Search Results (60)

The walnut (Juglans regia L.) holds a significant position among Kazakhstan’s nut crops, both in terms of cultivation and consumption. Although genetic resources of walnut are accessible within the country, they remain underexplored, yet they represent a valuable foundation for breeding initiatives and the development of locally adapted varieties. Currently, a comprehensive genetic profile of these resources is lacking, which hampers their effective utilization. The aim of this research was to evaluate the genetic diversity within a collection of walnut accessions collected from the southern and southeastern regions of Kazakhstan, including Almaty and Turkestan regions. To achieve this, eight SSR molecular markers were employed, providing insights into the genetic structure and relationships among the germplasm. All markers exhibited a high degree of polymorphism, with the WGA276 locus standing out as the most informative, displaying the greatest number of alleles and a high Shannon diversity index. The average expected heterozygosity (He) was 0.704 and was significantly higher than the observed heterozygosity (Ho = 0.547), which was confirmed by t-test (t = −6.426, p < 0.05). The findings indicated substantial genetic variation and intra-population polymorphism: on average, 5.875 alleles per locus were identified, and the Shannon index was 1.444. The population from Turkestan region (population 1, Sairam-Ugam) demonstrated the highest levels of diversity. Analyses of genetic structure, conducted through STRUCTURE, PCoA, and UPGMA methods, confirmed the existence of two genetically distinct groups exhibiting considerable diversity. Future research should focus on conserving the highly diverse populations in the Turkestan region to facilitate the development of stress-tolerant varieties. These findings highlight the importance of conserving and harnessing the genetic resources of Kazakhstan’s J. regia populations for future breeding efforts. Full article

This study used Xinxin 2 (Juglans regia L. ‘Xinxin2’), a major cultivated walnut variety in Xinjiang, China, to clarify the response and adaptation mechanisms of the anatomical structures of walnut related to source–sink–flow under altered source–sink relationships. We anatomically observed the leaves, fruit stalks, and fruit of bearing branches by artificially adjusting the leaf-to-fruit ratio (LFR). The LFR substantially affected the leaf structure and thickness of the fruit-bearing branches obtained via girdled (p < 0.05). The results of the analysis of the leaf anatomy revealed that a low LFR impeded leaf growth and internal structural development while accelerating senescence, whereas a high LFR promoted leaf growth and delayed senescence. The same trend was observed for the phloem area (PA) of the fruit stalk with the increase in fruit load when the number of leaves on the fruit branch was the same. The maximum PA was reached when the number of fruits was high (except for 4L:3F). This indicates that the micro-anatomical structure of the fruit stalk is more developed under the treatment of a higher number of pinnate compound leaves and fruit level of LFRs. The cells of the 1L:3F and 2L:3F were considerably smaller in the green peel and kernel of the fruit on the branches obtained via girdled than those of 5L:1F plants (p < 0.05). No significant difference was found in the number of cells per unit area or the cross-sectional area of cells in the pericarp and kernel of the fruit under LFRs (p > 0.05); however, a large difference was noted in the microanatomical structure of the pericarp and kernel of fruit. Changes in the structural adaptation characteristics of walnut leaves (source), fruit stalk (flow), and fruit (sink) are related to source–sink regulation. A change in the LFR affects the carbohydrate synthesis in the leaves (source), transport in fruit stalks (flow), and the carbohydrate reception in fruits (sink). Full article

