Lonicera Caerulea Research Articles

Evaluation of genetic diversity in some hybrid individuals of honeyberry (Lonicera caerulea L.) based on fruit characteristics, leaf morphology, vitamin C, antioxidant activity, and biochemical and nutritional contents

BackgroundGenetic diversity is a prerequisite for breeding programs, and one of the main goals here is to obtain quality products. Therefore, this study aims to evaluate the genetic diversity in some hybrid individuals of honeyberry (Lonicera caerulea L.) based on fruit characteristics, leaf morphology, vitamin C, antioxidant activity, biochemical, and nutritional content. In this context, superior quality individuals have been identified based on the 42 variables examined in our study. These hybrid individuals can be economically incorporated into production after the registration stages, and their sustainability for use in breeding programs can also be ensured.ResultsThe fruit weight ranged from 0.71 (‘H11’) to 1.66 g (‘H6’). The ascorbic acid varied between 17.13 (‘H7’) and 20.64 mg AAE/100 g (‘H15’). The antioxidant activity changed between 12.59 (‘Store’) and 15.03 µmol Trolox g–1 (‘Aurea’). The total anthocyanins were found to be highest in ‘Borrel Beast’ (163.79 mg cyn-3-gluc 100 g–1), followed by ‘H8’ (163.20 mg cyn-3-gluc 100 g–1). The highest nutrient levels in the fruits were found in the ‘H10’ individual, with calcium (2445.77 mg kg–1), potassium (2274.36 mg kg–1), phosphorus (2123.27 mg kg–1), magnesium (1263.95 mg kg–1), and sulfur (859.62 mg kg–1), respectively. The highest nutrient levels in the leaves were found in the ‘H14’ individual for calcium (19,493.21 mg kg–1), ‘H5’ for magnesium (5643.52 mg kg–1), ‘H8’ for sulfur (2312.11 mg kg–1), ‘H6’ for phosphorus (2007.51 mg kg–1), and ‘H6’ for potassium (1099.32 mg kg–1). In general, the nutrients in the fruit exhibited significant correlations among themselves at different levels (*, **, ***). Within the scope of principal component analysis, the first 8 principal components explained 80.69% of the total variance. According to the cluster and population analyses, it was determined that there was a high variation in subgroup B2. Additionally, although honeyberry is a relatively new fruit in Türkiye, efforts have begun to develop new cultivars through hybrid breeding.ConclusionsWhen 42 variables were evaluated together to determine genetic diversity, hybrid individuals ‘H14’, ‘H5’, ‘H8’, and ‘H1’ were identified as superior individuals, respectively.

Suppression of NNK Metabolism by Anthocyanin-Rich Haskap Berry Supplementation Through Modulation of P450 Enzymes

Oral supplementation of anthocyanins-rich haskap (Lonicera caerulea) berry (HB) reduces 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis, cytotoxicity, DNA damage, and modulated inflammation in vitro and in vivo. The procarcinogen NNK is metabolically activated by cytochrome P450 (P450) enzymes, producing reactive metabolites that induce lung carcinogenesis. Hypothesis: Therefore, we hypothesized that the HB-modulated protective effect against NNK could be due to its ability to suppress P450 enzymes. Methods: HB (6 mg of cyanidin-3-O-glucoside [C3G] in 0.2 g of HB/mouse/day) was given to A/J mice as a dietary supplement following subsequent administration of NNK (100 mg/kg body weight). The liver tissues of mice were analyzed to determine the expression of P450s and metabolites. Results: HB upregulated the expression of cyp2a4 and cyp2a5 mRNA and nuclear receptor/transcription factor (PPARα) in NNK-deprived hepatic tissues. With NNK, HB downregulated the expression of cyp2a4 and cyp2a5 and facilitated the formation of non-carcinogenic NNK metabolites. Molecular docking indicated a high binding affinity and strong hydrophobic interactions between C3G and its major metabolites, peonidin-3-O-glucoside, petunidin-3-O-glucoside, peonidin and cyanidin with Cyp2a5 and with human P450 homologue CYP2A13. Conclusions: HB could be a potential dietary supplement to inhibit the P450 activated NNK carcinogenic metabolites formation. Hence, inhibiting the activation of NNK by lung CYP2A13 through dietary HB supplementation could be a strategy to reduce lung carcinogenesis among smokers. Understanding the effect of HB on the activity of CYP2A13 in human studies is necessary before recommending these natural compounds as therapeutics.

