Next Article in Journal
Development of a Gravity-Driven Vis/NIR Spectroscopy Device for Detection and Grading of Soluble Solids Content in Oranges
Previous Article in Journal
Industrial Hemp Finola Variety Microgreens: A Sustainable Source of Selenium Biofortified Functional Foods
Previous Article in Special Issue
Grapevine Phenology, Vegetative and Reproductive Characteristics of Vitis vinifera L. cv Chardonnay in the Cape South Coast Region in South Africa
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Agriculture
Volume 16
Issue 3
10.3390/agriculture16030291
agriculture-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Diversity of Phenological Characteristics and Fruit Quality of the Chinese Honeyberry (Lonicera caerulea L.) Collection

by
Hao Yang
1,2,†,
Xiaohui Zhang
1,2,†,
Caihong Yu
1,
Ziqing Wang
1,
Ruijuan Hao
1,
Chunfang Wang
1,
Bingcui Zhang
1,
Jiayi Shi
1,
Jiacheng Li
1,2,
Dong Qin
1,2,3,
Huixin Gang
1,2,3,
Junwei Huo
1,2,3,
Chenqiao Zhu
2,3,4,* and
Min Yu
2,3,5,*
1
College of Horticulture & Landscape Architecture, Northeast Agricultural University, Harbin 150030, China
2
National-Local Joint Engineering Research Center for Development and Utilization of Small Fruits in Cold Regions, National Development and Reform Commission, Northeast Agricultural University, Harbin 150030, China
3
Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northeast Region), Ministry of Agriculture and Rural Affairs, Harbin 150030, China
4
College of Architecture and Horticulture, Yunnan Agricultural University, Kunming 650201, China
5
College of Life Sciences, Northeast Agricultural University, Harbin 150030, China
*
Authors to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Agriculture 2026, 16(3), 291; https://doi.org/10.3390/agriculture16030291
Submission received: 9 December 2025 / Revised: 16 January 2026 / Accepted: 21 January 2026 / Published: 23 January 2026
(This article belongs to the Special Issue Climate Change and Plant Phenology: Challenges for Fruit Production)
Browse Figures
Versions Notes

Abstract

Honeyberry (Lonicera caerulea L.) is a recently domesticated fruit crop, and there has been rather limited research on its phenological characteristics. In this study, we comprehensively evaluated the phenological and fruit quality traits of a honeyberry germplasm collection comprising 45 accessions. The annual growth period of the 45 accessions ranged from 153 (part of Russian accessions) to 173 days (part of Japanese accessions) in Harbin, China. The accessions of Japanese origin (‘Ri–5’, ‘Ri–68’, ‘RiM–3’, ‘Riwan’, ‘Riwandianlan’, and ‘Riwan–13’) consistently exhibited delayed flowering and ripening, as well as higher single fruit weights and fruit firmness. In contrast, the accessions of Russian and Chinese origins displayed relatively early to mid-season phenology, along with higher levels of vitamin C, anthocyanins, and soluble solids. Furthermore, there were great coefficients of variation (CVs) in total anthocyanins (CV = 35%), flavonoids (CV = 30%), phenolics (CV = 21%), and titratable acidity (CV = 19%) among the 45 accessions. Principal component analysis and hierarchical clustering revealed distinct clustering patterns among Japanese accessions. Among these accessions, ‘RiM–3’ exhibited both a relatively large fruit size and high firmness, implying its potential to overcome the inevitable trade-off between fruit size and firmness typically observed in Chinese and Russian honeyberry accessions. Our investigation and findings provide valuable information for honeyberry breeding aimed at optimizing the maturity period and enhancing fruit quality, as well as a reference for the current cultivation and management methods.

1. Introduction

Honeyberry, also known as blue honeysuckle (Lonicera caerulea L.), is a perennial deciduous shrub with a height and a canopy of approximately 1.5–2.0 m [1]. It produces high-quality berries with a sweet–sour taste and high levels of anthocyanins, flavonoids, vitamin C, and iridoids, making it an ideal fresh fruit or versatile raw material for functional food and pharmaceutical applications [2,3]. Polyphenols, abundant in honeyberry, are secondary compounds and a key source of dietary phenolics for human health. Based on their carbon skeletons, polyphenols can be categorized into phenolic acids, stilbenes, phenylpropanoids, flavonoids, and quinones [4]. Notably, honeyberry fruit contains not only abundant main polyphenols, such as phenolic acids (mainly 3-O-caffeoylquinic acid), flavonoids (mainly quercetin), and anthocyanins (mainly cyanidin 3-O-glucoside), but also more than ten terpenoids [5,6]. Polyphenols and terpenoids also possess certain anti-inflammatory properties, which can reduce the risks of metabolic diseases such as obesity and diabetes [7]. The rich and diverse polyphenols and iridoids in honeyberry fruit also affect the color and taste of the fruit, especially its aromatic flavor [8,9].
Due to its early maturity, high resistance to pests and diseases, and strong ecological adaptability to cold climates, honeyberry has attracted increased attention from growers and producers worldwide. Currently, it is widely cultivated in China, Russia, Japan, Canada, and the United States and experimentally planted in the Southern Hemisphere [10]. By 2022, the commercial cultivation area of honeyberry had reached approximately 5000 hectares in Northeast China [11,12], which is probably the largest production area of honeyberry worldwide. The rapid expansion of commercial honeyberry cultivation has attracted significant attention from breeders and potential growers, with particular concerns about its climate adaptability, fruit quality, and yield performance [13]. Growth conditions, varieties, and harvest times may have great impacts on the content of bioactive compounds, thereby affecting the fresh quality and processing properties of the fruit [14].
Therefore, many studies have been conducted to comprehensively explore the phenotypic plasticity and genetic diversity of honeyberry germplasms with diverse geographical origins and varying ploidy levels. For instance, a recent study found that honeyberry accessions collected from different regions had significant variations in the content of secondary metabolites, such as triterpenoids [15]. Another study of 11 honeyberry cultivars further confirmed that the levels of these compounds, along with the corresponding antioxidant and antibacterial activity, are largely predetermined by the genotype [16]. This finding is reinforced by the significant chemical variability observed among different honeyberry accessions, even when grown under identical geographical and cultivation conditions [17], underscoring the critical influence of the genotype. Furthermore, accession diversity is directly reflected in yields and physical traits, and different accessions are suitable for distinct purposes, such as fresh consumption, processing, or pharmaceutical applications, due to their specific characteristics [18]. Besides sweetness, researchers have highlighted the importance of saponin content in selecting accessions for greater human health benefits [19], further demonstrating the value of genotype-driven diversity. Beyond these relatively stable genetic factors, specific climatic conditions can also trigger distinct stress responses in honeyberry, leading to changes in the synthesis of various compounds [20]. Moreover, different ploidy levels and hybridization strategies can modulate the fruit color and accumulation of compounds in honeyberry [21,22]. Taken together, there is great diversity in the genetic, chemical, and agronomic traits of honeyberry, underscoring the significance of systematic research on its accession selection and industrial application, which may provide an important reference for the cultivation and breeding of honeyberry, as well as offering valuable insights for its biological research and genetic improvement [23,24,25].
However, to the best of our knowledge, the phenology of different honeyberry cultivars has not been investigated from west to east. In addition, there have been only sporadic agronomic evaluations on honeyberry germplasms globally, and no such research has been reported in China, despite the fact that Northeastern China is one of the major gene pools for wild honeyberry germplasms and probably the world’s largest production region for honeyberries. In addition, after approximately 30 years of mutually integrated processes, including wild selection, introduction, cross-breeding, cultivation tests, unintentional seed propagation, and empirical field selection, the Chinese honeyberry germplasm collection has become a novel gene pool, whose agronomic traits remain poorly understood. Thus, a comprehensive agronomic evaluation of Chinese honeyberry germplasm may not only directly provide potential materials for cultivar registration but also offer new insights for future long-term breeding programs.
In this study, we evaluated the Chinese honeyberry germplasm collection in Northeast Agricultural University (NEAU) in terms of their annual phenology, fruit phenotypic traits, and nutritional composition, aiming to establish trait-based selection indices for cultivation optimization and breeding and fill the critical knowledge gap regarding the agronomic characteristics of Chinese honeyberry accessions. This study proposed the following core hypotheses: (1) there would be significant phenological differences among the 45 accessions, and the differences may be correlated with certain physical characteristics or nutritional compositions; (2) through multiple comparisons, it was highly likely that we would find multi-advantaged materials among the 45 accessions, which could be used as potential breeding materials.

