ITS. Six characterization oligonucleotides were designed to hybridize within the variable ITS1 region; 93·5% of T. p. parva isolates examined were detected by probe TPP1 and 81·8% of T. p. lawrencei isolates were detected by TPL2 and/or TPL3a. There was no absolute distinction between T. p. parva and T. p. lawrencei and the former hybridized with fewer of the probes than did the latter. It therefore seems that a relatively homogenous subpopulation of T. parva has been selected in cattle from a more diverse gene pool in buffalo. The ITSs of both T. p. parva and T. p. lawrencei contained different combinations of identifiable sequence segments, resulting in a mosaic of segments in any one isolate, suggesting that the two populations undergo genetic recombination and that their gene pools are not completely separate.

Sign in / Sign up

Export Citation Format

Share Document