Search Results (54)

The study of the genetic diversity and adaptation mechanisms of the Kazakh apricot (Prunus armeniaca L.) is essential for breeding programs and the conservation of plant genetic resources in arid environments. Despite this species’ ecological and agricultural significance, its chloroplast genome remains poorly studied due to its complex repetitive structure and secondary metabolites that hinder high-molecular-weight DNA (HMW-DNA) extraction and long-read sequencing. To address this gap, our study aims to develop and optimise sequencing protocols for P. armeniaca under arid conditions using Oxford Nanopore’s MinION technology. We successfully extracted HMW-DNA with 50–100 ng/μL concentrations and purity (A260/A280) between 1.8 and 2.0, ensuring high sequencing quality. A total of 10 GB of sequencing data was generated, comprising 155,046 reads, of which 74,733 (48.2%) had a Q-score ≥ 8. The average read length was 1679 bp, with a maximum of 31,144 bp. Chloroplast genome assembly resulted in 33,000 contigs with a total length of 1.1 Gb and a BUSCO completeness score of 97.3%. Functional annotation revealed key genes (nalC, AcrE, and mecC-type BlaZ) associated with stress tolerance and a substantial proportion (≈40%) of hypothetical proteins requiring further investigation. GC content analysis (40.25%) and GC skew data suggest the presence of specific regulatory elements linked to environmental adaptation. This study demonstrates the feasibility of using third-generation sequencing technologies to analyse complex plant genomes and highlights the genetic resilience of P. armeniaca to extreme conditions. The findings provide a foundation for breeding programs to improve drought tolerance and conservation strategies to protect Kazakhstan’s unique arid ecosystems. Full article

Tree species are important factors affecting the carbon sequestration capacity of forests and maintaining the stability of ecosystems, but trees are widely distributed spatially and located in complex environments, and there is a lack of large-scale regional tree species classification models for remote sensing imagery. Therefore, many studies aim to solve this problem by combining multivariate remote sensing data and proposing a machine learning model for forest tree species classification. However, satellite-based laser systems find it difficult to meet the needs of regional forest species classification characters, due to their unique footprint sampling method, and SAR data limit the accuracy of species classification, due to the problem of information blending in backscatter coefficients. In this work, we combined Sentinel-1 and Sentinel-2 data to construct a machine learning tree classification model based on optical features, vegetation spectral features, and PolSAR polarization observation features, and propose a forest tree classification feature selection method featuring the Hilbert–Huang transform for the problem of mixed information on the surface of SAR data. The PSO-RF method was used to classify forest species, including four temperate broadleaf forests, namely, aspen (Populus L.), maple (Acer), peach tree (Prunus persica), and apricot tree (Prunus armeniaca L.), and two coniferous forests, namely, Chinese pine (Pinus tabuliformis Carrière) and Mongolian pine (Pinus sylvestris var. mongolica Litv.). In this study, some experiments were conducted using two Sentinel-1 images, four Sentinel-2 images, and 550 measured forest survey sample data points pertaining to the forested area of Fuxin District, Liaoning Province, China. The results show that the fusion model constructed in this study has high accuracy, with a Kappa coefficient of 0.94 and an overall classification accuracy of 95.1%. In addition, this study shows that PolSAR data can play an important role in forest tree species classification. In addition, by applying the Hilbert–Huang transform to PolSAR data, other feature information that interferes with the perceived vertical structure of forests can be suppressed to a certain extent, and its role in the classification of forest species, combined with PolSAR, should not be ignored. Full article

Supercritical fluid extraction using carbon dioxide (SFE-CO₂) brings a convincing advance in the production of plant oils used in cosmetics, in fortified foods and dietary supplements, and in pharmaceuticals and medicine. The SFE-CO₂-extracted, hexane-extracted, and cold-pressed plant oils of pumpkin (Cucurbita pepo L.), flax (Linum usitatissimum L.), linden (Tilia sp.), poppy (Papaver somniferum L.), apricot (Prunus armeniaca L.), and marigold (Calendula officinalis L.) seeds were investigated in terms of oil yield, fatty acid composition, unsaponifiable matter yield and composition, and the antioxidant activity of unsaponifiable matter. SFE-CO₂ proved to be the preferred extraction method for four out of six plant materials, especially for seeds with lower oil content. However, for seeds with higher oil content, such as apricots, cold pressing is a viable alternative. A comparison of fatty acid composition did not reveal significant differences between extraction techniques. SFE-CO₂ extraction improved the total phytosterol content of oils, especially pumpkin seed oil. A high variability in the antioxidant potential of the unsaponifiable matter studied was determined, with pumpkin seed oil showing the highest antioxidant activity. A correlation analysis was performed between unsaponifiable composition and antioxidant activity, and showed statistically significant correlations with squalene, cycloartenol, and an unidentified compound. This is the first comparison of the phytosterol compositions of linseed, apricot, linden, and marigold. Through continued optimization, SFE-CO₂ has the potential to revolutionize the production of plant oils and provide a sustainable and efficient alternative. Full article

