Meristem Culture Research Articles

Differential behavior of sugarcane (Saccharum species hybrid) genotypes towards varying concentrations of pH for rapid in vitro micropropagation

Sugarcane (Saccharum species hybrid) is not only an important cash crop but also major source of sugar industry worldwide. An effort was made to understand the effect of varying levels of medium pH for testing differential response of sugarcane genotypes (Co 86032, Co 85004 and Co 99004) on in vitro shoot initiation, induction, multiplication and root formation. The shoot apical meristem of the three varieties was cultured on MS medium with different pH levels. Aseptic meristem cultures of the three sugarcane genotypes were cultured in vitro on the medium with five pH concentrations, viz. 4.8, 5.0, 5.4, 5.6 and 5.8. Co 85004 was found to show its response towards the medium pH at 5.6 in producing highest number of shoots (~22). However, Co 99004 responded well towards medium pH at 5.4 which produced ~21 numbers of shoots and Co 86032 exhibited its potentiality towards pH only at 5.8 levels (~17) on 180 days after inoculation. The response of all the genotypes were on par towards pH 7.0 which produced highest number of roots. At pH 5.8 genotype, Co 86032 produced highest shoot length (~3 cm) followed by Co 85004 (~2 cm) and Co 99004 (~2 cm). The study revealed that medium adjusted with pH 4.8, pH 5.8 and pH 7.0 levels resulted in optimum in vitro shoot initiation, induction, multiplication and root formation responses in Co 85004, Co 99004 and Co 86032, respectively.

TUBER CHARACTERISTICS OF DISEASE FREE MERISTEM CLONES OF POTATO GENOTYPES

Potato seedlings of various potato genotypes free from the following viruses PVS (potato viruses S), PVX (potato viruses X), PVY (potato viruses Y), PLRV (potato leafroll virus), PVA (potato viruses A) and PMTV (potato mop-top viruses) were obtained via meristem culture and they were increased in vitro. Seedlings were grown in the greenhouse and mini tubers obtained were tested in the seed bed and in the field trials.
 When the results of greenhouse experiment were evaluated: clone Nif-1 was found to be high for single tuber number (3.0). Clone 6/7-1 had high means as compared to the remaining for single tuber weight (5.2 g) and single plant yield (14.5 g). The highest mini tuber number was obtained from Clone 6/7 in seedbed experiment. Also Hermes-1 had higher means for single tuber weight and Clone 122-1 had the higher means for plant yield and plot yield than that of other clones. Clones Atlantic-2; 3 and 1 (5.8 cm) had high tuber width and clone Hermes-1 and 2 (6.6 cm) had the highest means for tuber length in the seedbed trial. Based on the results of field experiment the highest minituber numbers were obtained from Clone 6/7-2 (10.7) and Clone 6/7-2 (10.3). Atlantic-1 (136.5 g) had high mean for tuber weight as compared to other clones. Nif-1 had the highest mean for plant yield as 920.2 g. Clone 122-1 was found to be higher than the other clones for plot yield (5.3 kg). Clones of Atlantic-1; 2 and 3 (5.9 cm) had high tuber width and clones of Juwel-1; 2 and Hermes-2 (6.8 cm) had the highest means for tuber length.

English

Considering the potential benefit of meristem culture in the mass production of quality propagation materials, an experiment was conducted to investigate meristem culture in KUWE (G1) and 223098 (G2) genotypes of anchote. Concentration levels of 6-benzylamimopurine (BAP) with and without gibberellic acid (GA3) and naphthalene acetic acid (NAA) for shoot induction while BAP and kinetin (Kn) for shoot multiplication were evaluated. Full and half nutrient-strength of Murashige and Skoog medium (FMS and HMS) with sole application of indole butyric acid (IBA) and indole acetic acid (IAA) were tested for root induction. About 80% (G2) and 71% (G1) of meristems induced shoots at 1 and 0.5 mg/L BAP, respectively. The highest shoot number (6.52), in G2, was recorded at 0.5 mg/L BAP while 0.5 mg/L BAP + 0.5 mg/L Kn produced 6.32 shoots in G1. FMS + 0.5 mg/L IBA was effective in 100% root induction in both genotypes. Survival rates of 58% (G1) and 42% (G2) were obtained. Generally, 0.5 mg/L BAP (G1) and 1 mg/L BAP (G) are best for shoot induction while 0.5 mg/L BAP (G2) and 0.5 mg/L BAP+0.5 mg/L Kn (G1) for multiple shoot development with best root formation on FMS+0.5 mg/L IBA. Key words: Direct regeneration, genotype, meristem explants, MS media, plant growth regulators (PGRs).

