Flowers In China Research Articles

Effects of different drying methods on the quality of daylily powder

Daylily is an edible flower in China. Daylily powder is prepared from the flowered or damaged by-products during its processing, which accounts for 10% of the total amount. In order to optimize the drying methods, the powder properties, internal structure, nutrition, and color of daylily powder prepared by natural air drying (ND), hot air drying (HD), vacuum freeze-drying (FD), and spray drying (SD) were studied and compared. The results showed that different drying methods had no effects on the internal structure of daylily powder. The diameter, bulk density, water holding capacity, oil holding capacity, and resting angle of daylily powder treated by four drying methods were significantly different. The nutrient indexes and color of daylily powder were significantly changed after different drying methods. HD prepared daylily powder can keep higher total protein, total sugar, and vitamin C; ND and FD prepared daylily powder had higher amino acid content and better flavor retention, while SD prepared daylily powder had smaller particle size, larger specific surface area, lighter color, and strong water and oil retention, which is more favorable for its use as a food additive. Compared with the other three methods, SD has obvious advantages and can be used as the optimal drying technology of daylily powder. The development and utilization of the waste daylily resources could be improved by using the pulverizing technology. This paper provided theoretical and technical support for the full utilization of daylily resources. The purpose of the study was to grow the daylily industry chain, Putting discarded daylily to comprehensive use. Novelty impact statement Powder processing is currently the best way to make full use of the abandoned damaged and flowered daylily resources and improves the added value.SD has obvious advantages and can be used as the optimal drying technology of daylily powder.

First Report of Necrosis of Balloon Flower (Platycodon grandiflorus) Caused by Nigrospora sphaerica in China.

Balloon flower (Platycodon grandifloras (Jacq.) A.DC.) is a perennial dicotyledonous herb. It is one of the most commonly usedmost used medicinal plants in China with broad applications. It is also a functional food rich in polysaccharides, minerals, and fibres (Lee et al. 2014). Field surveys conducted in August and September of 2020 in major balloon flower-growing regions of Anhui province (115°25 'E, 33°08' N) in China revealed the occurrence of an unknown disease with characteristic necrosis symptoms. The disease occurred in 6 to 8% of the balloon flower leaves. Symptoms were characterized by leaf necrosis and plant withering. Infected leaves were cut into small pieces, surface-sterilized with 2% NaOCl for 2 min, rinsed in sterile distilled water for three times, and dried by blotting filter paper. Treated tissues were placed on potato dextrose agar (PDA) and incubated at room temperature (25 ± 2C) for 2 days. Colonies grew rapidly and reached 8 cm in diameter after 15 days at 25C. Pure cultures were obtained, and their colonies were initially white and eventually turned grey. Conidia were black, single-celled, smooth, spherical, 10 to 22 μm in diameter (n = 30), and borne singly on a hyaline vesicle at the tip of each conidiophore. Based on the characteristics of colony morphology, the fungus was identified as Nigrospora species. Pathogenicity test was conducted on healthy balloon flower plants grown under greenhouse conditions to complete Koch's postulates. The adaxial surface of each of five healthy leaves was pricked and inoculated with a disc grown with the 6-day-old mycelium of Nigrospora species. Five leaves inoculated with PDA-only discs served as the controls. Treated leaves were wrapped with parafilm and treated plants were covered with polyethylene bags for 24 to 48 h. After 10 days of inoculation, typical necrotic lesions and stem necrotic developed on the inoculated leaves while no symptoms developed on the control leaves. The same fungus was re-isolated from diseased leaves and its identity confirmed based on morphology and culture characteristics. To confirm the identification, total DNA was extracted and the internal transcribed spacer region (ITS), a partial sequence of the β-tubulin (TUB) gene, and the translation elongation factor 1-α (TEF1) gene were amplified and sequenced using the primers ITS1/ITS4 (5'-TCCGTAGGTGAACCTGCGG-3' and 5'-TCCTCCGCTTATTGATATGC-3') (White et al. 1990), Bt2a/Bt2b (5'-GGTAACCAAATCGGTGCTGCTTTC-3' and 5'-ACCCTCAGTGTAGTGACCCTTGGC3') (Glass and Donaldson 1995), and EF1-728F/EF1-986R (5'-CATCGAGAAGTTCGAGAAGG3' and 5'TACTTGAAGGAACCCTTACC-3') (Carbone and Kohn 1999), respectively. The sequences (GenBank acc. no. MW082789 for ITS, MW368916 for TUB, and MW368915 for TEF1) were aligned using Blastn in GenBank, revealing 100% identity (97% coverage) with Nigrospora sphaerica for ITS (MW081353), 100% identity (97% coverage) with N. sphaerica for TUB (MN719407), and 99% identity (98% coverage) with N. sphaerica for TEF1 (MN053315). Based on morphological, microscopic, and molecular characteristics, the associated fungal pathogen was identified as N. sphaerica. This is the first report of N. sphaerica causing necrosis disease on balloon flower in China. This study provides important information for the identification of the balloon flower fungal disease, which will help develop management strategies to reduce economic losses caused by the disease.

