Initial Breeding Research Articles

Spatio-temporal variation in reproductive characteristics of invasive fish Pseudorasbora parva (Temmick & Schlegel, 1846) in the lakes region of Türkiye.

Invasive species present a serious peril to aquatic ecosystems worldwide, thus it is essential to have a comprehensive understanding of the reproductive dynamics, spreading characteristics, and biological properties of these species in order to effectively manage their population structure and mitigate both the ecological damage and economic loss they can cause. For this reason, we delved into the reproductive dynamics of Pseudorasbora parva, an invasive species of inland water fish found in Türkiye. We focused on three populations inhabiting Beyşehir (Konya, Isparta) and Eğirdir Lakes (Isparta) and Onaç Reservoir (Burdur). Sampling was carried out on a monthly basis from March 2021 to June 2022, utilizing a variety of tools such as multimesh nets, seine nets, and electrofishing. The developmental stages of gonads and reproductive cells were determined through morphological and microscopic examinations. A total of 1186 P. parva individuals were captured from all three lakes. Our results showed that the Beyşehir Lake population spawned from March to July, while the Eğirdir Lake population did so between May and October, and the Onaç Reservoir population laid their eggs from June to August. Female individuals in Beyşehir Lake, Eğirdir Lake, and Onaç Reservoir had initial breeding lengths of 3.49, 4.89, and 5.35 cm, respectively. In comparison, male individuals measured 5.56, 4.80, and 5.40 cm. Interestingly, the Beyşehir Lake population exhibited the highest egg fecundity, with each individual at 2 years producing a remarkable 2949 eggs. The present findings provide valuable information for us to further understand the reproductive biology and dynamics of P. parva, which could be useful in managing and preventing the spread of this invasive species in inland aquatic ecosystems.

Scorpion mud turtle breeding in the Amazon: zootechnical and environmental activity for the species conservation

Commercial captive turtle breeding is an opportunity for Kinosternon scorpioides scorpioides conservation, as predatory hunting, destruction and habitat degradation are the main threats to its natural populations. In this sense, the goal of this study is to provide a synthesis of knowledge about the species Embrapa-developed captive breeding system. Below, we have set up the themes in a way that makes sense in the captivity flow, discussing important information about the species in the environmental context and its management from the initial breeding stock formation up to reproductive aspects, highlighting animal behaviour and the environmental approach of the activity, to support commercial breeding from the species conservation perspective. The discussion and conclusions have shown that the species has a low invasive potential in Brazilian biomes; the captivity site needs not much space, facilities or water; captive breeding is a zootechnical and environmentally appropriate activity for the species’ conservation because it is a way to avoid spending on programs that are made only for this purpose; and increasing knowledge of reproduction using molecular genetic tools is important. Keywords: conservation, chelonian, Kinosternon scorpioides, jurará, turtle breeding

Analysis of intervarietal soybean hybrids at the initial breeding stages

The results of the study of recombinant soybean hybrids in terms of the degree of heterosis effect, phenotypic dominance and transgressive variability in economically valuable traits with the subsequent selection of the most promising hybrid combinations are presented. The study was conducted from 2018 to 2022 in the laboratory of soybean breeding in the conditions of the steppe zone of the Primorsky Territory. Of the ten hybrid combinations obtained, the maximum effect of heterosis in the first generation was observed in the combinations Primorskaya 1385 × Kofu, Primorskaya 1385 × Dong nong 690, Hei He 38 × Taifun. Phenotypic overdominance of inheritance of indicators (from 1.6 to 76.7) was recorded in all hybrids. Transgressive variability of intervarietal soybean hybrids in the second and third generations varied by combination and generation. High values of the degree of transgression in the third generation were observed in the combinations Primorskaya 1385 × Kofu and Hei He 38 × Talppod-Fisk, in terms of the number of seeds per plant – Primorskaya 1385 × Taifun and Kofu × Taifun, in terms of seed weight per plant – Dong nong 690 × Taifun and Hei He 38 × Taifun. A decrease in the frequency of transgression of hybrids by the third generation was found. The highest values of the degree and frequency of transgression in plant height were observed in the hybrid combinations Hei He 38 × Taifun and Hei He 38 × Talppod-Fisk. Based on the results of the study of the promising soybean genotypes, recombinant hybrids with high productivity and 1000-seed weight in the combinations Kyoto × Dong nong 690 and Monsoon × Taifun were isolated. The hybrids tested had different ripeness groups. Not always the manifestation of high effect of heterosis and transgressive variability in the first – third generations serves as a guarantee of further obtaining samples with high economically valuable indicators.