Assessment of epigenetic methylation changes in hop (Humulus lupulus) plants obtained by meristem culture

In vitro meristem cultures have been used for the production of hop (Humulus lupulus L.) virus-free rootstocks worldwide, because multipropagation is considered to preserve the genetic stability of the produced plantlet. Nevertheless, in vitro tissue cultures can cause genetic and epigenetic changes. Therefore, we studied the genetic and epigenetic variability of Saaz Osvald’s clones, Sládek and Premiant cultivars on the DNA methylation level by methylation-sensitive amplification polymorphism (MSAP). In vitro propagated plants, acclimatised glasshouse rootstocks as well as derived mericlones and control plants under field conditions were used for the analyses. A total of 346 clearly and highly reproducible amplified products were detected in the MSAP analyses within the studied hop plants. We found 16 polymorphic products (4.6% of products) and 64 products with methylation changes (18.5% of products) in the analyses. The demethylation events were comparable to the de novo methylation events. Most demethylation changes were found in the in vitro plants, but only a few of them were found in the derived mericlones under field conditions. In contrast, the de novo methylation changes persisted in the acclimatised plants under glasshouse or field conditions. A hierarchical cluster analysis was used for the evaluation of the molecular genetic variability within the individual samples. The dendrogram showed that the individual samples of the same variety, more or less, clustered together. Because the methylation status varied during the virus-free rootstock production process, we suppose that de/methylation process is a natural tool of epigenetics and evolution in vegetatively propagated plants.

ACCELERATED PRODUCTION OF VIRUS-FREE POTATO PLANTING MATERIAL USING A BIOREACTOR

Potato production is one of the key branches of crop production that determines the food security of Kazakhstan. The Republic needs over 800,000 tons of seed potatoes per year. In addition to seed potatoes, which are grown in Kazakhstan, about 30,000 tons of seed potatoes are imported annually, while about 80% of this volume is imported from the Netherlands through private companies [1]. In 2018, 193.0 thousand hectares were occupied under potatoes in Kazakhstan, while the gross harvest amounted to 3806.9 thousand tons. At the same time, the yield in 2018 was only 19.8 t/ha. While in neighboring Uzbekistan in 2018, the yield was 33.68 t/ha, the maximum yield in New Zealand in 2018 was about 50.41 t/ha[2]. It is known that one of the main reasons for low potato yield is low-quality seed material. In Kazakhstan, mainly after obtaining virus-free plants in vitro through meristem culture, minitubers are obtained from them in most technological processes; in rare cases, microtubers are obtained from meristem plants in vitro and then minitubers from them. Research has shown that the bioreactor can massively clone meristem plants and get full-fledged virus-free microtubules reducing a significant proportion of manual labor, thereby reducing the impact on the result of the human factor, reduce infections, and reduce labor costs and material costs.