First Report of Cladosporium tenuissimum Causing Leaf Spots on Carnation in China.

Carnation (Dianthus caryophyllus L., Caryophyllaceae) is a popular and important market flower in China (Kayamori et al., 2012). Leaf spots of Cladosporium tenuissimum Cooke were first observed in early October 2016 on carnation grown on the academy of agricultural sciences as well as in parks in Xi'an city (108°54'18.6696"E, 34°15'12.9"N), with nearly 80% of leaves on individual plants infected. Carnation in five nearby parks were surveyed with 60 to 100% disease incidence. Initially, the symptoms appeared as small dark elliptical necrotic lesions surrounded by a dark brown halo. Some leaf spots in severe cases covered the entire leaf surface. Necrotic tissue was treated with lactophenol and used for microscopic examination. Sporulation was seen on the necrotic tissue. To identify the pathogen, eighteen leaf pieces (3-5 mm) with both infected and healthy portions were taken at the edge of lesions and surface-disinfected by placing them in 75% ethanol for 5 s, then transferred to a 0.1% aqueous mercuric chloride solution for 30 s and rinsed with sterilized water three times. Six sections were placed on each potato dextrose agar (PDA) at 25°C in the dark. Ten pure fungal cultures were obtained from single spores. Colonies on PDA were greyish to dark brown and showed a velvety texture. Subcylindrical to subclavate conidiophores were solitary or in loose groups, on leaves and stems erumpent through the cuticle or emerging through stomata, and measured 49-513 × 3-7 µm (n=50). Ramoconidia were subcylindrical, 15-31 × 4-5 µm, aseptate, basal hilum 2-3.5 µm diam. Morphological characteristics of the pathogen were similar to Cladosporium tenuissimum Cooke (Bensch 2010). For molecular identification, pure cultures of ten single-spore isolates were extracted from mycelium using the Plant Genomic DNA Kit (TIANGEN, China). Three different genomic DNA regions-ribosomal DNA internal transcribed spacer (ITS) region, partial translation elongation factor-1 alpha (EF), and actin (ACT) were amplified using the primers ITS1/ITS4 (White et al. 1990), ACT-512F/ACT-783R (Carbone and Kohn 1999), and EF1-728F/EF1-986R (Carbone and Kohn 1999), respectively. Phylogenetic analysis of multiple genes was conducted with the neighbor-joining method using MEGA 7 (Bakhshi et al. 2018). The sequences of our isolate (CTK) and seven published sequences of C. tenuissimum were clustered into one clade with a 100% bootstrap supporting level. The sequences of CTK have been deposited in GenBank with accessions MZ351731 for ITS, MZ351730 for ACT, MZ351732 for TEF1. Isolate pathogenicity was tested on surface disinfested leaves of two-month-old carnation plants by spraying a 2 × 106 conidial per ml at 25°C incubation temperature. Another set of plants was sprayed with sterile water as non-inoculated controls. Three replicates of every isolate were conducted, and each replicate included 5 carnation plants. After twelve days, only the inoculated leaves showed leaf blight resembling those observed on naturally infected carnation leaves. The pathogen was consistently reisolated from the infected leaves with the aim of completing Koch's postulates. To our knowledge, this is the first report of C. tenuissimum causing carnation leaf spots in China and worldwide. Thus, the identification of C. tenuissimum for this disease is important for the advancement of effective prevention and control approaches as future prospects.

