This paper discusses the importance of introducing domestic natural rubber production and presents the rediscovery of a rubber-producing species, Scorzonera tau-saghyz or “mountain gum”, originally discovered in 1929 on the Karatau mountains in Kazakhstan. This plant could potentially also be cultivated in the U.S. In this exploratory work, roots (2–5 years old) were harvested on June 16, 2021 from wild strands in the Karatau mountains, Kumantas ridge, and Saraba, Kazakhstan, and processed at the Ohio State University. The rubber extraction method was based on an indigenous method in Kazakhstan to make natural chewing gum. Water extraction followed by purification yielded 16.2 wt% rubber from the dry roots, in comparison with 4–8 wt% from most rubber dandelion (Taraxacum kok-saghyz) plants, also a potential domestic rubber producing plant. High-resolution size exclusion chromatography was used to analyze rubber samples. The molecular weights and gel and oligomer contents were very similar to the rubber from Hevea brasiliensis, the current commercial source of natural rubber. More detailed investigations of this very interesting rubber-producing plant are in progress.
In this paper, the effect of an organic fertilizer, namely, “vermicompost tea” (VCT), on the germination of seeds of the rare wild species Scorzonera tau-saghyz Lipsch. et & G.G. Bosse was studied. S. tau-saghyz is an alternative rubber plant to Hevea brasiliensis, and it was widely distributed and grew well in the northwestern spur of the Tien Shan in the pre-war years (1931–1943). In recent decades, the number of wild species of S. tau-saghyz in natural populations has declined sharply due to climate change and the impact of anthropogenic factors. In this context, it has become necessary to restore the number of wild species. One of the critical phases in the restoration of surviving S. tau-saghyz populations and domestication is seed germination. The approaches that have been explored to increase seed germination, such as stratification and seed dressing with ethyl mercuric chloride, have not yielded good results. The current study covered 4 and 8 h short-term seed treatments with 1, 5 and 10% VCT. The priming of S. tau-saghyz seeds with 10% VCT was found to significantly increase germination from 39.0 (in the control) to 76.7% and to improve seedling vigor, mean germination time, and seedling weight. The combination of soaking the seeds in 10% VCT for 8 h and cultivating the seedlings in soil with 20% vermicompost further improved both germination and seedling growth. The vermicompost incorporation lengthened the main root, which normally accumulates rubber, and it increased its crude biomass by 1.6 times compared to that of the control.
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30 September 2024 in Theoretical and Applied Ecology
Results of studying the main types of surfactants effect on earthworms Eisenia fetida andrey (Bouche, 1972) are presented. The worms were tested for survival and preference-avoidance behavioral reactions. Earthworms avoided sodium dodecyl sulfate (SDS) at 0.02 g/kg and above, cetyltrimethylammonium bromide – at 0.1 g/kg and above, and polysorbate 80 – at 30 mL/kg and above. The 100% mortality of earthworms occurred at 0.001, 0.01 and 0.02 g/kg of SDS on day 30, at 1 g/kg – on day 25, and at 1 g/kg – on day 2 of the experiment. Сetyltrimethylammonium bromide at 0.001 and 0.01 g/kg caused the 100% mortality of worms on day 30; at 0.1 g/kg – on day 25; at 0.5 g/kg – on day 5; and at 1.0 g/kg already on day 2 of the experiment. The 100% mortality of worms occurred at 0.1, 1 and 10 mL/kg of polysorbate 80 on day 30 of incubation; at 20 or 30 mL/kg – on day 20; at 50 mL/kg – on day 10 of experience. The following toxicity series (both in terms of g/L and in terms of g/mol) of the tested surfactants for earthworms was constructed on the basis of the results obtained (increasing toxicity): polysorbate 80 (non-ionic surfactant) < cetrimonium bromide (cationic surfactant) < sodium dodecyl sulfate (anion-active surfactant).
The aim of the present research is the isolation and morphological and molecular–phenological identification of nematophagous fungi of Southern Kazakhstan for the production of effective bionematicides on their basis. Nematophagous fungi, which include nematode-trapping, ovicidal, endoparasitic, toxin-producing, and special substance-producing fungi, are among the most effective biological agents in controlling phytoparasitic nematodes. To isolate and characterize nematophagous fungi, soil samples were collected at 12 sites in three regions of Southern Kazakhstan. The samples were collected using the envelope method. The content of nematophagous fungi in the samples was determined using the standard surface sowing technique. The obtained strains of nematophagous fungi were identified. The attractive and nematophagous activity of the obtained fungal strains was determined by using standard methods. In experiments on the isolation and morphological identification of nematophagous fungi, the nematode species Meloidogyne incognita was used. Identification of the strains was carried out by the method of determining the direct nucleotide sequence of the region of the nuclear ribosomal internal transcribed spacer, followed by determination of nucleotide identity with sequences deposited in the international GeneBank database. As a result, the following species of nematophagous fungi living in the soils of agricultural lands in Southern Kazakhstan were identified: Orbilia oligospora, Duddingtonia flagrans, Orbilia oligospora, and Arthrobotrys superba.