Combining thermotherapy with meristem culture for improved eradication of onion yellow dwarf virus and shallot latent virus from infected in vitro‐cultured shallot shoots

AbstractThe present study described a combining thermotherapy with meristem culture for improved eradication of onion yellow dwarf virus (OYDV) and shallot latent virus (SLV) from co‐infected in vitro‐cultured shallot shoots. In vitro‐cultured shoots infected with OYDV and SLV were thermo‐treated at a constant temperature of 36°C for 0, 2 and 4 weeks, and then meristems (0.5 mm) containing 1–2 leaf primordia were excised and cultured for shoot regrowth. Meristem culture without thermotherapy produced much higher levels of survival (100%) and shoot regrowth (55%) than those (62% survival and 32% shoot regrowth) produced by the procedure combining 4 weeks of thermotherapy with meristem culture. However, much higher virus‐free frequencies (70% for OYSV, 80% for SLV and 50% for both viruses) were obtained in the latter than those (10% for OYSV, 15% for SLV and 10% for both viruses) obtained in the former. Histological and subcellular studies showed that thermotherapy imposed stress or damage to the cells of meristems, thus resulting in reduced meristem survival and shoot regrowth. Studies on virus location revealed considerable alternations of virus distribution patterns in the thermo‐treated meristems. The results of histological and subcellular studies and analysis of virus distribution pattern added valuable experimental data in the combining thermotherapy with meristem culture for virus eradication. These data provided explanations as to why combining thermotherapy with meristem culture improved the eradication of OYDV and SLV from the virus‐infected in vitro shallot shoots.

Molecular Viral Diagnosis and Sanitation of Yam Genetic Resources: Implications for Safe Yam Germplasm Exchange.

Yam (Dioscorea spp.) is an important crop in tropical and subtropical regions. Many viruses have been recently identified in yam, hampering genetic conservation and safe international exchanges of yam germplasm. We report on the implementation of reliable and cost-effective PCR-based detection tools targeting eight different yam-infecting viruses. Viral indexing of the in vitro yam collection maintained by the Biological Resources Center for Tropical Plants (BRC-TP) in Guadeloupe (French West Indies) unveiled a high prevalence of potyviruses, badnaviruses, Dioscorea mosaic associated virus (DMaV) and yam asymptomatic virus 1 (YaV1) and a high level of coinfections. Infected yam accessions were subjected to a combination of thermotherapy and meristem culture. Sanitation levels were monitored using PCR-based and high-throughput sequencing-based diagnosis, confirming the efficacy and reliability of PCR-based detection tools. Sanitation rates were highly variable depending on viruses. Sixteen accessions were successfully sanitized, paving the way to safe yam germplasm exchanges and the implementation of clean seed production programs worldwide.

Establishment of meristem culture for virus-free and genetically stable production of the endangered plant Hosta capitata

Hosta species endemic to Korea are currently suffering from infection with Hosta virus X (HVX), and it has been difficult to produce virus-free plants when using infected plants as a source of material for in vitro and vegetative propagation in continuous production processes. Genetic variation in in vitro-regenerated plants has also been detected in some Hosta cultivars. Therefore, we aimed to develop an in vitro propagation method for the production of virus-free and genetically stable plants. First, we collected Hosta capitata showing symptoms of viral infection and confirmed the presence of an HVX virus gene using reverse transcription (RT)–PCR, followed by optimization of the sterilization of in vivo bulbs. Meristems derived from sterilized bulbs were cultured in media containing different concentrations of 1-naphthaleneacetic acid (NAA) with either benzyl aminopurine (BA) or thidiazuron (TDZ). The combination of 0.1 mg/l NAA and 3.0 mg/l BA generated the highest number of shoots per explant, and these shoots had a higher fresh weight. The addition of nano-silver (NAg) particles to the regeneration medium distinctly stimulated plant growth. According to the results of RAPD analysis, the meristem-derived plants were genetically stable compared with donor plants grown in a greenhouse, and absence of the HVX gene was also observed, indicating freedom from HVX infection. Therefore, they would be highly valuable for use in the landscape industry. We expect that the method proposed in this study will also prove helpful for generating virus-free, genetically stable plants in the commercial production of other Hosta species.

Micropropagation and pathogen elimination in elderberry (Sambucus nigra L.)