МИКРОКЛОНАЛЬНОЕ РАЗМНОЖЕНИЕ ЖИМОЛОСТИ СЪЕДОБНОЙ И ЕЕ ВЕГЕТАТИВНОЕ РАЗВИТИЕ В УСЛОВИЯХ IN VITRO

Honeysuckle (Lonicera edulis) is a valuable plant with extreme early maturity - its fruits ripen 7-10 days earlier than strawberries in the conditions of the Republic of Tatarstan. Currently, there is a great demand for seedlings of fruit and berry crops in Russia. This is due to the increase in areas in industrial, homestead and collective gardening. Having conducted statistics on agricultural mortgages, we identified a huge trend for families to return to private homesteads. Therefore, clonal micropropagation is the most effective method for obtaining a large amount of high-quality planting material to create not only industrial plantings, but also to provide the population with standard seedlings. At the stage of introduction into the culture in vitro, effective sterilization modes were selected, and at the stage of reproduction, the further development of micro plants in the culture was studied. During the rooting process, two varieties of edible honeysuckle were observed and the effect of auxin on root formation and growth of the above-ground part of the plant was studied. The most viable sterile explants were observed with successive sterilization in solutions of 0.1% KMnO4 (3 min), 7.5% "Belizna" (7 min) and 0.01% Miramistin (1 min). The yield of sterile explants in this case averaged 69.8%. The best results were obtained with the Assol variety with an above-ground part growth of 6.3 cm and root system formation of 19.6 cm. At the fourth stage of "Adaptation", no varietal differences in survival were found. Both varieties of edible honeysuckle (Peter 1 and Assol) showed high survival rates.

Combination transcriptomic and metabolomic reveal deterioration of the blue honeysuckle (Lonicera caerulea L.) fruit and candidate genes regulating metabolism in the post-harvest stage

Blue honeysuckle, a new berry with high nutritional value, possesses typical berry postharvest properties, including extreme perishability, rapid quality loss, and high sensitivity to microbial infections. At present, the underlying mechanisms of postharvest quality deterioration, senescence, and low-temperature regulation remain largely unknown. This study aimed to elucidate the metabolic shifts and genetic regulation underlying the preservation or deterioration of blue honeysuckle during storage at room temperature (25 °C) and low temperature (4 °C). Storage at 4 °C inhibited fruit decay and preserved better visual quality, weight, firmness, and total soluble solid and acid contents. We identified 24 key differentially accumulated metabolites that specifically changed during the qualitative shift at room temperature and were effectively regulated by 4 °C. Commonly associated metabolites, sorbitol, succinic acid, malic acid, naringenin, pinobanksin, and taxifolin, characterize the deterioration of blue honeysuckle. These metabolites were integrated with transcriptomic data for weighted correlation network analysis (WGCNA). Regulatory networks were used for the identification of key genes and transcription factors (TFs) influencing sugar, organic acid, flavonoid, and phenolic acid metabolism during storage. The findings provide insight into metabolic regulation and the improvement of flavor in postharvest blue honeysuckle fruit.

First report of leaf spot disease caused by Fusarium asiaticum on Lonicera caerulea L. in Heilongjiang Province, China.

Heilongjiang is the largest province with the small, cultivated fruit plant, blue honeysuckle (Lonicera caerulea L.), in China (Sun et al. 2024). Between September 2022 and September 2023, a leaf spot disease was observed on about 10 percent of blue honeysuckles of the 'Lanjingling' cultivar grown in a 6.66-ha field in Mudanjiang (129.38°E, 44.59°N), Heilongjiang Province, China. The typical symptoms include a few small brown sunken leaf spots (approximately 2 mm) in the fruiting stage that gradually expand into larger brown sunken lesions (approximately 10 mm) in the senescence stage (Fig. S1). Small 3-4-mm segments of infected tissue from 100 randomly selected leaf samples with typical symptoms were surface sterilized with 75% ethanol and 5% sodium hypochlorite, rinsed in sterile distilled water, and transferred to 9-cm Petri dishes containing potato dextrose agar (PDA) after drying. Finally, 10 isolated fungi were obtained through single-spore culture on PDA, and their conidia displayed a morphology consistent with Fusarium spp. (Zheng et al. 2023), and no other fungi were isolated. The fungal colonies on PDA were pink to dark red with fluffy aerial mycelium and pigmentation (Fig. S2). Microconidia were not observed, and the macroconidia of fungi had 2 to 6 septa, which were slender, sickle-shaped to nearly curved, with an average size of 38.83 (21.30 to 55.20) × 3.87 (2.70 to 6.60) μm (n = 50) on carnation leaf agar (Fig. S3). Genomic DNA was extracted from the representative isolate LD-245 for molecular verification, and PCR amplification was performed with ITS1/ITS4 (White et al. 1990), RPB2-5F2/RPB2-7CR (Liu et al. 1999), and EFl/EF2 (O'Donnell et al. 1998) primers. Sequences of LD-245 ITS (OR565903), RPB2 (OR584061), and TEF (PP965657) revealed 99 to 100% (494/494, 722/726, and 654/654) of identity with Fusarium asiaticum (MT322117, MH582121, and MT330257). Phylogenetic tree was constructed based on the concatenated sequences of ITS, RPB2, and TEF genes, and LD-245 was clustered with F. asiaticum (Fig. S4, Table S1). Therefore, based on the morphological characteristics and molecular phylogeny, LD-245 was identified as F. asiaticum. Six two-year-old healthy plants of the 'Lanjingling' cultivar were selected for a pathogenicity test. Three plants were inoculated with LD-245 conidial suspension (1 × 106 spores/ml) or with sterile water as an experimental control. All plants were cultured in a greenhouse (28℃, 75% relative humidity, 12 h light and dark cycle), and each experiment was replicated three times. Typical leaf spot symptoms were observed on inoculated leaves after 10 days (Fig. S5), whereas no symptoms were detected on water-treated leaves. The pathogens re-isolated from infected leaves displayed the same morphological and molecular traits as the initial isolate, and were again identified as F. asiaticum, confirming Koch's postulate. F. asiaticum was previously reported on giant elephant's ear (Alocasia macrorrhizos) (Zheng et al. 2023), causing leaf spot disease in China. This study is the first report of blue honeysuckle leaf spot disease caused by F. asiaticum in China. China has the largest blue honeysuckle cultivation area globally, and the production of blue honeysuckle with horticultural value is important for growers (Sun et al. 2024). Therefore, we hope researchers can develop efficient measures to manage emerging plant diseases in the future.

