Rapid ecological change in the coastal zone of Lake Baikal (East Siberia): Is the site of the world\u27s greatest freshwater biodiversity in danger?

Ecological degradation of the benthic littoral zone is an emerging, urgent problem at Lake Baikal (East Siberia), the most species-rich lake on Earth. Within the last five years, multiple changes have occurred in the nearshore benthos where most of the lake\u27s endemic species reside. These changes include proliferation of benthic algae, deaths of snails and endemic sponges, large coastal wash-ups of dead benthic algae and macrophytes, blooms of toxin-producing benthic cyanobacteria, and inputs of industrial contaminants into parts of the lake. Some changes, such as massive coastal accumulations of benthic algae, are currently shared with the Laurentian Great Lakes (LGLs); however, the drivers of these changes differ between Lake Baikal and the LGLs. Coastal eutrophication from inputs of untreated sewage is causing problems at multiple sites in Lake Baikal, whereas in the LGLs, invasive dreissenid mussels redirect pelagic nutrients to the littoral substrate. At other locations in Lake Baikal, ecological degradation may have different causes including water level fluctuations and the input of toxic industrial contaminants. Importantly, the recent deterioration of the benthic littoral zone in both Lake Baikal and the LGLs has occurred while little change has occurred offshore. This highlights the necessity of monitoring both the littoral and pelagic zones of large lakes for assessing ecosystem health, change and conservation

New varieties of winter rye of intensive type

The work of breeders of the Leningrad Research Institute of Agriculture Belogorka on the creation of new short-stature varieties of intensive type winter rye, characterized by increased resistance to adverse soil and climatic conditions of northern Europe is briefly described. The methods of selection used in the institute are presented, including the method of directed transpollination of crops “on a flower bed” developed in the winter rye laboratory. The characteristic of new varieties based on economic and useful features and on the main elements of the crop structure is given. It was shown that the new varieties significantly exceeded the standard Volkova variety in winter and lodging resistance, which allows obtaining a stable grain harvest even in unfavorable years. In addition, new varieties are characterized by the size and uniformity of seeds at the weight of 1000 grains 38–42 g, practically not inferior in this indicator to tetraploid and hybrid varieties of winter rye, which are more demanding of cultivation conditions

THE PHYTO SANITARY SITUATION OF SPRING WHEAT SOWINGS IN THE NORTH-WEST OF NON BLACK EARTH (NECHERNOZEMIE) AREA

The conducted researches estimated a present phyto sanitary situation of spring wheat sowings in the north-west of Non Black earth area. A phyto sanitary situation is usually characterized with an average level of weediness, moderate infection with leaf diseases, and slight damage with pests. The varietal composition of harmful organisms and the species of economic value for spring wheat cultivation have been clarified for the region. They are 7 kinds of weeds, larvae of click beetles, Swedish oats fly and cereal aphids, powdery mildew, septoriosis, brown leaf rust. The article considers the change of the phyto sanitary situation under the influence of a variety, a forecrop, sowing terms and seeding rates, fertilizing. The varieties of foreign breeding are more susceptible to the local infectants that results in their strong infection with leaf diseases. The choice of a forecrop effects on a weediness of spring wheat and a damage of its sprouts with wireworms. The most favorable and popular forecrop for spring wheat is potatoes, the most unfavorable forecrop are perennial grasses. The late sowing terms of the crop worsen the situation with phyto pathogens. The grain infection with funguses increases that result in a black head, mold and root rot. The reduced sowing rates of spring wheat increase the weediness of spring wheat. Fertilizing promotes the formation of large phyto mass of weeds, increases the infection of plants with leaf diseases. The fields surrounded with forests are more resistant to pests, but less resistant to leaf diseases

Fifteen shades of green: The evolution of Bufotes toads revisited.

