Culture Technology Research Articles

The influence of cultivation technologies on the contamination of spring wheat crops and yield in the conditions of the Nizhny Novgorod region

The article presents the results of research of the influence of various cultivation technologies on the contamination of spring wheat crops and its yield for 2022–2023 in the conditions of the Nizhny Novgorod region on light gray loamy forest soil. There were studied the technologies various in methods of primary soil tillage (traditional, minimal – Mini-till, without tillage – No-till), and intensification level (basic, intensive). Spring wheat of the ʻZlataʼ cultivar was cultivated in the chain of rotation: clean fallow – peas - spring wheat. During the research period, it was established that the No-till technology contributed to an increase in the total contamination of spring wheat crops on an average for two years in the "tillering" phase (before herbicide treatment) to 36.2 pcs/m2 (84.7 % higher than the total contamination of wheat crops when cultivated using Mini-till technology and by 118.1 % –using traditional technology) and in the phase of "full grain ripeness" (before harvesting) up to 30.1 pcs/m2 (110.5 % higher than the total contamination of wheat crops cultivated using Mini-till technology and by 155.1 % according to traditional technology). It has been established that intensification of wheat production (application of mineral fertilizers in a dose of N70P50K50 before pre-sowing cultivation; using fungicide and herbicide in the "tillering" phase) results on average among studied technologies in decreasing the total contamination of crops during the "full grain ripeness" phase on average for two years up to15.7 pcs/m2 which is 38.2 % lower compared to the basic intensification degree of wheat cultivation technologies. It was found that the cultivation of spring wheat using traditional technology and Mini-till technology provides high yields: 3.09–3.43 t/ha, that is 0.63–0.96 t/ha higher than its yield when cultivated using No-till technology. There were no differences in the level of yield of spring wheat over the years of observation when cultivating it using traditional and Mini-till technologies. The intensification of spring wheat production makes it possible to increase the level of its yield for each of the studied technologies.

Design of Business Ecosystem Mapping in the Black Soldier Fly Industry of Bandung City

BSF (Black Soldier Fly) maggot cultivation is an alternative organic waste management that is growing rapidly in the city of Bandung. This research aims to design a business ecosystem map for the BSF maggot cultivation industry in Bandung City. The method used is business ecosystem mapping with a qualitative approach modified by Zheng Ma. The research results show that the BSF maggot cultivation industry in Bandung City has six main groups of actors, namely maggot producers, maggot consumers, maggot raw material suppliers, maggot cultivation equipment and technology suppliers, government, and research institutions. Interactions between actors are driven by shared values, such as sustainability, circular economy and economic value. External factors that influence the development of the BSF maggot cultivation industry in Bandung City are government policy (politics), market trends (economics), public awareness (social) and technological progress (technology). Reconfiguration of the BSF maggot cultivation business ecosystem in Bandung City by incorporating elements of changes in external factors. The map of changes in the BSF maggot cultivation business ecosystem in the city of Bandung over the next 5 years includes: (1) increasing BSF maggot production to meet market demand, (2) developing new products and services based on BSF maggots, (3) increasing collaboration between actors, (4) strengthening human resource capacity, and (5) encouraging the development of environmentally friendly BSF maggot cultivation technology.

Comprehensive assessment of elite forms of black currant of the Ural selection for suitability to mechanized harvesting

In the conditions of the Sverdlovsk region (Middle Urals), a comprehensive assessment of elite forms of black currant was carried out to identify those suitable for mechanized harvesting with intensive cultivation technologies. The objects of research were 12 elite forms of black currant bred by the Sverdlovsk Breeding Station of Horticulture (planting 2018, layout 3×1 m). The research was carried out in 2021–2023 according to generally accepted methods. The studies were carried out according to generally accepted methods. According to the height of the bush, elite forms 3-2-05-08, 3-8-05-08, 5-2-05-08, 2-11-05-08 were distinguished – the measurement result was 100...110 cm; by the width of the bush – 3-1-05-08, 3-5-05-08, 3-8-05-08, 5-2-05-08 – 110...120 cm. The diameter of the base of the bush for most variety samples was 20.. 30 cm. The number of bent branches in all forms was less than 5 %, the diameter of the branches 8...15 mm. The average weight of berries was 1.5 1.8 g for elite forms 2-11-05-08, 3-5-05-08, 4-6-05-08, 4-7-05-08, 5-2 -05-08. The crushing force of berries in the studied variety samples was 201...367 g. Based on the force of berry separation, elite forms 3-5-05-08, 4-5-05-08, 5-4-05-08 stood out – 50 57 g. According to the results of the assessment of suitability for mechanized harvesting, the elite form of black currant 3-5-05-08 has optimal values in all parameters. Elite forms 2-11-05-08, 3-1-05-08, 3-8-05-08, 5-2-05-08, 4-6-05-08, 4-7-05-08, 5-4-05-08 are subjected to testing under production conditions. The following variety samples are not suitable for mechanized harvesting: 3-4-05-08, 4-5-05-08, 5-1-05-08, 5-3-05-08. In the conditions of 2023, elite forms 4-5-05-08, 5-1-05-08 were characterized by resistance to fungal diseases.