2. Materials and Methods

2.1. Plant Materials and Cultivation Methods

The study was carried out at the ‘Berry Germplasm Nursery’ of NEAU, Harbin City, Heilongjiang Province, China (BD-09 system: 45.75° N, 126.74° E, 127.95 m). Three clones of 45 honeyberry accessions (Table 1) were propagated through cuttings and planted in an open field from 2016 to 2018 (row spacing = 1.5 m; plant spacing = 1.2 m). The soil type was chernozem, which had basic nutrition, with total nitrogen of 0.25%, available phosphorus of 8.13 ppm, and available potassium of 114.0 ppm. The plants showed consistent and vigorous growth, with no observable pest infestations or disease symptoms. The cultivation and management were carried out under low-input conditions, without fertilization, pesticide application, or pruning. Weed control was managed by using woven plastic mulch throughout the experimental period.

2.2. Meteorology and Phenological Investigation

The cultivation area had a typical four-season climate, classified as a mid-temperate continental monsoon climate [26,27]. In 2024, the annual average temperature was 6 °C and the annual precipitation reached 660 mm. The primary meteorological variables, including the maximum and minimum temperatures, are presented in Figure 1. Climatic data were sourced from the Meteomanz database (http://www.meteomanz.com/, accessed on 5 February 2025).
The phenology of each accession was monitored following the previously established primary BBCH code of honeyberry [28,29]. Phenological observations were conducted on nine branches of a single accession. The dates of 11 key secondary growth stages were recorded, namely ‘end of bud burst’ (09), ‘unfolding of the first pair of leaves’ (11), ‘emergence of the second inflorescence’ (52), ‘beginning of flowering’ (60), ‘full flowering’ (67), ‘flowering ending’ (69), ‘initiation of fruit enlargement’ (73), ‘primary stage of fruit color turning’ (76), ‘end of fruit enlargement‘ (78), ‘fruit fully ripe’ (89), and ‘beginning of senescence’ (90) (Figure 2). The phenological investigation began in the last week of March 2024 and was carried out on a fixed branch of a fixed tree at three-day intervals during the bud break and leaf expansion stages, at two day intervals during the flowering period, and at three-day intervals during the fruit development stage.

2.3. Agricultural Trait Determination

Fruit color (FC) was measured using a spectrophotometer (CM-700d, KONICA MINOLTA, Tokyo, Japan) based on the CIELab standard, with values recorded as L*, a*, and b* relative to the instrument’s built-in white calibration plate. Fruit longitudinal diameter (FL), fruit transverse diameter (FT), leaf length (LL), and leaf width (LW) were measured using vernier calipers with precision of 0.01 mm (DL91150, Deli, Tianjin, China), and the fruit shape index (FSI) was calculated as ‘FL/FT’. The single fruit weight (SFW) was determined using an electronic balance with precision of 0.001 g (PUCHUN, Shanghai, China). Fruit firmness (FH) was measured using a fruit firmness tester (GY-4-HPA, HANDPI, Wenzhou, China, precision ± 0.01 kg/cm2). The soluble solid content (SSC) and titratable acidity (TA) of mature fruit were assessed using a PAL-BXIACID-F5 pocket brix acidity meter (ATAGO, Tokyo, Japan), following the manufacturer’s instructions.

2.4. Determination of Total Phenolics, Flavonoids, Vitamin C, and Anthocyanins

The total phenolics content (TPC) was quantified using a modified Folin–Ciocalteu method [30]. Briefly, 1.0 g of sample was homogenized in 25 mL of 60% ethanol, ultrasonicated for 15 min, and centrifuged. Subsequently, 0.5 mL of supernatant was mixed sequentially with 0.5 mL Folin’s reagent, 1.5 mL of 20% Na2CO3 solution, and 10 mL deionized water. After 2 h of incubation at 25 °C, the absorbance was measured at 750 nm. The total flavonoid content (TFC) was determined using the aluminum nitrate–sodium nitrite colorimetric method [31], with minor modifications. A 0.5 g sample was ground in 5 mL ethanol, ultrasonicated for 30 min, and centrifuged for 20 min. A 3 mL aliquot of the supernatant was mixed with 1 mL of 5% NaNO2 solution and left to stand for 6 min. Then, 1 mL of 10% Al(NO3)3 solution was added, and the sample was mixed thoroughly and left to stand for another 6 min. Finally, 3 mL of 4% NaOH solution was added and the sample was mixed. After standing for 15 min, the absorbance was measured at 510 nm. Vitamin C (VC) content was determined by molybdenum blue colorimetry [32], with minor modifications. Fresh fruit tissue (4.0 g) was homogenized in a mortar with oxalate–EDTA solution and then diluted to 25 mL with the same solution. After centrifugation, 1 mL of supernatant was mixed sequentially with 4 mL oxalate–EDTA, 1 mL 5% H2SO4, 0.5 mL metaphosphoric–acetic acid, and 2 mL 5% ammonium molybdate solution. The mixture was incubated in a 30 °C water bath for 15 min, and the absorbance was measured at 760 nm. For the determination of the total anthocyanin content (TAC) [33], a 2.0 g sample was added to 20 mL 1% HCL–60% C2H5OH solution and mixed well. After 30 min of ultrasound treatment and 20 min of centrifugation, 0.5 mL supernatant was obtained. This was combined with 4.5 mL CH3COONa solution with pH 4.5 and 4.5 mL KCl-HCl solution with pH 1.0, respectively, and then kept away from light for 60 min, and the absorbance was determined at 520 nm and 700 nm.

2.5. Statistical Analysis

All experiments were carried out in three biological replicates, and the results were expressed as the mean ± standard deviation (SD). Significant differences between treatment groups were analyzed using Duncan’s test (p ≤ 0.05). Data processing and standardization were performed using Excel 2013 (Microsoft Corp) and IBM SPSS Statistics for Windows, Version 27.0.1.0 (IBM Corp., Armonk, NY, USA). Principal component analysis was conducted using Origin, Version 2022 (OriginLab Corp., Northampton, MA, USA). Hierarchical clustering with heatmap visualization was performed using Python (version 3.7) with the Pandas library (version 0.25.1). Clustering was conducted using the complete linkage method with the Euclidean distance as the similarity metric.

