Production, Properties and Swelling of Composite Agar-Pectic Gel Particles in an Artificial Gastroenteric Environment

The purpose of the present work was to obtain and study the properties of composite calcium-agar-pectic gel particles (CaAPGPs) obtained from aqueous solutions of agar (AA) and apple pectin (AP), from aqueous solutions of agar (AA) and pectin heracleuman (HS) in the presence of Ca2+ ions (0.34 M). The swelling of the obtained composite CaAPGPs in an artificial gastroenteric environment was also investigated. Methods and Results: We used commercial AP AU701 (AP, Herbstreith & Fox KG, Germany), HS isolated from the aerial part of the Sosnovskyi hogweed Heracleum sosnowskyi Manden, and food agar (AA). Spherical composite CaAPGPs were obtained from low-methyl esterified AP with a molecular weight of 406 kDa, pectin HS with a molecular weight >300 kDa, and food agar (AA) in the presence of Ca2+ ions (0.34 M) as a cross-linking agent by the method of ionotropic gelation. It was found that dry CaAPGPs based on AP (Ca-AA-AP) have a diameter of 1.16±0.14-1.23±0.05 mm, which was greater than the diameter of dry CaAPGPs based on HS (Ca-AA-HS) (0.95±0.12-1.16±0.05 mm). The density of dry CaAPGPs based on AP (Ca-AA-AP) with an increase in the concentration of AP in their composition from 1% to 2% increased by 1.7 times – from 0.37±0.07 mg/mm3 to 0.63±0.05 mg/mm3. Dry composite CaAPGPs based on HS (Ca-AA-HS) were denser. With an increase in the HS concentration in their composition from 1% to 2%, the degree of particle density increases by 2.2 – from 0.45±0.03 mg/mm3 to 0.97±0.19 mg/mm3. The swelling and degradation of the obtained dry composite CaAPGPs in an artificial gastroenteric environment were studied. It was found that CaAPGPs formed from 1% AP and 2% AA degraded almost immediately in SIF. Whereas, CaAPGPs formed from 2% AP and 1% or 2% AA completely degraded in SCF after 1 hour of incubation in it. CaAPGPs formed from 1% HS and 2% AA, and particles obtained from 2% HS and 1% AA, remained stable in SIF, and then completely degraded immediately upon entering in SCF. CaAPGPs, consisting of 2% HS and 2% AA, dissolve in SCF after 1 hour of incubation in it.

Genetic Diversity in Invasive Populations of Lupinus polyphyllus Lindl. and Heracleum sosnowskyi Manden.

In our study, two aggressive-invasive species, Lupinus polyphyllus Lindl. and Heracleum sosnowskyi Manden. from Russia and Ukraine, were investigated. The success in naturalization of both species is associated with human activities, since they have been used in agriculture and floriculture and both have qualities such as environmental tolerance, high fertility and phenotypic plasticity. The purpose of this study was to determine the level of genetic diversity of both species. For Heracleum sosnowskyi Manden., genetic diversity was compared in invasive and native populations. For Lupinus polyphyllus Lindl., the genetic diversity was compared in variety, feral and invasive populations. A genetic diversity was formulated using RAPD, ISSR and REMAP. For Heracleum sosnowskyi Manden., the average genetic diversity within the invasive population was similar (0.432), but slightly less (0.502) than within the native Caucasian population. This may suggest the successful naturalization of invaders and almost complete reconstruction of their genetic diversity. For Lupinus polyphyllus Lindl., the genetic diversity for the invasive population was the highest, with an average of 0.294, while for variety, it was the lowest, with an average of 0.194. The feral population had an intermediate place with an average of 0.248, which could suggest an increase of diversity in the process of naturalization.

