Genomic Analyses of Phenotypic Differences Between Native and Invasive Populations of Diffuse Knapweed (Centaurea diffusa)

Invasive species represent excellent opportunities to study the evolutionary potential of traits important to success in novel environments. Although some ecologically important traits have been identified in invasive species, little is typically known about the genetic mechanisms that underlie invasion success in non-model species. Here, we use a genome-wide association (GWAS) approach to identify the genetic basis of trait variation in the non-model, invasive, diffuse knapweed [Centaurea diffusa Lam. (Asteraceae)]. To assist with this analysis, we have assembled the first draft genome reference and fully annotated plastome assembly for this species, and one of the first from this large, weedy, genus, which is of major ecological and economic importance. We collected phenotype data from 372 individuals from four native and four invasive populations of C. diffusa grown in a common environment. Using these individuals, we produced reduced-representation genotype-by-sequencing (GBS) libraries and identified 7,058 SNPs. We identify two SNPs associated with leaf width in these populations, a trait which significantly varies between native and invasive populations. In this rosette forming species, increased leaf width is a major component of increased biomass, a common trait in invasive plants correlated with increased fitness. Finally, we use annotations from Arabidopsis thaliana to identify 98 candidate genes that are near the associated SNPs and highlight several good candidates for leaf width variation.

Phytotesting of heavy metal contamination of Donbass soils

The article presents the results of phytotesting of soil solutions with high concentrations of heavy metal ions. The sensitivity of Donbass species plant to soil pollution was established by specific transformations in the structures of the embryonic root Achillea nobilis L., Artemisia vulgaris L., Centaurea diffusa Lam., Galinsoga parviflora Cav., Senecio vulgaris L., Tripleurospermum inodorum (L.) Sch. Bip. Model experiments on plant germination were carried out in laboratory conditions with fixed concentrations of individual metals and with joint pollution, as well as when testing soil samples taken in the zones of influence of industrial facilities of Don-bass.

MELITTOPHILIC COMPLEX OF PLANTS PROVIDING FORAGE BASE FOR HONEY BEES (APIS MELLIFERA) IN THE MOUNTAIN-FOREST ZONE OF CRIMEA

For the first time, in the mountain-forest ecosystems of Crimea of parcel organization level adjacent to the beehives of honey bees (Apis mellifera L.), a species composition of plants representing the melittophilic complex has been identified which provides honey bees with pollen and nectar during the entire warm season. The complex includes 57 species of plants where the honey bees that collect pollen or nectar have been registered. The core of the melittophilic complex consisted of 35 species of plants, the proportion of simultaneously flowering (in any period of the season) flowers of each one exceeded 2.5 % of the total number of flowers of all flowering species at this time. In early spring, the list of such species included 15 plant species belonging to 14 genera and 12 families. In this period, the decisive forage value (species whose flower share exceeded 10 % of all flowering flowers) was represented by 4 plant species: Cornus mas L., Corylus avellana L., Dentaria quinquefolia M. B. and Prunus divaricata Ledeb., the important value (the flowers share made <10 %, but >2.5 %) had 4 species: Ficaria verna Huds., Galanthus plicatus M. Bieb., Primula vulgaris Huds. and Scilla bifolia L. In spring, the forage base made up 20 plant species belonging to 18 genera and 7 families. Four species had decisive forage value: Cerasus avium L., Malus sylvestris L., Prunus spinosa L. and Pyrus elaeagrifolia Jacq., 7 species had important value: Crataegus monogyna Jacq., Fragaria vesca L., Lamium purpureum L., Crepis pulchra L., Prunus domestica L., Thlaspi arvense L. and Trifolium ambiguum M. Most of the species belonged to the Rosaceae family (10 species). In summer period, the forage basis comprised 20 species of melittophilic plants belonging to 19 genera and 9 families. 5 species had decisive value: Cichorium intybus L., Cirsium arvense (L.) Scop., Echium vulgare L., Medicago sativa L. and Trifolium ambiguum M., the important value had 7 species: Achillea millefolium L., Betonica officinalis L., Ballota nigra L., Centaurea diffusa Lam., Clematis vitalba L., Linaria vulgaris Mill. and Onobrychis sativa Lam. The representatives of the Asteraceae family (7 species) dominated; the representatives of Fabaceae (5 species) and Lamiaceae (4 species) also played a significant role. In autumn, there were the following food sources for honey bees: Diplotaxis tenuifolia (L.) DC., Centaurea diffusa Lam., Erýngium campéstre L., Carduus crispus L., and on the steppe slopes of the mountains: Scilla autumnalis L. and Crocus speciosus M. B. It has been established that the greatest number of melittophilic plant species in the studied mountain-forest biogeocenoses grow on parcels of forest edges and glades, steppe slopes of the mountains in their natural state. Oak-hornbeam and floodplain tree-shrub parcels have a smaller variety of species, but are essential for bees in early spring and spring..