This study systematically analyzed the fruit traits of four sources and 117 families of Juglans mandshurica Maxim. in Jilin Province. By measuring key traits such as fruit phenotype and nut phenotype, the relationship between fruit characteristics and environmental adaptability was explored, leading to the selection of superior materials with high oil content potential. The study used fruit from J. mandshurica of 117 families (random sampling) across four provenances as experimental materials and measured 13 fruit phenotypic traits, including fruit length and fruit width. Finally, principal component analysis and genetic variation parameters were conducted. The results of the variance analysis (ANOVA) indicated that except for the nut roundness index, all other traits exhibited highly significant differences among provenances and families (p < 0.01). The range of genetic and phenotypic variation coefficients for the various traits was 7.47–23.23% and 8.76–29.59%. The family heritability ranged from 0.968 to 0.988. Correlation analysis among fruit traits revealed a non-significant correlation between fruit width and seed yield, fruit type index and nut weight, kernel weight and kernel yield, as well as nut longitudinal diameter and kernel yield. However, significant correlations were observed among all other traits. The Pearson correlation analysis between fruit traits and environmental factors revealed a significant negative correlation between longitude and seed yield. Cluster analysis results, based on the Euclidean distance method, showed that materials from four provenances were categorized into three groups at a genetic distance of 5. Principal Component Analysis (PCA) revealed that the cumulative contribution rate of four principal components reached 87.00%. PCI demonstrated the highest contribution rate and included traits such as fruit length, nut longitudinal diameter, nut transverse diameter, nut side diameter, three-diameter mean, and nut weight. One elite provenance and five elite families were preliminarily selected. The realized gain for the selected provenance fruit traits was higher for fruit weight and kernel weight, with values of 2.41% and 3.67%, respectively. For the selected families, the genetic gain was highest for kernel yield and kernel weight, with values of 16.51% and 26.66%, respectively. The findings will provide insights into breeding strategies to enhance walnut oil yield. The identified traits may be used to guide breeding programs for developing high-oil-content varieties; However, further validation studies are required to confirm these traits and their applicability in large-scale breeding efforts. Full article

The aim of this study was to investigate the factors affecting the occurrence of walnut canker disease and the effect of low-temperature treatment on its occurrence in Hotan County, and provide a theoretical basis for the prevention and control of the disease. The occurrence of canker disease was investigated in walnut plantations of different varieties, plant and row spacing, and diameter at breast height (DBH) from April to August of 2023 and 2024. In laboratory research, the spread area of disease spots on isolated branches of peach was studied under different temperature treatments and different treatment times. The occurrences of walnut canker for the two consecutive years were basically the same. The number of new lesions showed an upward trend in April and May and reached its highest in May. The number of new lesions tended to stabilize in June and July in Hotan County. The walnut variety with more severe disease was “Xinfeng”. The disease was most serious in plots with plant spacing and row spacing of 10 m × 7 m. The DBH of the more susceptible walnut trees was >30 cm. Low-temperature treatment and treatment time had a significant impact on the walnut canker lesion expansion area (p < 0.05). The key factor in lesion expansion was low temperature. The maximum lesion expansion area was 1.70 × 10⁴ mm² under treatment at 20 °C for 5 h. The walnut variety and the plant and row spacing were the key factors affecting the occurrence of walnut canker disease, with low temperature being the main factor affecting its spread. Full article

This study used Juglans regia leaves from the Gran Jefe variety; this indigenous cultivar from Nerpio is highly valued for its quality and distinct characteristics. This type of walnut is traditionally cultivated in the region and is noted for its organoleptic properties and adaptation to local climatic conditions. Two solvents were tested to determine the optimal extraction conditions for phenolic compounds: 80% ethanol and water. Direct homogenization with an Ultra-Turrax, direct ultrasound, and indirect ultrasound treatments were compared for ethanol extraction. Water extractions were conducted using direct and indirect ultrasound, infusion, and decoction. Compared to water extraction, 80% ethanol proved to be more efficient. Extracting phenolic compounds from ’Gran Jefe’ walnut leaves was most effective when using direct extraction methods without either ultrasound assistance or indirect ultrasound treatment. The main compounds identified were trans-3-caffeoylquinic acid and quercetin-3-hexoside isomer 1. The ethanolic extract obtained through direct extraction was selected to study further the bioactivities of ’Gran Jefe’ walnut leaves using C. elegans as an in vivo model. Results indicated that the leaf extract enhanced thermal and oxidative stress resistance, promoted fertility, and exhibited neuroprotective effects in models of Alzheimer’s and Parkinson’s diseases. The observed bioactivities were attributed to the free phenolics present in the ethanolic extract. Full article