Genetic resources of lotus (<i>Nelumbo</i>) and their improvement

Lotus (<i>Nelumbo</i>) is one of the top ten flowers in China, which has high ornamental, edible and medicinal value. Lotus has a been cultivated for thousands of years. Through discovery and cultivation, more than 4,000 cultivars have been recorded. However, the information related to lotus breeding is quite scattered, and the related genetic rules and trait formation mechanisms are still poorly understood, which has caused a greater impact on lotus genetic breeding. This article systematically introduces lotus germplasm resources, including wild species and cultivated species, summarizes lotus breeding methods and breeding directions, and focuses on the latest progress in the isolation and functional identification of structural and regulatory genes related to important horticultural traits. Prospects for the protection and utilization of lotus resources, breeding and industrialization are reported.

The R2R3-MYB gene PsMYB58 positively regulates anthocyanin biosynthesis in tree peony flowers

Tree peony (Paeonia suffruticosa Andr.) is a well-known ornamental flower in China with diverse colors. Flower color is one of the most important economic characteristics of tree peony and is mainly determined by anthocyanins. In this study, we cloned a PsMYB58 gene, which contained a 654 bp open reading frame (ORF), encoding a polypeptide of 218 amino acids. Sequence and phylogenetic analysis indicated that PsMYB58 is an anthocyanin regulatory R2R3-MYB gene. The transcription levels of PsMYB58 in different developmental stages of tree peony flowers were similar to those of the anthocyanin biosynthetic genes PsCHS, PsCHI, PsDFR, and PsANS. A bimolecular fluorescence complementation assay showed that PsMYB58 interacted with PsbHLH1 and PsbHLH3 in vivo. The overexpression of PsMYB58 in tobacco enhanced anthocyanin accumulation in various organs. Comparative transcriptome analysis showed that 943 genes were upregulated and 1203 downregulated in PsMYB58 transgenic tobacco, among which genes involved in the anthocyanin pathway were positively activated. Real-time quantitative PCR analysis verified that anthocyanin biosynthetic genes, including NtCHS, NtCHI, NtF3H, NtF3′H, NtDFR, and NtANS, and an anthocyanin regulatory bHLH gene, NtAN1b, were significantly upregulated in PsMYB58 transgenic tobacco. Our results indicated that PsMYB58 is a positive anthocyanin regulator in tree peony flowers. In summary, the functional identification of PsMYB58 furthers our understanding of the mechanism of peony flower color formation, thus providing a foundation for flower color improvement and molecular breeding.

Functional Annotation of a Full-Length Transcriptome and Identification of Genes Associated with Flower Development in Rhododendronsimsii (Ericaceae).

Rhododendronsimsii is one of the top ten famous flowers in China. Due to its historical value and high aesthetic, it is widely popular among Chinese people. Various colors are important breeding objectives in Rhododendron L. The understanding of the molecular mechanism of flower color formation can provide a theoretical basis for the improvement of flower color in Rhododendron L. To generate the R. simsii transcriptome, PacBio sequencing technology has been used. A total of 833,137 full-length non-chimeric reads were obtained and 726,846 high-quality full-length transcripts were found. Moreover, 40,556 total open reading frames were obtained; of which 36,018 were complete. In gene annotation analyses, 39,411, 18,565, 16,102 and 17,450 transcriptions were allocated to GO, Nr, KEGG and COG databases, correspondingly. To identify long non-coding RNAs (lncRNAs), we utilized four computational methods associated with Protein families (Pfam), Cooperative Data Classification (CPC), Coding Assessing Potential Tool (CPAT) and Coding Non Coding Index (CNCI) databases and observed 6170, 2265, 4084 and 1240 lncRNAs, respectively. Based on the results, most genes were enriched in the flavonoid biosynthetic pathway. The eight key genes on the anthocyanin biosynthetic pathway were further selected and analyzed by qRT-PCR. The F3′H and ANS showed an upward trend in the developmental stages of R. simsii. The highest expression of F3′5′H and FLS in the petal color formation of R. simsii was observed. This research provided a huge number of full-length transcripts, which will help to proceed genetic analyses of R. simsii. native, which is a semi-deciduous shrub.