The volatile compounds in the fruits of 24 apricot cultivars were quantitatively and qualitatively determined via headspace solid-phase microextraction and gas chromatography–mass spectrometry (HS-SPME-GC–MS). A total of 429 volatile compounds were detected in these fruits, and the greatest number of detected terpenoids was 77. Significant differences were found among the cultivars in terms of the total volatile compound content of the fruits, with variation from 112.76 (‘ZSHYX’) to 317.36 µg/g (‘JNL’). Using relative odor activity value (rOAV) analysis, 42 key aroma compounds were identified. The rOAVs of (2S,4R)-4-methyl-2-(2-methylprop-1-enyl)oxane, (E)-non-2-enal, (3-methyl-3-sulfanylbutyl) formate, and thiophen-2-ylmethanethiol were above 1000, and most had green, fruity, and woody odors; these results indicated that these substances were important contributors to the overall aroma of the apricot fruits. Our study provides a comprehensive analysis of the volatile compounds from 24 representative apricot cultivars and can aid in the further scientific understanding of the metabolites and aroma in apricots. These findings provide a reference for controlling fruit quality and for future apricot cultivar breeding. Full article

Water scarcity is a significant global risk affecting health, food security, economic development, social stability, environmental sustainability, and climate change adaptation. Implementing deficit irrigation strategies can improve water efficiency and agricultural resilience. Spain, particularly the Region of Murcia, has pioneered apricot cultivation, with the ‘Mirlo Rojo’ variety known for its high productivity, Sharka virus resistance, and exceptional organoleptic qualities. This study evaluates the effects of regulated deficit irrigation (RDI) on the quality, antioxidant activity, fatty acid profile, and volatile compounds of ‘Mirlo Rojo’ apricots. Four irrigation treatments (100% ETc, 60% ETc, 33% ETc, and 0% ETc) were tested during the final growth stages in May 2023. Results showed no adverse effects on the evaluated parameters. RDI treatments increased total soluble solids, glucose, and fructose content, improving maturity and sweetness indices. RDI also enhanced phenolic content and antioxidant activity, optimizing water use without compromising fruit quality and bioactive compounds. Full article

This study examined the effects of hot air drying (HAD), infrared radiation drying (IRD), microwave vacuum drying (MVD), freeze drying (FD), and freeze drying combined with microwave vacuum drying (FD-MVD) on the drying kinetics, color, rehydration ratio, titratable acidity, and vitamin C content of small white apricots (Prunus armeniaca L.). Results showed drying times of 12.5 h (IRD), 14.1 h (FD), 16 h (HAD), 0.53 h (MVD), and 6.15 h (FD-MVD). FD-MVD significantly outperformed MVD, HAD, and IRD in color, vitamin C, titratable acidity, and rehydration, though was slightly inferior to FD. Microstructural analysis revealed that FD-MVD preserved the most uniform pore structure, better maintaining apricots’ original appearance. In contrast, IRD and HAD caused severe surface shriveling, compromising quality. In conclusion, FD-MVD emerges as a promising drying method to enhance apricot quality and market competitiveness in food processing. Full article

