Influence of the chemical mutagens on the seed germination, the growth and manifestation of decorative characteristics in the seed offspring of the representatives of the genus Pinus L.

The influence of various concentrations of chemical mutagens on the seed germination, the growth and manifestation of decorative traits in the seed offspring of mountain pine (Pinus mugo Turra), Scots pine (Pinus sylvesrtis L.), and Scots pine “witch’s broom” (“WB”) is assessed. A 0.1 % aqueous solution of colchicine, as well as 0.1, 0.5, and 1.0 % aqueous solutions of dimethyl sulfate (DMS) was used as mutagens. The species-specificity of the influence of chemical mutagens on the seed germination was established. Thus, the treatment of mountain pine seeds with aqueous solutions of colchicine and DMS had some stimulating influence on their germination. On the contrary, the germination of the Scots pine seeds and the seeds collected from the Scots pine “WB” decreased with increasing the DMS concentration in the solution. Among the offspring obtained using chemical mutagens, specimens were identified with changes in the growth strength towards dwarfism, the branching features of which manifested themselves in the form of apical dominance violation and shoot formation growth, with changes in the color of needles, including winter color changes of different-intensity color from green to yellow, bronze or bronze yellow. As a result of the research, 363 specimens with atypical traits were selected for further breeding work.

Effect of Light Conditions on In Vitro Adventitious Organogenesis of Cucumber Cultivars

The response on callus and shoot formation under different light incubation conditions was evaluated in cucumber (Cucumis sativus L.). Four-day-old cotyledon explants from the inbred line 'Wisconsin 2843' and the commercial cultivars 'Marketer' and 'Negrito' were employed. A four-week culture was conducted on MS-derived shoot induction medium containing 0.5 mg L-1 IAA and 2.5 mg L-1 BAP, under an 8-h dark/ 16-h light regime, or by a one- or two-week dark pre-incubation followed by the same photoperiod. Significant differences were obtained for the regeneration of shoots in all cultivars. The response in both frequency and number of shoots under continuous photoperiod was at least 3-6 fold higher than with dark pre-incubation. The highest genotypes response was obtained by 'Negrito' and 'Marketer' with identical values. All explants formed callus, and in two of the three cultivars, the response on callus extension was not significantly affected by incubation conditions. The results clearly show that shoot induction under continuous photoperiod regime was beneficial for adventitious shoot regeneration in cucumber.

Determination of the Effect of Magnesium Oxide Nanoparticles (MgO-NP) on in Vitro Culture of Cowpea (Vigna Unguiculata L. Walp)

This study was carried out to determine the effect of different doses of MgO nanoparticles (MgO-NP's) on in vitro regeneration of cowpea. MgO NPs used in the study were synthesized using walnut shell extract by green synthesis method. MgO nanoparticles with 35-40 nm size were used in this research. In the study, the effect of different doses of MgO NP applied to cowpea plant on all in vitro parameters was found to be significant. Considering the parameters examined, the best results in morphogenesis were 185 mg/L, 370 mg/L and 555 mg/L MgO-NPs applications, the highest shoot formation rate was obtained 82.50% with 555 mg/L(MgO-NPs) and 72.50% with 370 mg/L (MgO-NPs). The highest mean values of shoot number, shoot number per explant and shoot length were observed in the application of 370 mg/L MgO-NPs with 61.25, 17.50, and 2.075 (unit) respectively. The best root formation rate was obtained from control and 370 mg/L MgO application at a rate of 27.50%. The highest values were 6.75 (pieces) and 370 mg/L MgO-NPs in the number of roots per explant, 555 mg/L MgO-NPs with 10% in callus formation, and 1.575 (cm) and 370 mg/L MgO-NPs in root length. When all the examined parameters were evaluated, it was determined that the application of 370 mg/L MgO-NPs gave the best results in terms of in vitro parameters.

Transcriptome analysis of ovary culture-induced embryogenesis in cucumber (Cucumis sativus L.)