CPTA treatment reveals potential transcription factors associated with carotenoid metabolism in flowers of Osmanthus fragrans

Osmanthus fragrans is one of the top ten traditional flowers in China. It is divided into three different groups according to its color. α-Carotene and β-carotene are the main determinants to distinguish the color differences between three groups. However, the dominant genes and transcription factors involved in carotenoid metabolism remain unclear. CPTA treatment (0.7 mmol · L−1) remarkably promoted lycopene, α-carotene and β-carotene contents in flowers. Transcriptome sequencing analysis revealed that CPTA treatment could trigger chain reactions in carotenoid metabolism pathway genes. Four up-regulated and 10 down-regulated transcription factors which have close association with carotenoid variation were significantly induced by CPTA treatment. The up-regulated TFs such as MYB43, MYB123, HSF, were further subjected to transcript expression determination in different cultivars with drastic colors. Among them, transcript expression of four up-regulated TFs coincided with the carotenoid accumulation in different cultivars. We selected up-regulated OfMYB43 to verify its function, which is related to stress tolerance and transcriptional regulation. Transient overexpression of OfMYB43 in O. fragrans flowers showed that it could remarkably promote the expression of PDS, ZISO, LCYE and CCD4, leading to increased accumulation of β-branch carotenoids. OfMYB43 was a potential positive regulator of carotenoid biosynthesis in O. fragrans flowers. This study provides insight into the molecular mechanism of carotenoid metabolism in O. fragrans.

Comparative Evaluation of Key Aroma-Active Compounds in Sweet Osmanthus (Osmanthus fragrans Lour.) with Different Enzymatic Treatments

Sweet osmanthus (Osmanthus fragrans Lour.) (OF) is one of the ten most famous flowers in China for its unique and delicate fragrance. A combined solid-phase microextraction and solvent-assisted flavor evaporation method was used to accurately capture the overall aromatic profile and characterize the predominant odorants of fresh osmanthus with the help of gas chromatography (GC)-olfactometry and comprehensive two-dimensional GC-quadrupole time-of-flight mass spectrometry (GC × GC-QTOF-MS). Twenty-six volatiles were identified for the first time in OF. A total of 23 potent odorants, dominated by monoterpene oxides and C6 aliphatic aldehydes, were identified. The efficacy of pectinase, β-glucosidase, and their combination on the aroma enhancement of OF was evaluated by quantitation of the target aroma components using GC-triple quadrupole-MS. The total concentration of key aroma components increased in all three enzyme treatment groups, and the increase was more significant in two β-glucosidase-treated groups. Changes in odor activity values and odor spectrum values of key odorants indicated that the pectinase-treated sample had more prominent floral, green, and potato-like scents. In contrast, the β-glucosidase-treated sample had more dominant floral, woody, almond-like, and fruity notes but less green odor, which was confirmed by sensory evaluation. β-Glucosidase and pectinase complement one another very well, and together, promote a remarkable aroma enhancement in OF.

Chemical Composition of Essential Oil from Flower of 'Shanzhizi' (Gardenia jasminoides Ellis) and Involvement of Serotonergic System in Its Anxiolytic Effect.

Gardenia jasminoides Ellis is a famous fragrant flower in China. Previous pharmacological research mainly focuses on its fruit. In this study, the essential oil of the flower of ‘Shanzhizi’, which was a major variety for traditional Chinese medicine use, was extracted by hydro distillation and analyzed by GC-MS. Mouse anxiety models included open field, elevated plus maze (EPM), and light and dark box (LDB), which were used to evaluate its anxiolytic effect via inhalation. The involvement of monoamine system was studied by pretreatment with neurotransmitter receptor antagonists WAY100635, flumazenil and sulpiride. The monoamine neurotransmitters contents in the prefrontal cortex (PFC) and hippocampus after aroma inhalation were also analyzed. The results showed that inhalation of G. jasminoides essential oil could significantly elevated the time and entries into open arms in EPM tests and the time explored in the light chamber in LDB tests with no sedative effect. WAY100635 and sulpiride, but not flumazenil, blocked its anxiolytic effect. Inhalation of G. jasminoides essential oil significantly down-regulated the 5-HIAA/5-HT in the PFC and reduced the 5-HIAA content in hippocampus compared to the control treatment. In conclusion, inhalation of gardenia essential oil showed an anxiolytic effect in mice. Monoamine, especially the serotonergic system, was involved in its anxiolytic effect.