Research on the economic efficiency of organic farming versus traditional farming

The method of organic farming is becoming more and more popular. All farmers are still concerned about finding workable ways to cut back on the number of treatments and minimize the usage of pesticides. The effort aims to establish a technical technique for producing some horticultural species that satisfies ecological agriculture requirements, as well as to explore some aspects of biological control to limit the spread of some diseases and pests in some horticultural species. The goal of this research is to investigate some aspects of biological control in order to prevent the development of certain diseases and pests in some horticultural species, as well as to design a technical approach for producing some horticultural species that fits the standards of ecological agriculture. It also includes a study on the economic effectiveness of an ecological culture technology for producing goods with high ecological purity in certain horticulture plants. Because the cost of the seedlings obtained ecologically is 50–150% greater than that of the conventional system, the total cost of tomato crops in the ecological system is higher than that of the conventional system.

Trophectoderm grade is associated with the risk of placenta previa in frozen-thawed single-blastocyst transfer cycles.

Do obstetric and perinatal complications vary according to different blastocyst developmental parameters after frozen-thawed single-blastocyst transfer (SBT) cycles? Pregnancies following the transfer of a blastocyst with a grade C trophectoderm (TE) were associated with an increased risk of placenta previa compared to those with a blastocyst of grade A TE. Existing studies investigating the effect of blastocyst morphology grades on birth outcomes have mostly focused on fetal growth and have produced conflicting results, while the risk of obstetric complications has rarely been reported. Additionally, growing evidence has suggested that the appearance of TE cells could serve as the most important parameter for predicting implantation and live birth. Given that the TE ultimately develops into the placenta, it is plausible that this independent predictor may also impact placentation. This retrospective cohort study at a tertiary-care academic medical center included 6018 singleton deliveries after frozen-thawed SBT cycles between January 2017 and December 2021. Singleton pregnancies were grouped into two groups according to blastocyst developmental stage (Days 5 and 6), four groups according to embryo expansion (Stages 3, 4, 5, and 6), three groups according to inner cell mass (ICM) quality (A, B, and C), and three groups according to TE quality (A, B, and C). The main outcomes included pregnancy-induced hypertension, preeclampsia, gestational diabetes mellitus, preterm premature rupture of membrane, placenta previa, placental abruption, placenta accreta, postpartum hemorrhage, preterm birth, low birth weight, small for gestational age, and birth defects. Multivariate logistic regressions were performed to evaluate the effect of blastocyst developmental stage, embryo expansion stage, ICM grade, and TE grade on measured outcomes adjusting for potential confounders. No association was found between blastocyst developmental stage and obstetric or perinatal outcomes both before and after adjusting for potential confounders, and similar results were found with regard to embryo expansion stage and ICM grade. Meanwhile, the incidence of placenta previa derived from a blastocyst with TE of grade C was higher compared with those derived from a blastocyst with TE of grade A (1.7%, 2.4%, and 4.0% for A, B, and C, respectively, P = 0.001 for all comparisons). After adjusting for potential covariates, TE grade C blastocysts had 2.81 times the likelihood of resulting in placenta previa compared to TE grade A blastocysts (adjusted odds ratio 2.81, 95% CI 1.11-7.09). No statistically significant differences were detected between any other measured outcomes and TE grades both before or after adjustment. The study is limited by its retrospective, single-center design. Additionally, although the sample size was relatively large for the study group, the sample size for certain subgroups was relatively small and lacked adequate power, particularly the ICM grade C group. Therefore, these results should be interpreted with caution. The study extends our knowledge of the potential downstream effect of TE grade on placental abnormalities. This study was supported by the National Key Research and Development Program of China (2023YFC2705500, 2023YFC2705501, 2023YFC2705505, 2019YFA0802604); National Natural Science Foundation of China (82130046, 82320108009, 82371660, 32300710); Shanghai leading talent program, Innovative research team of high-level local universities in Shanghai (SHSMU-ZLCX20210201, SHSMU-ZLCX20210200, SHSMU-ZLCX20180401), Shanghai Jiaotong University School of Medicine Affiliated Renji Hospital Clinical Research Innovation Cultivation Fund Program (RJPY-DZX-003), Science and Technology Commission of Shanghai Municipality (23Y11901400), Shanghai's Top Priority Research Center Construction Project (2023ZZ02002), and Three-Year Action Plan for Strengthening the Construction of the Public Health System in Shanghai (GWVI-11.1-36). The authors have no conflicts of interest to declare. N/A.