To date, more than 75% of Austrian elderberry acreage is planted with cultivar ‘Haschberg’. This leads to high costs during harvest, since most of the berries have to be harvested at the same time and need to be frozen within hours after picking. In order to improve the spectrum of elderberry cultivars micropropagation of five elderberry cultivars was optimized. To meet the requirement for certified planting material, thermotherapy and chemotherapy (ribavirin), followed by meristem tip culture, were succesfully applied to eliminate various plant pathogens from elderberry plants. Virus detection was carried out by RT-PCR and confirmed by electron microscopy. An efficient protocol was developed using the cytokinins, BA for multiplication and meta-Topolin for shoot elongation and rooting of Sambucus nigra L. plants. Two commercial arbuscular mycorrhizal inoculants were evaluated for their potential to improve the process of ex-vitro-acclimatization. Both inoculants significantly enhanced survival rates, shoot length and root colonization levels of elderberry plants. Pathogen free elderberry plants were produced via thermotherapy or chemotherapy followed by meristem culture. Culture media for micropropagation were optimized. Acclimatization of plants was significantly improved by artificial inoculation with AMF products.

Development rate of meristem potato plants (Solanum tuberosum) in vitro under the influence of biologically active product nano silicon

Healthy seed-potato production is possible through certified mini tubers from complete healthy meristem micro plants in a medium which contains all micro and macro nutrients. Addition of nano silicon a biological activity booster, can provoke the growth, development and productivity of plants at specific concentrations. Based on this, a research was carried out during 2020 at the Laboratory of Agricultural Plant Biotechnology of Samara Scientific Research Agricultural Institute, Samara, Russia to study the influence of modifications in Murashige and Skoog medium by adding the biologically active nano silicon product in two concentrations of 1.5 and 3.0 ml/L on the growth and development of potato meristem micro plants of Rainbow and Grand varieties. Forty micro-plants of each variety were grown in a meristem culture with a 16-hour photoperiod for 30 days. The lighting source was fluorescent lamps with the wavelength from 440 nm to 670 nm and illuminance of 5000 lux. The temperature in the growing room was maintained at 22°C during daytime under lighting and 18°C at nighttime. The relative humidity in growing room was 75–80%. There were two cycles of cultivation for each variety. At the close of each growing cycle, the morphological characteristics that show the growth intensity and development of regenerants (the plant length and the number of internodes) were measured. The growth and development of potato regenerants was influenced by modification in Murashige and Skoog medium with the addition of 1.5 ml/L concentration of the biologically active nano silicon. A significant increase was recorded in the length of potato meristem micro plants of both Rainbow and Grand varieties, as well as a significant increase in the number of micro plant internodes of the mid-ripening potato variety Grand.

English

Vegetatively propagated crops are exposed to pests every growing season, providing them with the opportunity to feed on the plants and transmit diseases. Meristem culture is an important method to clean for viruses to restore high yields. Media optimizations with different concentrations and combinations of 6-benzylamino purine (BAP) and Naphthalene Acetic Acid (NAA) were tested for their effects on shoot initiation from meristems. This was followed by regeneration and shoot multiplication from nodal cuttings in five elite varieties of sweet potato. There was a highly significant genotype (variety) x environment (media) interaction for all experiments. Concentrations and combinations of BAP and NAA significantly affected the percentage of meristem survival/regeneration and subsequent shoot multiplication. The best combination of the plant growth regulators was NAA (0.1 mg/L) and BAP (1.0 mg/L). For further propagation, shoot numbers per single nodal cuttings were significantly affected by BAP concentrations (p < 0.05) and genotypes. The medium which gave maximum numbers of shoots was ½ MS media supplemented with BAP (2.5 mg/L) and GA3 (0.5 mg/L). The tallest shoots, with the highest number of internodes, suitable for transfer to soil, was obtained from ½ MS media without any growth regulators for all of the cultivars.   Key words: Media, meristem, multiplication, regeneration, shoot, sweet potato.

