Effect of Cryopreservation Method Supported With Biochemical Analyses in the Axillary Bud of Jewel Orchid, Ludisia Discolor

This study was conducted to investigate the potential of conserving an endangered terrestrial jewel orchid Ludisia discolor using in vitro grown axillary buds. Excised segments of axillary buds (4 - 5 mm in length) were precultured on a modified Murashige and Skoog (MS) medium supplemented with 0.2 M sucrose for 24 h and osmoprotected in a loading solution for 20 min. Then, axillary buds were dehydrated in PVS2 solution for 10 min at 0°C and incubated in liquid nitrogen for 1 h. Subsequently, axillary buds were rewarmed rapidly by dilution solution and transferred to a growth recovery medium supplemented with 0.05 µM melatonin under in vitro conditions that led to an improved survival chance (16.67%) for cryopreserved L. discolor. The abiotic stresses and the overproduction of reactive oxygen species (ROS) during cryopreservation stages may contribute to cryoinjuries and poor survival. The varied response towards stress was detected with significantly increased values recorded at certain cryopreservation stages, including proline activity at the dehydration stage (5.51 µmol/g), catalase at the preculture (85.64 U/g) and dehydration (70.87 U/g) stages, peroxidase at the rewarming stage (565.37 U/g) and ascorbate peroxidase during the loading stage (12.19 U/g). Hence, this first attempt to cryopreserved L. discolor indicates that future experimental designs could include exogenous antioxidants and different vitrification solutions to improve survival and regeneration.

Gold nanoparticles affect the cryopreservation efficiency of in vitro-derived shoot tips of bleeding heart

The popularity of nanoparticles (NPs) is continuously increasing. To date, however, there has been little research on the application of NPs in plant cryopreservation, i.e. storage of tissues in liquid nitrogen (LN). The aim of this study is to analyze the effect and evaluate the usefulness of gold nanoparticles (AuNPs) in regard to cryobiology studies. In vitro-derived shoot tips of Lamprocapnos spectabilis ‘Valentine’ were cryopreserved with the encapsulation-vitrification protocol. Gold nanoparticles (at 10–30 ppm concentration; 13 nm in size) were added either into the preculture medium; to the protective bead matrix during encapsulation; or to the recovery medium after rewarming of samples. The control plants were produced from cryopreserved explants non-treated with nanoparticles or treated with colloid dispersion medium without NPs. A non-LN-treated standard was also considered. The influence of AuNPs on the cryopreservation efficiency was determined by evaluating the recovery rate of explants and their morphogenic response; the membrane stability index (MSI); the concentration of pigments in shoots; and the antioxidant enzymes activity. The genetic stability of the plant material was evaluated using Start Codon Targeted Polymorphism (SCoT) markers. It was found that 10 ppm of AuNPs added into the alginate bead matrix improved the recovery level of LN-derived shoot tips (70.0%) compared to the non-NPs-treated cryopreserved control (50.5%). On the other hand, the presence of nanoparticles in the recovery medium had a deleterious effect on the survival of explants. AuNPs usually had no impact on the MSI (73.9–85.9%), except for those added into the recovery medium at the concentration of 30 ppm (decline to 55.8%). All LN-derived shoots were shorter and contained less chlorophyll and carotenoids than the untreated standard. Moreover, the application of AuNPs affected the enzymatic activity in L. spectabilis. Minor genetic variation was found in 8.6% of plants if AuNPs were added either into the preculture medium (at 10 and 20 ppm) or to the alginate matrix (at 30 ppm). In conclusion, AuNPs added at a lower concentration (10 ppm) into the protective bead matrix can significantly improve the cryopreservation efficiency in L. spectabilis with no alternation in the DNA sequence.

Refractory equipment for firing aluminum nitride substrates

The features of firing aluminitride substrates, characterized by a high temperature of more than 1800 0С and the presence of a reducing environment, are described. It is shown that the high quality of substrates in parallelism, thermal conductivity, and other properties can be achieved, along with the establishment of optimal firing modes, using a special design of a capsule based on boron nitride, which is a container that consists of a body - a box of rectangular cross section, bottom and plane-parallel dividing plates with supports. To create a local (inside the capsule) clean recovery medium, thorn-groove interlocks between the body and the bottom are provided, filled with a heat-resistant inert powder.