The main objective of this study was to monitor apricot development and ripening through gene expression analysis of key candidate genes using the RT-qPCR technique. Eight apricot cultivars were selected to analyze phenological and genetic patterns from pre-ripening stages through to postharvest. In addition, 19 selected genes were analyzed in the contrasting cultivars ‘Cebas Red’ and ‘Rojo Pasión’ in different stages (two preharvest stages S1 and S2, one harvest stage S3, and two postharvest stages S4 and S5). This pool of genes included genes related to fruit growth and ripening, genes associated with fruit color, and genes linked to the fruit’s nutraceutical aspects. Among the studied genes, Polygalacturonase (PG), Pectin methylesterase (PME), Aminocyclopropane-1-carboxylate synthase (ACS), and Myo-inositol-1-phosphate synthase (INO1) were directly related to fruit maturation and quality. Significant differential expression was observed between the cultivars, which correlated with variations in firmness, shelf life, and sensory characteristics of the apricots. ‘Rojo Pasión’ displayed high levels of PG, associated with rapid maturation and shorter postharvest shelf life, whereas ‘Cebas Red’ exhibited lower levels of this gene, resulting in greater firmness and extended shelf life. Genes CCD4, CRTZ, and ZDS, related to carotenoids, showed varied expression patterns during growth and postharvest stages, with higher levels in ‘Rojo Pasión’. On the other hand, Sucrose synthase (SUSY) and Lipoxygenase (LOX2) were prominent during the postharvest and growth stages, respectively. Additionally, GDP-L-galactose phosphorylase (VTC2_5) was linked to better postharvest performance. This research provides valuable insights for future breeding initiatives aimed at enhancing the quality and sustainability of apricot cultivation. Full article

Drying is one of the best methods to preserve the quality of fresh fruits and prolong their shelf life. This study focuses on Prunus armeniaca L. cv. ‘Diaogan’ (commonly known as Diaogan apricot) sourced from Xinjiang, China to explore the impact of two natural drying methods (shade drying and open-air drying in the rocky desert) on the drying kinetics, color, textural characteristics, microstructure, chemical properties, and antioxidant capacity of Diaogan apricots. The experimental results indicate that throughout the natural drying process, the time required for open-air drying in the rocky desert was reduced by 26.47% compared to shade drying. The L*, a*, and b* values of the shade- and ventilation-dried Diaogan apricots were higher than those sun-dried in the rocky desert, exhibiting a lower color difference (ΔE) than apricots dried through rocky desert sun drying. Specifically, the ΔE for shade-dried Diaogan apricots was 19.66 ± 0.24. The Diaogan apricots dried in the rocky desert exhibited greater hardness, lower elasticity, stronger adhesiveness, and higher chewiness compared to those dried in the shade, with the hardness, adhesiveness, and chewiness being, respectively, 14.71%, 18.89%, and 35.79% higher. Scanning electron microscopy (SEM) observations revealed that the high temperatures experienced during open-air drying in the rocky desert caused rapid dehydration of the Diaogan apricot’s skin, leading to clogging and crust formation in the flesh pores, along with deformation or tearing of the tissue structure, ultimately resulting in poor rehydration ability. After drying, there was a significant increase in the soluble solids in the Diaogan apricots, whereas titratable acidity, total phenols, ascorbic acid, and antioxidant capacity were significantly decreased (p < 0.05). In summary, the quality of dried Diaogan apricots post-drying is dependent on the natural drying method employed, with shade drying resulting in superior quality of Diaogan apricots compared to open-air drying in the rocky desert. This study offers fundamental data and serves as a theoretical reference for the industrialized production of apricots. Full article

The present study focused on evaluating the biochemical profiles of four apricot cultivars (cv.) (Prunus armeniaca L.) grown in Latvia and demonstrating their processing to obtain the food product, dried candied fruit (DCF). The fingerprinting of apricot fruit approached by LC-MS and ultraviolet–visible spectroscopy revealed the abundance of bioactives responsible for the antioxidant activity. The outstanding composition of group compounds, i.e., phenolics, flavonoids, and vitamin C, was observed in the cv. ‘Dimaija’, followed by cv. ‘Gundega’ and cv. ‘Velta’. The lowest values were found in the cv. ‘Boriss’ and fruit from a market of Greek origin. However, the latter two contained the highest carotenoid levels due to a more pronounced maturity. Amongst the 13 individual phenolics detected, rutin, chlorogenic and neochlorogenic acids, catechin, and epicatechin prevailed. The concentrations observed were the highest in cv. ‘Dimaija’, followed by cv. ‘Velta’ and cv. ‘Gundega’. Osmotic dehydration and convective drying of apricot fruit variedly influenced the content of bioactives in DCF products. The most substantial decrease due to thermal lability was observed in the vitamin C content in DCF, accounting for a 95.3% loss for all cultivars. The content of total phenolics, flavonoids, and carotenoids in DCF, on average, was 62.7%, 49.6%, and 87.6% lower than that observed in the raw fruit, respectively. On average, the content of individual phenolics in DCF, such as rutin and chlorogenic acid, decreased by 63.8% and 20.8%, respectively. The decline in the content of bioactives was conditioned by the physical migration of the cell components to the hypertonic solution. However, the increase in the content of cell wall-bound phytochemicals, such as catechin and epicatechin, after osmotic dehydration and convective drying, was observed in DCF, corresponding to a 59.5% and 255.64% increase compared with the raw fruit, respectively. Panelists generally responded positively to the developed DCF; however, greater preference was given to products with a lower phenolic content, such as cv. ‘Boriss’ and those produced from the market fruit. It is believed that the high flavan-3-ols content, along with chlorogenic acid, contributed to the bitter taste of DCF. Overall, apricot fruits represent the abundance of bioactives retained in DCF after osmotic dehydration and convective drying. The findings observed in the current study allow to consider DCF as a functional food; however, given the high sugar content, their consumption should be in moderation. Full article