Human infrastructures correspond to higher Adélie penguin breeding success and growth rate.

Anthropogenic activities generate increasing disturbance in wildlife especially in extreme environments where species have to cope with rapid environmental changes. In Antarctica, while studies on human disturbance have mostly focused on stress response through physiological and behavioral changes, local variability in population dynamics has been addressed more scarcely. In addition, the mechanisms by which breeding communities are affected around research stations remain unclear. Our study aims at pointing out the fine-scale impact of human infrastructures on the spatial variability in Adélie penguin (Pygoscelis adeliae) colonies dynamics. Taking 24 years of population monitoring, we modeled colony breeding success and growth rate in response to both anthropic and land-based environmental variables. Building density around colonies was the second most important variable explaining spatial variability in breeding success after distance from skua nests, the main predators of penguins on land. Building density was positively associated with penguins breeding success. We discuss how buildings may protect penguins from avian predation and environmental conditions. The drivers of colony growth rate included topographical variables and the distance to human infrastructures. A strong correlation between 1-year lagged growth rate and colony breeding success was coherent with the use of public information by penguins to select their initial breeding site. Overall, our study brings new insights about the relative contribution and ecological implications of human presence on the local population dynamics of a sentinel species in Antarctica.

Recovering a Targeted Mutation in Mice from Embryonic Stem Cell Chimeras or CRISPR-Cas Founders.

Following the production of chimeras from targeted embryonic stem (ES) cells or obtaining founders from CRISPR-Cas gene editing in preimplantation embryos, the desired targeted mutation must be recovered and established in the heterozygous state in a strain or stock of mice for further study. The breeding schemes for ES chimeras and CRISPR-Cas founders differ. For ES cell chimeras, we discuss the relative benefits of breeding from male or female chimeras. We discuss the importance of genetic background and provide practical advice for putting the mutation on inbred or outbred backgrounds or producing a coisogenic strain. For CRISPR-Cas founders, which will most likely be mosaic for different mutations, initial breeding strategies are discussed to maintain a desired genetic background at the same time as producing progeny to segregate different alleles. Strategies for testing the progeny to recognize indels, missense mutations, and knock-in mutations are discussed. In the event that ES cell chimeras or CRISPR-Cas founders produce no offspring or fail to transmit the mutant allele(s), there is a troubleshooting guide to pinpoint the problem. If heterozygous offspring from the chimeras or founders are normal, fertile, and of both sexes, the analysis of homozygous effects of the mutation can now begin; if not, possible dominant effects are considered.

Study of wheat (Triticum aestivum L.) breeding material potential for in vitro androgenesis.

