scholarly journals Communities of Ditylenchus Destructor Satellite Species of Nematodes in Infected Potato Tubers: Species Composition of Phytonematode Complex and the Structure of their Infracommunities

2019 ◽  
Vol 53 (6) ◽  
pp. 443-458
Author(s):  
D. D. Sigareva ◽  
S. V. Fedorenko ◽  
T. I. Bondar ◽  
O. O. Sokolova ◽  
V. V. Kornyushin

Abstract Within September–April 2016–2017 potato tubers affected by the potato rot nematode Ditylenchus destructor were selected in the potato storage facilities of the Institute of Potato Production of NAAS. 18 species of phytonematodes were identified, including an edificator species of microparasitocenosis and 17 satellite species of this pathogenic phytohelminth, mycohelminths (6 species) and saprobiotic nematodes (11 species). These phytonematodes are representatives of two orders, Rhabditida (11 species from 4 families) and Tylenchida (7 species from 4 families). Nematodes that are part of the group formed by D. destructor and its satellite species are divided into five groups according to quantitative indicators (the prevalence of invasion P and intensity of invasion I). The dominant is one species — D. destructor. Satellite species of D. destructor are divided into four groups, these are subdominants (4 species) and common species (3 species), which together with the dominant species form the core of the group, as well as rare (6) and accidental (4). It was shown that in the course of the disease a regular succession occurs, the species composition of phytonematodes, the grouping structure, the relationship between the number of species of various trophic groups, and the number of certain species change. There are five stages in the course of the disease, from D. destructor colonisation of the tuber, the penetration of the mycohelminths and saprobionts into the focus of the disease, and the disappearance of D. destructor. The maximum number of D. destructor occurs at stage III, mycohelminths — at stage IV, and saprobiotic nematodes — at stage V. Infracommunities consist of from two to seven species. The distribution of all the studied tubers by the number of species in the infracommunity is close to normal, most often 3–4 species of nematodes were found, several species of nematodes of the same genus are extremely rare in a particular infracommunity.

Author(s):  
Yelena Rakhimova

After the revision, it was found that the biota of slime molds in the Ile Alatau (Kazakhstan) has 62 species. The article provides a systematic list of slime molds. In the Ile Alatau these fungi-like organisms are represented by two classes: Protosteliomycetes and Myxomycetes. The Myxomycetes class is more widely represented and has 4 orders. The largest number of species is characteristic of the genera Trichia (8 species), Physarum (6), Arcyria, Diderma (5 species each) and Badhamia (4 species). The most common species in the research area are Lycogala epidendrum, Fuligo septica, Hemitrichia clavata, Trichia varia, Stemonitis axifera, S. fusca, S. splendens and Stemonitopsis typhina. Representatives of slime molds were found on various 18 substrates. The largest number of slime molds species (54) was recorded on Picea schrenkiana. There are 13 species on Populus tremula and 4 species on Betula tianschanica. The remaining substrates are characterized by 1-2 species. It is necessary to note the species of the genus Diderma that appear in early spring after snowfall: Diderma niveum, found on Artemisia juncea and representatives of Poaceae, and D. radiatum on dry grasses, leaves and branches of shrubs.


2016 ◽  
Vol 67 (3) ◽  
pp. 327 ◽  
Author(s):  
James R. Tweedley ◽  
Chris S. Hallett ◽  
Richard M. Warwick ◽  
K. Robert Clarke ◽  
Ian C. Potter

Runoff from an extreme storm on 22 March 2010 led, during the next 3 months, to the formation of a pronounced halocline and underlying hypoxia in the upper reaches of the microtidal Swan–Canning Estuary. Benthic macroinvertebrates were sampled between January 2010 and October 2011 at five sites along 10km of this region. By mid-April, the number of species, total density, Simpson’s evenness index and taxonomic distinctness had declined markedly, crustaceans had disappeared and the densities of annelids and molluscs had declined slightly. These faunal attributes (except Simpson’s index) and species composition did not recover until after the end of the hypoxia. The survival of annelids and loss of crustaceans in this period reflects different sensitivities of these taxa to severe environmental stress. The results emphasise that microtidal estuaries with long residence times are highly vulnerable to the effects of environmental perturbations, particularly during warmer periods of the year.