ВЛИЯНИЕ АГРОТЕХНОЛОГИИ ВОЗДЕЛЫВАНИЯ ГОРОХА НА БИОЛОГИЧЕСКИЕ И АГРОХИМИЧЕСКИЕ СВОЙСТВА ЛУГОВО-ЧЕРНОЗЕМНОЙ ПОЧВЫ

The aim of research is to establish patterns of changes in biological and agrochemical parameters of meadow-chernozem soil with long-term use of resource-saving treatments and chemicalization means in the conditions of the southern forest-steppe of Western Siberia. Stationary studies were conducted in the forest-steppe of the Omsk Region in a grain-fallow crop rotation (fallow – wheat – peas – wheat – barley) under a pea crop at the Omsk Agricultural Research Center. The parameters of changes in the number of individual physiological groups of microorganisms and indicators of biological activity of meadow-chernozem soil under peas were established using agricultural technologies with different levels of intensification, including the minimum-zero tillage system in crop rotation. It was determined that when using complex chemicalization agents in combination with No-till technology of soil cultivation, the activity of bacteria capable of fixing atmospheric nitrogen increased by 34 %, saprotrophic and amylolytic microorga¬nisms – by 13 and 17 % in relation to the control, respectively. The activity of the oxidation-reduction enzyme catalase when using intensification agents, regardless of the technology of pea cultivation, decreased to 28 % of the control. The use of intensification agents led to an increase in the content of nitrate nitrogen in the soil during the budding period, mobile phosphorus by 4 or more times. When assessing the anthropogenic impact on soil microflora, we used the definition of total biological activity, including all the studied biological tests in relative percentages. According to this indicator, soil cultivation options are arranged in a row in ascending order: combined < moldboard < minimum-zero.

Rational design of self-assembling ultrashort peptides for the shape- and size-tunable synthesis of metal nanostructures.

Peptides have attracted great interest as platforms for the design of nanocomposite hydrogels due to their distinct bioactivity, biofunctionality and biocompatibility. Previously, we have reported on a family of peptides that self-assembled to form stabilised three-dimensional hydrogel networks, displaying potent antimicrobial activity. In this paper, we report on the use of these hydrogelator sequences and their analogues as stabilisers and growth controllers to synthesise anisotropic gold nanoparticles (AuNPs) of different sizes and shapes. In particular, hollow spherical nanoparticles were obtained for HG2.81-AuNPs, whereas hexagonal nanoparticles were observed for TOH_1N-AuNPs and PentaOH-AuNPs in their respective hydrogel networks. The PentaOH-AuNPs' hydrogel exhibited excellent results with high antimicrobial potency against Staphylococcus aureus and Pseudomonas aeruginosa ATCC 27853 and negligible cytotoxicity. On the other hand, TOH_1N-AuNPs showed no antibacterial activity and no cytotoxicity, demonstrating the versatility of these peptides. This work gives credence towards the development of these materials towards further applications such as in tissue culture technology and wound dressing materials.