Doubled haploid technology is a valuable biotechnological approach in plant breeding that enables one to quickly create new varieties through the single-stage production of homozygous lines. The aim of this study was to assess the indicators of in vitro androgenesis in the anther culture of the initial breeding material of varieties and combinations of F1 and F2 and to identify promising accessions with good responsiveness. For that purpose, the plant material that proved promising for the breeding programs of Siberian Research Institute of Plant Production and Breeding (SibRIPP<B) was used. Ten cultivars of common wheat and the F1 and F2 hybrids of nine combinations were evaluated for the main parameters of in vitro androgenesis such as the number of new formations, albino, green and all regenerated plants. Induction of androgenesis in vitro was carried out in anther culture in growth medium Chu (N6) containing 1 mg/l of growth regulator 2,4-D. The studied samples showed different responses to induction. The maximum level of new formations was found in F2 hybrids Novosibirskaya 15 × Lutescens ShT-335. The largest number of green plants was found in F1 Novosibirskaya 15 × Lutescens ShT-335. According to the results of variance analysis, a significant ( p < 0.01) influence of genotype on the studied traits was established. Varieties with good responsiveness to anther culture (Novosibirskaya 15) and lack of responsiveness to in vitro androgenesis (Novosibirskaya 31) were identified. Novosibirskaya 16 was characterized by a low regeneration capacity of new formations. A significant heterotic effect was revealed considering the number of new formations per 100 anthers among the hybrids of such combinations as Novosibirskaya 15 × Lutescens ShT-335, Novosibirskaya 15 × Lutescens 111/09, and Zagora Novosibirskaya × Obskaya 2. Novosibirskaya 15 was recommended for inclusion in crossings as a parental form that provides high hybrid responsiveness during in vitro androgenesis. The use of doubled haploid technology made it possible to quickly create DH-lines based on the breeding material.

Оценка хозяйственной ценности плодов лещины обыкновенной (Corylus avellana L.) в Воронежской области

The selection of promising forms of common hazel (Corylus avellana L.) for forestry and fruit growing in the Voronezh region is the most important task of breeding work. Despite the high economic value of this breed, the yield and quality of fruits depending on growing conditions remain unstudied, which is important for breeding work. The purpose of the work is to study the phenological characteristics, determine the size of the harvest (depending on forest conditions) and assess the quality of the fruits of common hazel (Corylus avellana L.) to identify and select the highest quality initial breeding materials. The objectives of the research included: determining optimal forest conditions for the growth of common hazel (Corylus avellana L.), allowing for the greatest amount of harvest; establish the timing of the onset of phenological phases to predict the amount of harvest and indirectly assess the adaptive potential; assess the quality of fruits depending on the types of forest conditions. The onset of phenological phases of common hazel (Corylus avellana L.) begins in mid-March and ends in June. Despite the danger of spring frosts, which limit the cultivation of common hazel (Corylus avellana L.) in the Voronezh region, the identified phenological features make it possible to indirectly recommend widespread breeding of the most resistant forms. The average yield in C2D reaches 2.6±0.12 kg. In addition, in these forest growing conditions, the greatest variation in the amount of harvest was noted, which will allow for the selection of the best forms. It was revealed that the largest quantity of harvest and the best quality of common hazel fruits (Corylus avellana L.) prevail in the types of forest growing conditions C2D and D2.