Complete chloroplast genome sequence of the medicinal plant Arctium lappa

Arctium lappa, commonly called burdock, has a long medicinal and edible history. It has recently gained increasing attention because of its economic value. In this study, we obtained the complete chloroplast genome of A. lappa by Illumina Hiseq. The complete chloroplast genome of A. lappa is a typical circular structure with 152 708 bp in length. The GC content in the whole chloroplast genome of A. lappa is 37.7%. A total of 37 tRNA genes, 8 rRNA genes, and 87 protein-coding genes were successfully annotated. And the chloroplast genome contains 113 unique genes, 19 of which are duplicated in the inverted repeat. The distribution of 39 simple sequence repeats was analysed, and most of them are in the large single-copy (LSC) sequence. An inversion comprising 16 genes was found in the LSC region, which is 26 283 bp long. We performed multiple sequence alignments using 72 common protein-coding genes of 29 species and constructed a Maximum Parsimony (MP) tree. The MP phylogenetic result shows that A. lappa grouped together with Carthamus tinctorius, Centaurea diffusa, and Saussurea involucrata. The chloroplast genome of A. lappa is a valuable resource for further studies in Asteraceae.

Volatile Components from Aerial Parts of Centaurea diffusa and C. micrantha ssp. melanosticta and Their Biocidal Activity on Microorganisms Affecting Historical Art Crafts

The chemical composition of the essential oils from aerial parts of two taxa of Centaurea belonging to subgenus Acrolophus, Centaurea diffusa Lam. and C. micrantha Hoff. ssp. melanosticta (Lange) Dostàl, respectively collected in Croatia and Spain, were evaluated by GC and GC-MS. The main components of C. diffusa were hexadecanoic acid (31.1%), ( Z,Z)-9,12-octadecadienoic acid (10.7%) and damascenone isomers (6.4%), whereas hexahydrofarnesyl acetone (27.8%), hexadecanoic acid (8.3%) and caryophyllene oxide (6.4%) were the most abundant components of C. micrantha ssp. melanosticta. The oils showed good antibacterial and antifungal activities against some microorganisms that infest historical art works.

Seed traits and germination of native grasses and invasive forbs are largely insensitive to parental temperature and CO2 concentration

The structure and function of grassland ecosystems can be altered by a changing climate, including higher temperature and elevated atmospheric CO2 concentration. Previous studies suggest that there is no consistent trend in seed germination and seedling recruitment as affected by these conditions. We collected seeds of two native and two invasive species over 6 years from a field study with elevated CO2 (600 p.p.m.) and temperature (1.5/3.0°C day/night) on the mixed-grass prairie of Wyoming, USA. Seed fill, viability and mass were evaluated and germination tests were conducted under alternating temperatures in growth chambers. Thermal time requirements to reach 50% germination (θ50) and base temperatures (Tb) for germination were determined using thermal time models. Climate change conditions had limited effects on seed fill, viability and mass. The combination of CO2 enrichment and warming increased germination of Bouteloua gracilis. Centaurea diffusa and Linaria dalmatica, two invasive species in this study, had the lowest θ50 and Tb required for germination among all the species studied. Although final germination percentages of these invasive species were not affected by treatments, previous studies reported increased seed production under future climate conditions, indicating that they could be more invasive at the regeneration stage in the future. We conclude that projected future temperature increases will have little effect on seed reproductive traits of native species. In addition, the distribution and abundance of B. gracilis and invasive species may be favoured by global climate change due to enhanced germination or seed production traits caused by elevated parental CO2 and temperature conditions.

