Intraspecific structure of the Coregonus lavaretus complex in water bodies of Siberia: a case of postglacial allopatric origin of Yukagirian whitefish

The results of morphological and genetic analyses of forms/species of the Coregonus lavaretus pidschian (Gmelin, 1789) complex from the Indigirka and Kolyma river basins are presented in the context of there being recent postglacial speciation events. It has been found that the studied whitefishes belong to the sparsely rakered and low lateral-line forms and have previously been described as Coregonus lavaretus pidschian n. jucagiricus Drjagin (Berg), 1932. Based on these characters, this whitefish does not differ from most Arctic whitefish populations (in particular from Coregonus lavaretus glacialis Kirillov, 1972). Analysis of variability of the ND1 gene (mtDNA) showed that whitefishes from the Indigirka and Kolyma basins belong to a distant phylogenetic lineage, which is significantly different from all previously studied whitefish lineages from the Ob, Yenisei, Lena, Anadyr, and Amur river basins. Analysis of variability of the ITS1 fragment (nDNA) showed that all studied forms/species (from Ob River to Amur River basins), including C. l. pidschian n. jucagiricus, have a tandem arrangement of two identical nucleotide fragments and very similar nucleotide composition of the ITS1 region. Based on contemporary data, this phylogenetic lineage of the C. pidschian complex could be considered a young postglacial allopatric species.

Evidence of dispersal between the Yenisei and the Lena river basins during the late Pleistocene within the whitefish (Coregonus lavaretus pidschian) complex

The Coregonus lavaretus (Linnaeus, 1758) complex is a morphologically and genetically diverse group of whitefish. Its taxonomic structure has been controversial for almost a century. At least 25 forms of C. lavaretus have been described in Siberia, but there is still no consensus on their intraspecific structure and taxonomy. Coregonus lavaretus pidschian (Gmelin, 1789) was described as a subspecies of C. lavaretus. Recently, it was assumed that this subspecies is also a complex. The purpose of this study was to compare the distributions of pidschian-like whitefish haplotypes in two basins of large Siberian rivers, Yenisei and Lena, and to assess the gene flow between basins of these rivers, which were connected after the last glaciation. The sequence of the following mitochondrial DNA genes, 16S rRNA (partial), tRNA-Leu (full), NADH dehydrogenase subunit 1 (full), tRNA-Ile (full), and tRNA-Gln (partial), were used for the inference of intraspecific genetic structure of C. l. pidschian. Whitefish haplotypes were clustered into two groups according to their distribution between two large Siberian river basins; however, there were shared haplotypes indicating events of migration and hybridization, which could occur when Bolshoi Yenisei and Lena river systems were connected after the last glaciation (the Late Pleistocene).

Biotic Relations Between Pathogenic Leptospires And Green Algae

Leptospira interrogans spirochetes belong to a group of pathogens of particularly dangerous infections that cause leptospirosis in many species of wild, farm and domestic animals, as well as humans. Significant economic damage caused by this disease to livestock around the world, numerous cases of death from leptospirosis, and mainly waterborne transmission of the infection determine the topicality of studying all the aspects of the existence of L. interrogans in freshwater ecosystems. The objective of our study was to determine the nature of ecological relationships between L. interrogans and green algae. We used green algae of the Desmodesmus brasiliensis species as a model object. In the experiments, sterile algae culture filtrates were added to L. interrogans containers grown at 27–28 °C. Comparison of the content of spirochete cells in the experiment and control samples, conducted 24 hours after exposure, showed that the reproduction of L. interrogans is markedly inhibited in the samples containing algae secretions at the dilutions of 1:10 and 1:100. In order to reduce resistance to the allelopathic influence of D. brasiliensis algae, leptospira strains were located as follows: Pomona, Australis, Hebdomadis, Canicola, Sejroe, Icterohaemorrhagiae, Grippotyphosa, Tarassovi. The obtained results indicate a complex intraspecific structure of L. interrogans and their high ecological plasticity. In addition, experimental data indicate that, due to the release of biologically active substances into the aquatic environment, green algae have the potential to affect the dynamics of a number of leptospirosis pathogens in situ. Given the important epidemiological and epizootic significance of pathogenic leptospira, further research is necessary to determine the patterns of their interactions and existence in the environment.

Genome-wide markers redeem the lost identity of a heavily managed gamebird

Heavily managed wildlife may suffer from genetic homogenization and reshuffling of locally adapted genotypes with non-native ones. This phenomenon often affects natural populations by reducing their evolutionary potential and speeding up the ongoing biodiversity crisis. For decades, the red-legged partridge ( Alectoris rufa ), an intensively managed gamebird of conservation concern and considerable socio-economic importance, has been subjected to extensive releases of farm-reared hybrids with the chukar partridge ( Alectoris chukar ) and translocations irrespective of subspecific affinity. These practices have led to serious concerns that the genetic integrity and biogeographic structure of most red-legged partridge populations are irreversibly affected, as suggested by previous studies based on few genetic markers. Using over 168 000 genome-wide loci and a sampling across the entire A. rufa range, we detected unexpectedly limited and spatially uneven chukar introgression as well as significant intraspecific structure. We demonstrate that species widely feared to have irretrievably lost their genetic identity are likely to be much less affected by unsuitable management practices than previously assumed. Our results spell the need for a radical re-think on animal conservation, possibly restoring native status to populations long treated as compromised. Our study exemplifies how the application of innovative conservation-genomic methods is key to solving wildlife management problems dealing with introgressive hybridization worldwide.