THE RESULTS OF BREEDING THE SELECTION-VALUABLE POTATO HYBRIDS BY THE METHOD OF STEPWISE INTERVARIETAL HYBRIDIZATION

To implement programs of applied potato breeding at Lviv NЕU, when creating the initial breeding material, the staged intervarietal crossings were carried out. Its idea was to combine a complex of valuable economic traits that were inherent in the original parental forms into one genotype. As a result of the stepwise intervarietal hybridization in Lviv NЕU, several new hybrid forms of potatoes of different origins and maturing periods were created. The original parental forms for hybridization used potato varieties of Ukrainian selection, namely Borodianska Rozheva, Vodohrai, Hibrydna 14, Volia, Zakhidna, Zov, Lishchyna, Lvivianka, Oksamyt, Povin, Svitanok Kyivskyi, and foreign varieties, such as Nevskа, Suzorye, Aminca, Sante, hybrid SVP. The task of the research was to give a comprehensive assessment of promising intervarietal hybrids of potatoes according to their valuable economic and biological characteristics so that the best forms could be recommended as candidates for new varieties. The research was conducted during 2020–2022. 9 new potato hybrids of different maturity groups were used for the studies. Each of the hybrids and the corresponding standard varieties of potatoes were planted on land plots with a plant feeding area of 70×35 cm, which amounted to 40.8 thousand plants per 1ha. The experimental sites were placed in triplicate, using a systematic method. The registered area of the site was 25 m2. Potato varieties of domestic selection were used as standards, in particular, Vodohrai variety – for the mid-early group, Volia variety - for mid-ripening, and Zakhidna – for mid-late. It is established that the stepwise intervarietal hybridization allows combining potentially high productivity (1000g/bush and higher), intensive crop formation with increased starch content in tubers (16–18%), and high resistance to late blight (at the level of 7–8 points). Basing on the conducted research of the comprehensive evaluation of the economic and biological characteristics of new intervarietal hybrids of potatoes, the mid-early hybrid 02/10-40 (Borodianska rozheva × Suzorye), the mid-ripening 11/4-1 (Zakhidna × Vodohrai) and the mid-late hybrid 16/17-1 [(Zakhidna × Sante) × (Volia × Lishchyna)] were marked as they significantly prevailed in the complex of economic and valuable characteristics of the corresponding standard varieties. It is proposed to continue further selection work with them according to the accepted schemes and potato selection, intensively multiply, and prepare to pass to the State variety tests as candidates for new varieties of the crop.

End-user preferences to enhance prospects for varietal acceptance and adoption in potato breeding in Uganda.

Potato varieties have diverse biophysical characteristics, so it is important for breeders to have the capacity to choose those that meet the preferences of end users, such as mealiness, firmness, and taste, among others. Combining user preferences with descriptive information regarding the sensory characteristics of boiled potatoes can contribute to the improvement of consumer-driven varieties. This study aimed to factor in the preferences of end users to improve the prospects for varietal acceptance, adoption, and discrimination among genotypes in potato breeding. The priority quality traits (traits that play the most significant roles in acceptance and adoption) of the boiled potatoes were determined by evaluating gender and livelihood using the G+ tool. The G+ tool is designed to assess gender impact on roots, tubers and bananas (RTB) traits by serving as a validation check to reflect on important gender-based issues in agricultural food systems in order to reduce harm and promote positive impact. Potato genotypes were differentiated by penetration (textural parameters as measured by standard texture probe)and the procedure was repeatable, as there was no significant difference between the cooking replicates at 40 min of cooking. Instrument-based texture parameters, such as penetration peak force (hardness/firmness) and area (area under the curve, whichrepresents energy needed to penetrate) of boiled potato tubers were significantly associated with sensory attributes such as fracturability and hardness in the mouth. An attempt to differentiate genotypes using near-infrared spectroscopy (NIRS) revealed that the average results observed for the calibration for yellow color (r2 = 0.70), homogeneity of color (r2 = 0.48), moisture in mass (r2 = 0.40), and uniformity of texture (r2 = 0.56) suggested that these parameters could be used for initial breeding screening purposes. The preferred traits of the boiled potato can be integrated into the potato-breeding program/product profile. Near-infrared spectroscopy shows strong potential to predict potato color and the ability of NIRS models to predict some texture attributes is also promising. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Variability in the productivity of peanut accessions (&lt;i&gt;Arachis hypogaea&lt;/i&gt; L.) at ecological-geographical testing