The modulatory effects of Lonicera caerulea L. extract and omega-3 on sarcopenia via regulating PI3K and FOXO signaling pathways in rats

Introduction: Sarcopenia is an inflammatory disease caused by a disruption of muscle homeostasis. Lonicera caerulea L. (Haskap berry) (HB) extract and omega-3 (ω−3) possess antioxidant and anti-inflammatory activities. This study assesses the potential ameliorating effects of HB extract and ω−3 supplementation on dexamethasone (DEXA)-induced sarcopenia. Methods: Rats were divided into five groups; the negative control group was injected with saline (i.p.); groups 2, 3, 4, and 5 were injected with DEXA (2 mg/kg/d, i.p.); groups 3 and 4 also received 400 mg/kg/d and 100 mg/kg/d of HB extract and ω−3, respectively, while group 5 received both treatments daily for 21 days. The ameliorative effects of treatments were investigated by measuring lysosomal proteolytic enzyme cathepsin activity, phosphatidylinositol 3 kinase (PI3K) activity, nuclear factor kappa beta (NF-κB) level, and heme oxygenase-1 (HO-1) activity. The gene expression levels of muscle ring-finger protein (MuRF) and forkhead box O (FOXO) transcription factor were also evaluated. Biochemical and histological examinations were done on muscle tissues. Results: DEXA caused a significant elevation (P<0.05) in NF-κβ level and cathepsin activity in muscle tissue. Also, it significantly upregulated the muscle atrophy markers. Meanwhile, PI3K and HO-1 activities were significantly reduced. HB extract and ω−3 administration significantly (P≤0.05) reversed these effects and downregulated the mRNA expression levels of MuRF and FOXO. Also, the histopathological examination confirmed these results. Conclusion: The current study proved the ameliorative effects of HB extract and ω−3 on sarcopenia parameters. Therefore, they might be potential therapeutic agents for myopathy/sarcopenia.

Comparative Evaluation of the Phytochemical Composition of Fruits of Ten Haskap Berry (Lonicera caerulea var. kamtschatica Sevast.) Cultivars Grown in Poland

The aim of this study was to investigate the qualitative and quantitative fruit profiles of ten cultivars (cvs.) of haskap berry (Lonicera caerulea var. kamtschatica Sevast.) to determine their antioxidant activity (ABTS test, CUPRAC test, ability to capture superoxide (O2˙−) and hydroxyl radicals (OH˙)), cytotoxic activity (against cancer cell lines breast, MCF-7; colon, HT-29; and melanoma, SK-Mel-28) and physicochemical properties. Most of the selected cultivars had not previously been analyzed for these properties. A total of 19 polyphenolic compounds were identified in the fruits of the tested genotypes, with a quantitative range of 2166.3–3597.0 µg/g. The polyphenol profile was dominated by anthocyanins (90.0–92.4%), and the remaining classes occurred in the following order: phenolic acids > flavonols > flavan-3-ols. The highest concentrations of these polyphenol groups were found in the cultivars ‘Honeybee’, ‘Sinij Uties’ and ‘Usłada’. The fruits of these cultivars were also characterized by the highest antioxidant activity (546.6–683.5 µg/mL for O2˙− and 541.2–652.1 µg/mL for OH˙) and cytotoxic activity (103.6–649.2 µg/mL). The data obtained indicate that the fruits of the new haskap cultivars are a good source of bioactive compounds with possible health-promoting properties.

