scholarly journals Diversity of pathogenic Pseudomonas isolated from citrus in Tunisia

AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Maroua Oueslati ◽  
Magdalena Mulet ◽  
Mohamed Zouaoui ◽  
Charlotte Chandeysson ◽  
Jorge Lalucat ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Pseudomonas Syringae ◽  
Ice Nucleation ◽  
Phylogenetic Study ◽  
Future Studies ◽  
Citrus Orchards ◽  
First Time ◽  
New Cultivars

Abstract The damages observed in Tunisian citrus orchards have prompted studies on the Pseudomonas spp. responsible for blast and black pit. Prospective orchards between 2015 and 2017 showed that the diseases rapidly spread geographically and to new cultivars. A screening of Pseudomonas spp. isolated from symptomatic trees revealed their wide diversity according to phylogenetic analysis of their housekeeping rpoD and cts genes. The majority of strains were affiliated to Pseudomonas syringae pv. syringae (Phylogroup PG02b), previously described in Tunisia. However, they exhibited various BOX-PCR fingerprints and were not clonal. This work demonstrated, for the first time in Tunisia, the involvement of Pseudomonas cerasi (PG02a) and Pseudomonas congelans (PG02c). The latter did not show significant pathogenicity on citrus, but was pathogenic on cantaloupe and active for ice nucleation that could play a role in the disease. A comparative phylogenetic study of citrus pathogens from Iran, Montenegro and Tunisia revealed that P. syringae (PG02b) strains are closely related but again not clonal. Interestingly P. cerasi (PG02a) was isolated in two countries and seems to outspread. However, its role in the diseases is not fully understood and it should be monitored in future studies. The diversity of pathogenic Pseudomonas spp. and the extension of the diseases highlight that they have become complex and synergistic. It opens questions about which factors favor diseases and how to fight against them efficiently and with sustainable means.

Phylogenetic placement and redescription of the spider genus Atelidea Simon, 1895 (Araneae, Tetragnathidae)

Zootaxa ◽  
2011 ◽  
Vol 2761 (1) ◽  
pp. 51 ◽  
Author(s):  
FERNANDO ÁLVAREZ-PADILLA ◽  
SURESH P. BENJAMIN
Keyword(s):  
Phylogenetic Analysis ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Type Specimen ◽  
Future Studies ◽  
Phylogenetic Placement ◽  
Microscope Images ◽  
First Time ◽  
Larger Sample ◽  
Scanning Electron

The spider genus Atelidea Simon, 1895 previously included two described species, A. spinosa Simon, 1895 and A. globosa Yamaguchi, 1957. In this study we describe for the first time the female of A. spinosa, and provide illustrations and scanning electron microscope images of external and internal features. The phylogenetic placement of this genus was investigated by including A. spinosa in a recent phylogenetic analysis with 23 tetragnathids. Parsimony analyses under equal and implied weights were performed. Our results suggest that Atelidea belongs to Tetragnathidae and in particular nests within Leucauginae, this last node is well supported and expected to endure future analysis; however, the relationships of Atelidea to other leucaugine species and its validity as a genus need to be assessed in future studies with a larger sample of leucaugine taxa. The second species described in the genus, A. globosa, is only known from its now lost type specimen from Japan and it is proposed as a nomen dubium leaving Atelidea monotypic.

Systematics of Simothraulopsis Demoulin, 1966 (Ephemeroptera: Leptophlebiidae)

Zootaxa ◽  
2017 ◽  
Vol 4285 (1) ◽  
pp. 1 ◽  
Author(s):  
JEANE M. C. DO NASCIMENTO ◽  
FREDERICO F. SALLES ◽  
NEUSA HAMADA
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Current Knowledge ◽  
External Morphology ◽  
Biological Information ◽  
Phylogenetic Study ◽  
First Time

In the present paper, based on specimens from different regions of Brazil, we review the current knowledge of the Neotropical genus Simothraulopsis. A phylogenetic study was performed in order to address the relationships between all species and to test the monophyly of Simothraulopsis. For this purpose, 48 characters related to the external morphology of adults and nymphs were investigated. As a result, four new species are described; S. caliginosus sp.nov., S. dominguezi sp. nov., S. eurybasis sp. nov., S. inaequalis sp. nov. New taxonomic and biological information are added to this genus. Nymphs of S. diamantinensis Mariano, 2010 and S. janae Mariano, 2010 are described for the first time and several new distributional records for Brazil are provided. Additionally, keys for male imagos and nymphs of the genus are proposed. The phylogenetic analysis corroborated the monophyly of Simothraulopsis, however, the division in two subgenera as previously proposed was not recovered in our reconstruction. 