Comparing the efficiency of conventional and novel methods of virus elimination using molecular techniques

Viral pathogens significantly affect pear growth and reduce annual production across the world. This study aimed to examine whether conventional virus elimination methods, including thermotherapy (0, 7, 14 and 21 d at 38 °C), meristem culture (less than 0.2 mm, between 0.2 to 0.7 mm and larger than 0.7 mm) and adventitious shoot regeneration from leaf explants can lead to virus-free pear seedlings when compared to chemotherapy (sodium nitroprusside (SNP); 0, 10, 17, 25, 50 and 70 μM). Five pear cultivars (“Abate Fetel”, “Beiruti”, “Dargazi”, “Coscia” and “Louise Bonne”) were investigated to check if those treatments are capable of eliminating three key viruses in pear, namely Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV) and Apple stem grooving virus (ASGV). The plant’s infection to the viruses was examined using reverse transcription polymerase chain reaction (RT-PCR), followed by applying the treatments, meristem culture and in vitro cultivation. Results surprisingly showed a direct relationship between an increase in duration of thermotherapy and virus elimination. Moreover, it was shown that small size of the cultivated meristem increased the rate of virus elimination, even though the responses were different in terms of the cultivars and viruses. Shoot regeneration had very low efficiency in leaf explants as it could only eliminate ASPV from pear explants. Interestingly, the experiment demonstrated that nitric oxide treatments were more effective in virus elimination than the other treatments. A year later, samples that were diagnosed virus-free were proliferated, rooted and transferred into pots to be used for later propagation and establishment of a mother orchard.

IN VITRO ELIMINATION OF DAHLIA MOSAIC VIRUS BY USING MERISTEM CULTURE, ELECTROTHERAPY AND CHEMOTHERAPY

This study was conducted to investigate the effect of different in vitro techniques on elimination of dahlia mosaic virus. Meristems of Dahlia mosaic virus (DMV) infected dahlias, with 0.2-0.3 mm in length, were cultured on Murashige and Skoog (MS) medium. Based on DAS-ELISA, 100% of the survived plantlets by meristem culture were virus-free. DMV infected stem segments with two axillary buds were treated at three different levels of electric currents (15, 25 and 35 mA) and two time courses (10 and 20 min) in an electrophoresis tank and cultured on MS medium. The treatment of 35 mA for 20 min was the best for viral elimination from diseased dahlias by 85% followed by 25 mA for 20 min by 70%. Acyclovir and salicylic acid were the antivirals were used to eliminate DMV from the infected dahlias. For chemotherapy, nodes were cultured on MS media supplemented with antivirals at 0, 10, 20, 30, 40 and 50 mg/l for 20 and 30 days. The highest concentration of acyclovir (50 mg/l) for 30 days were the best treatments as its highest effectiveness on elimination ability (90.67%) but gave only 49% for plantlet survival. Whereas 40 mg/l acyclovir for 30 days gave elimination ability (80%) and plantlet survival (89.67%). The therapy containing salicylic acid at 40 mg/l for 30 days was the best as its highest effectiveness on DMV elimination ability (100%). But the concentration of salicylic acid at 30 mg/l for 30 days was the best treatment (chemotherapy efficiency= 49.21) as well as DMV elimination ability (75.33%) and plant survival (65.33%). The in vitro developed dahlia plantlets were tested for DMV-freeness using DAS-ELISA. The using therapies (electrotherapy and chemotherapy) can play a good role in virus elimination because they need the minimum period of time to regenerate fully developed healthy plants as long as 2-3 months.

Virus Infection and Growth of Advanced Generations in Northern-type Garlic bulbs from Meristem Culture

Virus Infection and Growth of Advanced Generations in Northern-type Garlic bulbs from Meristem Culture

A novel sustainable aeroponic system for healthy seed potato production in India – An update