Composition and micromorphological determination of blue honeysuckle fruit (Lonicera caerulea L.) cuticular wax and its effects on fruit post-harvest quality

The chemical composition and structure of the cuticular wax in blue honeysuckle fruit were investigated using gas chromatography–mass spectrometry (GC–MS) and scanning electron microscopy (SEM). The results revealed that the cuticular wax was dense and uniform, taking on a tubular form. A total of 158 wax components were identified, including alkanes, terpenes, ketones, alcohols, fatty acids, and esters. The wax was found to be particularly rich in alkanes. After storage, the wax content decreased, whereas an increase in 1-undecanol. The destruction or reduction of cuticular wax resulted in a more rapid decline in storage quality, loss of nutrients, and a decrease in antioxidant phytochemicals. Meanwhile, wax metabolizing enzyme activity and gene expression increased. This study presents a deeper understanding of blue honeysuckle fruit cuticular wax composition and aids to developing effective measures to delay its postharvest fruit quality deterioration.

Determination of antioxidant capacity and phenolic content of haskap berries (Lonicera caerulea L.) by attenuated total reflectance-Fourier transformed-infrared spectroscopy

The total phenolic content (TPC) and antioxidant capacity (TAC) of haskap berries cultivated in various locations across Alberta were analyzed using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. The Folin–Ciocalteu assay was used to determine TPC, while TAC was quantified by 2,2-diphenyl-1-picrylhydrazl radicals (DPPH) assay and oxygen radical absorbance capacity (ORAC) assay. Three tenfold cross-validated partial least-squares regression (PLSR) models and three fivefold cross-validated deep learning models were developed separately based on FT-IR spectra collected from 22 haskap berry samples and their corresponding reference values determined through Folin-Ciocalteu, DPPH, and ORAC assays. The deep learning models (R2 = 0.95, 0.93, and 0.90 for Folin-Ciocalteu, DPPH, and ORAC assays, respectively) demonstrated better prediction capability compared to the PLSR models (R2 = 0.74, 0.72, and 0.66 for Folin-Ciocalteu, DPPH, and ORAC assays, respectively). In addition, PLS loading plots indicated that phenolic contents and polysaccharides in haskap berries could contribute to their antioxidant capacity. Using ATR-FTIR to estimate the TPC and TAC of fruits offers a rapid alternative to the conventional chemical assays.

Coding and description of phenological stages of blue honeysuckle (Lonicera caerulea L.) according to the BBCH scale

Blue honeysuckle (Lonicera caerulea L.) is an emerging fruit crop from the temperate to circumpolar climate regions with outstanding agronomic traits, substantial nutritional value, and versatile processing applications. However, the limited understanding of its phenology poses substantial challenges to its cultivation, breeding, and research. In this study, we characterized the progressive phenological growth stages of blue honeysuckle according to the BBCH (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie) scale by investigating three major cultivars (L. caerulea) and a wild accession (L. caerulea var. edulis) in Harbin, China (hot-summer humid continental climate) during 2022–2023. The annual growth of blue honeysuckle was characterized by eight primary stages, including bud development (0), leaf development (1), shoot development (3), inflorescence emergence (5), flowering (6), fruit development (7), fruit ripening (8), and senescence and dormancy (9). Additionally, 35 secondary growth stages were documented, among which eight stages are related to fruit development and ripening. The annual growth period of blue honeysuckle spans 6.5–7 months, starting from late March and ending in early October. The flowering season lasts for 2–3 weeks, ranging from late April to mid-May. The fruit development and ripening last for 7–9 weeks, beginning in early May and ending in early July. This study provides valuable insights for the cultivation and research of blue honeysuckle.

Comprehensive structural analysis of anthocyanins in blue honeysuckle (Lonicera caerulea L.), bilberry (Vaccinium uliginosum L.), cranberry (Vaccinium macrocarpon Ait.), and antioxidant capacity comparison

The objectives of this research were to analyze anthocyanins in blue honeysuckle (Lonicera caerulea L.), bilberry (Vaccinium vitis-idaea L), and cranberry (Vaccinium macrocarpon Ait.), using HPLC-ESI-QTOF-MS2, Fourteen, fifteen, and eight anthocyanins were identified in blue honeysuckle, bilberry, and cranberry, respectively. Cyanidin-3-glucoside (C3G) and peonidin-3-glucoside were detected in all three types of berries, with blue honeysuckle showing the highest C3G content at 5686.28 mg/100 g DW. Total phenolic content (TPC) and total flavonoid content (TFC), along with ABTS, DPPH, and FRAP assays, were measured. Blue honeysuckle exhibited the highest levels of TPC and TFC. The SOD, POD, and CAT activities in blue honeysuckle were 1761.17 U/g, 45,525.65 U/g, and 1043.24 U/g, respectively, which were significantly superior to those in bilberry and cranberry. The antioxidant mechanisms of these enzymes were investigated by molecular docking, C3G showed a higher affinity for POD, confirming the effectiveness of C3G as an antioxidant.