The first report of Xenorhabdus indica from Steinernema pakistanense: co-phylogenetic study suggests co-speciation between X. indica and its steinernematid nematodes

2018 ◽  
Vol 93 (1) ◽  
pp. 81-90 ◽  
Author(s):  
A.H. Bhat ◽  
A.K. Chaubey ◽  
V. Půža
Keyword(s):  
Phylogenetic Analysis ◽  
First Generation ◽  
Biochemical Characterization ◽  
Original Description ◽  
Molecular Data ◽  
Phylogenetic Study ◽  
First Report ◽  
Humid Region ◽  
Virulence Assay ◽  
First Time

AbstractDuring a survey in agricultural fields of the sub-humid region of Meerut district, India, two strains of entomopathogenic nematodes, labelled CS31 and CS32, were isolated using the Galleria baiting technique. Based on morphological and morphometric studies, and molecular data, the nematodes were identified as Steinernema pakistanense, making this finding the first report of this species from India. For the first time, we performed a molecular and biochemical characterization of the bacterial symbiont of S. pakistanense. Furthermore, a co-phylogenetic analysis of the bacteria from the monophyletic clade containing a symbiont of S. pakistanense, together with their nematode hosts, was conducted, to test the degree of nematode–bacteria co-speciation. Both isolates were also tested in a laboratory assay for pathogenicity against two major pests, Helicoverpa armigera and Spodoptera litura. The morphology of the Indian isolates corresponds mainly to the original description, with the only difference being the absence of a mucron in first-generation females and missing epiptygmata in the second generation. The sequences of bacterial recA and gyrB genes have shown that the symbiont of S. pakistanense is closely related to Xenorhabdus indica, which is associated with some other nematodes from the ‘bicornutum’ group. Co-phylogenetic analysis has shown a remarkable congruence between the nematode and bacterial phylogenies, suggesting that, in some lineages within the Steinernema / Xenorhabdus complex, the nematodes and bacteria have undergone co-speciation. In the virulence assay, both strains caused a 100% mortality of both tested insects after 48 h, even at the lowest doses of 25 infective juveniles per insect, suggesting that S. pakistanense could be considered for use in the biocontrol of these organisms in India.

scholarly journals Phylogenetic Analysis of Indian Freshwater Pond Mussels Lamellidens corrianus and L. phenchooganjensis (Bivalvia: Unionidae) from the Upper Brahmaputra Basin of Assam, India

2021 ◽  
Vol 18 (1) ◽  
pp. 197-206
Author(s):  
Jyotish Sonowal ◽  
Pankaj Chetia ◽  
Devid Kardong
Keyword(s):  
Phylogenetic Analysis ◽  
18S Rrna ◽  
Gene Sequence ◽  
18S Rrna Gene ◽  
Phylogenetic Study ◽  
Rrna Gene ◽  
Rrna Gene Sequence ◽  
Gene Sequences ◽  
Freshwater Molluscs ◽  
First Time

To update the present knowledge of freshwater molluscs, a phylogenetic analysis of two species of Indian pond mussels was carried out using amplified sequence of 18S rRNA gene. From the phylogenetic study of 18S rRNA gene sequencing, it was found that the Lamellidenscorrianus and L. phenchooganjensis are phylogenetically closely related to 18S rRNA gene sequences of other freshwater bivalve mussels belonging to the family Unionidae of order Unionida. Like other members of the Unionidae family, the two Lamellidensspp. showed monophyletic evolutionary lineage and shared a common ancestor. The result obtained from the phylogenetic analysis of Lamellidensspp. was significant as the 18S rRNA gene sequence of L. phenchooganjensis was submitted for the first time in the global nucleotide database (Genbank, NCBI). Similarly, the 18S rRNA gene sequence of L. corrianuswas also submitted to the database for the first time from this region having unique ecological niche. Therefore, the present study on phylogenetic analysis is a contribution to the global database of 18S rRNA gene sequences of freshwater mollusc, particularly from this part of the region.