BACKGROUND: Russia is one of the largest peanut-buying countries. At the same time, in the south of the country, a number of zones meet the requirements for the cultivation of peanuts.&#x0D; AIM: Identification of a new source material for peanut breeding by the method of ecological and geographical testing of collection samples.&#x0D; MATERIALS AND METHODS: The work used 30 of peanuts accessions from the VIR collection of various origins. To assess the stability of productivity, standard deviation (s), coefficient of variation (Cv) and regression (i) for environmental conditions according to Eberhart and Russell were used.&#x0D; RESULTS: As a result of the study, the possibility of growing individual varieties of peanuts in the south of the RF under modern conditions was confirmed. It was determined that some samples are more productive and suitable as starting material for the conditions of the Krasnodar Territory (k-283, k-1157), others for the conditions of the Astrakhan region (k-317, k-868). The accessions of the VIR collection were found to be more productive at 2 points experience, also marked as plasticity k-751, k-283, k-626, k-1533, k-1987.&#x0D; CONCLUSIONS: In contrasting conditions (two geographical points for 3 years of study), peanuts accessions were identified that strongly react to changes in environmental conditions. Stable and plastic in productivity accessions can serve as the initial breeding material. It has been established that peanuts can be cultivated in the south of the Russian Federation, namely in the Astrakhan Region and the Krasnodar Territory.

INHERITANCE OF MORPHO-ECONOMIC TRAITS AND COMBINING ABILITY ANALYSIS IN INTRASPECIFIC HYBRIDS OF GOSSYPIUM BARBADENSE L.

In intraspecific F1 diallel hybrids of Gossypium barbadense L., the inheritance study of traits plant height, boll weight, plant productivity, and 1000-seed weight, with combining ability analysis took place in 2020–2022 at the Institute of Genetics and Plant Experimental Biology, Academy of Sciences, Uzbekistan. These polygenic traits’ inheritance showed different ways in the fine-fiber cotton F1 hybrids. The plant height trait’s inheritance with overdominance and intermediate level of the high/low-performance cultivars. The boll weight trait was mainly in negative overdominance with incomplete dominance of the low-performance cultivar. The inheritance of seed cotton yield had the positive overdominance main control, while the 1000-seed weight had negative and positive overdominance. According to combining ability analysis, the highest positive general combining ability effects resulted in fine-fiber cotton cultivars Surkhan-14 (ĝi = 8.71) and Bo'ston (ĝi =1.86) for plant height, Guzor (ĝi = 0.12) for boll weight, in genotypes Marvarid (ĝi = 2.44) and Surkhan-14 (ĝi = 2.95) for plant productivity, and in cultivars Marvarid (ĝi = 2.3) and Guzor (ĝi = 2.8) for 1000-seed weight. The F1 hybrids Guzor × Surkhan-14, Marvarid × Bo'ston, and Bo'ston × Surkhan-14 showed the highest positive and desirable specific combining ability effects for 1000-seed weight and seed cotton yield. Results concluded that fine-fiber cotton cultivars Marvarid, Surkhan-14, and Guzor can benefit as initial breeding material in selecting high-yielding cotton cultivars.

Creation of potato hybrids (Solanum tuberosum) progeny with high field resistance against phytophotorosis

The creation of new potato varieties with prominent economically valuable properties and comprehensive resistance against the most common diseases is one of the main areas of crop breeding at present. First of all, this is due to the possibility of increasing the gross production of potatoes, improving its economic performance, as well as the tasks of protecting the environment from pesticide pollution, which contributes to a substantial improvement in the environment and obtaining environmentally safe products. The purpose of this study was to identify varieties with a prominent level of yield and resistance against potato blight in the western region of Ukraine. The study was conducted using field (assessment of disease development), laboratory, analytical, and mathematical and statistical methods. The paper provides a theoretical substantiation and a new solution to the important scientific task of establishing the specific features of the use of Ukrainian and foreign varieties, intervarietal and multispecies hybrids by parental forms in potato breeding. The study summarized the features of the manifestation of productivity components, quality traits, resistance to potato blight, correlations between economic and valuable traits, selection of new parent forms for intervarietal and interspecies hybridization, nature of high productivity, quality and potato blight resistance of breeding material, and created genetically valuable varieties with great value in potato selection and for agricultural production of Ukraine. Based on this, the possibility and effectiveness of the combination of the transfer of traits to the offspring and their inheritance was proven, which will expand the existing base of initial breeding material for further work on the creation of promising potato varieties of different maturity groups with highly valuable economic traits