The Economic Cost of Noxious Weeds on Montana Grazing Lands

We distributed a 16-question survey concerning noxious weed abundance, impacts, and management to livestock producers grazing on privately owned or leased grazing lands in Montana. The noxious weeds most commonly reported as being present on respondents’ grazing units were Canada thistle [Cirsium arvense (L.) Scop.] (64% of grazing units) and leafy spurge (Euphorbia esula L.) (45% of grazing units), and these species also reportedly caused the greatest reductions in livestock forage. Houndstongue (Cynoglossum officinale L.) was more prevalent than either spotted knapweed (Centaurea stoebe L.) or diffuse knapweed (Centaurea diffusa Lam.) (39% vs. 32% and 10%, respectively, of grazing units), but collectively C. stoebe and C. diffusa were reported to cause greater forage reductions than C. officinale. The top three strategies used to manage noxious weeds were chemical control, grazing, and biological control. Combining survey responses with forage-loss models derived from field data for C. stoebe and E. esula, we estimated the combined cost of noxious weed management and forage losses on privately owned rangeland to be $3.54 ha−1 yr−1, or $7,243 annually for an average size grazing unit (i.e., 2,046 ha [5,055 ac]). Our estimates of economic losses are lower than many estimates from previous studies, possibly because we focused only on direct costs related to private grazing land, while other studies often consider indirect impacts. Nonetheless, our estimates are substantial; for example, our estimated loss equates to 24% of the average per-hectare lease rate for Montana grazing land.

Host specificity of Aceria centaureae (Nalepa), a candidate for biological control of Centaurea dίffusa De Lamarck

Filed collected rosettes or twigs of Centaurea diffusa De Lamarck, infested by the gall mite Aceria centaureae, were fixed onto appropriately grown and planted test plants of ten different species in the area of Thessaloniki, Greece, in 1985 and 1986. The test plants were inspected for presence of galls and mites a few to several days after their contact with the infested twigs. Gall formation occurred on all of the Centaurea diffusa test plants, either of Greek or U.S. origin, and on some of the Centaurea solstitialis, L. test plants. No galls or other mite damage could be found on the other test plants, which were Carthamus tinctorius L. (safflower), Cirsiton creticion (De Lamarck) D’Urville, of local origin and six Cirsium species of U.S. origin, i.e. cymosum (Greene) J. T. Howell, occidentals (Nutt) Jeps., pastoris Howell, andersonii (Gray) Petrak, brevistylum Crong; and undulation (Nutt.) Spreng. These results suggest that A. centaureae most probably has a very restricted host plant range, feeding only on weedy Centaurea spp. Thus the mite should be considered as a possible candidate for biological control of diffuse knapweed in the U.S.A. and Canada.

Naturalized alien plants in Penza Region

The paper deals with naturalized alien plants in Penza Region. There are 75 naturalized alien plant species in the flora of the Penza Region, the most dangerous for natural ecosystems of them are 10 transformers species ( Acer negundo , Bidens frondosa , Echinocystis lobata , Elaeagnus angustifolia , Elodea canadensis , Fraxinus lanceolata , Fraxinus pennsylvanica , Phalacrolomaseplentrionale , Salix euxina , Ulmus pumila ), 20 alien species, actively settled and invasive in semi-natural and natural habitats ( Amelanchier spicata , Conyza canadensis , Cuscuta campestris , Echinochloa crusgalli , Epilobium adenocaulon , Epilobium pseudorubescens , Geranium sibiricum , Heracleumsosnowskyi , Helianthus subcanescens , Hippopha rhamnoides , Impatiens glandulifera , Juncus tenuis , Malus domestica , Oenothera villosa s.l., Parthenocissus inserta , Phragmites altissimus , Sambucus racemosa , Sambucus sibirica , Solidago canadensis s.l., Xanthium albinum ), 45 alien species, invasive and settled at present in disturbed habitats ( Acroptilon repens , Amaranthus albus , Amaranthus blitoides , Amaranthus retroflexus , Ambrosia artemisiifolia , Ambrosiatrifida , Anisantha tectorum , Arrhenatherumelatius , Artemisia sieversiana , Atriplex tatarica , Bassia sieversiana , Berberisvulgaris , Cannabisruderalis , Caragana arborescens , Cardaria draba , Centaurea diffusa , Chamomilla suaveolens , Crataegus monogyna , Cyclachaena xanthiifolia , Elsholtzia ciliata , Galega orientalis , Galinsoga quadriradiata , Galinsoga parviflora , Grindelia squarrosa , Gypsophila perfoliata , Hordeum jubatum , Impatiens parviflora , Kali collina , Lepidium densiflorum , Leymusracemosus , Lolium perenne , Lupinus polyphyllus , Oenothera biennis , Oenothera rubricaulis , Onobrychisviciifolia , Populusbalsamifera , Portulaca oleracea , Robiniapseudoacacia , Senecio viscosus , Sisymbriumvolgense , Symphyotrichum salignum s.l., Symphytumcaucasicum , Typha laxmannii , Vinca minor , Xanthoxalis stricta ).