Stone fruits, such as the apricot (Prunus armeniaca L.), are frequently consumed. As such, a substantial volume of apricot waste is generated at each stage of the food supply chain, including harvesting, processing, packaging, warehousing, transportation, retailing, and eventual consumption. This generates tons of waste annually on a global scale. The significant amounts of phenolics present in these wastes are primarily responsible for their antioxidant capacity and the subsequent health advantages they provide. As such, apricot pulp by-products could be a valuable reservoir of bioactive compounds, such as tocopherols, polyphenolic compounds, proteins, dietary fibers, etc. Moreover, apricot kernels are also recognized for their abundance of bioactive compounds, including polyphenols and tocopherols, which find utility in diverse sectors including cosmetology and the food industry. Both conventional and green methods are employed, and generally, green methods lead to higher extraction efficiency. The antimicrobial properties of apricot kernel essential oil have been widely recognized, leading to its extensive historical usage in the treatment of diverse ailments. In addition, apricot kernel oil possesses the capacity to serve as a viable resource for renewable fuels and chemicals. This review examines the potential of apricot waste as a source of bioactive compounds, as well as its utilization in diverse applications, with an emphasis on its contribution to health improvement. Full article

This study involved the extraction of polysaccharides from jujube for application in apricot storage. Although near-freezing temperature (NFT) storage is commonly employed for preserving fresh fruit, its effectiveness is somewhat limited. Incorporating jujube polysaccharides was proposed to augment the preservative effect on apricots. Our findings demonstrated that the combined use of NFT and jujube polysaccharides can maintain fruit color, and effectively inhibit decay. Additionally, Tandem Mass Tag (TMT) quantitative proteomic technology was utilized to analyze protein variations in ‘Diaogan’ apricots during storage. This dual approach not only markedly lowered the activity of polyphenol cell wall-degrading enzymes (p < 0.05) but also revealed 1054 differentially expressed proteins (DEPs), which are related to sugar and energy metabolism, stress response and defense, lipid metabolism, and cell wall degradation. The changes in DEPs indicated that the combined use of NFT and jujube polysaccharides could accelerate the conversion of malic acid to oxaloacetic acid and regulate antioxidant ability, potentially extending the storage lifespan of apricot fruit. Full article

The apricot (Prunus armeniaca L.) is a fruit that belongs to the Rosaceae family; it has a unique flavor and is of important economic and nutritional value. The composition and content of soluble sugars and organic acids in fruit are key factors in determining the flavor quality. However, the molecular mechanism of sugar and acid accumulation in apricots remains unclear. We measured sucrose, fructose, glucose, sorbitol, starch, malate, citric acid, titratable acid, and pH, and investigated the transcriptome profiles of three apricots (the high-sugar cultivar ‘Shushanggan’, common-sugar cultivar ‘Sungold’, and low-sugar cultivar ‘F43’) at three distinct developmental phases. The findings indicated that ‘Shushanggan’ accumulates a greater amount of sucrose, glucose, fructose, and sorbitol, and less citric acid and titratable acid, resulting in a better flavor; ‘Sungold’ mainly accumulates more sucrose and less citric acid and starch for the second flavor; and ‘F43’ mainly accumulates more titratable acid, citric acid, and starch for a lesser degree of sweetness. We investigated the DEGs associated with the starch and sucrose metabolism pathways, citrate cycle pathway, glycolysis pathway, and a handful of sugar transporter proteins, which were considered to be important regulators of sugar and acid accumulation. Additionally, an analysis of the co-expression network of weighted genes unveiled a robust correlation between the brown module and sucrose, glucose, and fructose, with VIP being identified as a hub gene that interacted with four sugar transporter proteins (SLC35B3, SLC32A, SLC2A8, and SLC2A13), as well as three structural genes for sugar and acid metabolism (MUR3, E3.2.1.67, and CSLD). Furthermore, we found some lncRNAs and miRNAs that regulate these genes. Our findings provide clues to the functional genes related to sugar metabolism, and lay the foundation for the selection and cultivation of high-sugar apricots in the future. Full article