Effect of Bead Composition, PVS Type, and Recovery Medium in Cryopreservation of Bleeding Heart ‘Valentine’—Preliminary Study

Bleeding heart (Lamprocapnos spectabilis (L.) Fukuhara) is a valuable ornamental and medicinal perennial. To date, there are few studies focused on cryopreservation of this species, although it could be useful in storage and breeding. This research is aimed at analyzing the effect of bead composition, type of plant vitrification solution (PVS), and the recovery medium of cryopreservation of bleeding heart. Shoot tips of L. spectabilis ‘Valentine’ were used in the study. The explants were precultured on modified Murashige and Skoog medium (MS; 1962), supplemented with 9% sucrose, 1.0-mg·L−1 kinetin (KIN), and 2.62-mg·L−1 abscisic acid. Next, in the first experiment, the shoot tips were embedded in 3% calcium alginate, based either on an MS medium or distilled sterile water. The produced synseeds were inoculated on the recovery medium with 3.0-mg·L−1 KIN, 0.5-mg·L−1 6-benzyladenine (BA), or cytokinin–free control. Based on the results of the first study, in the second experiment, precultured shoot tips were embedded in 3% calcium alginate based on MS medium and dehydrated with PVS2 or PVS3 for various durations. The pre-treated explants were plunged in liquid nitrogen and, after rewarming, inoculated on the recovery MS medium with 0.5-mg·L−1 BA. PVS3 was more effective in securing the shoot tips than PVS2. The highest recovery level (68.3%) was reported after a 150-min pretreatment with PVS3. Explants from this experimental combination also proliferated the highest number of shoots, as well as those with the greatest length. On the other hand, a higher share of dry weight was found in PVS2-derived shoots (13.5–18.2%) compared with plants produced after PVS3 treatment (10.6–11.4%). The obtained results here can serve as a good basis for further studies related to synthetic seeds and cryopreservation of bleeding heart.

TRANSFORMATION OF THE ECONOMIES OF IRAN AND RUSSIA UNDER THE NEW CORONAVIRUS OUTBREAK

The new coronavirus outbreak has created a serious problem for the economies of Iran and Russia, which are experiencing sanctions and low oil prices. In this article, the author tries to explain the impact of the new coronavirus outbreak on the economies and politics of Iran and Russia. The major results show that the three challenges associated with sanctions, the shock of global oil prices, and the new coronavirus outbreak can lead to different scenarios for the future of Iran and Russia. Eight different scenarios (slow economic growth, economic prosperity, weak recession, economic recovery, medium recession, economic stagnation, strong recession, and economic transformation) are identified and explained by combinations of these three issues. Regarding the current low oil prices (due to the pandemic and the Saudi price war), Western sanctions against Iran and Russia, and also uncertainty about the end of the coronavirus, scenario No. 8 (economic transformation) will be the most likely situation for the economies of Russia and Iran. As the results of this scenario, the digitalization of the economies in these two countries will be improved, and the role of governments in economic mechanisms will be higher than before the coronavirus outbreak. In addition, regionalization and Asianization will be accelerated to reduce the effect of sanctions.

Critical vitrification steps towards survival of Garcinia hombroniana (Clusiaceae) shoot tips after cryopreservation

A cryopreservation protocol was developed for in vitro shoot tips of Garcinia hombroniana using the vitrification technique. Four critical steps in the technique were investigated, namely preculture, loading, dehydration with Plant Vitrification Solution 2 (PVS2), and unloading. Shoot tips precultured for 48 hr gave significantly higher survival (75 %) compared to 24 hr preculture (50 %) after cryopreservation. Treatment with 1 M glycerol plus 0.4 M sucrose as a loading solution gave higher survival (45.83 %) compared to the other treatments (0.4 M sucrose + 2 M glycerol; 0.4 M sucrose). Shoot tips dehydrated with PVS2 for 25 min gave the highest survival after immersion in liquid nitrogen. Stepwise PVS2 treatment for 15 min with 50 % PVS2 followed by 10 min with 100 % PVS2 solution improved survival of the shoot tips after cryopreservation (41.67 %). Murashige and Skoog medium with 0.4 M sucrose gave significantly higher survival (66.67 %) than MS with 1.2 M sucrose (25 %) as an unloading solution. Water content was shown to decrease throughout the whole vitrification steps from 6.83 ± 1.66 g g-1 dw for fresh shoot tips down to 2.93 ± 0.28 g g-1 dw after PVS2 treatment. Further study on each step including recovery medium is required to improve the survival. Nevertheless, the present study showed the potential of using the vitrification technique for cryopreservation of G. hombroniana.