The walnut (Juglans regia) is a woody oilseed crop with high economic and food value as its kernels are edible and its hulls can be widely used in oil extraction and plugging, chemical raw materials, and water purification. Currently, red walnut varieties have emerged, attracting consumer interest due to their high nutritional values as they are rich in anthocyanins. WD40 is a widespread superfamily in eukaryotes that play roles in plant color regulation and resistance to stresses. In order to screen for JrWD40 associated with walnut color, we identified 265 JrWD40s in walnuts by genome-wide identification, which were unevenly distributed on 16 chromosomes. According to the phylogenetic tree, all JrWD40s were classified into six clades. WGD (Whole genome duplication) is the main reason for the expansion of the JrWD40 gene family. JrWD40s were relatively conserved during evolution, but their gene structures were highly varied; lower sequence similarity may be the main reason for the functional diversity of JrWD40s. Some JrWD40s were highly expressed only in red or green walnuts. In addition, we screened 16 unique JrWD40s to walnuts based on collinearity analysis. By qRT-PCR, we found that JrWD40-133, JrWD40-150, JrWD40-155, and JrWD40-206 may regulate anthocyanin synthesis through positive regulation, whereas JrWD40-65, JrWD40-172, JrWD40-191, JrWD40-224, and JrWD40-254 may inhibit anthocyanin synthesis, suggesting that these JrWD40s are key genes affecting walnut color variation. Full article

Sustainability is becoming increasingly important in the world we live in, because of the rapid global population growth and climate change (drought, extreme temperature fluctuations). People in developing countries need more sustainable protein sources instead of the traditional, less sustainable meat, fish, egg, and dairy products. Alternative sources (plant-based, such as grains (wheat, rice sorghum), seeds (chia, hemp), nuts (almond, walnut), pulses (beans, lentil, pea, lupins), and leaves (duckweed), as well as mycoproteins, microalgae, and insects) can compensate for the increased demand for animal protein. In this context, our attention has been specifically focused on duckweed—which is the third most important aquatic plant after the microalgae Chlorella and Spirulina—to explore its potential for use in a variety of areas, particularly in the food industry. Duckweed has special properties: It is one of the fastest-growing plants in the world (in freshwater), multiplying its mass in two days, so it can cover a water surface quickly even in filtered sunlight (doubling its biomass in 96 hours). During this time, it converts a lot of carbon dioxide into oxygen. It is sustainable, environmentally friendly (without any pesticides), and fast growing; can be grown in indoor vertical farms and aquaculture, so it does not require land; is easy to harvest; and has a good specific protein yield. Duckweed belongs to the family Araceae, subfamily Lemnoideae, and has five genera (Lemna, Spirodela, Wolffia, Wolffiella, Landolita) containing a total of approximately 36–38 recognised species. Duckweed is gaining attention in nutrition and food sciences due to its potential as a sustainable source of protein, vitamins, minerals, and other bioactive compounds. However, there are several gaps in research specifically focused on nutrition and the bioaccessibility of its components. While some studies have analysed the variability in the nutritional composition of different duckweed species, there is a need for comprehensive research on the variability in nutrient contents across species, growth conditions, harvesting times, and geographic locations. There has been limited research on the digestibility, bioaccessibility (the proportion of nutrients that are released from the food matrix during digestion), and bioavailability (the proportion that is absorbed and utilised by the body) of nutrients in duckweed. Furthermore, more studies are needed to understand how food processing (milling, fermentation, cooking, etc.), preparation methods, and digestive physiology affect the nutritional value and bioavailability of the essential bioactive components in duckweed and in food matrices supplemented with duckweed. This could help to optimise the use of duckweed in human diets (e.g., hamburgers or pastas supplemented with duckweed) or animal feed. More research is needed on how to effectively incorporate duckweed into diverse cuisines and dietary patterns. Studies focusing on recipe development, consumer acceptance, palatability, and odour are critical. Addressing these gaps could provide valuable insights into the nutritional potential of duckweed and support its promotion as a sustainable food source, thereby contributing to food security and improved nutrition. In summary, this article covers the general knowledge of duckweed, its important nutritional values, factors that may affect their biological value, and risk factors for the human diet, while looking for technological solutions (covering traditional and novel technologies) that can be used to increase the release of the useful, health-promoting components of duckweed and, thus, their bioavailability. This article, identifying gaps in recent research, could serve as a helpful basis for related research in the future. Duckweed species with good properties could be selected by these research studies and then included in the human diet after they have been tested for food safety. Full article