Long-term trends in distribution and regional composition of the catches of hatchery pink and chum salmon during autumn migrations in the basin of the Sea of Okhotsk

Long-term trends in distribution and regional composition of the catches of hatchery pink and chum salmon during autumn post-catadromous migrations in the basin of the Sea of Okhotsk in 2011–2017 were evaluated based on the otolith marking data. Qualitative and intraspecific structure of the hatchery fish aggregations was analyzed in connection to the interannual variety in forming abundant and not abundant generations of pink salmon. The analyze is carried out allowed to find out that the aggregation density of Russian and Japan hatchery juvenile chum salmon in the eastern part of the Sea of Okhotsk is higher in the even years of observation. Along that the distribution of the active migrants of the Sakhalin-Kurile and Hokkaido stock complexes in the north-east direction withing the Okhotsk Sea basin is better expressed. We think, that the main reason is low abundance of pink salmon generations (odd years of spawning) on West Kamchatka during autumn migration in the even years.In general the results obtained indicate that the cyclic migration of juvenile pink and chum salmon in the basin of the Sea of Okhotsk during post-catadromous migrations is of a systemic and mass character. Hatchery and wild fish have been engaged. The scheme of the juvenile distribution is similar in even and odd years.

Analysis of infection with fungi of the genus Fusarium seed and vegetative organs of crops

Studying the specific and intraspecific structure of populations of causative agents of Fusarium ear of grain crops. The results of experimental studies of samples of grain crops affected by microscopic fungi p.Fusarium. The analysis of the infection of grains, stems and roots of various types of cereals with mitospores fungi was carried out. The variability of pathogenic properties of Fusarium fungi depending on the part of the ear is shown. The results of the research are important for the targeted diagnosis of fusarium of grain crops and plants of the ear.

The intraspecific structure of the Yellow-spotted ringlet Erebia manto (Denis & Schiffermüller, [1775]), with special reference to the bubastis group: an integration of morphology, allozyme and mtDNA data (Lepidoptera, Nymphalidae, Satyrinae)

Present-day intraspecific diversity has largely been shaped by previous climatic events, but the spatial and temporal scales of differentiation processes in most species remain to be clarified. In Europe, the Pleistocene glacial cycles have generated population structures that remain especially evident in montane taxa. The intraspecific variation of the European subalpine Yellow-spotted Ringlet, Erebia manto (Denis & Schiffermüller, [1775]), shows a hierarchical, two-level structure that allows us to study intermediate stages of speciation. Morphologically, three subspecies clusters have been described in this butterfly: the manto, bubastis and vogesiaca type. An allozyme study previously revealed two genetic lineages within the manto type, and two within the vogesiaca type, but lacked bubastis representatives. To further our knowledge of the intraspecific structure of E. manto, we sampled all known and presumed intraspecific groups and sequenced 1,496 base pairs of the mitochondrial gene COI for 152 specimens from 15 localities. A median joining haplotype network, based on 40 parsimony informative sites, confirmed the four allozyme based lineages. The bubastis type was acknowledged as a fifth genetic lineage, replacing the manto type populations in the southern part of the western Alps, and separated from it by a well-known zoogeographic borderline. We discuss how the present-day distributions, genetic relationships and timing of the differentiations align.

Characteristic of the zimoseptoria tritici population by virulence in the of the Central Black Soil region of Russia

Based on the analysis of the intraspecific structure of the fungus Zimoseptoria. tritici, it was found that this species has significant polymorphism. Using monogenic wheat lines (Oasis (Stb1), Veranopolis (Stb2), Israel (Stb3), Tadinia (Stb4), CS / Synthetic (Stb5), Estanzuela Federal (Stb7)), the population of Z. tritici in the Central Black Earth region was tested. High heterogeneity of monosporous isolates of Z. tritici by virulence was revealed.

Genetic Diversity and Place in the General Phylogeographic Structure of Capercaillie, Tetrao Urogallus (Galliformes, Phasianidae), from Belarus

We report on the assessment of the level of genetic diversity of the capercaillie in Belarus. This species of birds is a valuable biological resource, and also acts as a natural indicator for the state of large forests and the degree of their disturbance by human activities. Two subspecies of the capercaillie —Tetrao urogallus major (C. L. Brehm, 1831) and Tetrao urogallus pleskei (Stegmann, 1926) have been described for Belarus. The first domain of the mitochondrial DNA control region was used as the molecular marker for the study. An additional assessment of the level of genetic diversity of the capercaillie was carried out by calculating the effective size of its population (Ne) in Belarus. We found that the absence of subspecific structure is characteristic for all samples of the capercaillie from Belarus. The data on the intraspecific structure and genetic diversity of the capercaillie from Belarus allows us to considerits population in the central and eastern parts of the country as stable and sustainable. This can be explained by its inclusion in the general phylogeographic structure of birds of the boreal lineage. The low values of the effective population size for the partially isolated capercaillie population from the western part of the country indicate the need for increased attention and further monitoring of that population.