Vladimir Vladimirov

Chromosome counts of Tragopogon L. (Asteraceae) from Turkey

In the present study, mitotic chromosome numbers of 18 Tragopogon taxa from Turkey, including five endemic species, were counted. The plant material originates from 30 populations. The chromosome numbers of T. albinervis (2n = 12), T. dshimilensis (2n = 12), T. oligolepis (2n = 12), T. porrifolius subsp. abbreviatus (2n = 12) and T. subacaulis (2n = 12) are reported for the first time. The chromosome numbers are published for the first time from Turkish accessions, except for T. coloratus, T. latifolius var. latifolius, T. reticulatus, and T. porrifolius subsp. longirostris. Of the studied plants 13 taxa proved to be diploid (2n = 12) and five taxa tetraploid (2n = 24). The chromosome numbers obtained from the present study are consistent with previous reports.

Suppressive effect of some forage plants on the growth of Ambrosia artemisiifolia and Iva xanthiifolia.

A pot trial in greenhouse conditions has been carried out to investigate the role of some plant species in suppression of Ambrosia artemisiifolia and Iva xanthiifolia growth. Screening of several plant species (Medicago sativa L., Lolium perenne L., Dactylis glomerata L. and Elymus repens (L.) Gould - all from both turf and seeds) was conducted. The results of the experiment showed that some perennial plants, especially L. perenne, D. glomerata and M. sativa, can be a reliable means of suppression of the growth and seed production of A. artemisiifolia and I. xanthiifolia. Moreover, simple greenhouse screening turned to be a reliable method for predicting this potential suppressive role under certain conditions.

Impact of interspecific hybridization within a polyploid agamic complex of Pilosella (Asteraceae, Cichorieae) in Bulgaria compared with Central Europe

Abstract: The species-mixed Pilosella populations comprising diploid sexual and polyploid facultatively apomictic biotypes were studied in Bulgaria. Parentage of co-occurring recent hybrids was inferred from a combination of morphology and ploidy level that corresponded to simple/multiple crosses of basic species via either reduced or unreduced gametes. The flow cytometric seed screening illustrated the capacity for heteroploid hybridization both in open-pollinated plants in the mixed-ploidy populations and in crossing experiments. The diploid sexual species in Bulgaria have a limited impact on interspecific hybridization, and simple inter-cytotype hybrids are only sporadically formed. The origin of the most common hybrids in Bulgaria that are apomictic and retain the pentaploid/hexaploid ploidy level of a co-occurring putative apomictic parent remains unclear. The absence of stabilized hybridogeneous species and scarcity of commonly hybridizing polyploid sexual biotypes are crucial attributes that distinguish the Pilosella populations in Bulgaria from those in the Czech Republic and Germany. No recent high-polyploid hybrids of 2n + n origin that would potentially become drivers of ongoing hybridization in the mixed sexual-apomictic Pilosella populations similar to those in Central Europe have been recorded in Bulgaria. The pattern of co-occurring cytotypes in Bulgaria likely limits interspecific hybridization due to stronger ploidy barriers. Citation: Krahulcová A., Krahulec F. & Vladimirov V. 2018: Impact of interspecific hybridization within a polyploid agamic complex of Pilosella (Asteraceae, Cichorieae) in Bulgaria compared with Central Europe. – Willdenowia 48: 345–362. doi: https://doi.org/10.3372/wi.48.48302 Version of record first published online on 8 October 2018 ahead of inclusion in December 2018 issue.

Reproductive Features of Three Invasive Alien Species of Erigeron (Asteraceae) in Bulgaria

Embryological studies have been carried out on some established populations of three invasive alien species of the genus Erigeron in Bulgaria: E. bonariensis, E. canadensis and E. sumatrensis. The mode of reproduction and features of the reproductive system, especially these which facilitate the successful distribution and invasiveness of the species were established: a high amount of viable pollen; multicellular antipodal complex; antipodal and endosperm haustoria; simultaneous formation of mature embryos in the florets of the capitulum. All observed embryological features together with the enormous number of flower heads per individual and long flowering period, self-pollination, self-compatibility, autonomous production of achenes and their high dispersal capacity undoubtedly increase the invasive potential of the studied Erigeron species.

Intelligent modular service mobile robot controllable via internet

Abstract The article focuses on the research. Development and prototyping of the “Intelligent Modular Service Mobile Robot Controllable via Internet” using open-source meta-operating system/platform ROS. The robot can be controlled either locally via an immediate console or remotely (via Internet) using a remote terminal. The immediate control is implemented by means of a computer terminal. The remote connection can be made over any TCP/IP enabled network such as the Internet. Software architecture of the remotely controlled robot consists of two major parts – ROS part and remote interface. The Remote control consists of two parts – Server and Client. The Client accepts user input and transmits the corresponding commands remotely to the Server via TCP/IP connection over a network (i.e. the Internet). The Server listens for Client connections and accepts commands from the connected Client. Such kind of mobile service robots can be used for servicing of elderly and/or disabled people, in a semiautonomous of fully autonomous mode of control from a distance via Internet As they are a great number of such applications it increases the social stability of the society.

Typification and Current Taxonomic Position of Senecio arnautorum Velen.

The name Senecio arnautorum Velen. is lectotypified with a herbarium specimen kept at PR. In most taxonomic works the taxon was considered synonymous with Senecio pancicii Degen or treated at infraspecific rank under the latter species. Careful examination of Velenovskýs material revealed that S. arnautorum differs from S. pancicii and is identical to Jacobaea subalpina (W.D.J. Koch) Pelser & Veldk. (Senecio sub-alpinus W.D.J. Koch).