Background. Ovary culture is a useful technique used to generate double haploid (DH) cucumber (Cucumis sativus L.) plants. However, cucumber ovary culture have a low rate of embryo induction and plant regeneration. Moreover, the cucumber embryogenesis mechanism remains unclear. In this study, we explored the molecular basis of cucumber embryogenesis in order to establish a foundation for a more efficient ovary culture method. Using transcriptome sequencing, we also investigated the differential expression of genes during the embryogenesis process. Methods. Cytological and morphological observations have divided cucumber ovary culture into three stages: early embryo development (T0), embryo morphogenesis (T1, T2, T3 and T4), and shoot formation (T5). We selected six key time points for transcriptome sequencing and analysis: T0 (the ovules were cultured for 0 d), T1 (the ovules were cultured for 2 d), T2 (the embryos were cultured for 10 d), T3 (the embryos were cultured for 20 d), T4 (the embryos were cultured for 30 d), and T5 (the shoots after 60 d culture). Results. We used cytology and morphology to observe the characteristics of the cucumber’s developmental transformation during embryogenesis and plant regeneration. The differentially expressed genes(DEGs) at developmental transition points were analyzed using transcriptome sequencing. In the early embryogenesis stage, the cells expanded, which was the signal for gametophytes to switch to the sporophyte development pathway. RNA-seq revealed that when compared to the fresh unpollinated ovaries, there were 3,468 up-regulated genes in the embryos, including hormone signal transduction genes, hormone response genes, and stress-induced genes. The reported embryogenesis-related genes BBM, HSP90 and AGL were also actively expressed during this stage. In the embryo morphogenesis stage (from cell division to cotyledon-embryo formation), 480 genes that functioned in protein complex binding, microtubule binding, tetrapyrrole binding, tubulin binding and other microtubule activities were continuously up-regulated during the T1, T2, T3 and T4 time points. This indicated that the cytoskeleton structure was continuously being built and maintained by the action of microtubule-binding proteins and enzyme modification. In the shoot formation stage, 1,383 genes were up-regulated that were mainly enriched in phenylpropanoid biosynthesis, plant hormone signal transduction, phenylalanine metabolism, and starch and sucrose metabolism. These up-regualted genes included six transcription factors that contained a B3 domain, nine genes in the AP2/ERF family, and two genes encoding WUS homologous domain proteins. Conclusions. Evaluation of molecular gynogenesis events may contribute to a better understanding of the molecular mechanism of cucumber ovarian culture.

The formation of (Ni-Co-Sb)-Ag-As ore shoots in hydrothermal galena-sphalerite-fluorite veins

Unusual hydrothermal native As-sulfide ± native Ag ± arsenide ± antimonide ± sulfosalt ore shoots and their co-genetic sulfide-fluorite-barite-quartz host veins, which are common in the region and in whole Central Europe, were investigated at three localities in the Schwarzwald, SW Germany, to understand the physico-chemical processes governing the change from a normal (= common) hydrothermal to an exceptional ore shoot regime. Based on fluid inclusions, the formation of the gangue minerals is the result of binary mixing between a NaCl-rich brine and a CaCl2-rich brine (both ~ 20 wt% NaCl aq.). This mixing correlation, major and minor fluid composition, formation temperature (~ 150 °C), and δ34S signature are identical (within error) in ore shoots and host veins. Thermodynamic modeling indicates that ore shoot formation must have resulted from a change in redox conditions by a local influx of a volumetrically minor reducing agent, probably hydrocarbons. The elemental content and the mineralogy of each ore shoot locality (Ag-As-rich: Münstertal; Ag–Ni-As-rich: Urberg; Ag–Ni-As-Sb-rich: Wieden) reflect the metal content of the binary mixed fluid, while mineral textures, successions, and assemblages are thermodynamically and, regarding sulfur, kinetically controlled. The formation of vein and ore shoot sulfides requires an addition of sulfide, most probably from the sulfide-bearing host rocks, because thermodynamic and kinetic reasons suggest that the two major vein-forming and metal-bearing fluids are not the source of the sulfur. The final ore shoot textures are influenced by later hydrothermal remobilization processes of As and Ag. This results in a number of sulfosalts, mostly proustite-pyrargyrite. Interestingly, the greater thermodynamic stability of Sb-endmember sulfosalts enables them to form even in As-dominated fluid systems.

Response of in vitro propagated fig (Ficus carica L.) shoots to the concentrations of benzyl amino purine and coconut water

In this study, several concentrations of benzyl amino purine (BAP) and coconut water (CW) were investigated along with the interaction between two factors to the growth of in vitro propagated fig shoots. The investigated factors consisted of BAP concentration: 0, 1, 3, 5 mg L−1 and coconut water concentration: 0, 100, 200, 300 ml L−1. A total of 16 treatment combinations with 6 replications resulting in 96 experimental units consisting of a single fig shoot explant per culture medium. The observed parameters including living explant rate, contamination rate, browning rate, day of first shoot emergence, shoot formation rate, explant height addition, number of leaves, callus formation rate, and number of roots were conducted every week from 1 to 8 weeks after proliferation (WAP). The result indicated that in 8 WAP, the living explant rate reached 23.95%. The combination of concentration 200 ml L−1 CW and 3 mg L−1 BAP + 200 ml L−1 CW-induced early emergence of new shoots at 7 days after proliferation (DAP). The highest shoot formation rate (100%) was observed at a concentration of 300 mL L−1CW. The highest explant height addition (7.10 cm) was observed at a concentration of 200 mL L−1 CW. The highest number of leaves (5.80) was observed at a concentration of 1 mg L−1 BAP + 200 mL L−1 CW. The highest callus formation rate (50%) was observed at a concentration of 100 ml L−1CW and 300 ml L−1 CW. The highest number of roots (17) was observed in the control.