Growth and Fecundity of Nonnative Blue Honeysuckle Cultivars: Comparisons with Native and Invasive Congeners in a Maine Field Trial

Blue honeysuckle (Lonicera caerulea) is a circumpolar species complex with representatives in Europe, Asia, and North America. Although honeysuckles (Lonicera spp.) from Eurasia have a history of invasiveness in North America, farmers and homeowners are interested in growing nonnative blue honeysuckle hybrids because of their edible blue fruits. To assess whether these cultivars and closely related native blue honeysuckles (Lonicera caerulea subsp. villosa) might have similar growth and fecundity, we planted five nonnative cultivars of blue honeysuckle and five native genotypes in a common garden in Orono, ME, USA, along with invasive red-fruited honeysuckles [Tatarian honeysuckle (Lonicera tatarica) and European fly honeysuckle (Lonicera xylosteum)] for comparison. Rooted cuttings were planted into a field plot in Jun 2016 and fully maintained during the first season; thereafter, maintenance consisted of weeding once annually. Seventy-three percent of native blue honeysuckle plants survived to the end of the study, whereas survival and growth of nonnative cultivars were more robust. In 2021, nonnative cultivars had an average height of 81 cm and width of 86 cm, which were 2.8 times the height and 2.9 times the width of surviving native plants. The estimated canopy volumes of nonnative blue honeysuckles were an average of 20 times those of their native counterparts. The bloom periods of native and nonnative blue honeysuckles overlapped considerably. However, only seven of the 22 living native plants produced fruits in 2021, with an average of three fruits per plant among them. In contrast, nearly all plants of the nonnative cultivars produced fruits, with an average of 616 fruits per plant. In comparison, the red-fruited invasives had an average of 9739 fruits per plant. Native blue honeysuckles produced very few seeds, whereas nonnative cultivars had an average of 13,918 seeds per plant, which was approximately one-fourth the number produced by invasive red-fruited honeysuckles. We concluded that native and nonnative genotypes of blue honeysuckle differ strikingly in survival, growth, and production of fruits and seeds. However, invasive red-fruited honeysuckles grew faster with higher fecundity than nonnative blue honeysuckles in our full-sun landscape. Because bloom times overlapped substantially between native and nonnative blue honeysuckles, the potential for gene flow to occur from planted cultivars into native populations merits consideration. Several possible explanations of differences in performance among blue honeysuckles include hybrid vigor of cultivars or shallow rooting or poor adaptability of native genotypes to the environment of the common-garden trial. Our results, which demonstrated that nonnative blue honeysuckles are likely to be distinct from their native relatives in terms of competitiveness and fecundity, suggest that caution is warranted during the introduction and cultivation of agricultural genotypes.

First report of leaf spot disease caused by Pseudopithomyces chartarum on Lonicera caerulea L. in Heilongjiang Province, China.