The Effect of Application of Biocomplex AgroMaximum Antistress + Protection on Soybeans in the Conditions of the Krasnodar Territory

The article deals with the results of the influence of the biological complex AgroMaximum Antistress + Protection on the productivity of soybeans while using the production technology of cultivation in the conditions of the Krasnodar Territory. It was found that the use of the preparations as foliar treatment of plants in the phase of one to three true trifoliate leaves stimulates the immune system, increases plant resistance to pathogens and ensures the increase in seed yield by 16.9%.

A Study on Motivational Factors and the Constraints Faced by Distance Learners of ODL Certificate Course Tea Cultivation Technology

A Study on Motivational Factors and the Constraints Faced by Distance Learners of ODL Certificate Course Tea Cultivation Technology

Yield stability of biofertilizer treatments to soybean in the rainy season based on the GGE biplot

Abstract Soybeans (Glycine max L.) play an essential role in meeting the nutritional needs of Indonesians. However, national soybean production cannot meet domestic needs. Increasing the planting frequency during the rainy season is an effort to increase the national soybean production. Planting soybeans in the rainy season will reduce the yield and growth of soybeans, so cultivation technology is needed to increase soybean yields in the rainy season, one of which is the use of biofertilizers and cultivars. This study aimed to analyze a suitable combination of cultivation and biofertilizer doses to increase soybean production during the rainy season. Selection of the right cultivar combination and biofertilizer dosage will increase yields. The research was conducted from 2021 to 2023 during the rainy season in Majalengka Regency, West Java Province, Indonesia. The cultivation technology that provides stable soybean yields was analyzed using a GGE biplot. The results of this research show that the appearance of soybean yields varies every year, and there is an interaction between the application of cultivation technology and the year of planting. Cultivation technologies that show a stable appearance are Anjasmoro variety + 20 kg h−1 dose biofertilizer, Dega 1 variety + 0 kg h−1 dose biofertilizer and Dega 1 variety + 10 kg h−1 dose of biofertilizer. These results can be used as a reference for farmers planting soybeans during the rainy season.

Organ chips with integrated multifunctional sensors enable continuous metabolic monitoring at controlled oxygen levels

Despite remarkable advances in Organ-on-a-chip (Organ Chip) microfluidic culture technology, recreating tissue-relevant physiological conditions, such as the region-specific oxygen concentrations, remains a formidable technical challenge, and analysis of tissue functions is commonly carried out using one analytical technique at a time. Here, we describe two-channel Organ Chip microfluidic devices fabricated from polydimethylsiloxane and gas impermeable polycarbonate materials that are integrated with multiple sensors, mounted on a printed circuit board and operated using a commercially available Organ Chip culture instrument. The novelty of this system is that it enables the recreation of physiologically relevant tissue-tissue interfaces and oxygen tension as well as non-invasive continuous measurement of transepithelial electrical resistance, oxygen concentration and pH, combined with simultaneous analysis of cellular metabolic activity (ATP/ADP ratio), cell morphology, and tissue phenotype. We demonstrate the reliable and reproducible functionality of this system in living human Gut and Liver Chip cultures. Changes in tissue barrier function and oxygen tension along with their functional and metabolic responses to chemical stimuli (e.g., calcium chelation, oligomycin) were continuously and noninvasively monitored on-chip for up to 23 days. A physiologically relevant microaerobic microenvironment that supports co-culture of human intestinal cells with living Lactococcus lactis bacteria also was demonstrated in the Gut Chip. The integration of multi-functional sensors into Organ Chips provides a robust and scalable platform for the simultaneous, continuous, and non-invasive monitoring of multiple physiological functions that can significantly enhance the comprehensive and reliable evaluation of engineered tissues in Organ Chip models in basic research, preclinical modeling, and drug development.

Assessment of the potential nutritional value of cell-cultured chicken meat in light of European dietary recommendations

In 2023, the United States Department of Agriculture approved cell-cultured chicken meat (CCM) made with animal cell culture technology; similar applications may soon be submitted for assessment in Europe. This study employed data submitted to the US Food and Drug Administration to re-evaluate the nutritional and safety of CCM manufactured by one US-based company in the light of European Union recommendations. Compared to conventional chicken meat, serum-free CCM revealed lower content of protein, and the majority of indispensable amino acid contents, Mg, and vitamin B3, but higher levels of total fat, saturated fatty acids, cholesterol, vitamins B5, B6, and A, and minerals Ca, Cu, Fe, K, Mn, Na, P, Se, and Zn. Toxic elements (As, Cd, Pb, Hg) did not exceed allowance thresholds, though serum-free CCM had higher levels of Cd and Pb than conventional chicken meat. Although this first assessment of CCM generally falls within the European Union requirements, it is crucial to optimize the reproducibility of the production process due to observed variabilities in nutrient levels between tested lots. This study represents a re-evaluation of CCM offered by a single product, yet it should not be extrapolated to the entire field of cultured meat.