As global climate change escalates, horticultural crops, especially walnuts, face increased vulnerability to frost damage. Cold hardiness—a crucial trait for survival—is influenced by complex physiological and biochemical mechanisms. This study assessed the cold hardiness of five walnut cultivars—‘Xinxin 2’, ‘Wen 81’, ‘Wen 185’, ‘Zha 343’, and ‘Xinzaofeng’—under simulated low-temperature stress, focusing on differences in freezing tolerance. One-year branches were gradually cooled to temperatures as low as −30 °C. Key physiological metrics, including electrolyte leakage (EL) and regrowth (RG) potential, along with biochemical metrics like antioxidant enzyme activities and osmoregulatory compounds, were used to evaluate cold hardiness. A comprehensive cold resistance indicator, derived using the subordination function method, highlighted cultivar resilience. Results showed significant variation in cold tolerance, with ‘Wen 185’ and ‘Wen 81’ exhibiting superior resilience, while ‘Xinxin 2’ was the most susceptible. Logistic regression analysis of relative electrolyte conductivity (REC) data estimated the semi-lethal temperature (LT50), identifying ‘Wen 81’ as the most cold-tolerant cultivar (LT50 = −21.73 °C). Antioxidant enzymes and osmoregulatory compounds were crucial for maintaining cellular stability and recovery after freezing. These findings offer practical insights for breeding cold-resistant cultivars and strategies to mitigate frost damage. Full article

Common walnut (Juglans regia L.) is a valuable nut crop widely distributed within the temperate climate zone. It has several secondary centers of origin associated with refugia formed during the LGM (Last Glacial Maximum) period, one of which was presumably located in the Caucasus region. Currently, walnut populations of the Caucasus are studied fragmentarily, especially in the northeast. Our study is aimed at investigating the genetic diversity, population structure, and possible walnut introduction processes in the Caspian region of the Northeast Caucasus (Dagestan). Genotyping using 11 SSR markers was performed for 158 samples from local walnut populations. Also, to identify the introduction facts, 42 varieties of different geographical origin were added to research. The SSR markers genetic diversity in the analysis of population varied from four to 20 alleles per locus, with an average value of 9.82. Analysis of the genetic structure revealed significant genetic differences between the subpopulations of the Mountain and Flatland Dagestan. Presumably, the structure of the gene pool could have been influenced by terrain factors and ethnocultural characteristics. Subpopulations of Flatland Dagestan have an intermediate position between the western cultivars and the gene pool of Mountain Dagestan, which subpopulations showed significant genetic isolation. In the studied samples set of population selections, the established introduction facts were rare. We have suggested that a significant part of the walnut gene pool from Mountain Dagestan has an autochthonous origin from plants that survived the LGM in the Caucasian refugia. Our results are the basis for further studies of the local gene pool and verification of hypothesis about the presence of an indigenous germplasm preserved in this region from the LGM period. Full article

This study developed a new energy bar using the astringent ‘Rojo Brillante’ variety of persimmons to address postharvest losses. The bar was formulated with dehydrated persimmons, walnuts, hazelnuts, and chia seeds to enhance their nutritional profile. The proximate composition was evaluated and the mechanical and optical properties, soluble tannins, carotenoids, and antioxidant activities were monitored during storage. In addition, in vitro gastrointestinal digestion was performed to determine the recovery index of the bioactive compounds. The results showed that the formulated energy bar contained higher levels of healthy fats, proteins, and fibers than other fruit energy bars. The mechanical properties of dehydrated persimmon effectively supported the consistency of the bar, eliminating the need for hydrocolloids or syrups. During storage, soluble tannin content decreased, mitigating astringency issues commonly found in persimmon products, whereas carotenoid levels and antioxidant activity remained stable. In vitro digestion analysis revealed a higher recovery index for soluble tannins (180.08%) than carotenoids (9.87%). This persimmon-based energy bar offers a sustainable and nutritious option for the snack industry, catering to consumer preferences for natural products while contributing to the reduction of agricultural waste. Full article