Blue honeysuckle (Lonicera caerulea L.) cultivation has gradually expanded in China but continues to be limited by challenges such as leaf spot disease. Between September 2022 and September 2023, a leaf spot disease was observed on approximately 30% of 'Lanjingling' blue honeysuckles grown in a 2.66 ha field (a total of about 11,000 plants) in Jiamusi city (130.47°E, 46.16°N), Heilongjiang Province, China. Affected plants displayed brown necrotic lesions on their leaves that gradually expanded in area until the leaves fell off the plant entirely. Small, 3 to 4 mm segments of infected tissue from 50 randomly selected leaves were surface sterilized with 75% ethanol for 30 s and 5% sodium hypochlorite (NaOCl) for 3 min, rinsed three times with sterile distilled water, dried on paper towels, and plated in 9 cm Petri dishes containing potato dextrose agar (PDA) (Yan et al. 2022). Five pathogens (LD-232, LD-233, LD-234, LD-235, and LD-236) were isolated on PDA and displayed a conidia morphology consistent with Pseudopithomyces spp. (Perelló et al. 2017). The fungal colonies on PDA were villiform, white, and whorled and had sparse aerial mycelium on the surface with black conidiomata. The conidia were obpyriform and dark brown, had 0 to 3 transverse and 0 to 1 longitudinal septa, and measured 9.00 to 15.30 μm × 5.70 to 9.30 μm in size (n = 50). Genomic DNA was extracted from a representative isolate, LD-232, for molecular verification and PCR amplification was performed with ITS1/ITS4 (White et al. 1990), LROR/LR7 (Carbone and Kohn 1999), and RPB2-5F2/RPB2-7CR (Liu et al. 1999) primers. Sequences of LD-232 ITS (OR835654), LSU (OR835652), and RPB2 (OR859769) revealed 99.8% (530/531 nt), 98.8% (639/647 nt), and 99.8% (1015/1017 nt) shared identity with Pseudopithomyces chartarum sequences (OP269600, OP237014, and MK434892), respectively (Wu et al. 2023). Bayesian inference (BI) was used to construct the phylogenies using Mr. Bayes v. 3.2.7 to confirm the identity of the isolates (Ariyawansa et al. 2015). Phylogenetic trees cannot be constructed based on the genes' concatenated sequences because selective strains do not have complete rDNA-ITS, LSU, and RPB2 sequences. Therefore, based on the morphological characteristics and molecular phylogeny, LD-232 was identified as P. chartarum (Perelló et al. 2017; Wu et al. 2023). A pathogenicity test was performed with six healthy, two-year-old 'Lanjingling' blue honeysuckle plants. Three plants were inoculated by spraying the LD-232 conidial suspension (1 × 106 spores/ml) or clean water as an experimental control condition (Wu et al. 2023; Yan et al. 2023). All plants were cultured in a greenhouse at 28℃ under a 12-h light/dark cycle, and each experiment was replicated three times. Typical leaf spot symptoms were observed on inoculated leaves after 10 days. The same pathogens were reisolated from infected leaves, displayed the same morphological and molecular traits, and were again identified as P. chartarum, confirming Koch's postulate. P. chartarum previously caused leaf spot disease on Tetrapanax papyrifer in China (Wu et al. 2023). To our knowledge, this is the first report of blue honeysuckle leaf spot caused by P. chartarum in China. Identification of P. chartarum as a disease agent on blue honeysuckle will help guide future management of leaf diseases for this economically important small fruit tree.

Assessment of Selected Chemical and Morphological Properties of Lonicera var. kamtschatica and Lonicera var. emphyllocalyx Treated with Gaseous Ozone.

Lonicera caerulea L. fruits are a rich source of vitamins, organic acids, and phenolic compounds, which are characterised by their health-promoting properties. The content of bioactive compounds in this fruit may vary depending on the cultivar and the harvest date. This study analysed the effect of applying 5 ppm gaseous ozone for 1, 3, and 5 min on the chemical properties of L. kamtschatica varieties and newly created clones of L. emphyllocalyx for three years of cultivation. The fruits harvested from L. emphyllocalyx, depending on the year of harvest, had significantly larger size and weight compared to L. kamtschatica. On average, the acidity of the L. emphyllocalyx clones was 6% higher than other tested varieties. The average content of ascorbic acid was highest in L. emphyllocalyx clone '21-17'-57.80 mg·100 g-1; the year of harvest will significantly affect the content of vitamin C, reaching the highest level in 2022-53.92 mg·100 g-1. The total content of polyphenols was significantly dependent on the year of cultivation; reaching, on average, 54.8% more in 2022 compared to the rest of the years. The total antioxidant value using the FRAP, DPPH, and ABTS methods varied depending on the variety; exposure to ozone significantly increased the antioxidant value in each case. On the basis of the study, both botanical varieties can be used in food processing. Gaseous ozone exposure can significantly influence chemical composition, increasing the health-promoting value of fruit.

Effects of Drought Stress on Photosynthesis and Chlorophyll Fluorescence in Blue Honeysuckle.

Blue honeysuckle (Lonicera caerulea L.) is a deciduous shrub with perennial rootstock found in China. The objectives of this study were to explore the drought tolerance of blue honeysuckle, determine the effect of drought stress on two photosystems, and examine the mechanism of acquired drought tolerance. In this study, blue honeysuckle under four levels of simulated field capacity (100%, 85%, 75%, and 65% RH) was grown in split-root pots for drought stress treatment, for measuring the changes in chlorophyll content, photosynthetic characteristics, and leaf chlorophyll fluorescence parameters. The chlorophyll content of each increased under mild stress and decreased under moderate and severe stress. The net photosynthetic rate, transpiration rate, intercellular carbon dioxide concentration, and stomatal conductance of blue honeysuckle decreased with the increase in water stress. However, the water utilization rate and stomatal limit system increased under mild and moderate stress and decreased under severe stress. The maximum fluorescence (Fm), maximum photochemical efficiency, and quantum efficiency of photosystem II decreased with the decrease in soil water content, and the initial fluorescence increased significantly (p < 0.01). With the decrease in soil water content, the energy allocation ratio parameters decreased under severe drought stress. The main activity of the unit reaction center parameters first increased and then decreased. ABS/CSm, TRo/CSm, ETo/CSm, and REo/CSm gradually declined. After a comprehensive analysis, the highest scores were obtained under adequate irrigation (CK). Overall, we concluded that the water irrigation system of blue honeysuckle should be considered adequate.