Insight into the short-term effects of TiO2 nanoparticles on the cultivation of medicinal plants: Comprehensive analysis of Panax ginseng physiological indicators, soil physicochemical properties and microbiome

To meet societal needs, a large number of medicinal plants are cultivated artificially. However, issues such as diseases and continuous cropping obstacles (CCO) have severely impacted their quality and yield. Exploring and innovating the cultivation technology for medicinal plants is essential to meet their high demand and ensure sustainable development. The role of titanium dioxide nanoparticles (nano-TiO2) in medicinal plant cultivation remains unclear. To advance the application of nanotechnology in this field, a comprehensive exploration of its potential benefits is necessary. In this study, nano-TiO2 was applied to ginseng (Panax ginseng C.A. Meyer) to acquire a holistic comprehension of its impact on ginseng growth, rhizosphere, and ginseng-used soil. Our findings reveal that nano-TiO2 significantly enhances ginseng root activity and has notable effects on antioxidant enzyme systems. The two concentrations of nano-TiO2 markedly influenced the structure and composition of microbial communities in the rhizosphere and ginseng-used soil, including key microorganisms such as Chloroflexi and Acidobacteriota, which are closely involved in soil function. Furthermore, nano-TiO2 altered the competitive and cooperative relationships within microbial networks. Nano-TiO2 application significantly increased soil organic matter (SOM) content in rhizosphere and ginseng-used soils and affected the activities of several important soil enzymes. Environmental factors, such as EC, pH, and soil nutrients, were found to be the main factors influencing the microbial community. In conclusion, our findings illuminate the complex effects of nano-TiO2 on the “plant-microbial-soil” system in the context of ginseng cultivation. This work offers novel strategies for optimizing medicinal plant growth and development, as well as improving cultivated soil by using nanomaterials.

The Usefulness of Soil Penetration Resistance Measurements for Improving the Efficiency of Cultivation Technologies

The research results of soil penetration resistance (SPR) tests carried out on sandy clay using four cone probes with different dimensions of the measuring tip are presented in this study. It was indicated that the values of SPR can be used to diagnose the cultivation layer and, on this basis, determine whether it is necessary to cultivate it and select tools for the required treatment. Tests were carried out on three levels of soil density, 1.37, 1.43 and 1.51 g∙cm−3, and two moisture contents, 7.64% and 10.4%. The results show that the probe with the smallest cone with apex angles of 30° and 60° on the least dense soil indicated higher SPR by over 50% more than other probes with the highest cone and the same opening angles. The change in cone opening angle from 30° to 60° led to an increase in probe indications in the range of 10–25%, depending on the diameter of the cone tip. The statistical analysis shows that values of probe indications were statistically significant and were influenced by soil density, probe cone tip dimensions, the surface of the base and the apex angle. The values of SPR are fundamental in diagnosing the quality of the soil’s top layer, determining the necessity of breaking it up, and selecting the optimal tools for this procedure. To improve the efficiency of agricultural crop cultivation technologies. This is particularly important when carrying out cultivation procedures in an environmentally friendly manner. The measurements will help support the introduction of sustainable farming practices, including direct seeding, no-till cultivation, or precision agriculture, reducing soil degradation and increasing environmental benefits.