3. Results and Discussion

3.1. Phenological Diversity of Chinese Honeyberry Germplasm Collection

The annual growth period of the 45 honeyberry accessions in Harbin (2024) started between April 3 and April 9 and concluded between September 8 and September 28, spanning approximately 153 to 173 days (Table S1). The ‘bud development’ of the 45 accessions lasted for 2–5 days, occurring between April 3 (‘CBS–5’ and ‘Altai–1’) and April 9 (‘P2–2’ and ‘Ri–5’). ‘Development of the first pair of leaves’ lasted for 3–9 days, spanning April 5 (‘CBS–5’ and ‘Altai–1’) to April 13 (‘Ri–68’). ‘Emerging inflorescences to clearly visible inflorescences and then to fully developed inflorescences’ persisted for 8–14 days, occurring between April 9 (‘CBS–5’, ‘Altai–1’, and ‘RB’) and April 20 (‘RiM–3’). The ‘beginning of flowering’ to ‘10% of petals fallen’ lasted for 3–8 days, occurring between April 19 (‘A–1’, ‘A–2’, and ‘MC–8’) and April 27 (‘HSY–32’, ‘Ri–5’, ‘RiM–3’, ‘Ri–68’, ‘Riwan’, ‘Riwandianlan’, and ‘Riwan–13’). The ‘full flowering’ stage, defined as the time at which 50% of the petals had fallen, lasted for 5–11 days, occurring between April 26 (‘Mishan–1’ and ‘A–1’) and May 4 (‘RiM–3’, ‘Ri–68’, ‘Riwan’, ‘Riwandianlan’, and ‘Riwan–13’).
During the fruit development period, the stage from the ‘end of flowering’ to ‘fruit setting’, defined as the period from 80% of petals fallen to the beginning of fruit setting, spanned from May 3 (‘Altai–1’) to May 13 (‘RiM–3’, ‘Ri–68’, ‘Riwan’, ‘Riwandianlan’, and ‘Riwan–13’). The median flowering duration was 14 days, with ‘MC–8’ (18 days) and ‘HL–2’ (17 days) having the longest flowering durations, while ‘Altai–2’, ‘A–4’, and ‘HSY–32’ displayed the shortest flowering durations (10 days). ‘Fruit color turning’ lasted for 5–10 days, occurring from May 18 (‘CBS–5’, ‘MC–1’, ‘MC–2’, ‘MC–4’, ‘MC–6’, ‘MC–7’, ‘MC–8’, ‘MC–9’, ‘MC–11’) to June 4 (‘Ri–5’, ‘Ri–68’, ‘Riwan’, ‘Riwandianlan’, and ‘Riwan–13’). ‘Completion of fruit color turning’, defined as the stage from full color development to the initial onset of fruit softening, lasted for 7–13 days, spanning from May 26 (‘A–1’, ‘A–3’, ‘A–4’, ‘A–5’, ‘L–5’, ‘HL–1’, ‘MC–1’, ‘MC–2’, ‘MC–5’) to June 13 (‘Riwan’, ‘Riwandianlan’, and ‘Riwan–13’). The ‘fruit ripening’ stage, defined as the stage at which the fruit softens and reaches commercial maturity, spanned from June 5 (‘A–1’, ‘A–2’, ‘A–3’, ‘A–4’, ‘A–5’, ‘L–5’, ‘MC–5’, ‘Geerda’, and ‘Lanrou’) to June 23 (‘Ri–68’, ‘Riwan’, ‘Riwandianlan’, and ‘Riwan–13’). The median fruit development cycle was about 33 days, and ‘Ri–68’, ‘Riwan’, ‘Riwandianlan’, and ‘Riwan–13’ (41 days) and ‘MC–5’ (27 days) were the accessions with the longest and shortest cycles, respectively. The ‘beginning of leaf fall’ to ‘50% of leaves fallen’ spanned September 8 (‘CBS–5’, ‘Altai–2’, ‘A–4’, ‘L–5’, ‘P3–20’, ‘Geerda’, ‘Lanrou’, ‘L–50’, ‘RB’, and ‘VRK’) to September 28 (‘RiM–3’, ‘Ri–68’, ‘Riwan’, ‘Riwandianlan’, and ‘Riwan–13’).
The above results reveal distinct stage-specific characteristics in phenology among different honeyberry accessions. In early-season phenological events, including bud development, leaf development, and flowering, all accessions showed relatively consistent timing and durations. However, as the season progressed, some phenological stages, such as fruit coloring, fruit ripening, and leaf senescence onset, emerged as key indicators for distinguishing different honeyberry accessions, indicating that varietal specificity in phenology becomes particularly pronounced during the later stages of the annual growth cycle (Tables S1 and S2). Specifically, some accessions from Russia and China (‘MC–1’, ‘MC–2’, ‘Altai–1’, ‘CBS–5’, ‘A–1’, ‘A–3’, ‘A–4’, ‘A–5’, ‘L–5’) showed earlier phenological stages, while those from Japan (‘Ri–5’, ‘RiM–3’, ‘Ri–68’, ‘Riwan’, ‘Riwandianlan’, ‘Riwan–13’) exhibited relatively later phenological stages.
The lack of research comparing the phenology across germplasms with different origins has directly hindered improvements in cultivation and field management, such as pollination tree pairing, and also indirectly constrained the in-depth exploration of potential genetic resources such as germplasms that are extremely precocious or late-maturing. To the best of our knowledge, this is the first report on the phenological diversity of honeyberry germplasms; it provides a novel comparison perspective with germplasms from other countries and climate regions. The late phenological characteristics associated with deep dormancy in Japanese accessions may provide an agronomic advantage for honeyberry, particularly when expanding its cultivation into temperate climate zones in the future [34,35]. In the northeast of Asia, this trait can help to mitigate spring frost damage, extend the fruit supply period, and reduce the risks of secondary budbreak and flowering induced by autumn temperature fluctuations. Hence, these germplasms might be valuable for future resistance breeding.

3.2. Fruit Morphology Diversity of Chinese Honeyberry Germplasm Collection

The fruit size, shape, weight, firmness, and color of the 45 honeyberry accessions were investigated (Figure 3 and Table S3). The fruit longitudinal diameter (FL) ranged from 12.27 mm (‘RB’) to 27.31 mm (‘A–4’), with a mean value of 19.30 mm and a CV of 19%. Th fruit transverse diameter (FT) ranged from 6.62 mm (‘HSY–32’) to 12.26 mm (‘RiM–3’) (mean, 9.03 mm; CV, 16%). The fruit shape index (FSI) ranged from 1.33 (‘Riwan’) to 3.12 (‘MC–9’) (mean, 2.19; CV, 21%). The single fruit weight (SFW) ranged from 0.43 g (‘HSY–32’) to 1.20 g (‘A–3’) (mean, 0.85 g; CV, 24%). The fruit firmness (FF) ranged from 0.30 N (‘HL–2’) to 3.76 N (‘RiM–3’) (mean, 1.59 N; CV, 47%). The L* value ranged from 27.68 (‘Ri–5’) to 40.52 (‘HL–9’) (mean, 33.80; CV, 9%). The a* value ranged from −1.54 (‘MC–8’) to 0.63 (‘Ri–5’) (mean, −0.76; CV, 68%). The b* value ranged from −8.15 (‘Altai–2’, ‘Mishan–1’) to −0.87 (‘RiM–3’) (mean, −6.26; CV, 30%).
The 45 accessions showed a longitudinal diameter range of 12.27 mm to 27.31 mm (CV = 19%), a transverse diameter range of 6.62 mm to 12.26 mm (CV = 16%), a fruit shape index (FSI) range of 1.33 to 3.12 (CV = 21%), a fruit firmness (FF) range of 0.30 N to 3.76 N (CV = 47%), and a single fruit weight (SFW) range of 0.43 g to 1.20 g (CV = 24%) (Figure 3A–E and Table S3). Generally, the Chinese honeyberry germplasm collection was characterized by a mean size of 19.30 mm × 9.03 mm, a mean FSI of 2.19, a mean SFW of 0.85 g, a mean FF of 1.59 N, a mean L* value of 33.80, a mean a* value of −0.76, and a mean b* value of −6.21. Compared with honeyberry germplasms from other non-originating countries, such as Turkey (fruit transverse diameter: 8.16–11.84 mm; fruit longitudinal diameter: 13.89–24.50 mm; fruit weight: 0.71–1.66 g) [36], Canada (fruit transverse diameter: 8.78–14.38 mm; fruit longitudinal diameter: 14.76–26.41 mm; fruit weight: 0.61–2.18 g) [37], and Ukraine (fruit transverse diameter: 7.77–12.34 mm; fruit longitudinal diameter: 16.42–27.29 mm; fruit weight: 0.73–1.60 g) [38], the Chinese honeyberry germplasm displayed similar morphological characteristics. This similarity suggests commonality and limitations in the appearance of the current global honeyberry germplasm.
SFW was used to generally reflect the fruit size and partially reflect the yield potential. Notably, ‘RiM–3’, ‘Riwandianlan’, and ‘HL–4’ showed relatively higher SFW values (exceeding 1.15 g), while ‘HSY–32’, ‘MC–9’, and ‘RB’ exhibited relatively lower SFW values (less than 0.60 g). Accessions with SFWs greater than 1.10 g originated from Russia (‘A–1’, ‘A–2’, ‘A–3’, ‘A–4’, ‘A–5’, ‘MC–1’, ‘HL–2’, ‘HL–4’) and Japan (‘RiM–3’, ‘Riwan’, ‘Riwandianlan’, ‘Riwan–13’), while those with SFWs lower than 0.70 g were predominantly of Russian origin (‘HL–12’, ‘HL–11’, ‘HL–9’, ‘HSY–32’, ‘RB’, ‘MC–9’, ‘MC–10’, ‘MC–4’, ‘P2–2’, ‘VRK’, ‘Geerda’). In terms of FF, ‘RiM–3’ and ‘Ri-68’ showed high values (above 3.00 N), while ‘HL–2’ and ‘P4-9’ displayed low values (below 0.70 N). High-firmness fruits (above 2.00 N) were mainly from both Japan (‘RiM–3’, ‘Ri–68’, ‘MC–5’, ‘Ri–5’, ‘Riwan–13’, ‘Riwan’) and Russia (‘MC–6’, ‘Altai–2’), whereas low-firmness fruits (below 0.80 N) were exclusively derived from Russia (‘HL–2’, ‘HL–4’, ‘HL–8’, ‘P4–9’, ‘MC–8’). Notably, the Japanese accessions represented by ‘RiM–3’ not only displayed a relatively greater single fruit weight but also higher fruit firmness compared with other accessions, implying that their application in future breeding projects could potentially overcome the inevitable trade-off between fruit size and firmness that commonly exists in Chinese and Russian honeyberry cultivars. However, this accession demonstrated poor fresh eating quality due to its low juiciness, distinctly mealy pulp texture, and lack of the characteristic honeyberry flavor, specifically the typical balance of sweetness, acidity, and distinct aromatic notes.