The radiation of Palearctic green toads (Bufotes) holds great potential to evaluate the role of hybridization in phylogeography at multiple stages along the speciation continuum. With fifteen species representing three ploidy levels, this model system is particularly attractive to examine the causes and consequences of allopolyploidization, a prevalent yet enigmatic pathway towards hybrid speciation. Despite substantial efforts, the evolutionary history of this species complex remains largely blurred by the lack of consistency among the corresponding literature. To get a fresh, comprehensive view on Bufotes phylogeography, here we combined genome-wide multilocus analyses (RAD-seq) with an extensive compilation of mitochondrial, genome size, niche modelling, distribution and phenotypic (bioacoustics, morphometrics, toxin composition) datasets, representing hundreds of populations throughout Eurasia. We provide a fully resolved nuclear phylogeny for Bufotes and highlight exceptional cyto-nuclear discordances characteristic of complete mtDNA replacement (in 20% of species), mitochondrial surfing during post-glacial expansions, and the formation of homoploid hybrid populations. Moreover, we traced the origin of several allopolyploids down to species level, showing that all were exclusively fathered by the West Himalayan B. latastii but mothered by several diploid forms inhabiting Central Asian lowlands, an asymmetry consistent with hypotheses on mate choice and Dobzhansky-Muller incompatibilities. Their intermediate call phenotypes potentially allowed for rapid reproductive isolation, while toxin compositions converged towards the ecologically-closest parent. Across the radiation, we pinpoint a stepwise progression of reproductive isolation through time, with a threshold below which hybridizability is irrespective of divergence (<6My), above which species barely admix and eventually evolve different mating calls (6-10My), or can successfully cross-breed through allopolyploidization (>15My). Finally, we clarified the taxonomy of Bufotes (including genetic analyses of type series) and formally described two new species, B. cypriensis sp. nov. (endemic to Cyprus) and B. perrini sp. nov. (endemic to Central Asia). Embracing the genomic age, our framework marks the advent of a new exciting era for evolutionary research in these iconic amphibians

Fifteen shades of green: The evolution of Bufotes toads revisited

The radiation of Palearctic green toads (Bufotes) holds great potential to evaluate the role of hybridization in phylogeography at multiple stages along the speciation continuum. With fifteen species representing three ploidy levels, this model system is particularly attractive to examine the causes and consequences of allopolyploidization, a prevalent yet enigmatic pathway towards hybrid speciation. Despite substantial efforts, the evolutionary history of this species complex remains largely blurred by the lack of consistency among the corresponding literature. To get a fresh, comprehensive view on Bufotes phylogeography, here we combined genome-wide multilocus analyses (RAD-seq) with an extensive compilation of mitochondrial, genome size, niche modelling, distribution and phenotypic (bioacoustics, morphometrics, toxin composition) datasets, representing hundreds of populations throughout Eurasia. We provide a fully resolved nuclear phylogeny for Bufotes and highlight exceptional cyto-nuclear discordances characteristic of complete mtDNA replacement (in 20% of species), mitochondrial surfing during post-glacial expansions, and the formation of homoploid hybrid populations. Moreover, we traced the origin of several allopolyploids down to species level, showing that all were exclusively fathered by the West Himalayan B. latastii but mothered by several diploid forms inhabiting Central Asian lowlands, an asymmetry consistent with hypotheses on mate choice and Dobzhansky-Muller incompatibilities. Their intermediate call phenotypes potentially allowed for rapid reproductive isolation, while toxin compositions converged towards the ecologically-closest parent. Across the radiation, we pinpoint a stepwise progression of reproductive isolation through time, with a threshold below which hybridizability is irrespective of divergence (15My). Finally, we clarified the taxonomy of Bufotes (including genetic analyses of type series) and formally described two new species, B. cypriensis sp. nov. (endemic to Cyprus) and B. perrini sp. nov. (endemic to Central Asia). Embracing the genomic age, our framework marks the advent of a new exciting era for evolutionary research in these iconic amphibians.status: publishe