Breaking the borders: Gender dynamics in STEM portrayals in Turkish Netflix series

This study discusses the intricate relationship between science, technology, engineering and mathematics field representation by the media and the science, technology, engineering and mathematics field in reality, centring on two pivotal inquiries: (i) How is gender within science, technology, engineering and mathematics portrayed in visual culture? (ii) How do gendered representations in visual culture impact science, technology, engineering and mathematics professionals? By scrutinizing two Turkish TV series featuring science, technology, engineering and mathematics characters, namely, Sıcak Kafa ( Hot Skull, 2022, by Mert Baykal) and Yakamoz S-245 ( Into the Deep, 2022, by Tolga Karaçelik and Umut Aral), we assert that recent Netflix productions in Turkey showcase science, technology, engineering and mathematics characters in a less marginalized manner compared to mainstream series content. The study explores the intersection of science, technology, engineering and mathematics portrayals with actual gender experiences in the Turkish context. Findings show science, technology, engineering and mathematics professionals, particularly women, to be rendered invisible in being confined to gender-based definitions. Despite portraying male and female science, technology, engineering and mathematics professionals as equal and non-marginalized, male characters predominate in decision-making and implementation processes within many series. Furthermore, science, technology, engineering and mathematics professionals do not identify with their own character representations in media content, as they express through interviews. The study underscores there is room to challenge patriarchal norms, fostering more equitable depictions of science, technology, engineering and mathematics professionals, including women, to dismantle gender biases and foster inclusivity within science, technology, engineering and mathematics fields.

Role of 6mA in the Regulation of Metabolic Biosynthesis in Sorghum Callus.

Plant cell culture technology helps to obtain natural plant-derived metabolites. The callus of sorghum, a prominent cereal crop, possesses various metabolites with potential health benefits. However, the epigenetic mechanism regulating metabolic biosynthetic capabilities in sorghum remains unknown. Therefore, we conducted N6-methyladenine (6mA) methylome analysis using transcriptome profiling and metabolome analysis to investigate the role of 6mA alterations in two calluses having different biosynthetic capacities, which were derived from immature sorghum embryos. Our findings indicate that the 6mA upregulation within gene bodies is crucial in transcriptional activity potentially mediated by the DNA demethylase SbALKBH1. Furthermore, 6mA was significantly enriched in genes involved in the biosynthesis of flavonoids and isoflavonoids. This could serve as a novel source of bioactive compounds for human health. Thus, 6mA could play an essential role in flavonoid biosynthesis in the sorghum callus.

A real-time oxygen uptake rate monitoring approach suitable for the antibody production process

Significant progress has been achieved in large-scale mammalian cell culture technology for biotherapeutics manufacturing over the past decades, necessitating the Process Analytical Technology (PAT) for the real-time measurement of critical quality attributes and the guidance for precise process control to ensure productivity, quality, and consistency. The Oxygen Uptake Rate (OUR) serves as a crucial indicator for characterizing the energy metabolism of mammalian cells, offering insights into cellular state and metabolism dynamics. However, current cellular OUR monitoring in antibody production depends mainly on costly gas analyzers or periodic manual sampling. Here, we introduce a novel method for in-line monitoring of cellular OUR in bioreactors based on the stationary liquid phase balance (SLPB) theory, which extends its applicability to diverse aeration and foam conditions without additional equipment or labor expenditures. We modeled the kLa of the aerated stirred bioreactor, assessed the influence of foam on liquid surfaces induced by gas sparging on oxygen transfer, and processed raw OUR data using a sliding filter. The established method was applied to monitoring the real-time OUR of Chinese Hamster Ovary (CHO) cell cultures for antibody production, demonstrating its excellent accuracy, sensitivity and readability. Aligned with the Quality by Design (QbD) concept, this real-time OUR estimation enables rapid detection of metabolic changes, revealing cellular physiology and facilitating precise feedback control in biotherapeutics manufacturing.

Effects of Long-term Biochar Addition on Denitrification N2O Emissions from Bacteria and Fungi in Paddy Soil