3.3. Fruit Quality of Chinese Honeyberry Germplasm Collection

The soluble solid content (SSC) of the 45 accessions varied between 6.50% (‘HL–11’) and 13.07% (‘HL–1’) (mean: 10.64%; CV: 13%) and the titratable acidity (TA) from 1.18% (‘Ri–5’) to 3.15% (‘Altai–1’) (mean: 2.00%; CV: 19%), resulting in SSC/TA ratios from 3.22% (‘HL–11’) to 10.36% (‘HL–2’) (mean: 5.56%; CV: 25%) (Figure 4). The total phenolics (TPC) ranged from 22.91 mg/g (‘Ri–68’) to 61.82 mg/g (‘HSY–32’) (mean: 44.17 mg/g; CV: 21%). The total flavonoids (TFC) varied from 10.91 mg/g (‘MC–6’) to 39.71 mg/g (‘Ri–5’) (mean: 19.23 mg/g; CV: 30%). The total anthocyanins (TAC) ranged from 0.88 mg/g (‘Ri–68’) to 3.96 mg/g (‘HSY–30’) (mean: 2.21 mg/g; CV: 35%). The total vitamin C (VC) content spanned from 29.12 mg/100 g (‘Riwandianlan’) to 217.84 mg/100 g (‘A–5’) (mean: 71.40 mg/100 g; CV: 61%).
In the honeyberry industry of China, the lack of comprehensive comparisons of fruit quality among existing honeyberry accessions has hindered the targeted selection of parent combinations for crossing and the efficient identification of promising offspring and wild germplasms. Although honeyberry is known to be rich in bioactive compounds, previous studies have documented significant inter-accession differences in phytochemical profiles [39,40,41]. It has been reported that the TAC of Swiss and Canadian accessions ranges from 39.2 to 294.0 mg/100 g; the TFC ranges from 9.01 to 15.83 mg/g; the TPC ranges from 6.34 to 11.54 mg/g; and the SSC ranges from 9.74% to 18.3% [42]. Moreover, the TPC of ‘Lanjingling’, ‘Belle’, ‘14–13–2’, and ‘Smurf’ Chinese accessions ranges from 13 mg/g to 23 mg/g [43,44]. These TPC ranges are relatively low when compared to our TPC results (mean = 44.17 mg/g), which is attributable to the different cultivation regions and climates between years. For VC, a previous study has reported a wide range of 8.5 to 86.9 mg/100 g [40], which aligns with the high CV of VC in our results. Honeyberry has been identified as a fruit that inherently contains high TPC [45]. This is consistent with our findings, where over half of the accessions showed TPC exceeding 40 mg/g. Numerous previous studies have reported the diverse bioactivity of honeyberry TPC [46]. Biochemically, TPC is also correlated with TFC and TAC, both of which are important biochemical parameters with biofunctions. However, TPC is also responsible for the bitterness and astringency of the fruit, which significantly reduces the fresh quality and consumer acceptance of honeyberry. Therefore, regarding accessions with high TPC, such as ‘HSY–32’ (61.82 mg/g), ‘A–2’ (60.09 mg/g), and ‘A–3’ (53.30 mg/g), they can be selected as specialized pharmaceutical cultivars and should be cautiously incorporated into the fresh consumption targeted breeding program.
For the multipurpose application of emerging fruit crops such as honeyberry, it is crucial to develop clearly defined quality standards to facilitate their diverse commercial application and associated breeding efforts. For instance, honeyberry accessions for table purpose require low levels of secondary metabolites associated with astringency and bitterness, as well as a high sugar-to-acid ratio, to ensure optimal palatability. In contrast, accessions for processing or pharmaceutical applications require higher TAC and VC, or TPC and TFC, to meet specific product development requirements. These diverse application purposes highlight the critical significance of systematic germplasm evaluation in directing breeding programs. This study revealed considerable variations among the 45 honeyberry accessions in terms of VC (CV: 60%), TAC (CV: 35%), TPC (CV: 21%), TFC (CV: 30%), and SAR (CV: 25%). These variations provide a valuable genetic resource for pairing hybrid parents and setting breeding goals, helping to avoid undesirable traits and leverage superior traits. Honeyberry is not currently well-recognized regarding its VC concentration. This lack of awareness might be due to the unstable VC content of honeyberry found in previous reports, which was influenced by the different harvest times and production regions [47]. Nevertheless, the high VC content of ‘A5’, ‘L50’, and ‘RB’ (>200 mg/100 g), along with the high CV for VC among the 45 accessions (60%) in this study, indicates the potential for future high-VC breeding and selection of honeyberry. Moreover, ‘HSY–30’ exhibited the highest TAC content (3.96 mg/g), highlighting its great potential to be directly used as a natural pigment source and a candidate in high-TAC breeding initiatives. Since the content of secondary metabolites in honeyberry is influenced by multiple factors, such as the genotype and environment, and this study was carried out within only one year, further confirmation is still required for potential materials with strong functional components.