New and noteworthy lichen-forming and lichenicolous fungi 10

2020 ◽  
Vol 62 (1-2) ◽  
pp. 69-108
Author(s):  
S. Y. Kondratyuk ◽  
D. K. Upreti ◽  
G. K. Mishra ◽  
S. Nayaka ◽  
K. K. Ingle ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
South Korea ◽  
Eastern Europe ◽  
South Asia ◽  
New Combinations ◽  
Eastern Asia ◽  
Forest Zone ◽  
Mediterranean Europe ◽  
First Time ◽  
India And China

Eight species, new for science, i.e.: Lobothallia gangwondoana S. Y. Kondr., J.-J. Woo et J.-S. Hur and Phyllopsora dodongensis S. Y. Kondr. et J.-S. Hur from South Korea, Eastern Asia, Ioplaca rinodinoides S. Y. Kondr., K. K. Ingle, D. K. Upreti et S. Nayaka, Letrouitia assamana S. Y. Kondr., G. K. Mishra et D. K. Upreti, and Rusavskia indochinensis S. Y. Kondr., D. K. Upreti et S. Nayaka from India and China, South Asia, Caloplaca orloviana S. Y. Kondr. and Rusavskia drevlyanica S. Y. Kondr. et O. O. Orlov from Ukraine, Eastern Europe, as well as Xanthoria ibizaensis S. Y. Kondr. et A. S. Kondr. from Ibiza Island, Spain, Mediterranean Europe, are described, illustrated and compared with closely related taxa. Fominiella tenerifensis S. Y. Kondr., Kärnefelt, A. Thell et Feuerer is for the first time recorded from Mediterranean Europe, Huriella loekoesiana S. Y. Kondr. et Upreti is provided from Russia for the first time, and H. pohangensis S. Y. Kondr., L. Lőkös et J.-S. Hur for the first time from China, Phoma candelariellae Z. Kocakaya et Halıcı is new to Ukraine, and Staurothele frustulenta Vain. is recorded from the Forest Zone of Ukraine for the first time. Twelve new combinations, i.e.: Bryostigma apotheciorum (for Sphaeria apotheciorum A. Massal.), Bryostigma biatoricola (for Arthonia biatoricola Ihlen et Owe-Larss.), Bryostigma dokdoense (for Arthonia dokdoensis S. Y. Kondr., L. Lőkös, B. G. Lee, J.-J. Woo et J.-S. Hur), Bryostigma epiphyscium (for Arthonia epiphyscia Nyl.), Bryostigma lobariellae (for Arthonia lobariellae Etayo), Bryostigma lapidicola (for Lecidea lapidicola Taylor), Bryostigma molendoi (for Tichothecium molendoi Heufl. ex Arnold), Bryostigma neglectulum (for Arthonia neglectula Nyl.), Bryostigma parietinarium (for Arthonia parietinaria Hafellner et Fleischhacker), Bryostigma peltigerinum (for Arthonia vagans var. peltigerina Almq.), Bryostigma phaeophysciae (for Arthonia phaeophysciae Grube et Matzer), Bryostigma stereocaulinum (for Arthonia nephromiaria var. stereocaulina Ohlert), are proposed based on results of combined phylogenetic analysis based on mtSSU and RPB2 gene sequences. Thirty-one new combinations for members of the genus Polyozosia (i.e.: Polyozosia actophila (for Lecanora actophila Wedd.), Polyozosia agardhiana (for Lecanora agardhiana Ach.), Polyozosia altunica (for Myriolecis altunica R. Mamut et A. Abbas), Polyozosia antiqua (for Lecanora antiqua J. R. Laundon), Polyozosia bandolensis (for Lecanora bandolensis B. de Lesd.), Polyozosia behringii (for Lecanora behringii Nyl.), Polyozosia caesioalutacea (for Lecanora caesioalutacea H. Magn.), Polyozosia carlottiana (for Lecanora carlottiana C. J. Lewis et Śliwa), Polyozosia congesta (for Lecanora congesta Clauzade et Vězda), Polyozosia eurycarpa (for Lecanora eurycarpa Poelt, Leuckert et Cl. Roux), Polyozosia expectans (Lecanora expectans Darb.), Polyozosia flowersiana (Lecanora flowersiana H. Magn.), Polyozosia fugiens (for Lecanora fugiens Nyl.), Polyozosia invadens (for Lecanora invadens H. Magn.), Polyozosia juniperina (for Lecanora juniperina Śliwa), Polyozosia latzelii (for Lecanora latzelii Zahlbr.), Polyozosia liguriensis (for Lecanora liguriensis B. de Lesd.), Polyozosia massei (for Myriolecis massei M. Bertrand et J.-Y. Monnat), Polyozosia mons-nivis (for Lecanora mons-nivis Darb.), Polyozosia oyensis (for Lecanora oyensis M.-P. Bertrand et Cl. Roux), Polyozosia percrenata (for Lecanora percrenata H. Magn.), Polyozosia persimilis (for Lecanora hagenii subsp. persimilis Th. Fr.), Polyozosia poeltiana (for Lecanora poeltiana Clauzade et Cl. Roux), Polyozosia prominens (for Lecanora prominens Clauzade et Vězda), Polyozosia prophetae-eliae (for Lecanora prophetae-eliae Sipman), Polyozosia salina (for Lecanora salina H. Magn.), Polyozosia schofieldii (for Lecanora schofieldii Brodo), Polyozosia sverdrupiana (for Lecanora sverdrupiana Øvstedal), Polyozosia torrida (for Lecanora torrida Vain.), Polyozosia wetmorei (for Lecanora wetmorei Śliwa), Polyozosia zosterae (for Lecanora subfusca? zosterae Ach.)) are proposed.