Gene expression profiling of Rhododendron pulchrum leaves under drought stress

Droughts, due to global warming, have become a major abiotic stress for plants. Rhododendron pulchrum is among the top 10 most sought-after flowers in China; however, because of its sensitivity to water, it is often drought-stressed in landscaping practices. This has restricted its promotion in garden landscaping. Thus, we performed transcriptomic analyses of this species under moderate to severe dehydration and rehydration to investigate the dynamics of gene expression. A total of 310, 1452, and 2610 differentially expressed genes (DEGs) were identified under moderate drought stress vs control, moderate drought vs severe drought, and severe drought vs re-watering conditions, respectively. A total of 209 transcription factors (TFs) were shown to be dehydration-responsive. Trend analysis of all the DEGs yielded 26 profiles of dynamic expression patterns. Among them, 6 profiles could be further grouped into cluster 1 (1230 DEGs) and cluster 2 (1164 DEGs) representing drought-induced and drought-repressed conditions, respectively. Transcriptomic changes in the key GO/pathways in this plant were analyzed and have been discussed in relation to hormone signal transduction, metabolic processes, and protein protective activity during drought treatment. This study provides valuable dataset regarding R. pulchrum gene expression changes in response to drought and may facilitate identification of potential genes that could be used to improve drought tolerance via genetic engineering of non-model plant species.

Transcriptomic analysis of flower opening response to relatively low temperatures in Osmanthus fragrans

BackgroundSweet osmanthus (Osmanthus fragrans Lour.) is one of the top ten traditional ornamental flowers in China. The flowering time of once-flowering cultivars in O. fragrans is greatly affected by the relatively low temperature, but there are few reports on its molecular mechanism to date. A hypothesis had been raised that genes related with flower opening might be up-regulated in response to relatively low temperature in O. fragrans. Thus, our work was aimed to explore the underlying molecular mechanism of flower opening regulated by relatively low temperature in O. fragrans.ResultsThe cell size of adaxial and abaxial petal epidermal cells and ultrastructural morphology of petal cells at different developmental stages were observed. The cell size of adaxial and abaxial petal epidermal cells increased gradually with the process of flower opening. Then the transcriptomic sequencing was employed to analyze the differentially expressed genes (DEGs) under different number of days’ treatments with relatively low temperatures (19 °C) or 23 °C. Analysis of DEGs in Gene Ontology analysis showed that “metabolic process”, “cellular process”, “binding”, “catalytic activity”, “cell”, “cell part”, “membrane”, “membrane part”, “single-organism process”, and “organelle” were highly enriched. In KEGG analysis, “metabolic pathways”, “biosynthesis of secondary metabolites”, “plant-pathogen interaction”, “starch and sucrose metabolism”, and “plant hormone signal transduction” were the top five pathways containing the greatest number of DEGs. The DEGs involved in cell wall metabolism, phytohormone signal transduction pathways, and eight kinds of transcription factors were analyzed in depth.ConclusionsSeveral unigenes involved in cell wall metabolism, phytohormone signal transduction pathway, and transcription factors with highly variable expression levels between different temperature treatments may be involved in petal cell expansion during flower opening process in response to the relatively low temperature. These results could improve our understanding of the molecular mechanism of relatively-low-temperature-regulated flower opening of O. fragrans, provide practical information for the prediction and regulation of flowering time in O. fragrans, and ultimately pave the way for genetic modification in O. fragrans.