3.4. Principal Component and Hierarchical Clustering Analyses

Principal component analysis (PCA) was performed based on the 28 phenological, fruit morphological, and quality traits of the 45 honeyberry accessions (Figure 5). The first three principal components (PCs) collectively explained 59.8% of the total variance, with PC1, PC2, and PC3 explaining 38.7%, 12.4%, and 8.7% of the total variance, respectively. PC1 was characterized by strong positive correlations with the ‘primary stage of fruit color turning’, ‘end of fruit enlargement’, ‘beginning of senescence’, and ‘fruit fully ripe’ periods, while there were strong negative correlations with FSI and TPC. PC2 showed significant positive correlations with FSI, FL, and LW but negative correlations with TAC and TPC. PC3 was positively associated with TAC, VC, and TFC but negatively correlated with SSC and FSI. The PCA results highlighted that most Japanese accessions (‘Ri–5’, ‘RiM–3’, ‘Ri–68’, ‘Riwan’, ‘Riwandianlan’, and ‘Riwan–13’) were clustered around the positive direction of PC1. Since phenological events were positively correlated with PC1, it can be speculated that phenological divergence is the main source of genetic variability, establishing PC1 as a key determinant for distinguishing different honeyberry accessions.
A heatmap with hierarchical clustering was generated using normalized data from 28 trait indicators across the 45 honeyberry accessions, displaying the trait matrix among the accessions (Figure 6). The traits were divided into two main clusters: trait cluster I comprised eight traits, including four fruit quality traits (TFC, VC, TAC, and TPC) and four fruit morphological traits (SSC, SAR, FL, and FSI); trait cluster II consisted of 20 traits related to fruit, leaf, and phenological characteristics. The 45 accessions were also clustered into two distinct groups. Acc-cluster I included six Japanese accessions (‘Ri–5’, ‘Ri–68’, ‘RiM–3’, ‘Riwan’, ‘Riwandianlan’, and ‘Riwan–13’), which exhibited relatively lower nutrient content but significantly longer phenological cycles than other accessions. Acc-cluster II comprised 39 accessions from Russia and China, which had higher nutrient content and showed consistent phenological cycles compared with the Japanese accessions.
As collectively demonstrated in the PCA plot and clustering heatmap, the six accessions of Japanese origin (‘Ri–5’, ‘Ri–68’, ‘RiM–3’, ‘Riwan’, ‘Riwandianlan’, and ‘Riwan–13’) showed distinct specificity relative to other accessions. This specificity is predominantly associated with their relatively delayed phenology, higher fruit firmness, and distinct fruit hues. Notably, high fruit firmness and a late ripening period are currently the key breeding targets for honeyberry. Since fruit softening during ripening is mainly caused by pectin breakdown, which weakens the cell wall [48], the delayed maturation of Japanese accessions (midsummer) relative to Chinese and Russian accessions (early summer) at the experimental location (Harbin, China) might lead to heat shock for the enzymes related to pectin metabolism, thereby resulting in the higher fruit firmness of the Japanese accessions.
The current Chinese accessions showed greater similarities to Russian accessions in terms of phenological traits and fruit quality, suggesting that honeyberry breeding in China has predominantly utilized parental materials of Russian origin, while those of Japanese origin remain underutilized. Given the late spring sprouting and fruit ripening periods of Japanese accessions, future breeding endeavors might prioritize the utilization of Japanese germplasms to achieve better resistance to spring frost and late-maturing characteristics. In addition, it is possible to preserve the high anthocyanin content and desirable palatability of Chinese and Russian germplasms while incorporating the high fruit firmness of Japanese germplasms so as to develop new accessions with superior comprehensive traits.
However, it should be noted that, even though this study provides the first phenological evaluation of honeyberry germplasms, the investigation was only conducted during a single growing season. Since the phenological and agronomic performance of perennial plants is susceptible to the climatic conditions, it is necessary to conduct multi-year consecutive investigations on phenology and fruit traits in the future to clearly define the key agronomic characteristics and explore elite accessions. In summary, the diversity of honeyberry traits revealed in this study lays an important foundation for the targeted breeding of honeyberry, which can be utilized to develop more strategic hybrid combinations and efficiently select accessions that better meet the market demand [49].

4. Conclusions

This study demonstrates considerable phenotypic diversity among 45 honeyberry accessions in Harbin of China in terms of key phenological stages, fruit morphology, and nutritional quality. Specifically, the Japanese accessions, represented by ‘Ri–5’, ‘Ri–68’, ‘RiM–3’, ‘Riwan’, ‘Riwandianlan’, and ‘Riwan–13’, exhibited distinct agronomic traits, such as late flowering, late ripening, a high single fruit weight, and high fruit firmness, while they had generally lower levels of vitamin C, total anthocyanin content, and soluble solids. In contrast, Russian and Chinese accessions showed superior nutritional profiles but lower fruit firmness, with specific accessions excelling in vitamin C, anthocyanins, or soluble solids. High CVs (21–60%) were observed among the 45 accessions for total anthocyanins, total flavonoids, total phenols, and the solid acid ratio. Based on the findings, the honeyberry collection in China can be classified into distinct types according to the key traits of the ripening period (represented by the early-ripening ‘A–series’ and late-ripening varieties of Japanese origin), physical properties (the Japanese-origin varieties feature large fruit sizes and high firmness, while the ‘HL series’ has lower firmness), and nutritional composition (high SAR in ‘A–1’, ‘HL–2’, and ‘Ri–5’; high TAC in ‘HSY–30’, ‘A–3’, and ‘RB’; and high VC in ‘A–5’, ‘L–50’, and ‘RB’). Furthermore, certain accessions demonstrate specific potential, such as the early-ripening, high-TAC ‘A–3’ and the late-ripening, high-TAC ‘RB’, which can extend the harvesting window and meet the bulk raw material demand of the processing industry, thereby serving diverse production purposes. ‘RiM–3’ exhibits a high single fruit weight, firmness, and flavonoid content, aligning with market trends that favor large and shippable fruits. These evaluations constitute a first step for future hybrid parent selection and the utilization of such advantageous traits, providing valuable baseline information.

Supplementary Materials

The following supporting information can be downloaded at https://www.mdpi.com/article/10.3390/agriculture16030291/s1. Table S1. Accessions with significant differences in phenological performance during research. Table S2. Record of phenological event occurrence dates for different accessions. Table S3. Fruit morphological characteristics of 45 honeyberry accessions. Table S4. Fruit quality of 45 honeyberry accessions.

Author Contributions

Writing—original draft, H.Y. and X.Z.; Writing—review and editing, H.Y., X.Z., C.Z. and M.Y.; Investigation, H.Y.; Formal analysis, X.Z.; Visualization, C.Y. and C.W.; Resources, B.Z. and J.L.; Methodology, Z.W. and R.H.; Validation, J.S.; Project administration, D.Q.; Data curation, H.G.; Funding acquisition, J.H. and M.Y.; Conceptualization, J.H.; Supervision, C.Z. All authors have read and agreed to the published version of the manuscript.

Funding

This work was financially supported by the National Key R&D Program of China (2022YFD1600500), the Open Funds of the National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops (Horti-KF-2023-08), and the China Agriculture Research System (CARS-29).

Institutional Review Board Statement

Not applicable.

Data Availability Statement

The data presented in this study are available on request from the corresponding author (Min Yu, z11484@neau.edu.cn).

