Lily Bulbs Research Articles

LoSWEET14, a Sugar Transporter in Lily, Is Regulated by Transcription Factor LoABF2 to Participate in the ABA Signaling Pathway and Enhance Tolerance to Multiple Abiotic Stresses in Tobacco

Sugar transport and distribution plays an important role in lily bulb development and resistance to abiotic stresses. In this study, a member of the Sugar Will Eventually be Exported Transporters (SWEET) gene family, LoSWEET14, from Oriental hybrid lily 'Sorbonne' was identified. LoSWEET14 encodes a protein of 278 amino acids and is capable of transporting sucrose and some types of hexoses. The transcript level of the LoSWEET14 gene was significantly increased under various stress conditions including drought, cold, salt stresses, and abscisic acid (ABA) treatment. Overexpression of LoSWEET14 in tobacco (Nicotiana tabacum) showed that the transgenic lines had larger leaves, accumulated more soluble sugars, and were more resistant to drought, cold, and salt stresses, while becoming more sensitive to ABA compared with wild-type lines. Promoter analysis revealed that multiple stress-related cis-acting elements were found in the promoter of LoSWEET14. According to the distribution of cis-acting elements, different lengths of 5'-deletion fragments were constructed and the LoSWEET14-pro3(-540 bp) was found to be able to drive GUS gene expression in response to abiotic stresses and ABA treatment. Furthermore, a yeast one hybrid (Y1H) assay proved that the AREB/ABF (ABRE-binding protein/ABRE-binding factor) from lilies (LoABF2) could bind to the promoter of LoSWEET14. These findings indicated that LoSWEET14 is induced by LoABF2 to participate in the ABA signaling pathway to promote soluble sugar accumulation in response to multiple abiotic stresses.

Brown Rot Disease Caused by Trichoderma hamatum on the Edible Lily, Lilium leichtlinii var. maximowiczii

Lilium leichtlinii var. maximowiczii is commonly known as the edible lily or sweet lily. Bulbs of this edible lily are frequently used in traditional Chinese medicine, and they are revered for their nutritional content. As of 2018, brown rot disease on cultivated L. leichtlinii var. maximowiczii bulbs has become a disease of concern in Jilin Province, China, with a disease incidence of 29.43%. The bulbs infected with brown rot disease appear as large, regularly shaped, and yellow-brown or black-brown lesions. However, the causal agent is not yet known. Therefore, this study aims to confi rm both the causal pathogen by using Koch’s postulates and to further establish, to the species level, the identity of this organism via morphological and molecular methods. The pathogen was later identifi ed as Trichoderma hamatum. Healthy bulbs were inoculated with T. hamatum, which produced the initial disease symptoms with brown spots appearing at the inoculation sites; the same pathogen was then isolated again from diseased bulbs. To the best of our knowledge, this is the fi rst report of bulb rot disease of cultivated L. leichtlinii var. maximowiczii caused by T. hamatum in China. Our work may be benefi cial, especially for designing control measures for bulb rot disease in the commercial cultivation of L. leichtlinii var. maximowiczii.

Transcriptome profiling revealed salt stress-responsive genes in Lilium pumilum bulbs.

Lilium pumilum is an important ornamental, culinary and medicinal bulbous plants with salt tolerance. However, salt tolerance of lily, particularly the bulb, has been studied relatively little, which brings challenges to the cultivation of lily varieties with high salt tolerance. Here, we performed transcriptome sequencing on the bulb organs of L. pumilum under salt stress treatment, analyzed differential gene expressed levels and then identified several key genes associated with salt stress tolerance at genome-wide scale. For the first time, we revealed the obvious response against salt stress for L. pumilum bulb organs, while distinct from those for root organs. Several key genes obtained through transcriptome analysis and DEG screening include NF-YB3 transcription factor, metallothionein type 2 protein, vicilin like seed storage protein and bidirectional sugar transporter SWEET14. Rather than typical ROS scavengers like superoxide dismutase, peroxidase, and glutathione transferase, non-typical ROS scavengers such as the metallothionein type 2 protein, and vicilin like seed storage protein were upregulated in our work. The bidirectional sugar transporter SWEET14 protein and the hormone signaling proteins such as E3-ubiquitin protein ligases, PYL4 and protein phosphatase 2C were also upregulated, suggesting the role of sugars and hormones in the bulb organ responses to salt stress. Co-expression analysis of the DEGs further confirmed that NF-YB3 transcription factor acted as a hub gene, suggesting that salt stress can promote flowering of L. pumilum. Taken together, we identified important candidate genes associated with salt tolerance of the L. pumilum bulb organs, which may provide the excellent basis for further in-depth salt tolerance mechanisms of the lily bulbs.