Panicle formation order influence in rice Oryza sativa L in vitro androgenesis

A comparative analysis of rice Oryza sativa L. main and lateral panicles in androgenesis in vitro on F1 plants of two hybrid combinations: L×3P and K×3P to increase the number of cultivated anthers during the season was carried out. Donor plants were grown on the growing area in metal vessels filled with soil. The main panicle was used from three L×3P hybrids and one K×3P hybrid, single lateral panicle was cut from six L×3P plants and three K×3P plants. The genotypes number was calculated as the product of the calli number with doubled haploids by 1.25. In vitro culture 2050 anthers were introduced. According to the intensity of callus formation, the number of green regenerants per callus, and the doubled haploids proportion, there were no statistically significant differences between the main and lateral panicles in the L×3P combination. In total, 215 doubled haploids lines of twenty nine genotypes were obtained, which is theoretically sufficient for breeding a new variety. On the hybrid combination K×3P, 120 doubled haploids of five genotypes were formed from one donor plant with the main panicle. There were no statistically significant differences between the main and lateral panicles. It is concluded that it is expedient to use lateral rice panicles in vitro androgenesis to create the initial breeding material. Their use makes it possible to distribute labor force over time and increase the total volume of anthers cultivated in vitro, and, ultimately, the doubled haploids number and variability of one sample. In the time absence and other restrictions, it is preferable to use the main panicle.

Diallel crosses in Picea abies IV. Genetic variation and inheritance patterns in short-term trials

Abstract The complete diallel cross is the only mating design that provides estimates of variance components of general combining (GCA), specific combining ability (SCA), maternal and reciprocal effects, in addition to heritabilities and genetic correlations. To obtain such estimates, complete diallels were made among 10 trees in each of three natural Norway spruce populations from altitude 300 and 500 m in southern Norway. Seedlings from families from the diallels and open pollinations were tested in short-term tests on agricultural soil at one site at altitude 85 m until age 10 years from seed. Tree height at ages 7 and 10 years and diameter at age 10 had strongly significant GCA variance components within each population. The components for SCA and maternal effects were small and not significant, indicating low levels of non-additive genetic variation. For the days of initiation and cessation of the shoot elongation period the GCA components were dominating and had the highest heritability estimates in two of the diallels. Estimates of genetic correlations between traits measured in earlier nursery trials and height and diameter in the short-term trials had low and not consistent values in the three diallels. The duration of the shoot growth period and rate of growth showed positive relationships with height and diameter. Strong relationships were present between half-sib family means from the diallels and open-pollinated families for height, diameter and phenology traits. Progeny trials testing open-pollinated half-sib families from natural populations can be used for selection of candidates for the initial breeding populations.

EVALUATION OF SOME APPLE ELITES WITH GENETIC RESISTANCE TO DISEASES, CANDIDATES FOR OBTAINING NEW CULTIVARS

The researches performed at the Voinesti Research-Development Station for Fruit Growing have taken into consideration the highlight of the performance characteristics of some apple elites with a genetic resistance to diseases, obtained from hybrid combinations performed in the period 2004 – 2005. The apple elites, candidates for obtaining new cultivars, resulted from the selection of the 3260 apple hybrids, obtained from the initial breeding material with a great genetic diversity.The five selected apple elites have shown genetic resistance to diseases, fruits with a superior quality and correspond to the objectives that must be met by a cultivar.The elites obtained through sexual hybridisation from the ‘Goldenspur’ x ‘Florina’ had fruits that have an average above 160g, yellow or yellow-greenish colour and good taste. The elites obtained through sexual hybridisation from ‘Florina’ x ‘Idared’ have fruits that have an average of 160-180 g and covered up to ¾ of the surface with red.The apple elites with a genetic resistance to diseases, candidates for varieties, obtained at SCDP Voinesti in the period 2004 – 2005 correspond to the producer’s requirements, sensitive to economic efficiency, with an increased production potential, with quality fruits that for sure will meet the consumer’s requirements, which are continuously increasing.