The creation of a Taraxacum kok-saghyz high frequency regeneration system

The aim of this research was to study the morphogenetic ability of Taraxacum kok-saghyz root tissues and to optimize the culture medium for the subsequent genetic transformation of plants. The effects of exogenous hormone exposure on survival, in vitro shoot induction, and root formation were studied by using root tissues. For the cultivation the samples of kok-saghyz, the Murashige-Skuga nutrient medium was used as the basis, supplemented with sucrose 20 g/l, vitamins B5 1 mg/l, and also containing agar 5.5 g/l. The pH value is 5.7. For the plant regeneration induction, growth regulators, auxins and cytokinins were added in culture media. In this study, the roots of D 1 mm and two media variants were used for comparison: variant 1. MS + 6-BAP 1 mg/l; variant 2. MS + 6-BAP 1 mg/l + IAA 0.2 mg/l. An effective protocol for the regeneration of kok-saghyz explants was developed. There was a high percentage of regeneration of 87.6% on the medium containing a combination of cytokinin and auxin, as well as a high percentage of direct shoot formation, which was 65.1%, the degree of rooting was 100%, the resulting cultured plant tissues grew well and had a high survival rate after transplantation.

The effect of tillering on spring wheat productivity in various agro-weather conditions

The current study was carried out on the basis of the Institute of Seed Production and Agrotechnologies, located in the Ryazan Region in 2010–2019, in order to determine the participation share of tillering shoots in the formation of spring wheat productivity in various agro-weather conditions. The objects of the study were the varieties ‘Lada’, ‘Agata’, ‘RIMA’, ‘Maestro’ developed by the Federal Research Agro-Engineering Center VIM. The mean productivity of the studied spring wheat varieties, depending on the level of moisture supply of the growing seasons, had a significant range of 2.20–5.29 t/ha. The mean density of the stems varied from 216 to 620 pcs/m2 among the varieties. The minimum value of 153–253 pcs/m2 was formed under severe drought conditions. When moisture supply improved, the indicator sharply increased in 2.6 times. There has been established that in more humid conditions (HThC 0.98–1.55) the plants were able to realize their potential tillering to a greater extent, the general indicators of tillering among the varieties ranged from 1.06 to 1.23 and 1.63 to 2.11. There was estimated an effect of secondary shoots on productivity, which was 35.2% on average in the trial, and from 10.6% to 48.3% depending on the genotype and environmental conditions. There has been found a shoot formation decrease in 2.4 times of the variety ‘Lada’ under a moisture deficit. There has been determined that the variety ‘RIMA’ had the lowest tillering coefficient for all vegetation periods, and grain weight per a main spike mainly contributed to its productivity. During the moisture deficit periods, the share of the effect of lateral shoots in the variety ‘Agata’ was at the level of mean values, and on 9.9% and 13.1% more than in the varieties ‘Lada’ and ‘RIMA’, respectively. The maximum value of the productivity on the lateral shoots was formed by the variety ‘Maestro’, the productivity share of the secondary shoots during all periods was higher than that of all varieties and amounted to 39.1–48.3%.

Optimization of Callogenesis/Caulogenesis Induction Protocol in Saffron Plant (Crocus sativus L.) Using Response Surface Methodology

The Crocus sativus, an endangered medicinal and aromatic plant in Morocco, has a low propagation rate in natural conditions and, therefore, an efficient method for in vitro propagation is required. This study investigated the effects of various hormones on the induction of callogenesis and callogenesis in C. sativus corms using the Box-Behnken experimental design. The best shoot formation was obtained with Murashige and Skoog fortified with 3 mg/L 6-Benzylaminopurine. On the other hand, callus formation was obtained with 3 mg/L 1-Naphthaleneacetic Acid or 3 mg/L 2,4-Dichlorophenoxyacetic Acid. However, a combination of 3 mg/L 6-Benzylaminopurine, 1.056 mg/L Indole Butyric Acid, and 3 mg/L 2,4-Dichlorophenoxyacetic Acid allows 50% caulogenesis and 60% callogenesis. The in vitro regeneration system could be utilized for both conservation and largescale multiplication of Crocus sativus corms.