Transcriptome sequencing flower petals reveals insights into regulation of flavonoid biosynthesis in Osmanthus fragrans

Osmanthus fragrans Lour., one of the top 10 most popular flowers in China, is known for both its beauty and fragrance. It is rich in flavonoids, a class of secondary metabolites with significant neuroprotective, free-radical scavenging, and anti-oxidant activity. To understand the mechanisms regulating flavonoid biosynthesis, we conducted transcriptome sequencing O. fragrans flowers to analyze gene expressions during the full flowering stage. The RNA was isolated separately from petals of cvs. Yingui and Dangui, which were treated or not with jasmonic acid, salicylic acid, or abscisic acid. A total of 142 029 unigenes were denovo assembled, and 50 918 unigenes were annotated. The differentially expressed genes were identified, annotated, and classified. The results of transcriptome sequencing and real-time PCR revealed higher expressions of phenylalanine ammonia-lyase (PAL), PAL1, chalcone synthase (CHS), flavanone-3-hydroxylase (F3H), flavonol synthase (FLS), and lower expressions of dihydroflavonol-4-reductase (DFR), anthocyanidin synthase (ANS) in 'Yingui' than in 'Dangui'. Such an expression pattern facilitated the higher accumulation of flavonoids in 'Yingui'. Several genes of the flavonoid biosynthesis pathway were upregulated by jasmonic acid and salicylic acid in both the cultivars leading to flavonoid accumulation in their petals. In the v-myb avian myeloblastosis viral oncogene homolog 1(MYB1)-overexpressing petals, the expressions of PAL, PAL1, CHI, and FLS increased. The results suggest that MYB1 may participate in the flavonoid biosynthesis pathway and regulate the expression of some upstream genes in O. fragrans.

Mechanism of floral scent production in Osmanthus fragrans and the production and regulation of its key floral constituents, \u03b2-ionone and linalool

Sweet osmanthus (Osmanthus fragrans Lour.) is among the top ten most well-known flowers in China and is recognized as both an aromatic plant and ornamental flower. Here, manual sectioning, scanning electron microscopy, and transmission electron microscopy of sweet osmanthus petals revealed that large amounts of lipids are present inside the petal cells and on the cell surfaces. However, no secretory structures were observed. Instead, the petal cells protrude slightly outward, and the surfaces of the cells are adorned with highly regular brush-shaped hairs. The surfaces of the ‘Yingui’ petals possessed mostly curled and more numerous hairs, whereas the ‘Dangui’ petals possessed fewer brush-shaped and more sparsely arranged hairs. In addition, many granular substances were attached to the brush-shaped hairs, and the granules were denser on the hairs of the ‘Yingui’ petals compared to the hairs on the ‘Dangui’ petals. Furthermore, 35 aromatic components in the ‘Yingui’ petals and 30 aromatic components in the ‘Dangui’ petals were detected via GC-MS. The main aromatic component of the ‘Yingui’ petals was β-ionone, whereas that of the ‘Dangui’ petals was linalool and its oxides. Transcriptome sequencing and qRT-PCR indicated that the high β-ionone content in the ‘Yingui’ petals was due to the overexpression of CCD1 and CCD4 and that the high linalool content in the ‘Dangui’ petals was due to the overexpression of MECS, HDR, IDI1, and LIS1, which function upstream of the linalool synthetic pathway. In particular, the expression levels of CCD4 and LIS1 were upregulated by 5.5- and 5.1-fold in the ‘Yingui’ and ‘Dangui’ petals, respectively. One transcription factor (ERF61) was cloned and named, and the expression pattern of ERF61 in sweet osmanthus petals was found to be generally consistent with that of CCD4. Tobacco transformation experiments, yeast one-hybrid experiments, and electrophoretic mobility shift assays indicated that ERF61 binds to the CCD4 promoter and stimulates CCD4 expression, thereby regulating the synthesis of β-ionone in sweet osmanthus petals.

Complete chloroplast genome of ornamental orchids Eulophia flava

Eulophia flava (Lindl.) Hook.f. (Orchidaceae) is a high value ornamental plant especially for cutting flowers in China. In this paper, we reported and characterized the complete chloroplast genome sequence of E. flava by assembling from short reads generated by Illumina sequencing. Total chloroplast genome size was 148,903 bp, including inverted repeats (IRs) of 26,651 bp, separated by a large single copy (LSC) and a small single copy (SSC) of 84,465 and 13,132 bp, respectively. A total of 119 genes, including 36 tRNA, 8 rRNA, and 75 protein-coding genes, were identified. The GC content of E. flava is 36.8%. Phylogenetic analysis using the maximum-likelihood algorithm showed that E. flava is sister to a clade with one species in the genus Eulophia.