Denitrification driven by bacteria and fungi is the main source of nitrous oxide （N2O） emissions from paddy soil. It is generally believed that biochar reduces N2O emissions by influencing the bacterial denitrification process, but the relevant mechanism of its impact on fungal denitrification is still unclear. In this study, the long-term straw carbonization returning experimental field in Changshu Agricultural Ecological Experimental Base of the Chinese Academy of Sciences was taken as the object. Through indoor anaerobic culture and molecular biology technology, the relative contributions of bacteria and fungi to denitrifying N2O production in paddy soil and the related microorganism mechanism were studied under different long-term biochar application amounts （blank, 2.25 t·hm-2, and 22.5 t·hm-2, respectively, expressed by BC0, BC1, and BC10）. The results showed that compared with that in BC0, biochar treatment significantly reduced N2O emission rate, denitrification potential, and cumulative N2O emissions, and the contribution of bacterial denitrification was greater than that of fungal denitrification in all three treatments. Among them, the relative contribution rate of bacterial denitrification in BC10 （62.9%） was significantly increased compared to BC0 （50.8%）, whereas the relative contribution rate of fungal denitrification in BC10 （37.1%） was significantly lower than that in BC0 （49.2%）. The application of biochar significantly increased the abundance of bacterial denitrification functional genes （nirK, nirS, and nosZ） but reduced the abundance of fungal nirK genes. The contribution rate of fungal denitrification was significantly positively correlated with the N2O emission rate and negatively correlated with soil pH, TN, SOM, and DOC. Biochar may have inhibited the growth of denitrifying fungi by increasing pH and carbon and nitrogen content, reducing the abundance of related functional genes, thereby weakening the reduction ability of NO to N2O during fungal denitrification process. This significantly reduces the contribution rate of N2O production during the fungal denitrification process and the denitrification N2O emissions from paddy soil. This study helps to broaden our understanding of the denitrification process in paddy soil and provides a theoretical basis for further regulating fungal denitrification N2O emissions.

Initiation of Cassava Callus Culture and Its Prospect for Starch Production: A Systematic Mapping Study

Mass propagation of cassava on several hectares of arable land due to increasing demand for its starch is not feasible due to land availability, pests and disease invasion, and long cultivation period. Plant cell culture technology is a promising solution despite the scarcity of cassava callus culture for starch production applications. Therefore, a systematic mapping study (SMS) was performed to identify the applications of cassava tissue culture and its prospects in starch production and investigate the important parameters for cassava callus culture initiation. The SMS began with formulating research questions (RQs), conducting searches on various databases, collecting and screening related articles, and extracting and mapping the selected articles. A total of 56 of 589 articles in the initial searching phase were chosen to be used as references to answer each RQ. The extracted data indicates that cassava tissue culture was mostly used for micropropagation, while starch production from its tissue culture is still limited. Basal medium and plant growth regulators influence cassava callus culture initiation most. The findings of the SMS offer a better understanding of cassava tissue culture and the prospects of producing cassava starch.

CHARACTERISTICS OF THE GROWTH AND DEVELOPMENT OF RABBITS USING DIFFERENT GROWING TECHNOLOGIES IN THE CHERKASSY REGION

According to the results of the study of the process of forming indicators of meat productivity of rabbits of the California and silver breeds (n = 200 heads), which were raised on the farm using retro-keeping technologies (the rabbit farm of the "Rokitchenkov A. P." Cherkassy region) and in the conditions of the industrial type rabbit farm (the rabbit farm of the Cherkassy experimental Station of Bioresources of the NAAS, Cherkassy), a different level of realization of the potential of meat productivity by rabbits was established, both according to the breed and depending on the cultivation technology. It was established that during the entire period of the study, and in particular before slaughter, a probable predominance was noted in young animals, which were raised according to industrial technology, regardless of the breed, the difference when comparing the average values was 165–222 g (р < 0.01). In terms of breed affiliation, animals of the California breed had higher live weight indicators at this age. It was established that the maximum indicators of animal growth were registered for rabbits of the California breed at the age of 60–90 days; for animals of the silver breed, the process of forming the live weight indicator continued until the age of 120 days. The obtained results indicate that rabbits of the meat direction of productivity have higher values of the index of body fatness (63.8–65.5%), which is typical for rabbits of this breed. This indicator is determined by the ratio of chest girth (27.0–27.2 cm) to the length of the trunk (41.5–42.3 cm) and has the following pattern: the larger the length of the trunk, the smaller the index of the whiplash. Among the analog groups, no significant difference was found in terms of the knockdown index in California rabbits. For rabbits of the silver breed, given the higher body length index (45.2–45.2 cm) with a slight difference in the chest girth index (24.7–25.0 cm), the body leanness index was 54.4–55.3%. Based on the results of the study, it was established that the cultivation of rabbits using industrial technology, in our opinion, to a certain extent, neutralizes the effect of negative factors in the surrounding environment and makes it possible to effectively realize the potential of meat productivity.