Acknowledgments

The authors express their sincere gratitude for the valuable contributions of Lijun Zhang from the Daxing’anling Academy of Agriculture and Forestry Sciences, as well as Ying Zhan and Songlin Li, both of whom graduated from NEAU.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Frier, S.D.; Somers, C.M.; Sheffield, C.S. Comparing the performance of native and managed pollinators of Haskap (Lonicera caerulea: Caprifoliaceae), an emerging fruit crop. Agric. Ecosyst. Environ. 2016, 219, 42–48. [Google Scholar] [CrossRef]
  2. Sip, S.; Sip, A.; Szulc, P.; Cielecka-Piontek, J. Haskap Berry Leaves (Lonicera caerulea L.)—The Favorable Potential of Medical Use. Nutrients 2022, 14, 3898. [Google Scholar] [CrossRef] [PubMed]
  3. Becker, R.; Szakiel, A. Phytochemical characteristics and potential therapeutic properties of blue honeysuckle Lonicera caerulea L. (Caprifoliaceae). J. Herbal Med. 2019, 16, 100237. [Google Scholar] [CrossRef]
  4. Niu, M.; Bao, X.; Xu, G. Progress in the systematic classification of plant polyphenols. J. Gansu Agric. Univ. 2025, 60, 65–85. [Google Scholar] [CrossRef]
  5. Zhang, X.; Wang, L.; Zhang, W.; Pei, M.; Zhu, C.; Huo, J.; Gang, H.; Qin, D. Metabolomic and transcriptomic analyses reveal the formation mechanism of bitter components in blue honeysuckle. LWT 2025, 223, 117727. [Google Scholar] [CrossRef]
  6. Xia, T.; Su, S.; Wang, L.; Tang, Z.; Huo, J.; Song, H. Exploring bitter characteristics of blue honeysuckle (Lonicera caerulea L.) berries by sensory-guided analysis: Key bitter compounds and varietal differences. Food Chem. 2024, 457, 140150. [Google Scholar] [CrossRef]
  7. Sozański, T.; Kucharska, A.Z.; Rapak, A.; Szumny, D.; Trocha, M.; Merwid-Ląd, A.; Dzimira, S.; Piasecki, T.; Piórecki, N.; Magdalan, J.; et al. Iridoid–loganic acid versus anthocyanins from the Cornus mas fruits (cornelian cherry): Common and different effects on diet-induced atherosclerosis, PPARs expression and inflammation. Atherosclerosis 2016, 254, 151–160. [Google Scholar] [CrossRef]
  8. Xia, T.; Su, S.; Guo, K.; Wang, L.; Tang, Z.; Huo, J.; Song, H. Characterization of key aroma-active compounds in blue honeysuckle (Lonicera caerulea L.) berries by sensory-directed analysis. Food Chem. 2023, 429, 136821. [Google Scholar] [CrossRef]
  9. Oszmiański, J.; Kucharska, A.Z. Effect of pre-treatment of blue honeysuckle berries on bioactive iridoid content. Food Chem. 2018, 240, 1087–1091. [Google Scholar] [CrossRef]
  10. Tremblay, C.; Deslauriers, A.; Lafond, J.; Lajeunesse, J.; Paré, M.C. Effects of Soil pH and Fertilizers on Haskap (Lonicera caerulea L.) Vegetative Growth. Agriculture 2019, 9, 56. [Google Scholar] [CrossRef]
  11. Yan, H.; Li, Y.; Lv, Y.; Zhao, X.; Man, Z.; Chen, Z.; Guo, L.; Huo, J.; Sang, M.; Li, C.; et al. Postharvest fruit rot on blue honeysuckle (Lonicera caerulea L.) caused by Penicillium oxalicum newly reported in China. Crop Prot. 2025, 193, 107195. [Google Scholar] [CrossRef]
  12. Hummer, K.E. Blue honeysuckle: A new berry crop for North America. J. Am. Pomol. Soc. 2006, 60, 3–8. [Google Scholar] [CrossRef]
  13. Sharma, A.; Lee, H.-J. Lonicera caerulea: An updated account of its phytoconstituents and health-promoting activities. Trends Food Sci. Technol. 2021, 107, 130–149. [Google Scholar] [CrossRef]
  14. He, Y.; Liu, J.; Hua, M.Z.; Singh, K.; Lu, X. Determination of antioxidant capacity and phenolic content of haskap berries (Lonicera caerulea L.) by attenuated total reflectance-Fourier transformed-infrared spectroscopy. Food Chem. 2025, 463, 141283. [Google Scholar] [CrossRef] [PubMed]
  15. Becker, R.; Dashbaldan, S.; Pączkowski, C.; Golis, T.; Szakiel, A. Comparison of steroids and triterpenoids in leaf cuticular waxes of selected Polish and Russian cultivars and genotypes of edible honeysuckle. Phytochem. Lett. 2019, 30, 238–244. [Google Scholar] [CrossRef]
  16. Česonienė, L.; Labokas, J.; Jasutienė, I.; Šarkinas, A.; Kaškonienė, V.; Kaškonas, P.; Kazernavičiūtė, R.; Pažereckaitė, A.; Daubaras, R. Bioactive Compounds, Antioxidant, and Antibacterial Properties of Lonicera caerulea Berries: Evaluation of 11 Cultivars. Plants 2021, 10, 624. [Google Scholar] [CrossRef]
  17. Jurikova, T.; Sochor, J.; Rop, O.; Mlček, J.; Balla, Š.; Szekeres, L.; Žitný, R.; Zitka, O.; Adam, V.; Kizek, R. Evaluation of Polyphenolic Profile and Nutritional Value of Non-Traditional Fruit Species in the Czech Republic—A Comparative Study. Molecules 2012, 17, 8968–8981. [Google Scholar] [CrossRef]
  18. Szpadzik, E.; Trzcińska, J.; Molska-Kawulok, K.; Seliga, Ł.; Pluta, S. Yield Performance and Physicochemical Properties of Selected Honey Berry (Lonicera caerulea L. var. kamtschatica Sevast.), Under Central Polish Conditions. Agriculture 2025, 15, 2225. [Google Scholar] [CrossRef]
  19. Senica, M.; Stampar, F.; Mikulic-Petkovsek, M. Blue honeysuckle (Lonicera cearulea L. subs. edulis) berry; A rich source of some nutrients and their differences among four different cultivars. Sci. Hortic. 2018, 238, 215–221. [Google Scholar] [CrossRef]
  20. Razgonova, M.P.; Nawaz, M.A.; Rusakova, E.A.; Sabitov, A.S.; Tikhonova, N.G.; Golokhvast, K.S. Comparative Analysis of the Metabolomic Profile of Honeysuckle Lonicera caerulea L. from Four Eurasian Regions by Using HPLC-ESI-MS and ESI-MS/MS Analysis. Molecules 2025, 30, 3761. [Google Scholar] [CrossRef]
  21. Li, J.; Hoshino, Y. Elucidating the impact of ploidy level on biochemical content accumulation in haskap (Lonicera caerulea L. subsp. edulis (Turcz. ex Herder) Hultén) fruits: A comprehensive approach for fruit assessment. Sci. Hortic. 2024, 327, 112831. [Google Scholar] [CrossRef]
  22. Fujita, R.; Jin, S.; Matoba, K.; Hoshino, Y. Novel production of β-cryptoxanthin in haskap (Lonicera caerulea subsp. edulis) hybrids: Improvement of carotenoid biosynthesis by interspecific hybridization. Sci. Hortic. 2023, 308, 111547. [Google Scholar] [CrossRef]
  23. Qi, Y.; Li, C.; Liang, X.; Chen, A.; Zhao, G.; Bai, H.; Li, H.; Wang, Z.; Han, W.; Ma, Y.; et al. Evaluation of Lonicera caerulea Cultivar Diversity Based on Phenotypic Traits and Nutrient Composition. Forests 2025, 16, 25. [Google Scholar] [CrossRef]
  24. Tian, Y.; Nie, J.; Fei, D.; Mao, S.; Wang, J.; Wu, Q.; Huang, K. Phenotypic evaluation and analysis of important agronomic traits and nutritional quality in purple flowering stalk (Brassica campestris L. ssp. chinensis var. purpurea Hort.). Sci. Hortic. 2025, 340, 113921. [Google Scholar] [CrossRef]
  25. Jiang, N.; Zhu, X.-G. Modern phenomics to empower holistic crop science, agronomy, and breeding research. J. Genet. Genom. 2024, 51, 790–800. [Google Scholar] [CrossRef]
  26. Liu, Q.; Dong, Q.; Zhang, L.; Sun, C. Summer cooling island effects of blue-green spaces in severe cold regions: A case study of harbin, China. Build. Environ. 2024, 257, 111539. [Google Scholar] [CrossRef]
  27. Belda, M.; Holtanová, E.; Halenka, T.; Kalvová, J. Climate classification revisited: From Köppen to Trewartha. Clim. Res. 2014, 59, 1–13. [Google Scholar] [CrossRef]
  28. Zhu, C.; Quan, X.; Lv, J.; Zhang, R.; Zhao, Y.; Qin, D.; Huo, J.; Huang, Z.; Zhang, L.; Yu, M. Coding and description of phenological stages of blue honeysuckle (Lonicera caerulea L.) according to the BBCH scale. Sci. Hortic. 2024, 337, 113566. [Google Scholar] [CrossRef]
  29. Meier, U. Growth Stages of Mono- and Dicotyledonous Plants: BBCH Monograph; Open Agrar Repositorium: Quedlinburg, Germany, 2018. [Google Scholar] [CrossRef]
  30. Gao, J. Effects of Different Fresh-Keepingtechniques on the Storage Quality of Blue Honeysuckle. Master’s Thesis, Northeast Agricultural University, Harbin, China, 2020. [Google Scholar] [CrossRef]
  31. Zhao, J. Sudies on Extraction, Identification and Antioxidant Activity of Blue Honeysuckle (Lonicera caerulea L.). Master’s Thesis, Northeast Agricultural University, Harbin, China, 2010. [Google Scholar]
  32. Li, X. Studies on Ascorbic Acid Diversity in Leaves andRelationship with Fruit of Black Currant (Ribes nigium L.). Master’s Thesis, Northeast Agricultural University, Harbin, China, 2014. [Google Scholar]
  33. Wang, Y.F.; Xin, X.L.; Chen, L.; Huo, J.W. Total Anthocyanins Content in Different Species of Lonicera cearulea Linn. by pH-differential Spectrophotometry. Food Res. Dev. 2014, 35, 75–78. [Google Scholar]
  34. Thompson, M.M.; Chaovanalikit, A. Preliminary observations on adaptation and nutraceutical values of blue honeysuckle (Lonicera caerulea) in Oregon, USA. Acta Hortic. 2003, 626, 65–72. [Google Scholar] [CrossRef]
  35. Gerbrandt, E.M.; Bors, R.H.; Chibbar, R.N.; Baumann, T.E. Blue honeysuckle (Lonicera caerulea L.) vegetative growth cessation and leaf drop phenological adaptation to a temperate climate. Genet. Resour. Crop Evol. 2018, 65, 1471–1484. [Google Scholar] [CrossRef]
  36. Gürcan, K.; Yılmaz, K.U.; Tunç, Y.; Yaman, M.; Güneş, A.; Yıldız, E.; Demirel, F.; Demirel, S.; Khadivi, A. 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. BMC Plant Biol. 2024, 24, 1158. [Google Scholar] [CrossRef] [PubMed]
  37. Gerbrandt, E.M.; Bors, R.H.; Chibbar, R.N. Agronomic potential of fruit size and yield traits in blue honeysuckle (Lonicera caerulea L.) foundation germplasm. Euphytica 2018, 214, 107. [Google Scholar] [CrossRef]
  38. Grygorieva, O.; Klymenko, S.; Kuklina, A.; Vinogradova, Y.; Vergun, O.; Sedlackova, V.H.; Brindza, J. Evaluation of Lonicera caerulea L. genotypes based on morphological characteristics offruits germplasm collection. Turk. J. Agric. For. 2021, 45, 850–860. [Google Scholar] [CrossRef]
  39. Gerbrandt, E.M.; Bors, R.H.; Meyer, D.; Wilen, R.; Chibbar, R.N. Fruit quality of Japanese, Kuril and Russian blue honeysuckle (Lonicera caerulea L.) germplasm compared to blueberry, raspberry and strawberry. Euphytica 2020, 216, 59. [Google Scholar] [CrossRef]
  40. Gawroński, J.; Żebrowska, J.; Pabich, M.; Jackowska, I.; Kowalczyk, K.; Dyduch-Siemińska, M. Phytochemical Characterization of Blue Honeysuckle in Relation to the Genotypic Diversity of Lonicera sp. Appl. Sci. 2020, 10, 6545. [Google Scholar] [CrossRef]
  41. De Silva, A.B.K.H.; Rupasinghe, H.P.V. Polyphenols composition and anti-diabetic properties in vitro of haskap (Lonicera caerulea L.) berries in relation to cultivar and harvesting date. J. Food Compos. Anal. 2020, 88, 103402. [Google Scholar] [CrossRef]
  42. Auzanneau, N.; Weber, P.; Kosińska-Cagnazzo, A.; Andlauer, W. Bioactive compounds and antioxidant capacity of Lonicera caerulea berries: Comparison of seven cultivars over three harvesting years. J. Food Compos. Anal. 2018, 66, 81–89. [Google Scholar] [CrossRef]
