Morphological and molecular characterisation of Longidorus juglans sp. nov. and a sister species L. fangi Xu & Cheng, 1991 (Nematoda: Longidoridae) from China

Nematology ◽  
2017 ◽  
Vol 19 (8) ◽  
pp. 951-970 ◽  
Author(s):  
Yumei Xu ◽  
Kai Guo ◽  
Weimin Ye ◽  
Jianming Wang ◽  
Jingwu Zheng ◽  
...  

Longidorus juglanssp. nov. is a new needle nematode detected from the rhizosphere of a walnut tree in Shanxi Province, P.R. China. It was distinguished by female body length of 3.9-5.2 mm; lip region 14-18 μm wide, rounded and continuous, amphidial fovea pocket-shaped without distinct basal lobes; moderately long odontostyle (125-140 μm); guide ring at mid-odontostyle and situated 69-78 μm from anterior end; short and blunt conoid tail (30-41 μm long, c = 118-147, c′ = 0.6-0.9), bearing 2-3 caudal pores on each side. The male ofL. juglanssp. nov. is 5.1 mm long, with 13 ventro-median supplements, a short and blunt conoid tail bearing 3-4 caudal pores on each side, and spicules 73 μm long. Three developmental juvenile stages were recognised. This new species is very similar to another Chinese speciesL. fangiin general morphology, but can be distinguished by the number of juvenile stages and DNA sequences of SSU, ITS1, ITS2 and D2-D3 of LSU rDNA. Morphological and molecular characterisation was provided forL. fangirepresenting two new geographical records. The phylogenetic relationships among these species were analysed using data from SSU, D2-D3 of LSU, ITS1 and ITS2 rDNA, which revealed thatL. juglanssp. nov. andL. fangiwere clustered together withL. diadecturus,L. litchiiandL. jonesiwhose guide ring is located at mid-odontostyle level.

Nematology ◽  
2018 ◽  
Vol 20 (7) ◽  
pp. 617-639 ◽  
Author(s):  
Yumei Xu ◽  
Weimin Ye ◽  
Jianming Wang ◽  
Zengqi Zhao

Summary Longidorus pinus sp. n. from China is characterised by females 3.3-4.9 mm long; lip region 8-12 μm diam., distinctly offset by a constriction; amphidial fovea pocket-shaped without basal lobes; a short odontostyle (67-81 μm); anteriorly located guide ring (30-38 μm); and short and conoid tail (31-40 μm long, c = 84-138, c′ = 1.2-1.9), with one or two pairs of caudal pores on each side. Males were not found. Three developmental juvenile stages were identified, the first-stage juvenile with conoid tail (c′ = 2.4-2.9). The polytomous key codes for the new species are: A2(3), B1, C23, D4, E1, F2, G23, H23, I1, J2, K6. Molecular phylogenetic analyses based on SSU, D2-D3 of LSU, ITS1 and ITS2 rDNA sequences indicate that L. pinus sp. n. is closely related to L. hangzhouensis, L. asiaticus, and L. camelliae, all of which apparently share a common Asiatic geographic origin. In addition, a key for identification of Longidorus found in China, based on morphological characters of both female and first-stage juvenile, is provided.


Nematology ◽  
2021 ◽  
pp. 1-23
Author(s):  
Mei Na Liu ◽  
Yu Mei Xu ◽  
Zeng Qi Zhao ◽  
Jian Ming Wang

Summary This paper describes a new species of Bastiania, presents a new record and redescribes a known species of Tripyla. These nematodes are all in the order Triplonchida and were collected from Shanxi Province, North China. Bastiania sinensis sp. n. is characterised by having the female with a relatively slender body 1049-1295 μm long, dorsally arcuate after heat relaxation, with outer labial setae and cephalic setae in a single circle, an oval amphid, 7-8 laterodorsal cervical setae scattered in the pharyngeal region, orthometamenes and pseudocoelomocytes present, tail conoid with a mucron 1-2 μm long, two pairs of caudal setae present, a = 58.1-75.5, b = 4.0-4.6, c = 12.7-19.7, c′ = 4.1-7.8 and V = 61.1-67.7. Males were not found. Tripyla aquatica is recorded for the first time from China, and is redescribed. Tripyla setifera has been reported from China but without a detailed description – now provided. In addition, phylogenetic relationships among the species were analysed using data from the near full length small subunit (SSU) and D2-D3 segments of large subunit (LSU) of rRNA genes. Bastiania sinensis sp. n. is monophyletic with the Bastiania sequences available in GenBank, but is on an independent branch supporting its status as a separate species; T. aquatica and T. setifera are monophyletically clustered with known Tripyla species and grouped together with sequences from their respective species.