scholarly journals Cloud icing by mineral dust and impacts to aviation safety

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Slobodan Nickovic ◽  
Bojan Cvetkovic ◽  
Slavko Petković ◽  
Vassilis Amiridis ◽  
Goran Pejanović ◽  
...  
Keyword(s):  
Mineral Dust ◽  
Weather Conditions ◽  
Ice Nucleation ◽  
Aircraft Accidents ◽  
Ice Nuclei ◽  
Loss And Damage ◽  
Cloud Ice ◽  
Convective Weather ◽  
First Time ◽  
Engine Power

AbstractIce particles in high-altitude cold clouds can obstruct aircraft functioning. Over the last 20 years, there have been more than 150 recorded cases with engine power-loss and damage caused by tiny cloud ice crystals, which are difficult to detect with aircraft radars. Herein, we examine two aircraft accidents for which icing linked to convective weather conditions has been officially reported as the most likely reason for catastrophic consequences. We analyze whether desert mineral dust, known to be very efficient ice nuclei and present along both aircraft routes, could further augment the icing process. Using numerical simulations performed by a coupled atmosphere-dust model with an included parameterization for ice nucleation triggered by dust aerosols, we show that the predicted ice particle number sharply increases at approximate locations and times of accidents where desert dust was brought by convective circulation to the upper troposphere. We propose a new icing parameter which, unlike existing icing indices, for the first time includes in its calculation the predicted dust concentration. This study opens up the opportunity to use integrated atmospheric-dust forecasts as warnings for ice formation enhanced by mineral dust presence.

scholarly journals Pseudomonas syringae Strains Naturally Lacking the Classical P. syringae hrp/hrc Locus Are Common Leaf Colonizers Equipped with an Atypical Type III Secretion System

2010 ◽  
Vol 23 (2) ◽  
pp. 198-210 ◽  
Author(s):  
Christopher R. Clarke ◽  
Rongman Cai ◽  
David J. Studholme ◽  
David S. Guttman ◽  
Boris A. Vinatzer
Keyword(s):  
Pseudomonas Syringae ◽  
Type Iii Secretion ◽  
Plant Cells ◽  
Type Iii Secretion System ◽  
Ice Nucleation ◽  
Secretion System ◽  
Effector Proteins ◽  
Population Densities ◽  
Type Iii ◽  
Effector Genes

Pseudomonas syringae is best known as a plant pathogen that causes disease by translocating immune-suppressing effector proteins into plant cells through a type III secretion system (T3SS). However, P. syringae strains belonging to a newly described phylogenetic subgroup (group 2c) are missing the canonical P. syringae hrp/hrc cluster coding for a T3SS, flanking effector loci, and any close orthologue of known P. syringae effectors. Nonetheless, P. syringae group 2c strains are common leaf colonizers and grow on some tested plant species to population densities higher than those obtained by other P. syringae strains on nonhost species. Moreover, group 2c strains have genes necessary for the production of phytotoxins, have an ice nucleation gene, and, most interestingly, contain a novel hrp/hrc cluster, which is only distantly related to the canonical P. syringae hrp/hrc cluster. This hrp/hrc cluster appears to encode a functional T3SS although the genes hrpK and hrpS, present in the classical P. syringae hrp/hrc cluster, are missing. The genome sequence of a representative group 2c strain also revealed distant orthologues of the P. syringae effector genes avrE1 and hopM1 and the P. aeruginosa effector genes exoU and exoY. A putative life cycle for group 2c P. syringae is discussed.

scholarly journals Effects of atmospheric conditions on ice nucleation activity of <i>Pseudomonas</i>