The structure and antioxidant activities of three high molecular weight polysaccharides purified from the bulbs of Lanzhou lily

The structure and antioxidant activities of three high molecular weight polysaccharides purified from the bulbs of Lanzhou lily

Laser-induced breakdown spectroscopy (LIBS) for the detection of exogenous contamination of metal elements in lily bulbs

Natural products with the underground edible part have the risk of excessive heavy metals due to the influence of the growing environment. In this study, the content of five metal elements in lily bulbs was detected by laser-induced breakdown spectroscopy (LIBS). In view of the mutual interference among elements, multivariable analysis models were established to effectively eliminate the interference. The partial least squares regression (PLSR) multivariate analysis model was evaluated by combining different data preprocessing with variable selection methods to achieve the best fit. The results show that the best regression model for Cu, Pb, Zn, Al, and Mg content achieved the coefficients determination of prediction (Rp2) values of 0.9920, 0.9737, 0.9835, 0.9723 and 0.9939, respectively, and root mean square error of prediction (RMSEP) values of 3.2386 mg/kg, 5.8559 mg/kg, 4.6334 mg/kg, 6.0073 mg/kg and 2.8103 mg/kg, respectively. Comprehensively comparing the accuracy, robustness, and number of variables of each model, it can be found that the PLSR model on the least absolute shrinkage and selection operator (LASSO) achieved good results in the quantitative prediction model of three kinds of metal elements. This indicates the superiority of the LASSO-PLSR algorithm framework and confirms the feasibility of LIBS technology for the detection of various metal elements in natural products.

Effect of thermal blanching on the inactivation kinetics of polyphenol oxidase and peroxidase in lily bulb, and the functional properties of its flours

Effect of thermal blanching on the inactivation kinetics of polyphenol oxidase and peroxidase in lily bulb, and the functional properties of its flours

Mechanism of lily bulb and Rehmannia decoction in the treatment of lipopolysaccharide-induced depression-like rats based on metabolomics study and network pharmacology

Context Lily bulb and Rehmannia decoction (LBRD), consisting of Lilium henryi Baker (Liliaceae) and Rehmannia glutinosa (Gaertn) DC (Plantaginaceae), is a specialized traditional Chinese medicine formula for treating depression. However, the underlying mechanisms, especially the relationship between LBRD efficacy and metabolomics, remains unclear. Objective This study was aimed to investigate the metabolic mechanism of LBRD in treating depression. Materials and methods Network pharmacology was conducted using SwissTargetPrediction, DisGeNET, DrugBank, Metascape, etc., to construct component-target-pathway networks. The depression-like model was induced by intraperitoneal injection with lipopolysaccharide (LPS) (0.3 mg/kg) for 14 consecutive days. After the administration of LBRD (90 g/kg) and fluoxetine (2 mg/kg) for 14 days, we assessed behaviour and the levels of neurotransmitter, inflammatory cytokine and circulating stress hormone. Prefrontal metabolites of rats were detected by using liquid chromatography–mass spectrometry metabolomics method. Results The results of network pharmacology showed that LBRD mainly acted on neurotransmitter and second messenger pathways. Compared to the model group, LBRD significantly ameliorated depressive phenotypes and increased the level of 5-HT (13.4%) and GABA (24.8%), as well as decreased IL-1β (30.7%), IL-6 (32.8%) and TNF-α (26.6%). Followed by LBRD treatment, the main metabolites in prefrontal tissue were contributed to retrograde endocannabinoid signalling, glycerophospholipid metabolism, glycosylphosphatidylinositol-anchor biosynthesis, autophagy signal pathway, etc. Discussion and conclusions LBRD were effective at increasing neurotransmitter, attenuating proinflammatory cytokine and regulating glycerophospholipid metabolism and glutamatergic synapse, thereby ameliorating depressive phenotypes. This research will offer reference for elucidating the metabolomic mechanism underlying novel antidepressant agents contained LBRD formula.