2000 ◽  
Vol 16 (3) ◽  
pp. 387-415 ◽  
Author(s):  
Igor Debski ◽  
David F. R. P. Burslem ◽  
David Lamb

All stems ≥ 1 cm dbh were measured, tagged, mapped and identified on a 1-ha plot of rain forest at Gambubal State Forest, south-east Queensland, Australia. The spatial patterns and size class distributions of 11 common tree species on the plot were assessed to search for mechanisms determining their distribution and abundance. The forest was species-poor in comparison to many lowland tropical forests and the common species are therefore present at relatively high densities. Despite this, only limited evidence was found for the operation of density-dependent processes at Gambubal. Daphnandra micrantha saplings were clumped towards randomly spaced adults, indicating a shift of distribution over time caused by differential mortality of saplings in these adult associated clumps. Ordination of the species composition in 25-m × 25-m subplots revealed vegetation gradients at that scale, which corresponded to slope across the plot. Adult basal area was dominated by a few large individuals of Sloanea woollsii but the comparative size class distributions and replacement probabilities of the 11 common species suggest that the forest will undergo a transition to a more mixed composition if current conditions persist. The current cohort of large S. woollsii individuals probably established after a large-scale disturbance event and the forest has not attained an equilibrium species composition.


Fisheries ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. 52-60
Author(s):  
Andrey Bykov

Based on the results of comprehensive fisheries research, a brief description of the ecosystem of the lake of the Shaturskaya group operated in the mode of the cooling reservoir of the Shaturskaya GRES is given. The features of the thermal regime of the Shatursky lakes in the zone of the circulating flow of cooled waters are considered. A brief description of the species composition and quantitative indicators of the development of phytoplankton, zooplankton and macrozoobenthos communities is given. The structure of fish catches in the lakes depending on the fishing gear used is considered according to the data of accounting surveys with set nets and fry drag. The process of formation of the ichthyofauna of Shatursky lakes, characteristic of natural and man-made ecosystems of reservoirs-coolers of energy facilities, is shown. The occurrence of native and invasive fish species in catches is described, and the mechanism of seasonal migration of fish depending on the temperature and oxygen regimes of the Shatursky lakes is considered.


2007 ◽  
Vol 19 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Niek J.M. Gremmen ◽  
Bart van de Vijver ◽  
Yves Frenot ◽  
Marc Lebouvier

Altitudinal gradients provide excellent opportunities to study relationships between species distribution and climatic variables. We studied the species composition of 39 samples of moss-inhabiting diatoms, collected at 50 m intervals from 100–650 m above sea level. The samples contained a total of 130 diatom species, of which 51 occurred in 10 or more samples. Altitude appeared to be the most important variable explaining variation in species composition. Of the 51 common species, 33 showed a significant relationship with altitude. Although the majority of the latter declined with increasing altitude, for nine species the probability of occurrence first increased with increasing elevation, but decreased again at higher altitudes, and four species increased systematically with elevation. As a result, expected species richness per sample decreased from an estimated 43 at 100 m to 25 species per sample at 650 m. Diatom distribution patterns proved to be suitable predictors of the altitudinal position of sample sites. Cross-validation yielded a strong relationship between predicted and observed altitudes.


2016 ◽  
Vol 1 (1S) ◽  
Author(s):  
Marta Wojewódka ◽  
Edyta Zawisza ◽  
Sergio Cohuo ◽  
Laura Macario-González ◽  
Antje Schwalb ◽  
...  

<p>Cladocera species composition was analyzed in surface sediments of 29 lakes in Central America (Guatemala, El Salvador and Honduras). The material studied was collected with an Ekman grab in autumn 2013 from lakes located in lowland, highland and mountain regions. The study revealed high variability in qualitative and quantitative composition of subfossil Cladocera. A total of 31 Cladocera species (5 planktonic and 26 littoral) were identified, as well as 4 morphotypes that could not be identified (NRR<em> </em>1-4). Planktonic Bosminidae<em> </em>and<em> </em>Daphniidae were the most abundant families. Daphniidae were restricted to water bodies in mountain regions, whereas Bosminidae were widely distributed in lakes with different abiotic conditions. Moreover, Bosminidae species also occurred in highly mineralized waters (&gt; 900 µS cm<sup>-1</sup>). The great majority of the identified Cladocera species belonged to the littoral family Chydoridae. <em>Chydorus </em>cf.<em> sphaericus</em> was the most common species (found in 20 lakes), which probably reflects its tolerance to a wide spectrum of habitat conditions. Cluster analysis discriminated 6 groups of Cladocera species with a high correlation level within groups (≥0.8), which showed different types of correlation with lake characteristics and environmental variables. Canonical correspondence analysis (CCA) showed that altitude and secondly water electrical conductivity were the most important drivers of Cladocera species composition in the region studied. Furthermore, CCA analysis indicated lowland lakes with low water transparency were also characterized by peculiar species assemblages. <strong></strong></p>