First report of leaf spot disease caused by Cladosporium pseudocladosporioides on Lonicera caerulea L. in Heilongjiang Province, China.

Blue honeysuckle (Lonicera caerulea L.) has contributed to maintaining the forest's ecological balance and remarkable frost-resistant abilities, helping it withstand extremely cold conditions (-46 °C) and a wide pH range (5 to 8) (Sharma and Lee 2021). Between September 2022 and September 2023, leaf spots were observed on approximately 30% of blue honeysuckle plants of the 'Lanjingling' cultivar grown in a 1.13 ha field in Da Hinggan Ling Prefecture (50.32° N, 124.13° E) in Heilongjiang Province, China. The leaves of the affected plants displayed black-colored spots. To identify the causal agents, 10 healthy and symptomatic leaves were randomly collected from ten healthy and infected individual plants, respectively. Small (3 to 4 mm) segments of the symptomatic tissues were immersed in 5% sodium hypochlorite (NaOCl) for 3 min, rinsed three times with sterile distilled water, dried in a paper towel, and plated on 9-cm Petri dishes containing potato dextrose agar (PDA). Ten fungal colonies developed on the PDA plates with an isolation frequency of 100% from 10 symptomatic leaves, and all colonies displayed a morphology consistent with Cladosporium spp. (Bensch et al. 2018). Cladosporium-like fungi were not isolated from healthy leaves. Dark olive-colored mycelia were observed, with straight unbranched conidiophores bearing terminal light brown-colored limoniform conidia (1.80 to 4.50 × 2.10 to 12.60 μm) and surrounded by a thin line of white mycelium (Delisle-Houde et al. 2024). To confirm this identification, PCR amplification of two representative strains LD-299 and LD-300 genomic DNA was performed with ITS1/ITS4 (White et al. 1990) and ACT512F/ACT783R (Carbone and Kohn 1999) primers. Basic local alignment search tool (BLAST) analyses of the National Center for Biotechnology Information database showed that sequences of the ITS (PP600316, PP600317) and ACT (PP624334, PP624335) all revealed 100% (493/493 nt, 493/493 nt; 181/181 nt, 181/181 nt) shared identity with Cladosporium pseudocladosporioides strain ex-type MF473195 and HM148674 (Bensch et al. 2010), respectively. Using a neighbor-joining phylogenetic analysis based on the ITS and ACT sequences, isolates LD-299 and LD-300 clustered in the same clade of C. pseudocladosporioides. Therefore, based on its morphological characteristics and molecular phylogeny, the two isolates were identified as C. pseudocladosporioides (Cosseboom and Hu 2023). A pathogenicity test was performed using nine healthy two-year-old blue honeysuckle Lanjingling plants. Three plants were inoculated with either the LD-299 or the LD-300 conidial suspension (1 × 106 spores/ml) or with clean water as an experimental control (Aydoğdu et al. 2023). All plants were cultured in a greenhouse (28℃, 75% relative humidity, 12 h light and dark cycle), and each experiment was replicated three times. Typical leaf spot symptoms were first observed on the inoculated leaves after 10 days. Morphological and molecular characterization of re-isolated pathogens from the artificially infected leaves indicated that the two isolates were identical, thereby confirming Koch's postulates. Cladosporium pseudocladosporioides previously caused leaf spot disease on artichoke (Cynara scolymus) in Türkiye (Aydoğdu et al. 2023). To the best of our knowledge, this is the first report of C. pseudocladosporioides causing leaf spots on blue honeysuckle in China. Blue honeysuckle production losses due to the leaf spots are critical for growers. Therefore, further focus should be given to investigate the host range and geographic distribution of C. pseudocladosporioides.

Effects of Haskap (Lonicera caerulea L.) Extracts against Oxidative Stress and Inflammation in RAW 264.7 Cells.