Application Of Genetic Technology And Fruit Extracts To Improve Yogurt

Yogurt is a ubiquitous daily drink in our life, which is popular among the public because of its unique flavor and taste. Lactobacillus in yogurt is a symbiotic bacterium in human body, it promotes human health, and as probiotics is widely used in food processing industry and plays an important part in the processing and production of yogurt. Now, people's living standards are gradually improving and the pursuit of a healthy and happy life, it is particularly important to develop lactobacillus, which is more in line with the needs of human health and has more excellent traits, to improve the quality such as flavor improvement, taste enhancement and growth shelf life of yogurt. Yogurt quality is generally improved by adding some fruit / plant extract to the yogurt and mixing fermentation by lactic acid bacteria, resulting in a large improvement in flavor, taste, production time, and shelf life. Such as chitosan, bacteriocins, CMC (carboxymethylcellulose) can extend shelf life and Lotus / lily bulb powder thereby further increasing free amino acids, citric acid and free fatty acids concentrations in yogurt. And mouth feel by inducing protein-protein interactions to further increase the viscosity of yogurt; The inclusion of both grape seed extract and banana peel extract in yogurt substantially increases the post shelf life of yogurt so that nutrients are not easily lost. Moreover, mutagenesis breeding and CRISPR-Cas9 technology can obtain mutant strains with acid tolerance and weak H+-ATPase activity to avoid post-acidification.

Comparative metabolome analysis unravels a close association between dormancy release and metabolic alteration induced by low temperature in lily bulbs.

The correlation between dormancy release and metabolic metabolic changes in lily bulbs during low temperature storage was investigated. Low temperature is a major environmental factor required for dormancy release in lily bulbs. Although great advances in plant metabolomics have been achieved, knowledge about the molecular basis of lily bulb metabolomes at different developmental stages in response to low temperature is still limited. In this work, the dormancy release, vegetative growth, flowering, metabolic profile and gene expression in the less dormant cultivar Lilium longiforum × Oriental hybrid 'Triumphator' (T) and the more dormant cultivar Lilium Asiatic hybrid 'Honesty' (H) were compared. Exposure to low temperature (LT) successfully promoted stem elongation, floral transition and flowering of both T and H bulbs. However, exposure to room temperature (RT) restricted stalk elongation of both T and H bulbs, and prohibited floral transition and flowering of H bulbs. Correspondingly, higher antioxidant enzyme activity and total primary metabolite contents were observed in the apical bud of T bulbs. Gene expression analysis revealed that expressions of LiFT, LiFLK, LiSOC1 and LiCBF were decreased, whereas the expression of LiSVP and LiFLC were increased, in the apical bud of H bulbs under RT storage condition. Our findings reveal that the growth and dormancy breaking of lily bulbs are closely associated with the metabolic changes in the apical buds during postharvest storage.

Immunomodulatory activity and active mechanisms of a low molecular polysaccharide isolated from Lanzhou lily bulbs in RAW264.7 macrophages

Exploring immunomodulatory effects of polysaccharides mechanisms is highly significant. In this study, Lanzhou lily (Lilium davidii var. unicolor) polysaccharides (LP) of 6.80 × 103 Da were extracted using the freeze-thaw method. For analytical purposes, structure characterization was conducted using fourier transform infrared spectrometer (FTIR), ultraviolet spectrophotometer (UV–Vis), scanning electron microscope (SEM), and transmission electron microscopy (TEM). Results showed that LP exhibited characteristics of polysaccharide functional groups. Moreover, findings on its immune activity showed that LP can stimulate macrophage RAW264.7, promote macrophage proliferation, secrete nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). We use RNA-Seq to explore how LP mechanisms effect macrophages. Results revealed that LP likely plays an immunomodulatory role through cytokines secretion, cytokines that effectuate G-protein coupled receptor subunits, and activating downstream immune-related signaling pathways. This study can be used as a reference for the further development of LP while also offering an in-depth understanding of mechanistic immunoregulatory activity.

Effect of modified atmosphere packaging combined with plant essential oils on preservation of fresh-cut lily bulbs

Fresh-cut lily bulbs have broad consumption prospects in the vegetable market due to their high nutritional value and convenience in processing; however, potential discoloration and microbial infection during storage adversely affect their quality. This study investigated the effect of modified atmosphere packaging (MAP) and plant essential oils (EOs) on the preservation of lily bulbs. The results showed that MAP significantly preserved the color and weight of lily bulbs, and different MAP conditions caused different effects on bacterial inhibition. Low oxygen-MAP (L-MAP) showed a stronger antibacterial effect than air-MAP (A-MAP), whereas appropriate antibacterial agents were still needed to improve the antibacterial effect. Therefore, plant EOs were employed to further control the growth of microorganisms by preparing plant EO solid particles (PESP). The combined use of L-MAP and PESP significantly prolonged the shelf life of lily bulbs to 12 d with higher contents of nutrients and better appearance quality compared to the control. Furthermore, the physiological metabolism of lily bulbs was regulated by combined treatment with L-MAP and PESP, which inhibited starch degradation, MDA accumulation and respiratory oxidase activities.

Starch Degradation and Sucrose Accumulation of Lily Bulbs after Cold Storage.

Functional lilies are a group of edible lily cultivars with great potential for landscape application. Low-temperature storage can significantly improve their taste, but the knowledge of this process is largely unknown. In this study, we used the functional lilies ‘Fly Shaohua’ and ‘Fly Tiancheng’ as materials. Through physiological observation and transcriptome analysis during the bulbs’ cold storage, it was found that the starch degradation and sucrose accumulation in bulbs contributed to taste improvement. After 60 d of cold storage, the sucrose accumulation was highest and the starch content was lower in the bulbs, suggesting this time-point was optimal for consumption. Accompanying the fluctuation of sucrose content during cold storage, the enzyme activities of sucrose phosphate synthase and sucrose synthase for sucrose synthesis were increased. Transcriptome analysis showed that many differentially expressed genes (DEGs) were involved in the starch and sucrose metabolism pathway, which might promote the conversion of starch to sucrose in bulbs. In addition, the DEGs involved in dormancy and stress response were also determined during cold storage, which might explain the decreased sucrose accumulation with extended storage time over 60 d due to the energy consumption for dormancy release. Taken together, our results indicated sucrose accumulation was a main factor in the taste improvement of lily bulbs after cold storage, which is attributable to the different gene expression of starch and sucrose metabolism pathways in this process.

Infrared Drying Characteristics and Quality Variations of Lily Bulbs Under Blanching Pretreatment

Abstract Infrared drying characteristics and quality variations (color change, hardness, contents of polyphenol and flavonoid) of lily bulbs under blanching pretreatment are investigated. Influences of parameters such as pretreatment temperature and time and infrared drying temperature are discussed. Effective moisture diffusivity coefficient, activation energy, and energy consumption were calculated. Results showed that drying time was reduced by 62.5%, 56.3%, and 61.5% at 90 °C compared to 60 °C when blanching time was 4, 5, and 6 min, respectively. A blanching time of 5 min and drying temperature of 70 °C were ideal for pretreatment and drying to maintain good color quality. Hardness value of lily bulb decreased as drying temperature and blanching time increased. Seventy to eighty degree celcius was ideal drying condition to maintain good hardness quality. Blanching time and drying temperature differently affected contents of flavonoids and polyphenols of lily bulbs. Basically, when blanching time was relatively long and drying temperature was relatively high, the content of polyphenols was high.

Transcriptomic and physiological analyses identifying Lanzhou lily (Lilium davidii var. unicolor) drought adaptation strategies

Drought stress is the main limiting plant growth factor in arid and semiarid regions. The Lanzhou lily (Lilium davidii var. unicolor) is the only sweet-tasting lily grown in these regions of China that offers highly edible, medicinal, health, and ornamental value. The Tresor lily is an ornamental flower known for its strong resistance. Plants were grown under three different drought intensity treatments, namely, being watered at intervals of 5, 15, and 25 d (either throughout the study or during specific growth stages). We measured the biomass, leaf area, photosynthetic response, chlorophyll content (SPAD value), and osmoregulation of both the Lanzhou lily and the Tresor lily (Lilium ‘Tresor'). Additionally, we employed RNA sequencing (RNA-Seq) and qRT-PCR to investigate transcriptomic changes of the Lanzhou lily in response to drought stress. Results showed that under drought stress, the decreasing rate in the Lanzhou lily bulb weight was lower than the corresponding Tresor lily bulb rate; the net photosynthetic rate, transpiration rate, and stomatal conductance of the Lanzhou lily were all higher compared to the Tresor lily; osmoregulation constituents, such as glucose, fructose, sucrose, trehalose, and soluble sugar, in the Lanzhou lily were comparatively higher; PYL, NCED, and ERS genes were significantly expressed in the Lanzhou lily. Under moderate drought, the biosynthesis of flavonoids, circadian rhythms, and the tryptophan metabolism pathway of the Lanzhou lily were all significant. Under severe drought stress, fatty acid elongation, photosynthetic antenna protein, plant hormone signal transduction, flavone and flavonol biosynthesis, and the carotenoid biosynthesis pathway were all significant. The Lanzhou lily adapted to drought stress by coordinating its organs and the unique role of its bulb, regulating photosynthesis, increasing osmolyte content, activating circadian rhythms, signal transduction, fatty acid elongation metabolism, and phenylalanine and flavonoid metabolic pathways, which may collectively be the main adaptation strategy and mechanisms used by the Lanzhou lily under drought stress.

Energy metabolism as the target of 3-phenyllactic acid against Rhizopus oryzae

3-phenyllactic acid (PLA) has broad anti-fungal activity, however, target sites of PLA on fungal cells and its anti-fungal mechanism of action have been poorly studied. In this study, we explored the inhibition mechanism of Rhizopus oryzae (R. oryzae) on rotten lily bulbs by PLA. The minimum inhibitory concentration value of PLA against R. oryzae was 8 mg/mL. We observed the ultrastructure of R. oryzae by scanning electron microscopy and transmission electron microscopy which indicated that PLA did not damage the cell membrane, but destroyed the mitochondria and other organelles. Tandem mass tag proteomes showed that PLA significantly down-regulated (P < 0.05) the expression of hexokinase (HK), phosphofructokinase (PFK), a-ketoglutarate dehydrogenase (a-KGDH), adenylate kinase (ADK1), Cytochrome C oxidase and NADH dehydrogenase, and up-regulated (P < 0.05) the expression of mitochondrial ADP/ATP carrier proteins (AAC) and subunit IV (CCIO IV) in glycolysis, tricarboxylic acid cycle or oxidative phosphorylation metabolism. Following these findings, down-regulated HK and a-KGDH activity of aforementioned pathways was shown by enzyme activity assay, and regulated gene expression of ADK1, AAC, CCIO IV and NADH dehydrogenase was further confirmed by real-time quantitative PCR. Central carbon metabolomics showed that citric acid, cis-Aconitic acid, isocitric acid, alpha-Ketoglutaric acid, succinate, fumarate and malic acid of the tricarboxylic acid cycle metabolites were significantly down-regulated (P < 0.05), and ATP production by oxidative phosphorylation was also significantly reduced (P = 0.02), resulting in insufficient energy production. Thus, ROS levels increased by 141% of the control values and cytochrome C was released, resulting in gradual cell apoptosis. All data indicated that energy metabolism was the target of PLA against R. oryzae. This was the first study to show that energy metabolism could be the target of PLA against R. oryzae, which could provide a theoretical basis to study the mechanism of fungal inhibition.

An optimized method to\xa0obtain high-quality RNA from different tissues in Lilium davidii var. unicolor

The high quality, yield and purity total RNA samples are essential for molecular experiments. However, harvesting high quality RNA in Lilium davidii var. unicolor is a great challenge due to its polysaccharides, polyphenols and other secondary metabolites. In this study, different RNA extraction methods, namely TRIzol method, the modified TRIzol method, Kit method and cetyltrimethylammonium bromide (CTAB) method were employed to obtain total RNA from different tissues in L. davidii var. unicolor. A Nano drop spectrophotometer and 1% agarose gel electrophoresis were used to detect the RNA quality and integrity. Compared with TRIzol, Kit and CTAB methods, the modified TRIzol method obtained higher RNA concentrations from different tissues and the A260/A280 ratios of RNA samples were ranged from 1.97 to 2.27. Thus, the modified TRIzol method was shown to be the most effective RNA extraction protocol in acquiring RNA with high concentrations. Furthermore, the RNA samples isolated by the modified TRIzol and Kit methods were intact, whereas different degrees of degradation happened within RNA samples isolated by the TRIzol and CTAB methods. In addition, the modified TRIzol method could also isolate high-quality RNA from other edible lily bulbs. Taken together, the modified TRIzol method is an efficient method for total RNA isolation from L. davidii var. unicolor.

2‐aminoindan‐2‐phosphonic acid alleviates oxidative browning in fresh‐cut lily bulbs

2-aminoindan-2-phosphonic acid (AIP) functions as a particular inhibitor of polyphenol biosynthesis in phenylpropanoid pathway. In this study, the role of AIP in browning resistance of fresh-cut lily bulbs during storage was investigated. Application of 0.5 mmol/L AIP decreased browning degree of fresh-cut lily bulbs, which was accompanied by reduced total phenolics content (TPC) and enzymes related to enzymatic browning including polyphenol oxidase (PPO), phenylalanine ammonia-lyase (PAL) and peroxidase (POD). In comparison with the control, AIP efficiently maintained cell membrane integrity and lowered oxidative stress via inhibiting lipoxygenase (LOX) activity and malondialdehyde (MDA) content as well as promoting the activities of superoxide dismutase (SOD), catalase (CAT), and energy-metabolism related enzymes, thus controlling browning of fresh-cut lily bulbs. The browning inhibition of AIP was highly correlated with cell membrane structure, energy metabolism and enzymatic browning. These results show that AIP is a potential way to prevent browning of fresh-cut lily bulbs. Novelty impact statement The quality and shelf-life of fresh-cut lily bulbs are seriously reduced due to tissue browning. This work investigates the effect of AIP on alleviating oxidative browning of fresh-cut lily bulbs for the first time to our knowledge. The inhibitory effect of AIP on fresh-cut lily bulbs was highly correlated with cell membrane structure, energy metabolism and enzymatic browning.

Humik Asit Uygulamalarının Zambak Bitkisinin Gelişimi, Bitkideki Fenolojik ve Pomolojik Gözlemler Üzerine Etkisi

In this study, a pot study was carried out to reveal the effects of direct and foliar applications of humic acid to the growing medium in addition to basic fertilization on the development and plant quality characteristics of lily plants grown in peat + perlite medium. The experiment was carried out in an unheated greenhouse during the summer, in a greenhouse environment with a shade net on it. In the experiment, in addition to the control, the humic acid doses were 3.5 lt/da from soil, 7.5 lt/da from soil, 1.75 lt/da from leaf, 3.75 lt/da from leaf and soil + 3.5 lt/da from leaf + 1, It was applied 3 times as 75 lt/da. In the pot experiment established in three replications according to the randomized plots trial design, 10 lily bulbs were planted in each pot and humic acid applications were made at two-week intervals following plant emergence. In order to see the effect of the applications when the plant is harvested, the length of the flower stem (mm), the thickness of the flower stem (mm), the fresh weight of the branch (mm), the number of buds (pieces), the bud length (cm), the number of leaves (pieces), Full bloom stem (mm) and vase life (days) were examined. As the doses of humic acid increased, the vegetative weight of the lily plant increased, while the effect of the applications on the investigated properties was different. With the mineral elements, hormones and plant growth regulators in humic acid, it has the feature of promoting the increase of biomass in the plant.

Analysis of edible characteristics, antioxidant capacities, and phenolic pigment monomers in Lilium bulbs native to China

Lilium is cherished for its health-promoting properties in China. The bulbs of Lilium are rich in phenolic compounds, which are associated with antioxidant capacity. However, no systematic evaluation on phenolic compositions and antioxidant capacities for the edible Lilium native to China has been conducted. Herein, bulbs of 56 wild populations and three cultivars were collected. Their edible characteristics, antioxidant capacities, and pigments have been investigated and analyzed. The results showed that phenolic compounds contributed to the major colors (red, yellow and white) in Lilium bulbs. The seven phenolic pigment monomers responsible for the color of bulbs—cyanidin-3-O-rutinoside, isoquercitrin, regaloside B, regaloside C, regaloside H, regaloside A and regaloside D—were identified by the combination of HPLC-MS and NMR analysis. The population Lilium regale E. H. Wilson (Maoxian County, Sichuan Province) had the highest antioxidant capacity. According to the quantification results, Lilium bulbs with darker and redder colors possessed larger biomass, better nutrient compositions, significantly higher bioactive constituents, and higher antioxidant capacities than the three currently consumed cultivars of edible lily bulbs. Overall, these findings suggest that the mountainous area of southwest China could be the fourth source of edible lilies with the bulb-colored Lilium species.

Calibration and Verification Test of Lily Bulb Simulation Parameters Based on Discrete Element Method

In the simulation analysis of the lily harvesting process, the intrinsic parameters of the lily bulb and the contact parameters between the lily bulb and the lily mechanized harvesting equipment (Q235 steel) are deficient. Thus, the three-axis size, density, moisture content, Poisson’s ratio, elastic modulus, and other parameters of lily bulbs are measured in this paper with lily bulbs as the research object. Moreover, the discrete element model of the lily bulb was established using 3D scanning technology. The contact parameters between the lily bulb and Q235 steel were calibrated through bench test and simulation parameter test. The relative error between the measured value of the lily bulb accumulation angle and the simulated value is taken as response value to calibrate three parameters (collision recovery coefficient, static friction coefficient, and dynamic friction coefficient between lily bulbs). A regression model of the relative error of the stacking angle and three parameters is established, and the response surface is optimized. The results demonstrate that collision recovery coefficient, static friction coefficient, and dynamic friction coefficient between lily bulb and Q235 steel are 0.301, 0.423, and 0.063, respectively; these coefficients between lily bulbs are 0.455, 0.425, and 0.158, respectively. Additionally, a better combination of parameters is adopted to perform the simulation stacking test. The measured stacking angle is 32.31°, which is 0.34% in error with the stacking angle obtained by the physical stacking test. The test results suggest that the discrete element model and contact parameters of the lily bulb can be used in the discrete element simulation test. Furthermore, these research results could provide references for simulation tests, such as mechanized harvesting and post-harvest processing, of lily.