APPLICATION OF HERBICIDES IN THE CONTROL OF THE INVASIVE SPECIES HERACLEUM SOSNOWSKYI MANDEN. (SOSNOWSKY’S HOGWEED) IN FORESTRY

A representative of the family Apiacea, Sosnowsky's hogweed ( Heracleum sosnowskyi Manden.) previously cultivated as a fodder plant and now occupying vast territories along roads and railways, in and near settlements, uncultivated agricultural lands, on farms and in many other areas, poses a serious threat to human health. On these lands, an active eradication campaign has been going on for over 15 years. This invasive species also spreads actively on the lands of the forest fund including plantations, felling sites, young stands of natural origin, clearings and hayfields, forest stands of different ages with a small basal area, and in the most productive forest conditions. As a result, in forest plantations growth of woody plants (primarily of coniferous species) is inhibited, their death is observed, and environmental, aesthetic and industrial damage increases due to the growth and dominance of Sosnowsky's hogweed. As a result of field experiments in the Leningrad Region, a high effectiveness of a number of modern herbicides (Roundup, Anchor-85, and Magnum) for control of Sosnowsky's hogweed and other unwanted herbaceous vegetation, as well as their selectivity in relation to pine and spruce, has been demonstrated.

Effect of Heracleum sosnowskyi extract aqueous solution on the Allium cepa root meristem

Heracleum sosnowskyi (Apiaceae) contains a lot of useful chemical ingredients that can be used in industry, medicine and other fields as plant component extracts and as chemical compounds that have been extracted in different ways, which requires the last to be tested for chemical safety, including a genotoxic test in vivo. In the present paper, the 96-hour effect of the H. sosnowskyi extract aqueous solution at concentrations of 0.01, 0.05, 0.10, and 0.50 mL/L on the genetic apparatus and mitotic activity of the cells of the Allium cepa (Alliaceae) root meristem is discussed. Distilled water was applied as a negative control, and hydrogen peroxide 1% as a positive one. The extract was prepared from the plant’s fresh leaves by soaking them in acetone. It was then distilled at 57 ºС and diluted with distilled water to obtain the experimental concentrations. As extract content in the aqueous solution increased, a statistically significant decrease in mitotic activity, an increase in aberrant cell percentage and a concentration-dependent inhibition of root growth were observed. In the 0.5 mL/L solution, if compared against the other experimental concentrations, an increase in the metaphase, anaphase and telophase indices along with a decrease in the prophase index were observed. The most common aberrations for all the concentrations were lagging and sticking chromosomes, anaphase bridges, ring chromosomes and nuclear buds. The same solution and the positive control produced membrane damage; giant and ghost cells. The results of the experiment performed have demonstrated the extract’s aneugenic effect that causes spindle disturbance, mitodepression and inhibits the cells of the Allium cepa root meristem, prevails over its clastogenic effect.

A simple mechanistic model of the invasive species Heracleum sosnowskyi propagule dispersal by wind

Background Invasive species are one of the key elements of human-mediated ecosystem degradation and ecosystem services impairment worldwide. Dispersal of propagules is the first stage of plant species spread and strongly influences the dynamics of biological invasion. Therefore, distance prediction for invasive species spread is critical for invasion management. Heracleum sosnowskyi is one of the most dangerous invasive species with wind-dispersed propagules (seeds) across Eastern Europe. This study developed a simple mechanistic model for H. sosnowskyi propagule dispersal and their distances with an accuracy comparable to that of empirical measurements. Methods We measured and compared the propagule traits (terminal velocity, mass, area, and wing loading) and release height for H. sosnowskyi populations from two geographically distant regions of European Russia. We tested two simple mechanistic models: a ballistic model and a wind gradient model using identical artificial propagules. The artificial propagules were made of colored paper with a mass, area, wing loading, and terminal velocity close to those of natural H. sosnowskyi mericarps. Results The wind gradient model produced the best results. The first calculations of maximum possible propagule transfer distance by wind using the model and data from weather stations showed that the role of wind as a vector of long-distance dispersal for invasive Heracleum species was strongly underestimated. The published dataset with H. sosnowskyi propagule traits and release heights allows for modeling of the propagules’ dispersal distances by wind at any geographical point within their entire invasion range using data from the closest weather stations. The proposed simple model for the prediction of H. sosnowskyi propagule dispersal by wind may be included in planning processes for managing invasion of this species.