  43. Wu, W.; Ma, X.; Wang, Y.; Yu, Y.; Huo, J.; Huang, D.; Sui, X.; Zhang, Y. Amplifying Bioactivity of blue honeysuckle (Lonicera caerulea L.) fruit puree through Ultrasonication: Antioxidant and antiproliferative activity. Ultrason. Sonochemistry 2025, 112, 107179. [Google Scholar] [CrossRef]
  44. Peng, Z.; Chen, H.; Niu, B.; Wu, W.; Chen, H.; Farag, M.A.; Ding, Y.; Liu, R.; Gao, H. Composition and micromorphological determination of blue honeysuckle fruit (Lonicera caerulea L.) cuticular wax and its effects on fruit post-harvest quality. Food Chem. 2025, 463, 141330. [Google Scholar] [CrossRef]
  45. Liu, S.; You, L.; Zhao, Y.; Chang, X. Wild Lonicera caerulea berry polyphenol extract reduces cholesterol accumulation and enhances antioxidant capacity in vitro and in vivo. Food Res. Int. 2018, 107, 73–83. [Google Scholar] [CrossRef]
  46. Wang, Y.; Zhu, J.; Meng, X.; Liu, S.; Mu, J.; Ning, C. Comparison of polyphenol, anthocyanin and antioxidant capacity in four varieties of Lonicera caerulea berry extracts. Food Chem. 2016, 197, 522–529. [Google Scholar] [CrossRef]
  47. Molina, A.K.; Vega, E.N.; Pereira, C.; Dias, M.I.; Heleno, S.A.; Rodrigues, P.; Fernandes, I.P.; Barreiro, M.F.; Kostić, M.; Soković, M.; et al. Promising Antioxidant and Antimicrobial Food Colourants from Lonicera caerulea L. var. Kamtschatica. Antioxidants 2019, 8, 394. [Google Scholar] [CrossRef]
  48. Jiang, Y.; Ye, J.; Zhou, L.; Chen, M.; Wei, Y.; Jiang, S.; Chen, Y.; Shao, X. Cell wall metabolism during the growth of peach fruit: Association of hardness with cell wall pectins. Sci. Hortic. 2024, 330, 113058. [Google Scholar] [CrossRef]
  49. Burdon, R.D.; Li, Y. Genotype-environment interaction involving site differences in expression of genetic variation along with genotypic rank changes: Simulations of economic significance. Tree Genet. Genomes 2018, 15, 2. [Google Scholar] [CrossRef]
Agriculture 16 00291 g001
Figure 1. Meteorological conditions of the investigation year (2024, Harbin, China). Note: Monthly average (T avg), monthly maximum (T max) and minimum temperature (T min), and monthly precipitation (Prec) recorded in the nursery are shown.
Figure 1. Meteorological conditions of the investigation year (2024, Harbin, China). Note: Monthly average (T avg), monthly maximum (T max) and minimum temperature (T min), and monthly precipitation (Prec) recorded in the nursery are shown.
Agriculture 16 00291 g001
Agriculture 16 00291 g002
Figure 2. Phenological stages of the honeyberry accession ‘MC–5’ according to the BBCH scale. (A) ‘09’: end of bud burst; (B) ‘11’: unfolding of the first pair of leaves; (C) ‘52’: emergence of the second inflorescences; (D) ‘60’: beginning of flowering; (E) ‘67’: full flowering; (F) ‘69’: flowering ending; (G) ‘73’: initiation of fruit enlargement; (H) ‘76’: primary stage of fruit color turning; (I) ‘78’: end of fruit enlargement; (J) ‘89’: fruit fully ripe; (K) ‘90’: beginning of senescence.
Figure 2. Phenological stages of the honeyberry accession ‘MC–5’ according to the BBCH scale. (A) ‘09’: end of bud burst; (B) ‘11’: unfolding of the first pair of leaves; (C) ‘52’: emergence of the second inflorescences; (D) ‘60’: beginning of flowering; (E) ‘67’: full flowering; (F) ‘69’: flowering ending; (G) ‘73’: initiation of fruit enlargement; (H) ‘76’: primary stage of fruit color turning; (I) ‘78’: end of fruit enlargement; (J) ‘89’: fruit fully ripe; (K) ‘90’: beginning of senescence.
Agriculture 16 00291 g002
Agriculture 16 00291 g003
Figure 3. Fruit morphological characteristics of 45 honeyberry accessions. (A) Longitudinal diameter (mm); (B) transverse diameter (mm); (C) fruit shape index; (D) fruit firmness (N); (E) single fruit weight (g). Data are presented as mean ± standard deviation (SD) of three biological replicates. Different letters indicate significant differences between treatments (p < 0.05).
Figure 3. Fruit morphological characteristics of 45 honeyberry accessions. (A) Longitudinal diameter (mm); (B) transverse diameter (mm); (C) fruit shape index; (D) fruit firmness (N); (E) single fruit weight (g). Data are presented as mean ± standard deviation (SD) of three biological replicates. Different letters indicate significant differences between treatments (p < 0.05).
Agriculture 16 00291 g003
Agriculture 16 00291 g004
Figure 4. Fruit quality evaluation of 45 honeyberry accessions. (A) TAC: total anthocyanin content (mg/g); (B) TFC: total flavonoid content (mg/g); (C) VC: vitamin C (mg/100 g); (D) TPC: total phenolics content (mg/g); (E) SSC: soluble solid content (%); (F) TA: titratable acid (%); (G) SAR: solid acid ratio (%). Data are presented as mean ± standard deviation (SD) of three biological replicates. Different letters indicate significant differences between treatments (p < 0.05).
Figure 4. Fruit quality evaluation of 45 honeyberry accessions. (A) TAC: total anthocyanin content (mg/g); (B) TFC: total flavonoid content (mg/g); (C) VC: vitamin C (mg/100 g); (D) TPC: total phenolics content (mg/g); (E) SSC: soluble solid content (%); (F) TA: titratable acid (%); (G) SAR: solid acid ratio (%). Data are presented as mean ± standard deviation (SD) of three biological replicates. Different letters indicate significant differences between treatments (p < 0.05).
Agriculture 16 00291 g004
Agriculture 16 00291 g005
Figure 5. Principal component analysis of phenological traits and agronomic traits in 45 honeyberry accessions. (A) The first three principal components (PC1, PC2, and PC3) account for 59.2% of the total variance. The direction and length of each vector indicate its contribution to the principal components. FL: fruit longitudinal diameter, FT: fruit transverse diameter, FSI: fruit shape index, SFW: single fruit weight, FF: fruit firmness, L*, a*, b*: fruit color values, LL: leaf length, LW: leaf width, TAC: total anthocyanin content, TFC: total flavonoid content, VC: vitamin C, TPC: total phenolics content, SSC: soluble solid content, TA: titratable acid, SAR: solid acid ratio. (B) The distribution of the 45 honeyberry accessions within the PCA space based on these traits.
Figure 5. Principal component analysis of phenological traits and agronomic traits in 45 honeyberry accessions. (A) The first three principal components (PC1, PC2, and PC3) account for 59.2% of the total variance. The direction and length of each vector indicate its contribution to the principal components. FL: fruit longitudinal diameter, FT: fruit transverse diameter, FSI: fruit shape index, SFW: single fruit weight, FF: fruit firmness, L*, a*, b*: fruit color values, LL: leaf length, LW: leaf width, TAC: total anthocyanin content, TFC: total flavonoid content, VC: vitamin C, TPC: total phenolics content, SSC: soluble solid content, TA: titratable acid, SAR: solid acid ratio. (B) The distribution of the 45 honeyberry accessions within the PCA space based on these traits.
Agriculture 16 00291 g005
Agriculture 16 00291 g006
Figure 6. Hierarchical clustering heatmap based on 28 agronomic traits of 45 honeyberry accessions. FL: fruit longitudinal diameter, FT: fruit transverse diameter, FSI: fruit shape index, SFW: single fruit weight, FF: fruit firmness, L*, a*, b*: fruit color values, LL: leaf length, LW: leaf width, TAC: total anthocyanin content, TFC: total flavonoid content, VC: vitamin C, TPC: total phenolics content, SSC: soluble solid content, TA: titratable acid, SAR: solid acid ratio. Note: The Roman numerals I and II denote the two distinct clusters formed based on the similarity of agronomic traits.
Figure 6. Hierarchical clustering heatmap based on 28 agronomic traits of 45 honeyberry accessions. FL: fruit longitudinal diameter, FT: fruit transverse diameter, FSI: fruit shape index, SFW: single fruit weight, FF: fruit firmness, L*, a*, b*: fruit color values, LL: leaf length, LW: leaf width, TAC: total anthocyanin content, TFC: total flavonoid content, VC: vitamin C, TPC: total phenolics content, SSC: soluble solid content, TA: titratable acid, SAR: solid acid ratio. Note: The Roman numerals I and II denote the two distinct clusters formed based on the similarity of agronomic traits.
Agriculture 16 00291 g006
Table 1. Information about the 45 honeyberry (Lonicera caerulea L.) accessions evaluated in the study.
Table 1. Information about the 45 honeyberry (Lonicera caerulea L.) accessions evaluated in the study.
No.IDAccession NameOriginPedigree
1BerelBerelRussiasubsp. altaica × subsp. kamtschatica F1
2CBS–5--Chinasubsp. kamtschatica
3Altai–1CaлютRussiasubsp. altaica
4Altai–2CиpиycRussiasubsp. altaica
5Mishan–1--Chinasubsp. altaica × subsp. kamtschatica F1
6A–1Гopдocть БaкчapaRussiasubsp. turczaninowii
7A–2CильгинкaRussiasubsp. turczaninowii
8A–3ЧyлымcкaЯRussiasubsp. turczaninowii
9A–4БaкчapcкaяRussiasubsp. turczaninowii
10A–5CибиpЯЧкaRussiasubsp. turczaninowii
11L–5LanjinglingChina(subsp. altaica × subsp. kamtschatica) × subsp. kamtschatica
12HL–1AccoльRussiasubsp. altaica (natural pollination)
13HL–2ПpoвинциaлкaRussiasubsp. altaica (natural pollination)
14HL–4ЗoлyшкaRussiasubsp. altaica (natural pollination)
15HL–8БapxaтRussiasubsp. altaica (natural pollination)
16HL–9Oгнeнный oпaлRussiasubsp. altaica (natural pollination)
17HL–11ИллиaдaRussiasubsp. altaica (natural pollination)
18HL–12--Russiasubsp. altaica (natural pollination)
19HSY–30--Russiavar. edulis
20HSY–32--Russiavar. edulis
21MC–1--Russiasubsp. kamtschatica
22MC–2--Russiasubsp. kamtschatica
23MC–3--Russiasubsp. kamtschatica
24MC–4--Russiasubsp. kamtschatica
25MC–5--Russiasubsp. kamtschatica
26MC–6--Russiasubsp. kamtschatica
27MC–7--Russiasubsp. kamtschatica
28MC–8--Russiasubsp. kamtschatica
29MC–9CибиpячкaRussiasubsp. kamtschatica
30MC–10--Russiasubsp. kamtschatica
31MC–11--Russiasubsp. kamtschatica
32P3–20--Russiasubsp. kamtschatica
33P2–2--Russiasubsp. kamtschatica
34P4–9--Russiasubsp. kamtschatica
35Ri–5--Japansubsp. emphyllocalyx
36RiM–3--Japansubsp. emphyllocalyx
37Ri–68--Japansubsp. emphyllocalyx
38Riwan--Japansubsp. emphyllocalyx
39Riwandianlan--Japansubsp. emphyllocalyx
40Riwan–13--Japansubsp. emphyllocalyx
41GeerdaГepдaRussiasubsp. kamtschatica
42LanrouБapxaтRussiasubsp. altaica (natural pollination)
43L–50--China(subsp. altaica × subsp. kamtschatica) × subsp. kamtschatica
44RB--Japansubsp. emphyllocalyx
45VRK--Russiasubsp. kamtschatica
Note: Accession Name: Names originating from Russia are presented in their original registered form (e.g., ‘Caлют’, ‘Cиpиyc’).
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Yang, H.; Zhang, X.; Yu, C.; Wang, Z.; Hao, R.; Wang, C.; Zhang, B.; Shi, J.; Li, J.; Qin, D.; et al. Diversity of Phenological Characteristics and Fruit Quality of the Chinese Honeyberry (Lonicera caerulea L.) Collection. Agriculture 2026, 16, 291. https://doi.org/10.3390/agriculture16030291