Development and Identification of Expressed Sequence Tag-based SSR Markers Associated with the Heterostyly Trait in Primula forbesii

Heterostylous Primula forbesii is an important ornamental flower in China because of its long-lasting flowers and winter bloom. This study aimed to develop markers of expressed sequence tag–simple sequence repeats (EST-SSRs) that are associated with heterostyly and that can be used for molecular-assisted selective breeding in P. forbesii. We investigated 114,474 unigenes and identified 25,095 SSRs in P. forbesii. Dinucleotide repeats (46.14%), mononucleotide repeats (44.65%), and trinucleotide repeats (8.27%) were the most abundant SSRs. Among the 25,095 SSRs, 10,645 SSR primer pairs were successfully designed, of which 130 primer pairs were randomly selected for further amplification validation using eight accessions of P. forbesii; 98 pairs produced clear and stable polymerase chain reaction (PCR) products, and 28 pairs showed polymorphism. Bulked segregant analysis (BSA) was conducted for the F1 population with respect to thrum style and pin style by scanning 28 polymorphic SSR primer combinations. One SSR marker, c64326, linked to the heterostyly trait at a genetic distance of ≈3.70 cM was identified. The marker c64326 was further validated in two populations with an accuracy of 97.92% and 90.63%. The novel and linked EST-SSR markers can be valuable resources for genetic diversity analysis, mapping, and marker-assisted breeding in P. forbesii.

A systematic investigation on free phenolic acids and flavonoids profiles of commonly consumed edible flowers in China

Edible flowers of ornamental plants are non-toxic flowers that have been used since ancient times for their nutritional and health benefits. These health benefits are attributed to their phytochemicals such as phenolic acids and flavonoids. These phytochemicals exert positive health effects on chronic diseases such as cancer, inflammation, and diabetes. This research paper is focused on the systematic investigation of free phenolic acids and flavonoids (including anthocyanins) present in 70 commonly consumed edible flowers collected from local parks and Qingping market of Guangzhou, China. The phenolic acids and flavonoids of flower samples were determined by high performance liquid chromatography-photodiode array detector. The phenolic acids, flavones, flavonols, flavanones, and anthocyanins of different flower samples exhibit a wide range of variation. Gallic acid (1177.8–27717.2 μg/g), protocatechuic acid (66.7–9641.2 μg/g), p-hydroxybenzoic acid (43.6–1792.7 μg/g), quercitrin and hesperidin (49.9–14576.6 μg/g), and quercetin and luteolin (8.8–480.0 μg/g) were the predominant phenolic compounds in edible flowers samples under investigation. Anthocyanins were detected only in 14 kinds of flower samples and most of these flowers were of red or purple colour.

Over-expression of chrysanthemum CmDREB6 enhanced tolerance of chrysanthemum to heat stress

BackgroundChrysanthemum is among the top ten traditional flowers in China, and one of the four major cut flowers in the world, but the growth of chrysanthemum is severely restricted by high temperatures which retard growth and cause defects in flowers. DREB (dehydration-responsive element-binding) transcription factors play important roles in the response to abiotic and biotic stresses. However, whether the DREB A-6 subgroup is involved in heat tolerance has not been reported conclusively.ResultIn the present study, CmDREB6 was cloned from chrysanthemum (Chrysanthemum morifolium) ‘Jinba’. CmDREB6, containing a typical AP2/ERF domain, was classed into the DREB A-6 subgroup and shared highest homology with Cichorium intybus L. CiDREB6 (73%). CmDREB6 was expressed at its highest levels in the leaf. The CmDREB6 protein localized to the nucleus. Based on the yeast one hybrid assay, CmDREB6 showed transcription activation activity in yeast, and the transcriptional activation domain was located in the 3 ‘end ranging from 230 to 289 amino acids residues. CmDREB6 overexpression enhanced the tolerance of chrysanthemum to heat. The survival rate of two transgenic lines was as high as 85%, 50%, respectively, in contrast to 3.8% of wild-type (WT). Over-expression of CmDREB6 promoted the expression of CmHsfA4, CmHSP90, and the active oxygen scavenging genes CmSOD and CmCAT.ConclusionIn this study, DREB A-6 subgroup gene CmDREB6 was cloned from chrysanthemum ‘Jinba’. Overexpression of CmDREB6 enhanced heat tolerance of chrysanthemum by regulating genes involved in the heat shock response and ROS homeogenesis.