Long-term examinations of the lumbal disc and facet joint changes in 5 German Shepard dogs

The purpose of this first-time long-term observational study was to evaluate the changes of the caudal lumbar spine at the locations L5/6, L6/7, and L7/S1 in 5 German shepherd dogs over a 6-year time period using computed tomography (CT) and magnetic resonance imaging (MRI). The dogs had a mean age of 26 months at the time of the first examination. In addition, it was evaluated whether a breeding examination, with regard to disc degeneration, is justified in young dog. The locations L7/S1, L6/7, and L5/6 were examined in more detail with regard to their signal intensity changes, the facet joint angle changes in dorsal (dors) and transverse (trans) planes, and disc surface changes in sagittal (sag) and transverse (trans) reconstruction planes with CT and MRT in 2015 and 2021. All data were collected computer-based and analyzed statistically. Subsequently, the results were compared to the measured signal intensity and to the subjective disc degeneration grading according to Seiler used in practice. Over the period of 6 years a significant loss of the measured signal intensity of the intervertebral discs in the transverse plane and an overall facet joint widening in the transverse plane of 0.54° as well as in the dorsal plane of 1.8° was evident. In addition, there was no evidence of a relationship between the size of the facet joint angle and the degree of disc degeneration. Furthermore, regardless of the initial degree of degeneration, the discs showed low signal intensity and higher Seiler grade during follow-up. The results of the present study group indicate that an inconspicuous condition of the lumbar intervertebral discs at the time of the initial breeding examination in the young dog does not allow an accurate prediction of the subsequent degree of degeneration and that there are ongoing remodeling processes at the facet joints even in healthy German shepherd dogs.

Overview of Kyoto Fusioneering’s SCYLLA© (“Self-Cooled Yuryo Lithium-Lead Advanced”) Blanket for Commercial Fusion Reactors

This article outlines Kyoto Fusioneering’s (KF’s) initial engineering and development activities for its self-cooled lithium lead-type blanket: Self-Cooled Yuryo Lithium-Lead Advanced (SCYLLA©). We provide details on overall design, including an initial tritium breeding ratio (TBR) assessment via neutronics analysis, as well as the status of SCYLLA©-relevant R&D. This includes silicon carbide composite (SiCf/SiC) manufacturing techniques, tritium extraction, materials compatibility, and heat transfer, which are being explored via collaboration with Kyoto University. Results of previous work in relation to this R&D are presented. Permeability coefficients indicate a promising property of SiCf/SiC tritium hermeticity at high temperatures. Tritium extraction technology via vacuum sieve tray (VST) is shown to be demonstrated at engineering scale. A local TBR of up to 1.4 can be achieved with the SCYLLA© configuration. Fabrication methods for various SiCf/SiC components including the blanket module, heat exchanger, and flow path components are provided. A tritium compatible high-temperature SiCf/SiC heat exchanger is discussed. Commercial viability and reactor adaptability are considered as a theme throughout. Finally, KF’s plans to build a facility for demonstration reactor relevant testing of a SCYLLA© prototype in the mid-2020s, which will provide a significant step toward commercial fusion energy, are presented.

Selection of red clover for fodder quality

The article presents the results of studies of clover breeding for fodder quality in the conditions of North Ossetia-Alania. Based on the assessment of the initial breeding material, it was revealed that the quality of the chemical composition of the green mass of clover undergoes variability depending on climatic conditions, the protein content of the test samples varies from the phase of development, year of life, place of growth and genotype of the variety. With the rise of the mountain height, the crude protein increases, positive correlations have been established between the protein content and the traits: pubescence of the stems, foliage, intensity of the leaf pattern, leaf color, the correlated traits depend on the varietal characteristics and range from weak to close positive, the amount of essential amino acids varies from habitats, the content of extragenic isoflavones in wild forms is lower than in the cultivated variety, selection for a low content of isoflavones does not reduce yields. In order to select samples with a low content of isoflavones, an evaluation of the breeding material was carried out. Their content in different samples and places of growth was taken into account, taking into account vertical zonality. Our studies have established that in the phase of full flowering, the amount of isoflavones in wild-growing forms depends on the place of growth. In mountainous areas, wild-growing forms contain isoflavones 0.09-0.25% lower than the cultivar Osetinsky. Therefore, the selection of wild-growing forms, taking into account vertical zonality, will provide a valuable source material for breeding with a low content of isoflavones.