High yielding varieties and sound planting materials are prerequisites for sound seed potato production. Low multiplication rate, high seed (tuber) rate, dynamic amassing of degenerative infections, perishability and massiveness are the inherent issues in seed potato production. This may result in non-accessibility/non-availability of sufficient amounts of value seeds at reasonable cost and seed cost alone reflects 40% which is half of the aggregate expenses of development in potato. To go around a portion of these issues, a few alterations, for example, tuber ordering for infection opportunity, seed increase stages and seed accreditation guidelines have been created and incorporated with regular potato seed generation programs. The advent of tissue culture, in which virus-free plants can be produced through meristem culture, maintained indefinitely under controlled conditions and multiplied in artificial media under sterile conditions in the laboratory throughout the year irrespective of growing season, has revolutionized seed production in potato world over. Recent developments in automation of minitubers production have further enhanced adaptability of these techniques in potato seed production. In addition to quality assurance through meristem culture, aeroponic technique of minitubers production ensures high multiplication rate at initial stages of quality seed potato production.

Elimination of Garlic common latent virus from garlic through meristem culture and thermotherapy

Virus infection on garlic (Allium sativum) can be accumulated through vegetative propagation and may cause yield losses. It was evidenced in this study that infection of GCLV on garlic seed cv ‘Tawangmangu Baru’ reached 100% based on detection using DIBA (Dotimmuno binding assay). This research was initiated to obtain an elimination method of GCLV from garlic seed bulbs of cv ‘Tawangmangu Baru’. Tissue culture-based method was used in this research involving isolation of 1.0 mm meristem from micro shoots followed by thermotherapy at 25 °C, 28 °C, 31 °C, and heterogeneous temperatures for 4 wk. Virus indexing was conducted using RT-PCR on micro shoots that grown after treatment. The results showed that meristem culture and thermotherapy did not affect the growth of micro shoots based on assessment on the percentage of surviving explants, plant height, and the number of leaves. Infection of GCLV was still detected on micro shoots after thermotherapy, i.e. 64% to 91%. Virus infection on garlic cv ‘Tawangmangu Baru’ was not totally eliminated by meristem culture and thermotherapy. Factors affecting this result will be discussed in this paper as well as methodology improvement to produce virus-free garlic with high multiplication rate of explants.

DPROPAGACIÓN IN VITRO DE Alstroemeria var. ‘FIESTA DE 15 INTA’ A PARTIR DEL CULTIVO DE MERISTEMAS DE RIZOMA

Alstroemeria (Alstroemeriaceae) is a genus endemic to South America. Its species, which are distributed from Venezuela to Argentina and Chile, have a high impact on the ornamental plant market because of the color and attractive shape of their flowers. In vitro culture of meristems increases the efficiency of plant propagation and quality by contributing to the cleaning of systemic diseases. The present study aimed to develop an efficient protocol for rhizome meristems culture of Alstroemeria hybrida var. Fiesta de 15 INTA with the addition of growth regulators bencilaminopurine (BAP) and naftalenacetic acid (NAA) to a base culture medium. Whole plants, leaf production, shoot and root length, callus formation, necrosis and mortality of explants planted on MS; MS + 1 mg L-1 BAP; MS + 0.2 mg L-1 NAA; and MS + 0.2 mg L-1 NAA + 1 mg L-1 BAP were evaluated. An analysis of variance and evaluation of differences between means were performed by the Tukey test, which indicated that an efficient method for the micropropagation of Alstroemeria var. Fiesta de 15 INTA consists of MS supplemented with 0.2 mg L-1 NAA. This procedure resulted in a greater shoot (aerial) and root (radical)growth and, consequently, in a higher number of whole plants as well as a high plantsurvival rate after transfer to the greenhouse.

Callus Induction and Virus Free Potato Mini-Tuber Production through Meristem Culture

The experiments were conducted with a view to establish a protocol for virus free mini-tubers production, in vitro, using potato meristem as explant, collected from potato sprouts of three popular potato varieties Diamant, Cardinal, Granola. In the present study four levels of GA3 (100, 200, 300 and 400 ppm) were used to assess the influence on sprouting abilities in three selected potato verities. The maximum sprouting efficiency was observed in 400ppm GA3 treatment within short period of time in Granola variety. The effect of different combination and concentration of IBA, 2, 4-D and BAP was used along with fresh MS media to inoculate meristems of potato sprouts. IBA concentration were 0.25mg/L, 1.5mg/L; 2, 4-D concentration were 0.125mg/L, 0.25mg/L, 0.37mg/L, 0.50mg/L, 1.0mg/L 2.0mg/L and BAP concentration were 0.5 mg/L, 1.0 mg/L, 1.5 mg/L and 2mg/L. The effect of combined hormones was also studied. The Diamant variety showed the maximum callus size (0.74cm) within a very short period of time (2 days) while treated at the concentration of 0.25 mg/L IBA, 0.25 mg/L 2, 4-D and 1.00 mg/L BAP. Granola meristem inoculated in hormonal treatment showed the best results regarding minimum days required to shoot initiation (5.34 days) followed by Diamant (6.68) days and Cardinal (7.64 days). The highest number of shoots/plantlet (4.33 shoots/plantlet) and the longest plantlet (9.32 cm) was found in Granola variety followed by Diamond (3.67 shoots/plantlet; 7.53cm) and Cardinal (4.0 shoots/plantlet; 7.62 cm). Maximum numbers of leaves were also found in Granola variety (15 leaves) in the treatment combination of 0.25 mg/L IBA, 0.125 mg/L 2,4-D and 0.5 mg/L BAP. Granola gave maximum performance in respect of maximum length of root (6.55 cm roots/plantlets) within a short time of root initiation (20 days), followed by Diamant (4 cm roots/plantlets) of root initiation (4.47 days) and Cardinal (4.53 cm roots/plantlets) of root initiation (26.39 days). Rooted plantlets were gradually acclimatized and successfully established in the field. However, in overall observation in this study, Granola showed better performance from meristem tissue culture and all plants were found normal and free from potato viruses that were tested through ELISA test.

Analysis of potate quality: In vitro versus clonal propagation

Potato, one of the most important food crops in the world, is susceptible to viruses, which reduce its yield and production efficiency. The resistance of potatoes to viral infection is an essential factor in the preservation of the variety’s productive qualities. In addition, there are several ways of selection for recovering and obtaining the initial seed material that is free from viruses for further reproduction in the seed growing of potatoes. It should be noted that in the literature the issues of medium-late potato varieties resistance to viral diseases in the Forest-Steppe zone of Ukraine are not fully covered, which has become the subject of our research. In our studies we used the material obtained by the method of improving selections, as well as using thermotherapy and apical meristem culture. Over the years of reproduction both meristematic and seed material from improving selections, the virus infestation in plants wasn’t changed significantly, provided that all seed growing events were observed. It has been proven that the yield of super-super-elite of Lybid variety is not significantly changed depending on the method of obtaining the initial material. The variety Gorlitsa has higher yield in the plantations formed by clonal propagation. It has been established that the yield of variety Lybid super-elite varies, but not significantly, depending on the method of obtaining the initial material. The variety Gorlitsa has a higher super-elite yield when using the initial material from clonal propagation in breeding nurseries with use of improved selections. Significant influence on the manifestation of the sign, both in the cultivation of super-super-elites and super-elites, has the weather conditions of the year and the biological characteristics of the variety. In 2017, the highest yield of tubers was obtained at Gorlitsa – 3.74·104 kg ha-1, at Lybid the lower yield was 2.43·104 kg ha-1. In 2018, the highest yield of tubers was formed by Lybid variety – 3.50·104 kg ha-1, and the lowest was byt Gorlitsa variety – 2.56·104 kg ha-1.

A Review on Micropropagation Culture Method

Micropropagation is a vegetative propagation conducted under controlled and aseptic conditions in the microenvironment of the culture vessel, which have the all growth requirements of a plant in the natural conditions. Recently different techniques of propagation have been developed which could facilitate large scale production of plants and for the improvement of the species. An overview on the in vitro propagation via meristem culture, callus culture and protoplast culture etc. are presented here. Today micropropagation techniques are applied in order to produce large numbers of new high-quality plants in a relatively short time and space, in low cost and can also be preserved.