2012 ◽  
Vol 12 (22) ◽  
pp. 10667-10677 ◽  
Author(s):  
E. Attard ◽  
H. Yang ◽  
A.-M. Delort ◽  
P. Amato ◽  
U. Pöschl ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Pseudomonas Syringae ◽  
Ice Nucleation ◽  
Acidic Ph ◽  
Bacterial Cells ◽  
Atmospheric Conditions ◽  
Ice Nucleation Protein ◽  
Ice Melt ◽  
Nucleation Activity ◽  
Ice Nucleation Activity

Abstract. Although ice nuclei from bacterial origin are known to be efficient at the highest temperatures known for ice catalysts, quantitative data are still needed to assess their role in cloud processes. Here we studied the effects of three typical cloud conditions (i) acidic pH (ii) NO2 and O3 exposure and (iii) UV-A exposure on the ice nucleation activity (INA) of four Pseudomonas strains. Three of the Pseudomonas syringae strains were isolated from cloud water and the phyllosphere and Pseudomonas fluorescens strain CGina-01 was isolated from Antarctic glacier ice melt. Among the three conditions tested, acidic pH caused the most significant effects on INA likely due to denaturation of the ice nucleation protein complex. Exposure to NO2 and O3 gases had no significant or only weak effects on the INA of two P. syringae strains whereas the INA of P. fluorescens CGina-01 was significantly affected. The INA of the third P. syringae strain showed variable responses to NO2 and O3 exposure. These differences in the INA of different Pseudomonas suggest that the response to atmospheric conditions could be strain-specific. After UV-A exposure, a substantial loss of viability of all four strains was observed whereas their INA decreased only slightly. This corroborates the notion that under certain conditions dead bacterial cells can maintain their INA. Overall, the negative effects of the three environmental factors on INA were more significant at the warmer temperatures. Our results suggest that in clouds where temperatures are near 0 °C, the importance of bacterial ice nucleation in precipitation processes could be reduced by some environmental factors.

A cladistic revision of Tortopus Needham & Murphy with description of the new genus Tortopsis (Ephemeroptera: Polymitarcyidae)

Zootaxa ◽  
2010 ◽  
Vol 2481 (1) ◽  
Author(s):  
CARLOS MOLINERI
Keyword(s):  
Phylogenetic Analysis ◽  
Fore Wing ◽  
Type Species ◽  
New Genus ◽  
Lateral View ◽  
Median Line ◽  
Male And Female ◽  
Line Drawings ◽  
Neotropical Species ◽  
First Time

The 12 species previously placed in Tortopus together with 3 species newly described here, are revised and included in a phylogenetic analysis. Based on synapomorphic characters on the nymphs and adults of both sexes, Tortopus is restricted to T. igaranus Needham & Murphy, T. circumfluus Ulmer, T. harrisi Traver, T. zottai (Navás), T. bellus Lugo-Ortiz & McCafferty, and T. arenales sp. nov., and the genus is defined by: female parastyli receptors with long furrows anterior to sockets; penes entirely flattened; male ninth abdominal sternum almost separated in two portions by a median notch; mesosternum with furcasternal protuberances contiguous only on basal corner; and nymphs with two subapical tubercles on mandibular tusks. Tortopsis is newly described for T. bruchianus (Navás), T. limoncocha sp. nov., T. obscuripennis (Domínguez), T. parishi (Banks), T. primus (McDunnough), T. puella (Pictet), T. sarae (Domínguez), T. spatula sp. nov., and T. unguiculatus (Ulmer). Tortopsis is characterized by: R sector of female fore wing without additional veins between R 2 and IR; female parastyli receptors C or V-shaped, with sockets opening towards median line; male gonopore associated with a claw-like structure; penes separated from the base; parastyli more than 5 times length of pedestals; parastyli curved in lateral view; nymphs with a single subapical tubercle on mandibular tusks. The study of available type material permitted inclusion of comparative diagnoses, with figures and redescriptions as needed. The male imago of the type species of Tortopus (T. igaranus Needham & Murphy) is described for the first time, as are the female adults of Tortopus bellus Lugo-Ortiz & McCafferty and T. harrisi Traver. Three new Neotropical species based on male and female adults are described: Tortopus arenales and Tortopsis limoncocha from Ecuador, and Tortopsis spatula from Colombia. Keys to separate the adults and nymphs of the genera of Polymitarcyidae, and for male and female adults of all the species of Tortopus and Tortopsis are presented, as well as line drawings, pictures and SEM photographs of important structures.

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