This study aimed to evaluate the antioxidant and anti-inflammatory activities of Lonicera caerulea L. ethanol extract (LCEE) and water extract (LCWE) in vitro. We primarily evaluated the improvement effect of LCWE and LCEE on hydrogen peroxide (H2O2)-induced oxidative damage and lipopolysaccharide (LPS)-induced inflammatory damage in RAW 264.7 cells by detecting oxidation-related indicators and inflammatory factors, respectively. Cellular studies showed that LCWE and LCEE increased superoxide dismutase and catalase antioxidant enzyme levels and decreased malondialdehyde and nitric oxide peroxide levels in H2O2-induced RAW 264.7 cells. Moreover, LCWE and LCEE decreased the secretion of inflammatory factors [e.g., interleukin (IL)-6, IL-1β, and tumor necrosis factor-α] in LPS-induced RAW 264.7 cells. In conclusion, LCWE and LCEE demonstrated excellent antioxidant and anti-inflammatory effects in vitro. However, LCWE was superior to LCEE, which may be related to its chemical composition and requires further research.

Dietary Supplementation of Haskap Berry (Lonicera caerulea L.) Anthocyanins and Probiotics Attenuate Dextran Sulfate Sodium-Induced Colitis: Evidence from an Experimental Animal Model.

Haskap berry (Lonicera caerulea L.) is a rich dietary source of anthocyanins with potent anti-inflammatory properties. In this study, isolated haskap berry anthocyanins were encapsulated in maltodextrin and inulin (3:1) by freeze-drying to improve stability and bioavailability. The structural properties of microcapsules, encapsulation yield, efficiency, recovery, and powder retention were evaluated. The microcapsules that exhibited the highest encapsulation efficiency (60%) and anthocyanin recovery (89%) were used in the dextran sulfate sodium (DSS)-induced acute colitis in mice. Thirty-five BALB/c male mice of seven weeks old were divided into seven dietary supplementation groups (n = 5) to receive either free anthocyanins, encapsulated anthocyanins (6.2 mg/day), or probiotics (1 × 109 CFU/day) alone or as combinations of anthocyanin and probiotics. As observed by clinical data, free anthocyanin and probiotic supplementation significantly reduced the severity of colitis. The supplementary diets suppressed the DSS-induced elevation of serum inflammatory (interleukin (IL)-6 and tumor necrosis factor) and apoptosis markers (B-cell lymphoma 2 and Bcl-2-associated X protein) in mice colon tissues. The free anthocyanins and probiotics significantly reduced the serum IL-6 levels. In conclusion, the dietary supplementation of haskap berry anthocyanins and probiotics protects against DSS-induced colitis possibly by attenuating mucosal inflammation, and this combination has the potential as a health-promoting dietary supplement and nutraceutical.

A Systematic Review of Cardio-Metabolic Properties of Lonicera caerulea L.

In the light of growing concerns faced by Western societies due to aging, natality decline, and epidemic of cardio-metabolic diseases, both preventable and treatable, new and effective strategical interventions are urgently needed in order to decrease their socio-economical encumbrance. The recent focus of research has been redirected towards investigating the potential of haskap (Lonicera caerulea L.) as a novel functional food or superfruit. Therefore, our present review aims to highlight the latest scientific proofs regarding the potential of Lonicera caerulea L. (LC), a perennial fruit-bearing plant rich in polyphenols, in reversing cardio-metabolic dysfunctions. In this regard, a systematic search on two databases (PubMed and Google Scholar) from 1 January 2016 to 1 December 2023 was performed, the keyword combination being Lonicera caerulea L. AND the searched pharmacological action, with the inclusion criteria consisting of in extenso original articles, written in English. The health-enhancing characteristics of haskap berries have been examined through in vitro and in vivo studies from the 35 included original papers. Positive effects regarding cardiovascular diseases and metabolic syndrome have been assigned to the antioxidant activity, hypolipidemic and hypoglycemic effects, as well as to the hepatoprotective and vasoprotective potential. Latest advances regarding LCF mechanisms of action are detailed within this review as well. All these cutting-edge data suggest that this vegetal product would be a good candidate for further clinical studies.

Exploring bitter characteristics of blue honeysuckle (Lonicera caerulea L.) berries by sensory-guided analysis: Key bitter compounds and varietal differences

The taste of blue honeysuckle (Lonicera caerulea L.) berries is wrapped in bitterness, and awareness about the essence of bitterness is lacking. In the current study, 7-ketologanin, sweroside and loganin were isolated and identified as key bitter compounds using sensory-guided analysis. The bitterness thresholds of these compounds were determined to be 11.9 μg/mL, 33.5 μg/mL and 60.2 μg/mL. Subsequently, the differences in bitterness among 16 blue honeysuckle varieties were evaluated. The wild varieties A1 and A2 exhibited the highest bitter intensity. 7-Ketologanin, with the highest concentration of 34.70–37.11 mg/100 g and taste activity values of 29.16–31.18 in A1 and A2, was first identified as a bitter contributor in blue honeysuckle. There was no significant difference in bitter intensity between the reconstitution model and the original sample, confirming the contribution of the three bitter compounds. This study lays the foundation for the bitter improvement and variety selection of blue honeysuckle resources.