Cannabis has been cultivated for thousands of years for a variety of purposes, including fiber, seeds, oil, and medicinal compounds. The cannabis industry is growing rapidly because several countries have recently legalized the use of cannabis. In these countries, the industry related to cannabinoid ingredients such as cannabidiol (CBD) and Δ⁹-tetrahydrocannabinol (THC) is steadily increasing every year. High concentrations of cannabinoids are mainly produced in unfertilized female flowers. Maintaining plants with high cannabinoid content is essential for producing uniform substances in large quantities. This study established an in vitro micropropagation protocol that can maintain the mother plant characteristics of Cannabis sativa ‘Cheungsam’. As a result of this experiment, the shoot tips and nodes of Cannabis sativa ‘Cheungsam’ at various concentrations (0, 0.25, 0.5, 1.0 mg/L) of 2iP, BA, and mT plant growth regulators (PGRs), and all concentrations of 2iP showed better results compared to two other hormones. However, the cut surfaces turned black, and excessive hyperhydricity occurred. Based on these symptoms, activated charcoal was added to the medium with the assumption that necrosis and hyperhydricity occur due to the accumulation of reactive oxygen species (ROS). When treated with 0.5 g/L charcoal, hyperhydricity was not overcome, and there was no difference compared to the control. As a new alternative, we divided the experiments into MS (Murashige and Skoog) and DKW (Driver and Kuniyuki Walnut) medium, which were commercially available. As a result, the rate of hyperhydricity was reduced, the cut surface did not turn black, and the growth conditions were also improved. Subsequently, ½ MS medium and ½ DKW medium were treated with various concentrations of IBA alone and with combinations of IBA and NAA for rooting. As a result, ½ DKW with IBA 0.5 mg/L showed the highest rooting rate and the best root condition for Cheungsam. After 4 weeks, when considering rooted plants with a height above 5 cm that were acclimatized, the acclimatization rate reached 100%. In conclusion, the Cannabis sativa ‘Cheungsam’ plants used in this study produced healthy shoots on DKW medium containing 1.0 mg/L 2iP and 0.5 mg/L of IBA in ½ DKW medium showed the best rooting rate. Full article

Polyphenols, fatty acids, and mineral composition were studied in eight Persian walnut (Juglans regia L.) samples: ‘Milotai 10’ (M10) and ‘Alsószentiváni 117’ (A117) Hungarian varieties derived from two Hungarian growing areas (Pálháza—P and Berzék—B), ‘Chernivets’ky 1’ from Ukraine, and ‘Chandler’ from the United States of America, Chile, and Brazil purchased on the Hungarian consumer market. The aim was to reveal which walnut variety is the most suitable for consumption from a nutritive point of view. In comparison, both Hungarian varieties grown in Hungarian climatic conditions had on average approximately 33% more polyphenols, approximately 22% more SFAs (saturated fatty acids), and approximately 27% more MUFAs (monounsaturated fatty acids). Regarding the minerals, calcium, magnesium, phosphorus, and sodium were present in higher concentrations in both Hungarian varieties. Among the Hungarian-bred varieties, M10 mainly reached a higher compounds content, but the effects of the fruit site conditions were not clearly detected. Other varieties contained mainly potassium, copper, and zinc, such as ‘Chandler’ harvested from Chile. ‘Chernivets’ky 1’, harvested from Ukraine, had outstanding cinnamic acid and linoleic acid contents compared to the other examined varieties. All ‘Chandler’ samples (mainly the American) contained 11% more PUFAs compared to the samples derived from Hungary. Full article