AMA Style

Yang H, Zhang X, Yu C, Wang Z, Hao R, Wang C, Zhang B, Shi J, Li J, Qin D, et al. Diversity of Phenological Characteristics and Fruit Quality of the Chinese Honeyberry (Lonicera caerulea L.) Collection. Agriculture. 2026; 16(3):291. https://doi.org/10.3390/agriculture16030291

Chicago/Turabian Style

Yang, Hao, Xiaohui Zhang, Caihong Yu, Ziqing Wang, Ruijuan Hao, Chunfang Wang, Bingcui Zhang, Jiayi Shi, Jiacheng Li, Dong Qin, and et al. 2026. "Diversity of Phenological Characteristics and Fruit Quality of the Chinese Honeyberry (Lonicera caerulea L.) Collection" Agriculture 16, no. 3: 291. https://doi.org/10.3390/agriculture16030291

APA Style

Yang, H., Zhang, X., Yu, C., Wang, Z., Hao, R., Wang, C., Zhang, B., Shi, J., Li, J., Qin, D., Gang, H., Huo, J., Zhu, C., & Yu, M. (2026). Diversity of Phenological Characteristics and Fruit Quality of the Chinese Honeyberry (Lonicera caerulea L.) Collection. Agriculture, 16(3), 291. https://doi.org/10.3390/agriculture16030291

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop