Oil Peony Research Articles

Effects of different fertilization formulas on fruit quality and soil physical and chemical properties of oil peony in abandoned mining areas

Effects of different fertilization formulas on fruit quality and soil physical and chemical properties of oil peony in abandoned mining areas

Endosperm-specific expressed transcription factor protein WRINKLED1-mediated oil accumulative mechanism in woody oil peony Paeonia ostii var. lishizhenii

Paeonia ostii var. lishizhenii exhibits superiority of high α-linolenic acid in seed oils, yet, the low yield highlights the importance of enhancing oil accumulation in seeds for edible oil production. The transcription factor protein WRINKLED1 (WRI1) plays crucial roles in modulating oil content in higher plants; however, its functional characterization remains elusive in P. ostii var. lishizhenii. Herein, based on a correlation analysis of transcription factor transcript levels, FA accumulation rates, and interaction assay of FA biosynthesis associated proteins, a WRI1 homologous gene (PoWRI1) that potentially regulated oil content in P. ostii var. lishizhenii seeds was screened. The PoWRI1 exhibited an endosperm-specific and development-depended expression pattern, encoding a nuclear-localized protein with transcriptional activation capability. Notably, overexpressing PoWRI1 upregulated certain key genes relevant to glycolysis, FA biosynthesis and desaturation, and improved seed development, oil body formation and oil accumulation in Arabidopsis seeds, resulting an enhancement of total seed oil weight by 9.47–18.77 %. The defective impacts on seed phenotypes were rescued through ectopic induction of PoWRI1 in wri1 mutants. Our findings highlight the pivotal role of PoWRI1 in controlling oil accumulation in P. ostii var. lishizhenii, offering bioengineering strategies to increase seed oil accumulation and enhance its potential for edible oil production.

Discrete Element Model of Oil Peony Seeds and the Calibration of Its Parameters

Oil peony is an important oil crop that is primarily sown by using artificial methods at present. Its seeder encounters the problems of low efficiency of seeding that significantly limits the highly efficient mechanized production of high-quality peony oil. In this study, Fengdan white oil peony seeds were used as the research object and repose angle as the response value to establish a discrete element model (DEM) and parameter calibration. The range of parameters of oil peony seeds was first obtained through an experiment, and their repose angle was obtained by an inclinometer. A three-dimensional DEM of oil peony seeds was then established. The Plackett–Burman (PB) test was utilized to screen the parameters that had a significant influence on the repose angle, and the steepest ascent (SA) test was applied to determine their optimum range of testing. Following this, based on Box–Behnken (BBD) test results, a second-order regression model between the important parameters and the repose angle was constructed. Finally, the absolute minimum difference between simulated and measured repose angles was utilized as the objective of optimization to obtain the following optimum combination of parameters: The values of the seed–steel collision recovery coefficient (CRC), seed–seed static friction coefficient (SFC), seed–steel SFC, and seed–seed rolling friction coefficient (RFC) were 0.704, 0.324, 0.335, and 0.045, respectively. This optimal combination of parameters was confirmed through simulations, and the error between simulated and measured repose angles was only 0.67%, indicating that the calibrated DEM of oil peony seeds was reliable.

The innovative extraction and purification process of insoluble polyphenols from Paeonia ostii roots: Optimum study and in vitro activities

The oil tree peony (Paeonia ostii) is widely cultivated for their high value seed oil, and its roots also have high medicinal value, but they are often discarded and wasted as by-products. In this study, a set of steam explosion (SE) and ultrasound (US)-assisted extraction/purification methods of insoluble bound phenols (IPs) from oil peony roots (PR) were explored and developed. The IPs were obtained through SE pre-treatment (120 °C, 15 min) and US-assisted alkaline extraction (0.25 W/cm2, 4 h and 4 M NaOH). Their total phenolic content (TPC) significantly increased from 112.26 mg gallic acid/g dry weight (mg GAE/g dw) with traditional method to 185.59 mg GAE/g dw. Subsequently, the IPs were purified into PIPs using LX-83 resin. The optimized purification conditions were pH = 4, 3.0 mg GAE/mL of IPs, 0.25 W/cm2 adsorption for 120 min, as well as 60 % ethanol desorption solution, and 0.25 W/cm2 desorption for 30 min. The TPC of the PIPs increased to 254.74 mg GAE/g dw. Notably, typical compounds in IPs and PIPs were identified and quantified by HPLC-MS and their antioxidant and anti-tyrosinase activities were also evaluated by chronometry. The results showed that paeoniflorin and benzoyl-paeoniflorin increased by about 10-fold in the PIPs. Additionally, they demonstrated superior antioxidant and tyrosinase inhibitory activities compared to IPs. Therefore, the innovative extraction and purification process greatly improved the yield of bound phenols and recovered paeoniflorin from non-medicinal PR. The process may also provide a reference for the in-depth development of medicinal PR, ultimately achieving more efficient PR development and utilization.

The one-step synthesis of Fe-N co-doped peony pod-based porous carbon for the removal of tetracycline

The peony pod is a component of the cash crop oil peony (Paeonia suffruticosa Andr.), it accounts for more than half of the quality of the peony seed. However, indiscriminate disposal leads to resource waste. In addition, the pollution caused by the overuse of antibiotics and the evolution of resistance have been a conundrum. There is an urgent need to find a pollutant removal method that conforms to the current concept of sustainable development. In this study, the biomass porous carbon (PCN,Fe-0.5) was prepared and modified by one-step synthesis method using the by-product peony pod as carbon precursor, urea as nitrogen source, and steel slag as magnetic material. The utilization of biomass waste solved resources waste caused by the unreasonable disposal of agricultural solid waste. The doped materials were cheap and easy to obtain, and they improved the structure and function of porous carbon. The maximum adsorption capacity of PCN,Fe-0.5 reached 726.4 mg·g−1 with 100 mg·L−1 of tetracycline (TC). The adsorption mechanism was summarized as pore filling, van der Waals force, π-π EDA, surface complexation, hydrogen bonding and chemisorption. A low-budget tetracycline (TC) removal method was explored through the investigation on the adsorption performance and recovery capability of PCN,Fe-0.5, which was also conducive to realizing the recycling of biomass waste and industrial waste.

Identification of Different Varieties of Oil Peony Seeds Combining ICP-MS with Chemometrics and Assessment of Associated Health Risk.

Peony seed is an excellent oil crop, and peony seed oil is rich in unsaturated fatty acids needed by the human body. In this study, inductively coupled plasma mass spectrometry (ICP-MS), fingerprint, and chemometrics, the correlation between the content of inorganic elements in oil peony seeds, their origins, and varieties were investigated. Meanwhile, estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and carcinogenic risks (CR) were combined to evaluate the comprehensive health risks of heavy metals in peony seed oil. The results showed that the difference in the content of inorganic elements could identify the varieties of oil peony seeds. Sr, K, Ca, V, Al, Fe, Cu, Ba, As, Ga, Co, and Rb were the characteristic inorganic elements that played a role in identification. In addition, The THQs and HIs (< 1) for non-carcinogenic elements indicated no risk. The CRs indicated that the carcinogenic harm was negligible. The study concluded that three varieties of peony seed oil would not pose any health hazard. It provided an effective comprehensive method for the identification of oil peony seeds and predicted the potential health risks of edible peony seed oil, providing a reference for the development and consumption of peony seed oil food.

Potential Source Identification and Ecological Risk Assessment of Heavy Metals in Surface Soil of Heze Oil Peony Planting Area Based on PMF-PCA/APCS and PERI

To study the sources and potential risks of heavy metals in soils of characteristic agricultural product producing areas is of great significance for the scientific management and safe utilization of soil and crop resources. The contents of heavy metals As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in the 254 surface soil samples collected from the Heze oil peony planting area were determined. The content characteristics and correlation of heavy metals were analyzed using multivariate statistical methods. The sources of heavy metals in topsoil were analyzed using Igeo, PMF, and PCA/APCS. The ecological risks of the eight heavy metals were assessed through the potential ecological risk index (PERI). The results showed that the average contents of seven heavy metals in the soil were basically consistent with the background values of soil elements in Heze City, except that the average value of Cd was 1.44 times higher than the background value in Heze City. Correlation analysis and cluster analysis revealed that Pb, Hg, and Cd elements in the soil were greatly affected by human activities in the later period. The sources of eight heavy metals in the study area were natural sources, agricultural fertilizer sources, industrial coal sources, and domestic transportation sources, with the contribution rates of 81.31%, 15.45%, 2.74%, and 0.50%, respectively; 84.25% of the sites in the study area were at slight ecological risk, whereas the moderate risk and strong risk sites accounted for 14.96% and 0.79%, respectively. Among them, Cd and Hg were the dominant elements of ecological risk in the study area.

Effects of NSC in different organs and at different growth stages on the yield of oil peony Fengdan with different ages.

Non-structural carbohydrates (NSC) as resource reserves of plants play important roles in energy supply for normal growth and reproduction under environmental stress. The yield of perennial crops is mainly determined by the carbohydrate production and allocation in the current growth season, as well as the re-allocation of NSC reserves. However, the contribution of NSC to crop yield has not been fully determined. Fengdan (Paeonia ostii) is a variety of oil Peony that is newly developed in China. The effects of tree age and NSC on yield were examined by investigated the variations of biomass, soluble sugars, starch, and NSC in the organ and whole tree levels in the dormant and ripening stages of Fengdan populations with 4-, 6-, and 8-year-old in 2020 and 5-, 7-, and 9- year old in 2021. Results showed that the biomass, yield (seed biomass), soluble sugars, starch, and NSC reserve of Fengdan at the whole tree level increased with the increase in age. Although consistent correlations were observed between soluble sugars, starch and NSC storage, and yield among the plants with different ages, Fengdan showed allometric growth relationships between the accumulation of soluble sugars, starch, and NSC and yield and biomass (standardized major axis analyses slope b ≠ 1). Tree age significantly affected biomass and its allocation and NSC levels, especially the yield of Fengdan plants. The results of the investigation of the variations in the relationships between the yield and seasonal fluctuations of NSC and biomass indicate that roots is the key storage structure, whereas stems both serve as sink and/or source functions for the adult (7-9a) plants. NSC level, particularly the concentration of soluble sugars, in stems mainly influences Fengdan yield. These findings together provide new insights into the mechanisms underlying the yield formation of Fengdan and have implications for manipulating sink-source relationship to achieve high yield.

A novel pathway based on the comprehensive utilization of oil peony pods into high yield polysaccharides and strong adsorption carbon

The main purpose of the study was to establish a new comprehensive utilization Standard Operating Procedure (SOP) for the oil tree peony pods (OTPP) and realize the green sustainable utilization of agricultural and forestry waste. The OTPP polysaccharide (OTPP-P) was extracted by ultrasonic-assisted extraction (UAE), and the yield was optimized by response surface methodology (RSM). The activated carbon (AC) was prepared by two-step activation using OTPP residue (OTPPR) as raw material, and the structure and adsorption properties of AC were evaluated. The results revealed that the yield of OTPP-P was up to 8.05% by UAE, two polysaccharides were isolated from OTPP-P, and the monosaccharides components were obtained. The PPAC-KOH had a good pore structure (SBET = 1363.39 m2/g and VTotal = 0.81 cm3/g), and had superior adsorption capacity for methyl orange (1113 mg/g), ciprofloxacin (696 mg/g) and norfloxacin (308 mg/g). The adsorption process mainly included electrostatic interaction, π-π interactions, and dominant physical absorption. Adsorption had good applicability and repeatability. This study provided a new way for the comprehensive utilization of OTPP and a reference for the high value-added transformation and sustainable development of waste.

Chemical fingerprinting and multivariate analysis of Paeonia ostii leaves based on HPLC-DAD and UPLC-ESI-Q/TOF-MS/MS

Paeonia suffruticosa Andr. (Tree peony) is a well-known traditional Chinese medicine, which has been widely cultivated for thousands of years and its root bark is used in many prescriptions. Oil peony (Paeonia ostii and Paeonia rockii) has been planted in large areas since tree peony seed oil was approved as a new food resource by the National Health Commission (Ministry of Health) of P.R. China in 2011. However, tree peony leaves were often regarded as waste resources during cultivation and there were few comparative studies on the chemical constituents of tree peony leaves from different origins. In this study, thirty-five P. ostii leaves from four provinces in China were taken as the research objects. The methods of high-performance liquid chromatography (HPLC-DAD) fingerprinting combined with multivariate analysis, including similarity analysis (SA), principal component analysis (PCA), orthogonal partial least square method-discriminant analysis (OPLS-DA) and hierarchical cluster analysis (HCA), were used to evaluate the difference of chemical composition between thirty-five samples. UPLC-ESI-Q/TOF-MS/MS and HPLC-DAD were used for qualitative and quantitative analysis of characteristic components. The results showed that seventeen common characteristic peaks were screened from HPLC fingerprints and the similarity of thirty-five samples was between 0.864 and 0.999. Thirty-five samples from different origin were divided into four groups by OPLS-DA and PCA, but not HCA. Meanwhile, ten compounds were found to be the most closely related marker components for quality evaluation. In addition, 56 characteristic chemical components were preliminarily identified from P. ostii leaves by UPLC-ESI-Q/TOF-MS/MS technology. Finally, the quantitative analysis results showed that there were some differences in the chemical contents of seven characteristic components in thirty-five P. ostii leaves. This study provided a reasonable method for the discrimination and quality evaluation of P. ostii leaves from different producing areas, and laid a foundation for the comprehensive utilization and development of P. ostii resources.

Peony seeds oil by-products: Chemistry and bioactivity

Peony seeds oil (PSO) is a high-end vegetable edible oil with good health care and edible value, and peony seeds shell (PSS) and peony seeds cake (PSC) are the two important by-products in the process of PSO production. The total mass of PSS and PSC accounts for more than 70% of peony seeds. The study on chemical and bioactivity of PSS and PSC plays a critical role in the healthy development of oil peony industry. PSS and PSC are rich in plant proteins, polysaccharides , monoterpene glycosides , oligostilbenes, flavonoids , sterols, phenolic acids and other active ingredients with various biological activities. The active ingredients in PSS and PSC can be used as raw material in food and pharmaceutical industries. Therefore, the present article aims to summarize structures, extraction, bioactivities and application of the active ingredients from the by-products of PSO processing, provide a reference for the development and utilization of PSS and PSC, and construct a foundation for the healthy development of oil peony industry. It is reasonable to believe that with the deepening of research, more high value-added products will be studied, developed and utilized from the nutritional profiles of PSS and PSC. • Peony seeds shell (PSS) and peony seeds cake (PSC) contain active ingredients. • The protein, monoterpene glycosides, flavonoids and phytosterols mainly exist in PSC. • Oligostilbenes, polyphenols and natural melanin mainly are found in PSS. • These active ingredients have many biological activities. • The active ingredients have wide application prospect in food and pharmaceutical industries.

Deciphering the microbial diversity associated with healthy and wilted Paeonia suffruticosa rhizosphere soil.

Plant health is closely related to the soil, where microorganisms play a critical and unique role. For instance, Paeonia suffruticosa is an emerging woody oil crop in China with attractive development and utilization prospects. However, black root rot causes wilting of the aboveground plant parts, which significantly affected its seed yield and quality. Studies found that soil microorganisms are critical in maintaining plant health, but how changes in the soil microbial communities affect the healthy and diseased oil peony is unclear. Therefore, our present study used high throughput sequencing and BIOLOG to analyze the rhizosphere soil microbial communities of healthy and diseased oil peonies. Our results revealed that the physical and chemical properties of the soil of the diseased plants had changed, with the ability to metabolize the carbon source being enhanced. Moreover, our research highlighted that the oil peony-infecting fungal pathogenic genus (Fusarium, Cylindrocarpon, and Neocosmospora) was closely associated with oil peony yield reduction and disease aggravation. Further network analysis demonstrated that the bacterial and fungal networks of the diseased plants were more complex than those of the healthy plants. Finally, the inter-kingdom network among the diseased plants further indicated that the lesions destroyed the network and increased the intraspecific correlation between the fungal groups.

Effect of spatial position on twig resource allocation of Fengdan (Paeonia ostii)

AbstractUnderstanding how a plant allocates biomass for reproduction and the effect of location position on twigs' biomass partitioning provides essential information on how to maximise fruit yields through pruning. Fengdan (Paeonia ostii) is a variety of oil Peony newly developed in China. In this paper, the pattern of biomass allocation and allometric growth of the modules within twig (fruit twigs) of five populations of Fengdan were investigated by using standardised major axis (SMA) analyses. The ANOVA results showed that the biomass of stem, seed, husk and fruit per twig significantly varied among populations and among twigs growing at different positions within an individual plant. The top twig had the largest stem and fruit biomass. Twig showed an allometric growth relationship between reproduction and growth (SMA slope b ≠ 1). An obvious trade‐off was found between seed number and 100‐seed weight in fruits. These findings demonstrate that the seated position of the Fengdan twig significantly influences its resource allocation pattern and fruit (seed) yield, implying the efficiency of creating a suitable growth environment and optimising tree architecture in increasing oil Peony yield.

Application of Grey Relational Analysis and Multiple Linear Regression to Establish the Cutting Force Model of Oil Peony Stalk

Oil peony is an important oil crop, which has high quality and oil content. In order to improve the cutting quality and harvest efficiency of oil peony, the cutting equipment of the pruning machine and harvester is a key component. Also, the accurate prediction of cutting force of oil peony stalk is one of the essential processes for the design of the cutting equipment. In this article, to accurately predicted the cutting force of the stalk, the physical property parameters and chemical components were considered as influencing factors, which were used to establish the model of mechanical property parameter of oil peony stalk. The physical property parameters of oil peony stalk included the stalk diameter, internode distance, fresh weight, dry weight, relative moisture content, volume, fresh density, and dry density. The chemical components of the stalk were cellulose, hemicellulose, and lignin. Besides, the modeling methods, which were the partial least squares regression (PLSR), principal component analysis (PCA) couple with multiple linear regression (MLR), and grey relational analysis (GRA) couple with MLR, were used to optimize the multiple parameters (physical property parameters and chemical components). The results showed that the internode distance and relative moisture content had significant effects on the cutting force of oil peony stalk. The R c 2 and R p 2 values of the GRA (0.5) + MLR method were 0.801 and 0.820, and RMSEC and RMSEP values were 2.862N and 4.715N, respectively. Consequently, the GRA + MLR method could be used to predict the cutting force of oil peony stalk, which was an important basis for the design of precision cutting equipment.

Drought Tolerance Mechanisms and Hydrological Effect of Oil Peony Planting in Chinese Loess Plateau

Drought Tolerance Mechanisms and Hydrological Effect of Oil Peony Planting in Chinese Loess Plateau

Effects of biochar application on soil nitrogen and phosphorous leaching loss and oil peony growth

The control of soil nutrient loss to lighten non-point source pollution to water body and improve soil fertility is a global problem. Biochar application to soil is widely considered as an effective method to improve soil fertility and reduce nutrient loss. However, the effect of biochar application to barren karst yellow soil in global karst regions on the loss of nitrogen (N) and phosphorous (P) and the growth of oil peony (an important woody oil crop) remains unclear. We conducted the indoor leaching experiments, in-site observation of the N and P loss with surface runoff under three types of rains and the comparative experiment of oil peony growth when the different amount of biochar was applied to karst yellow soil. The results indicated that soil pH, total nitrogen (TN), total phosphorous (TP), available N and available P contents in the soil increased with an increase of biochar application under indoor simulation but the loss of leaching solution decreased. 2 kg/m2 biochar application caused the least loss of TP, TN, nitrate nitrogen (NN) and ammonia nitrogen (AN) with the leaching solution compared with 0, 4 and 6 kg/m2 application. The rapid and slow attenuation of P and N concentrations, respectively, were observed in karst yellow soil with biochar application. The N/P change in leaching solution showed a parabolic form. Under natural rainfall, 4 kg/m2 biochar application had the best effect on a reduction of TP, TN and AN loss in surface runoff. Rainstorm caused AN and TP large loss but rainstorm, heavy and moderate rains all easily caused NN large loss. 4 kg/m2 biochar application had the best effect on the growth of plant height and base diameter, leaf SPAD and N and P content in organs in the fertilized area but 6 kg/m2 in the unfertilized area. Biochar application effectively improved the fertility of karst yellow soil, reduced the loss of N and P with vertical leaching and surface runoff, and promoted the growth of oil peony. This study provides new knowledge for biochar application.

Extraction, isolation and bioactivity of oligostilbenes from oil peony seed shells

An efficient strategy for the extraction of total oligostilbenes extract (TOE) from oil peony seed shells was developed. The chemical constituents, the antimicrobial and antitumor activities of TOE were also measured. Based on the results, the optimum conditions were as follows: an ultrasonic extraction temperature of 64.0 °C, an ultrasonic extraction time of 25.0 min, a liquid-to-solid ratio of 25.0 mL/g, and an ethanol concentration of 66.0%. With these conditions, the extraction yield of TOE was 20.5%. Bioactivity assays showed that the TOE had varying degrees of antibacterial activity and strong antitumor activity in vitro. Twelve oligostilbenes were isolated from the TOE, and trans-gnetin H and suffruficosol B were the main compounds in the oil peony seed shells. These results suggested that the TOE from oil peony seed shells can be prepared as value-added products for their good antimicrobial and antitumor activities.

First report of Colletotrichum gloeosporioides causing anthracnose on oil peony (Paeonia ostii) in China

First report of <i>Colletotrichum gloeosporioides</i> causing anthracnose on oil peony (<i>Paeonia ostii</i>) in China

Design and test of 2ZLX-2 transplanting machine for oil peony

In order to improve the quality of oil peony transplanting, based on the characteristics of peony seedlings and the transplanting effect, the transplanting process was analyzed. A peony seedling transplanting machine was designed, which was mainly composed of a chain-clamp type planting mechanism (clamp, transmission chain, sprocket), slideway, profiling wheels, trencher, the power transmission system and rack. Through the movement analysis of the planting mechanism and its operation process, its structural parameters were optimized. The effective length of the clamp was determined as L1=235 mm, the adjustment range was 235-285 mm, and the height of the planting trajectory was H=340 mm. Based on the physical characteristics and mechanical characteristics of the peony seedlings, the parameters of the slideway and the putter were determined. The effective length of the slideway was determined as L2=420 cm, the width T2=105 mm, the distance between the slideways S=45 mm. The initial angle difference of the putter was θ=13°, and the putter rotation angle β=37°, putter height ratio e=2. Based on the above parameters and design requirements, the radius of the planting sprocket R1=42 mm, R2=80 mm. “Feng Dan” peony seedlings were used as transplantation test objects. The results showed that: when the planting frequency was 60-75 plants/min, the upright rate was 89.2%-92.8%, the leakage rate was 0-0.28%, the injury rate of seedlings was 0, and the qualified rate of planting depth was 91.7%-95.3%, the variation coefficient of plant spacing was 0.25%-0.54%. This machine can effectively improve the quality and efficiency of transplanting, meeting the requirements of mechanical design and production needs. Keywords: peony transplanting, planting mechanism, oil peony, peony seedlings, parameter design, test analysis DOI: 10.25165/j.ijabe.20201304.5695 Citation: Ji J T, Cheng Q, Jin X, Zhang Z H, Xie X L, Li M Y. Design and test of 2ZLX-2 transplanting machine for oil peony. Int J Agric & Biol Eng, 2020; 13(4): 61–69.

Fertility variation among Paeonia lactiflora genotypes and fatty acid composition of seed oil

Herbaceous peony (Paeonia lactiflora Pall.) is a prospective oilseed crop and is widely cultivated in temperate regions. In the present study, eleven fertility characteristics of sixteen peony genotypes were systematically investigated through two consecutive years of observation, and correlation analysis between the parameter seed yield per stem and other ten parameters was performed. Then the fatty acid composition in the seed oil was further determined with six peony cultivars selected from the investigation. The results showed that the examined sixteen genotypes exhibited a wide range of significant differences in fertility traits. A significant positive correlation was observed between seed yield and other seven parameters (P < 0.01). And the parameter follicle symmetry (r = 0.570**) was further established as an indicative parameter in the early selection of high-yield peony genotypes. Further determination revealed that the average oil content of peony seeds was 32.71 %. Total ten fatty acids (FAs) were detected in peony seed oil and the unsaturated fatty acids (UFAs) accounted for 94.38–95.09 %. Oleic acid (OA), linoleic acid (LA) and linolenic acid (ALA) were three principal UFAs. The contents of these UFAs varied with genotype, but were overall more balanced than those in other seed oil. ‘Hangshao’ and ‘Fenghuang Niepan’ were eventually recommended for oilseed usage due to their considerable seed yields (30.75 g and 25.63 g per stem, respectively) and high seed oil content (33.34 % and 32.56 %, respectively). These findings would provide helpful references for the selection of oleaginous peony cultivars and accelerate the development of oil peony industry.