The phylogeographical architecture of Spermophilus citellus is expected to shed light on the putative long-term presence of the steppic ecosystem in SE Europe. Among 31 cyt b haplotypes, three highly divergent phylogenetic lineages were recognized. The estimated time for the deepest divergence is 0.58 Mya, suggests the long-term persistence of a short-grass steppic refugium in the southern Balkans. The three phylogeographical lineages of the European ground squirrel should be regarded as independent units for conservation management purposes.
COBISS.SI-ID: 1584595
The spatial distribution of breeding resources can have pronounced demographic and evolutionary consequences. We used 20 experimental groups of the bitterling (Rhodeus amarus), an annual fish with a promiscuous, resource-based mating system, and extended breeding season to investigate how the spatial distribution (clumped or regular) of bitterling oviposition sites (live freshwater mussels) affected offspring production, variation in reproductive success, and directional selection on phenotypic traits over their entire reproductive lifetime. We did not detect any effect of resource distribution on offspring production or variation in reproductive success among individual fish, although variation between replicates was higher with a clumped distribution. Breeding resource distribution had a significant effect on selection on male phenotypic traits. Stronger directional selection on traits associated with intrasexual competition for fertilizations, gonad mass (an indicator of sperm competition), and the extent of red, carotenoid-based pigment in the iris (an index of dominance status), was detected with a clumped resource distribution. With a regular resource distribution, a stronger positive selection on male body size was detected.
COBISS.SI-ID: 1655251
Current agricultural practice favours winter cover crops, which can not only optimize N management in field crop rotation; but also affect subsequent crops. Three field experiments were carried out in Eastern Slovenia to examine the effects of Italian ryegrass (Lolium multiflorum Lam.), winter rape (Brassica napus ssp.oleifera (Metzg.) Sinsk), subclover (Trifolium subterraneum L.), and crimson clover (Trifolium incarnatum L.) as winter cover crops on the mineral N (N(min)) content of soil and on the yield and N content of subsequent maize (Zea mays L.), fertilized with 120kg N ha(-1). Italian ryegrass and winter rape decreased soil N(min) contents before winter and in spring more than both clovers. In contrast, clovers accumulated significantly higher amounts of N in organic matter and had lower C/N ratios than winter rape and especially Italian ryegrass. In comparison to the control (bare fallow without cover crop), clovers increased the whole above ground maize dry matter yield, maize grain yield and N contents in whole above ground plants and in grain. The yields and N contents of maize following winter rape were on the same level as the control, while yields and N contents of maize following Italian ryegrass were, in two of the experiments, at the same level as the control. The effects of Italian ryegrass on the maize as subsequent crop in the third experiment were markedly negative. Maize in the control treatment exploited N much more efficiently than in treatments with cover crops. Therefore, cover crop N management should be improved, especially with a view to optimizing the timing of net N mineralization in accordance with the N demands of the subsequent crop.
COBISS.SI-ID: 2795052
We investigated the phylogenetic position the Ohiya rat, endemic to Sri Lanka, Srilankamys (Rodentia, Murinae), within the tribe Rattini based on the combined analysis of three independent genes (a mitochondrial one and two nuclear exons). Srilankamys was not affiliated to any of the representatives of the Dacnomys division, but clearly appeared as the first genus to diverge among the Rattus division. Molecular date of divergence between Srilankamys and the other representatives of the Rattus division falls within the interval 6.7 +- 0.74 Mya, coinciding with the time of the isolation of Sri Lanka from the Deccan peninsula and the aridification period owing to the climate change at the end of the Miocene epoch.
COBISS.SI-ID: 2081491
Genus Talpa shows high levels of endemism. Majority of small range species have ranges which overlap with the classical Mediterranean refugia. We assessed the molecular systematics of the genus using the mitochondrial cytochrome b gene from 8 of the 9 extant species. Results suggest a monophyletic origin of the genus and a common ancestor for the western moles while the eastern species are basally divergent. The estimated ages of divergence among lineages are in accordance with a Miocene origin of the extant moles and speciation events during the Miocene and the Pliocene.
COBISS.SI-ID: 1773011