Aquaporins play a crucial role in helping water molecules move across cell membranes. While some studies have examined the role of AQPs in model plants like Arabidopsis, their impact on the ability of non-model plants to withstand environmental stress is largely unknown. In this study, we have explored the functions of the PaPIP1-2 gene, which encodes a protein called PIP, in apricot kernels (Prunus armeniaca L.). Our findings reveal how the PaPIP1-2 gene behaves during both dormancy and sprouting phases. Using a network analysis, we identified its interaction with six genes related to cold resistance. The mRNA levels of PaAQP genes, which co-express with cold resistance genes, remain consistent throughout different stages of P. armeniaca flower bud development, including physiological dormancy (PD), ecological dormancy (ED), sprouting period (SP), and germination stage (GS). Furthermore, our investigation of the location of the GFP-tagged PaPIP1-2 protein showed that it is mainly found in the cell membrane. Yeast strains with overexpressed PaPIP1-2 exhibited improved cold resistance and higher protein content. Similarly, when we overexpressed PaPIP1-2 in Arabidopsis, it enhanced the growth of these transgenic plants under cold stress. This improvement was associated with reduced levels of MDA (malondialdehyde); decreased ion leakage; increased proline accumulation; superoxide dismutase (SOD) activity; and the expression of cold resistance genes like AtPUB26, AtBTF3L, AtEBF1-1, and AtRAV1, compared with the wild-type plants. In summary, our results highlight the role of the P. armeniaca PaPIP1-2 gene in enhancing cold resistance and its importance in the dormancy and germination stages. Full article

The production and quality of apricots in China is currently limited by the availability of germplasm resource characterizations, including identification at the species and cultivar level. To help address this issue, the complete chloroplast genomes of Prunus armeniaca L., P. sibirica L. and kernel consumption apricot were sequenced, characterized, and phylogenetically analyzed. The three chloroplast (cp) genomes ranged from 157,951 to 158,224 bp, and 131 genes were identified, including 86 protein-coding genes, 37 rRNAs, and 8 tRNAs. The GC content ranged from 36.70% to 36.75%. Of the 170 repetitive sequences detected, 42 were shared by all three species, and 53–57 simple sequence repeats were detected with AT base preferences. Comparative genomic analysis revealed high similarity in overall structure and gene content as well as seven variation hotspot regions, including psbA-trnK-UUU, rpoC1-rpoB, rpl32-trnL-UAG, trnK-rps16, ndhG-ndhI, ccsA-ndhD, and ndhF-trnL. Phylogenetic analysis showed that the three apricot species clustered into one group, and the genetic relationship between P. armeniaca and kernel consumption apricot was the closest. The results of this study provide a theoretical basis for further research on the genetic diversity of apricots and the development and utilization of molecular markers for the genetic engineering and breeding of apricots. Full article

The globose scale (GS) (Sphaerolecanium prunastri Boyer de Fonscolombe) is a sucking insect that feeds on saps of wild apricot tree (Prunus armeniaca L.) in the Xinjiang Uygur Autonomous Region of northwestern China. It feeds on branches of wild apricot leading to poor growth, leaf yellowing and leaf drop, and sometimes mortality. Since the initial infestation in 2018, all the main valleys of wild apricot trees have been affected, but there is little research on the host’s physiological response to GS infestation. We measured the differences in growth between infested and non-infested wild apricots. The results showed that the diameter of shoot branches, the fresh weight, dry weight, length, width, area, and chlorophyll content of leaves, and the longitudinal diameter of fruit, were all significantly less for infested wild apricot trees than for un-infested wild apricot. The branch length of shoots, cross diameter, and weight of fruit also decreased, although the differences were not significant. Overall, GS infestation significantly reduced the growth of wild apricot trees. Full article