Secondary metabolites, polyphenols, are widespread in the entire kingdom of plants. They contain one or more hydroxyl groups that have a variety of biological functions in the natural environment. These uses include polyphenols in food, beauty products, dietary supplements, and medicinal products and have grown rapidly during the past 20 years. Antimicrobial polyphenols are described together with their sources, classes, and subclasses. Polyphenols are found in different sources, such as dark chocolate, olive oil, red wine, almonds, cashews, walnuts, berries, green tea, apples, artichokes, mushrooms, etc. Examples of benefits are antiallergic, antioxidant, anticancer agents, anti-inflammatory, antihypertensive, and antimicrobe properties. From these sources, different classes of polyphenols are helpful for the growth of internal functional systems of the human body, providing healthy fats, vitamins, and minerals, lowering the risk of cardiovascular diseases, improving brain health, and rebooting our cellular microbiome health by mitochondrial uncoupling. Among the various health benefits of polyphenols (curcumin, naringenin, quercetin, catechin, etc.) primarily different antimicrobial activities are discussed along with possible future applications. For polyphenols and antimicrobial agents to be proven safe, adverse health impacts must be substantiated by reliable scientific research as well as in vitro and in vivo clinical data. Future research may be influenced by this evaluation. Full article

The R2R3-MYB gene family, encoding plant transcriptional regulators, participates in many metabolic pathways of plant physiology and development, including flavonoid metabolism and anthocyanin synthesis. This study proceeded as follows: the JrR2R3-MYB gene family was analyzed genome-wide, and the family members were identified and characterized using the high-quality walnut reference genome “Chandler 2.0”. All 204 JrR2R3-MYBs were established and categorized into 30 subgroups via phylogenetic analysis. JrR2R3-MYBs were unevenly distributed over 16 chromosomes. Most JrR2R3-MYBs had similar structures and conservative motifs. The cis-acting elements exhibit multiple functions of JrR2R3-MYBs such as light response, metabolite response, and stress response. We found that the expansion of JrR2R3-MYBs was mainly caused by WGD or segmental duplication events. Ka/Ks analysis indicated that these genes were in a state of negative purifying selection. Transcriptome results suggested that JrR2R3-MYBs were widely entangled in the process of walnut organ development and differentially expressed in different colored varieties of walnuts. Subsequently, we identified 17 differentially expressed JrR2R3-MYBs, 9 of which may regulate anthocyanin biosynthesis based on the results of a phylogenetic analysis. These genes were present in greater expression levels in ‘Zijing’ leaves than in ‘Lvling’ leaves, as revealed by the results of qRT-PCR experiments. These results contributed to the elucidation of the functions of JrR2R3-MYBs in walnut coloration. Collectively, this work provides a foundation for exploring the functional characteristics of the JrR2R3-MYBs in walnuts and improving the nutritional value and appearance quality of walnuts. Full article

Anthracnose is extremely detrimental to walnut production, because it seriously affects its yield. Therefore, this study aimed to identify anthracnose resistance genes in walnuts, to lay the foundation for cultivating novel anthracnose-resistant walnut varieties. In this study, the fruits of walnut varieties “Qinyou 1” and “Qinyou 2”, exhibiting relatively weak resistance to anthracnose, were used for transcriptome sequencing and identifying differentially expressed genes (DEGs). Thereafter, we used a quantitative real-time polymerase chain reaction to verify the reliability of the transcriptome data using the walnut varieties Qinyou 1, Qinyou 2, Qinyou 3, Liaohe 1, and Diamond 1. We identified 6326 DEGs post-infection in Qinyou 1, of which 3065 were upregulated and 3261 were downregulated. We also found 2055 DEGs (969 upregulated and 1086 downregulated genes) in the two varieties, after 6 days of anthracnose infection. Based on GO and KEGG enrichment analyses of the transcriptome data, we noted that the DEGs were primarily involved in metabolic processes, cell composition, cell structure, catalytic activity, and binding activity. Furthermore, KEGG functional enrichment analysis showed that the amino acid biosynthesis pathway and plant–pathogen interaction may be activated under anthracnose infection. We also noted that the expression levels of anthracnose resistance genes in different walnut varieties were significantly different. Thus, the findings of this study provide important genetic resources and molecular markers for the cultivation of novel anthracnose-resistant walnut varieties. Full article