2018 ◽  
Vol 32 (5) ◽  
pp. 1102 ◽  
Author(s):  
M. Bo ◽  
M. Barucca ◽  
M. A. Biscotti ◽  
M. R. Brugler ◽  
A. Canapa ◽  
...  

The Mediterranean black coral fauna includes type species of four antipatharian genera belonging to four different families, therefore phylogenetic studies hold great potential for enhancing systematics within the order. The analysis of six Mediterranean antipatharian species by means of nuclear sequence data of internal transcribed spacer (ITS1 and ITS2) rDNA confirms the separation into different families, as was previously noted on a morphological basis, with a clear distinction of the family Leiopathidae, whose position is supported by a unique number of mesenteries and lack of spines on thicker ramifications. The position of a newly recorded black coral species for the Mediterranean basin belonging to the genus Phanopathes is discussed. Antipathes dichotoma, the type species of the genus Antipathes, on which the order Antipatharia was based, does not group with other members of the family Antipathidae. Supporting a recent finding based on mitochondrial markers, this suggests a critical need for revision of the families that will be impacted by reassignment of this nomenclaturally important taxon.


Plant Disease ◽  
2002 ◽  
Vol 86 (7) ◽  
pp. 814-814 ◽  
Author(s):  
D. M. Woods ◽  
M. J. Pitcairn ◽  
D. G. Luster ◽  
W. L. Bruckart

Musk thistle, Carduus nutans L., is an introduced weed of pastures, rangelands, and natural areas in much of North America. Puccinia carduorum Jacky, an autoecious rust fungus from Turkey, has been evaluated for biological control of musk thistle since 1978, including a field study near Blacksburg, VA, from 1987 to 1990. After release of the fungus in Virginia, rusted musk thistle was found in eight eastern states by 1992, in Missouri by 1994 (1), and in Oklahoma by 1997 (2). A rust disease was discovered on musk thistle near Mt. Shasta, CA, on 22 September 1998, and near Mogul, NV, on 12 August 1999. The pathogen was identified as P. carduorum on the basis of pathogenicity on musk thistle and urediniospore morphology (ovate spores, 21 μm diameter, three germ pores equatorial in location, and echinulations over the upper two-thirds to three-quarters of urediniospores). Ribosomal RNA internal transcribed spacer DNA sequences (ITS1 and ITS2) were identical to those from the isolate obtained after the field release in Virginia, verifying that the California isolate is P. carduorum. The initial California infestation was observed on a few plants late in the season, and by September 2000, nearly 100% of plants were infected. The occurrence of P. carduorum in California is apparently the result of natural, unaided spread of the fungus on musk thistle from the East Coast of the United States. References: (1) A. B. A. M. Baudoin and W. L. Bruckart. Plant Dis. 80:1193, 1996. (2) L. J. Littlefield et al. Plant Dis. 82:832, 1998.


Nematology ◽  
2012 ◽  
Vol 14 (1) ◽  
pp. 109-119 ◽  
Author(s):  
Majid Pedram ◽  
Ebrahim Pourjam ◽  
Robert T. Robbins ◽  
Weimin Ye ◽  
Mohammad Reza Atighi ◽  
...  

Xiphinema mazandaranense n. sp. is described and illustrated. The new species belongs to morphospecies group 6, which is characterised by having two equally developed female genital branches that have spines in the uteri and a short, rounded tail. The new species is characterised by having spines in the tubular portion of the uterus, body 3.7-5.2 mm long, odontostyle 163-173 μm long, odontophore 96-100 μm long, body 62-80 μm diam., rounded tail, four juvenile stages, males rare with three ventromedian supplements next to the adcloacal pair and spicules 85 μm long. The polytomous identification codes of the new species are: A4-B3-C7b-D6-E456-F45-G4-H2-I23-J7b-K2-L1. The new species appears closely related to the members of X. pyrenaicum group which are characterised by a rounded tail with or without an inconspicuous projecting bulge and a uterus devoid of Z-differentiation but showing spiniform structures. The new species differs from members of the X. pyrenaicum group, which includes the recently described X. iranicum, by a more rounded tail without any projection. Beside morphological and morphometric data, molecular analyses of the near-full-length small subunit rDNA gene (SSU) placed the new species in close relationship with some species belonging to Xiphinema morphospecies group 6 and further separated this species from the X. pyrenaicum complex.