1987 ◽  
Vol 82 (1) ◽  
pp. 119-124 ◽  
Author(s):  
M. Dora Feliciangeli

A study on the ecology of phlebotomine sandfly fauna in a restricted focus of cutaneous leishmaniasis in northern Venezuela was undertaken in order to investigate the species responsible for the transmission. The study area and catching methods for phlebotomine sandflies are described. A total of 9,061 females and 1,662 males were collected during a year-term study. 12 species of Lutzomya and 1 species of Brumptomya sp. were identified. Absolute and relative abundance and ocurrence for each species were determined. The rel ative occurrence allowed to distinguish the common species, viz. L. panamensis, L. ovallesi, L. gomezi, L. tinidadensis, L. atroclavata, L. cayennensis, L. shannoni and L. olmeca bicolor from the rare species vis., L. punctigeniculata, L. rangeliana, L. evansi and L. dubitans. General comments on the species composition of the sandfly fauna in this locality are made.


2014 ◽  
Vol 9 (8) ◽  
pp. 777-795
Author(s):  
Andrzej Szczepkowski ◽  
Błażej Gierczyk ◽  
Anna Kujawa

AbstractIn 2010, 16 macrofungi species were found in greenhouses of the Botanical Garden in Warsaw-Powsin. These included 8 species of lepiotaceous fungi and a few species known from warmer areas. For 3 species identified, which are new to Poland (Agaricus subrufescens, Leucocoprinus heinemannii, Marasmius teplicensis), a description is given, with drawings of their microscopic features and photographs. Species composition of macrofungi is compared in 5 complexes of greenhouses (Bayreuth, Graz, Jena, Paskov, Warsaw) in 4 countries from Central Europe. The total number of species in these 5 studies is 206, including 27 (13.2%) lepiotaceous fungi. The smallest number of species identified was in Warsaw (16). More than twice this number was recorded in Jena (33) and Graz (34), while the richest fungal biotas were in Bayreuth (79) and Paskov (88). Of the 16 species found in Warsaw, 8 were also found in other greenhouses. In the group of 33 species recorded in at least two complexes of greenhouses, the most abundant were the lepiotaceous fungi (39.4%) and mycenaceous fungi (15.1%). Leucocoprinus cepistipes and L. straminellus were recorded most often, in 4 of the 5 studied greenhouse complexes. CCA analysis demonstrated that the highest impact on species diversity is the area of greenhouses.


Check List ◽  
2014 ◽  
Vol 10 (2) ◽  
pp. 335 ◽  
Author(s):  
Nurulhuda Zakaria ◽  
Juliana Senawi ◽  
Fakhrul Hatta Musa ◽  
Daicus Belabut ◽  
Chan Kin Onn ◽  
...  

A revised and updated checklist of the herpetofauna of the Krau Wildlife Reserve (KWR), Pahang is presented, which includes 61 species of amphibians and 65 species of reptiles. Five species of amphibians are listed under revised names i.e. Hylarana labialis, H. picturata, Ansonia latiffi, Microhyla mantheyi and Rhacophorus norhayatae; and two species are listed as new locality records for KWR: Hylarana cf. siberu and Theloderma licin. The amphibians and reptiles recorded in KWR are approximately 56% and 22% of the total number of species recorded from Peninsular Malaysia, respectively.


1987 ◽  
Vol 98 (1) ◽  
pp. 127-130 ◽  
Author(s):  
M. J. Colloff

SUMMARYThe mite fauna of dust from cloth-covered seats of four passenger trains and bedding from a British Rail linen store in Glasgow was investigated; 22 samples containing 4488 mg of dust from a total surface area of 5·5 m2 were taken. Sixteen samples were positive for mites and 33 specimens belonging to 10 species were found. The most common species were Dermatophagoides pteronyssinus (Trouessart), Glycyphagus domesticus (De Geer), G. destructor (Schrank) and Euroglyphus maynei (Cooreman). The species composition bore considerable resemblance to that of house dust (although the density of mites was far lower) and the mites have probably been transported from homes via clothing and pets. Only five intact specimens, which may have been alive at the time of sampling, were found. The dust from trains consisted mostly of particles of soot. Very few skin scales, the food source of house dust mites, were detected. The small numbers of intact mites found and the absence of an identifiable food source make it unlikely that permanent populations of mites survive in upholstered seats on trains.


Sign in / Sign up

Export Citation Format

Share Document