Thladiantha dubia Bunge as an invasively dangerous species in Ukraine

The distribution of a potentially invasive species from the Cucurbitaceae family — Thladiantha dubia is considered in Ukraine. The current significant increase in the distribution of the species in many regions of Ukraine has been clarified. It was established that the species was introduced in Uman in 1964. It was found that due to vegetative propagation the species spread beyond the primary introduction site in the botanical nursery of Uman National Univer- sity of Horticulture and around it. The absence of generative reproduction in the analyzed introductory population was established, as there are only male specimens of this dioecious plant. Measures to prevent further spread of Thladiantha dubia are recommended.

Lockdown botany 2020: some noteworthy records of alien plants in Kyiv City and Kyiv Region

Noteworthy records of 11 alien plant species in Kyiv City and Kyiv Region made mainly in 2020 are discussed. In particular, new localities of the following taxa are reported: Amaranthus spinosus, Artemisia tournefortiana, Chenopodium ucrainicum, Celastrus orbiculatus, Datura innoxia, Dysphania ambrosioides, Erechtites hieraciifolius, Mesembryanthemum ×vascosilvae (M. cordifolium × M. haeckelianum; recently described as Aptenia ×vascosilvae and reported here for the first time for Ukraine; earlier this ornamental hybrid was misidentified as Aptenia cordifolia), Parietaria officinalis, Phytolacca americana, Thladiantha dubia. The presence in Ukraine of several additional species, such as Datura wrightii and Phytolacca acinosa s.l. (incl. P. esculenta), that may occur as escaped near places of their cultivation, is reported; these species may be confused with D. innoxia and P. americana, respectively. The growing role of alien plants escaped from cultivation (ergasiophytes) in the present-day processes of formation of the alien flora of Ukraine is emphasized.

In vivo callus formation on the surface of tubers of Manchu tubergourd (Thladiantha dubia, Cucurbitaceae)

For the first time, shingles of callus-like structures were found in Thladiantha dubia. Of these formations, shoots and roots are intensively regenerated in vivo. Such a mechanism underlies the active vegetative propagation and wide distribution of this invasive species.

Urban forests in the city of Ivanovo

The paper deals with the issue of urban forests in the city of Ivanovo which were saved on the territories of three parks. On the basis of special studies during 2012-2018 the main types of forests have been briefly described. The data on the forest flora are presented (338 species were recorded in the park named after the 1905 Revolution, 235 - in the park named after Stepanov, 217 - in the park Kharinka). The forests are dominated by typical forest species, 5 rare plants preserved ( Epipactis palustris , Eryngium planum , Malaxis monophyllos , Ophioglossum vulgatum , Viola selkirkii ), they are included into the regional Red Data book. There are also old trees of native species. Planting trees, creating lawns and flower beds greatly enriched their flora. In general, the composition and structure of forests are disturbed, weed and ruderal alien species (groups of Acer negundo , Amelanchier spicata , Cerasus vulgaris , Cotoneaster lucidus , Fraxinus pennsylvanica , Malus domestica , Sambucus racemosa , etc.) are noted. Some species ( Cerasus maximowiczii , Crataegus monogyna , Padus pensylvanica , Parthenocissus inserta , Phellodendron amurense , Thladiantha dubia , Telekia speciosa ) belong to the rare invasive plants of the Ivanovo Region. The parks possess the status of specially protected natural areas, they are of great environmental, ecological, scientific and aesthetic value. As a result of the territory zoning of these valuable forest areas they have been assigned to the reserves with a strict protection regime.

Thladiantha Dubia Mosaic Virus: A Novel Potyvirus Infecting Manchurian Tubergourd (Thladiantha dubia) in Northeast China

A new virus with flexuous, filamentous particles approximately 650 nm long was discovered in Manchurian tubergourd (Thladiantha dubia Bunge) leaves exhibiting severe mosaic symptoms. The whole genome sequence of the virus was determined by reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The entire genome consisted of 10,112 nucleotides (nt) excluding the poly (A) tail, which shared the highest nucleotide sequence identity (73.8%) with that of papaya leaf distortion mosaic virus Hainan-DF isolate (PLDMV-Hainan-DF). A phylogenetic analysis showed that this virus clustered with PLDMV isolates in a subbranch within the potyviral clade. Of the 23 species of indicator plants tested, only potato and its original host were systemically infected by the virus tested upon mechanical inoculation. A field survey showed that the virus was widely distributed on T. dubia and potatoes in Northeast China. Moreover, this virus displayed a high degree of genetic variation as evaluated by the sequences of the coat protein (CP) gene. Based on these results, the name Thladiantha dubia mosaic virus (ThDMV) is proposed for this new potyvirus.