Author(s):  
Donald L. J. Quicke ◽  
Buntika A. Butcher ◽  
Rachel A. Kruft Welton

Abstract This chapter provides more information on manipulating text, presenting two examples. Example 1 focuses on standardizing names in a phylogenetic tree description, using R to reformat taxon names, create lists, sort data and use wildcards for when some things you are interested in don't have exactly the same length. The example tree description concerns parasitoids of caterpillars at a study site that have been DNA barcoded and their possible taxonomic identities added automatically. Example 2 deals with substrings of unknown length. This example search for a numeric substring of unknown length but with a standard prefix, using data of some DNA sequences from a set of Aleiodes wasps. The trimming of white spaces and/or tabs, use of wildcards to locate internal letter strings, finding of suffixes, prefixes and specifying of letters, numbers and punctuation, manipulation of character case, ignoring of character case, and specifying of particular and modifiable character classes are briefly described.


Nematology ◽  
2009 ◽  
Vol 11 (5) ◽  
pp. 719-737 ◽  
Author(s):  
Oleksandr Holovachov ◽  
Sven Boström ◽  
Manuel Mundo-Ocampo ◽  
Irma Tandingan De Ley ◽  
Melissa Yoder ◽  
...  

Abstract Hemiplectus muscorum, the type and single representative of its genus, is redescribed on the basis of abundant new material collected in the UK, Canada and the USA using both light and scanning electron microscopy. The phylogenetic relationships of the species are inferred from morphological as well as molecular data. Maximum parsimony, neighbour joining and maximum likelihood analyses of small subunit (SSU) rRNA sequences support a position nested among the Plectidae. This conflicts with our morphological assumptions of character polarity, as it implies that the absence of a valvate bulb in Hemiplectus is a reversal rather than a plesiomorphy. The excretory system of Hemiplectus is described more precisely. Its structure is highly reminiscent of the system in Plectus but differs in the presence of an anterior and posterior pair of pseudocoelomocytes flanking the renette cell. A pair of lateral somatic setae is identified as possible homologues of the 'deirids' in Plectus and Rhabditida. Measurements and descriptions are given of all four juvenile stages.


1999 ◽  
Vol 31 (05) ◽  
pp. 477 ◽  
Author(s):  
Natalia V. Ivanova ◽  
Paula T. Depriest ◽  
Vera K. Bobrova ◽  
Alexey V. Troitsky

Parasitology ◽  
2012 ◽  
Vol 139 (10) ◽  
pp. 1346-1360 ◽  
Author(s):  
KIRILL V. GALAKTIONOV ◽  
ISABEL BLASCO-COSTA ◽  
PETER D. OLSON

SUMMARYThe ‘pygmaeus’ microphallids (MPG) are a closely related group of 6 digenean (Platyhelminthes: Trematoda) Microphallus species that share a derived 2-host life cycle in which metacercariae develop inside daughter sporocysts in the intermediate host (intertidal and subtidal gastropods, mostly of the genus Littorina) and are infective to marine birds (ducks, gulls and waders). Here we investigate MPG transmission patterns in coastal ecosystems and their diversification with respect to historical events, host switching and host-parasite co-evolution. Species phylogenies and phylogeographical reconstructions are estimated on the basis of 28S, ITS1 and ITS2 rDNA data and we use a combination of analyses to test the robustness and stability of the results, and the likelihood of alternative biogeographical scenarios. Results demonstrate that speciation within the MPG was not associated with co-speciation with either the first intermediate or final hosts, but rather by host-switching events coincident with glacial cycles in the Northern Hemisphere during the late Pliocene/Pleistocene. These resulted in the expansion of Pacific biota into the Arctic-North Atlantic and periodic isolation of Atlantic and Pacific populations. Thus we hypothesize that contemporary species of MPG and their host associations resulted from fragmentation of populations in regional refugia during stadials, and their subsequent range expansion from refugial centres during interstadials.


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