Direct and indirect nutritional factors that determine reproductive performance of heifer and primiparous cows.

Pregnancy rate is a major determinant of population dynamics of wild ungulates and of productivity of livestock systems. Allocation of feeding resources, including stocking rates, prior to and during the breeding season is a crucial determinant of this vital rate. Thus, quantification of effects and interaction among multiple factors that affect pregnancy rate is essential for management and conservation of pasture-based systems. Pregnancy rate of 2982 heifers and primiparous cows was studied as a function of animal category, average daily gain during the breeding season, stocking rate, pasture type and body weight at the beginning of the breeding season. Data were obtained from 43 experiments conducted in commercial ranches and research stations in the Pampas region between 1976 and 2015. Stocking rate ranged from 200 to 464 kg live weight ha-1, which brackets values for most of the grazinglands in similar regions. Age at breeding was 14-36 months (24.6±7.5 months); initial breeding weights were 129-506 kg and 194-570 kg for heifers and primiparous cows. Pregnancy rate was modeled with an apriori set of explanatory variables where proximate variables (breed, body weight at start of breeding, weight gain during breeding and category) were included first and subsequently modeled as functions of other variables (pasture type, supplementation and stocking rate). This modeling approach allowed detection of direct and indirect effects (through nutrition and body weight) of factors that affect pregnancy rate. Bos taurus breeds (N = 1058) had higher pregnancy rate than B. Taurus x B. indicus crossbreed (N = 1924) females. Pregnancy rate of heifers and primiparous cows grazing in natural grasslands decreased with increasing stocking rate, but no effect of stocking rate was detected in cultivated and improved pastures. Pregnancy rate increased with increasing average daily gain during the breeding season. Use of cultivated or improved natural pastures promotes higher pregnancy rate, as well as allows an increase in stocking rate at the regional level. Body weight at the start of the breeding season is the primary determinant of pregnancy rates in heifer and primiparous cows.

A study on nuclear hydrogen production using a novel approach cobalt-chlorine thermochemical cycle in a laser driver fission fusion blanket for various molten salt fuels

This study presents the hydrogen production potentials of laser inertial fusion engine (LIFE) reactor using two different molten-salt (ThF4 and UF4) fuels. For the hydrogen production method the Co–Cl cycle, which is one of the latest thermochemical cycles, was selected in this study. The neutronic calculations were performed with MCNP nuclear code. Flibe as the main constituent was mixed with 2 vol % ThF4 and 2 vol % UF4 heavy metal molten salt. The initial tritium breeding (TBR) values were computed as 1.124 and 1.133, respectively, for corresponding heavy metal molten salt vol. fractions. Blanket initial energy multiplication values (M) have been calculated as 1.277 and 1.339, respectively, as a result of exoenergetic neutron absorption in 6Li. The highest M values over plant operation was approximately be found as (at the end of the 34th and 35th years) 9.882 and 5.921, respectively. Fuel burnup (BU) in the blanket was computed as 7.9 GWd/tM and 40.7 GWd/tM for the ThF4 and UF4 fuels, respectively. The amount of the hydrogen production (m˙H2) was calculated as 8.987 kg/s and 4.942 kg/s for the same fuels, respectively. According to the numerical results that were acquired from the simulations it can be said that the considered LIFE molten-salt fusion reactor has a high neutronic performance and can produce a considerable amount of the hydrogen production.