Physiological and Molecular Changes during Lily Underground Stem Axillary Bulbils Formation

Lily is regarded as one kind of the most economically important cut flowers in China. In this paper, lily cultivar ‘Aladdin’ (Lilium longiflorum × Lilium asiatic) was chosen as experimental material for its distinct high propagation coefficient in nature and three main conclusions were achieved. Firstly, our observation results revealed that the noticeable propagation coefficient of ‘Aladdin’ depended on strong capacity to form many underground stem axillary bulbils positioned on underground node of plant after 70 days of cultivation and having 1 cm flower buds. Secondly, in terms of physiological changes, zeatin riboside (ZR) relative concentration, soluble sugar and starch content peak when and where such bulbils are forming. Finally, two KNOX family Lilium genes were sequenced completely and one BELL family gene was sequenced partly; besides, there might be an interaction between KNOX-2 and BELL protein to accomplish their functions in bulbils organogenesis according to qRT-PCR results. As far as we know, it is the first time to study the formation mechanism of lily underground stem axillary bulbils. We illustrated physiological and molecular profiles, as well as offered a new prospect to lily molecular breeding in the future.

An APETALA2 Homolog, RcAP2, Regulates the Number of Rose Petals Derived From Stamens and Response to Temperature Fluctuations.

Rosa chinensis, which is a famous traditional flower in China, is a major ornamental plant worldwide. Long-term cultivation and breeding have resulted in considerable changes in the number of rose petals, while most wild Rosaceae plants have only one whorl consisting of five petals. The petals of double flowers reportedly originate from stamens, but the underlying molecular mechanism has not been fully characterized. In this study, we observed that the number of petals of R. chinensis ‘Old Blush’ flowers increased and decreased in response to low- and high-temperature treatments, respectively, similar to previous reports. We characterized these variations in further detail and found that the number of stamens exhibited the opposite trend. We cloned an APETALA2 homolog, RcAP2. A detailed analysis of gene structure and promoter cis-acting elements as well as RcAP2 temporospatial expression patterns and responses to temperature changes suggested that RcAP2 expression may be related to the number of petals from stamen origin. The overexpression of RcAP2 in Arabidopsis thaliana transgenic plants may induce the transformation of stamens to petals, thereby increasing the number of petals. Moreover, silencing RcAP2 in ‘Old Blush’ plants decreased the number of petals. Our results may be useful for clarifying the temperature-responsive mechanism involved in petaloid stamen production, which may be relevant for the breeding of new rose varieties with enhanced flower traits.

Total phenolics and antioxidants profiles of commonly consumed edible flowers in China

ABSTRACTEdible flowers are referred to the non-toxic flowers that can be consumed by human beings for their additional nutritional or medical properties. These flowers are rich source of natural antioxidants, thus exert specific positive health effects on chronic diseases and act as a potential function food. This research paper is focused on the determination of total phenolic content (TPC), total flavonoids content (TFC), and antioxidant capacities of different kinds of edible flowers in China and compared systematically. Sixty-five flower samples were collected from parks in Guangzhou and also purchased from Qingping Market. TPC, TFC, and three anti-oxidative assays (DPPH free radical scavenging activity, ABTS radical scavenging activity, and Ferric reducing antioxidant capacity (FRAP) assay) were conducted. Different flowers presented diverse range of antioxidant capacities, phenolic contents, and flavonoid contents. A high correlation between TPC and antioxidant activity (as accessed using three different methods) was reported. However, a low relationship was observed between TFC value and antioxidant capacities. This study revealed that five Rosa species exhibited strong antioxidant capacities among other samples, and these can be used as potential functional foods to counterbalance the effect of reactive oxygen species (ROS) and oxidative stress.