Ray Florets Research Articles

Two noteworthy Calea (Asteraceae: Neurolaeneae) from contact areas of the Atlantic Forest and Cerrado of Brazil

Systematic studies in the Calea myrtifolia complex have revealed two noteworthy new taxa from the contact, relict and transitional areas of the Atlantic Forest and Cerrado domains in Brazil: Calea grandiflora and Calea × parviantha, both having been treated as C. myrtifolia, now considered endemic to Minas Gerais state, Brazil. Thus, we herein provide morphological descriptions, illustrations, geographical distribution maps and discuss their taxonomic affinities. Moreover, their potential distributions are predicted. Calea grandiflora is related to C. arachnoidea and is recognized by the basal acrodromous venation (vs. semicraspedodromous), outer phyllary series 12.2–20 × 4.2–10.6 mm long (vs. 9–12 × 3–5 mm), and ray floret corolla 16.9–31 mm long (vs. 10–12 mm). Calea × parviantha is a new nothospecies, supported by a unique set of character states partially shared with the parental species C. parvifolia and C. triantha. The new hybrid species has intermediate morphology, as demonstrated by a multivariate analysis. It differs from C. parvifolia by the hispid, hispidulous or glabrous stems (vs. puberulous or puberulent) and coriaceous leaves (vs. chartaceous leaves), and from C. triantha by the rounded leaf base, sometimes subcordate (vs. cordate) and pappus scales 1.1–2.7 mm long (vs. 0.8–1.3 mm). Furthermore, we provide a taxonomic key for Calea in the states of São Paulo and Paraná.

Biosynthesis of α-Bisabolol by Farnesyl Diphosphate Synthase and α-Bisabolol Synthase and Their Related Transcription Factors in Matricaria recutita L.

The essential oil of German chamomile (Matricaria recutita L.) is widely used in food, cosmetics, and the pharmaceutical industry. α-Bisabolol is the main active substance in German chamomile. Farnesyl diphosphate synthase (FPS) and α-bisabolol synthase (BBS) are key enzymes related to the α-bisabolol biosynthesis pathway. However, little is known about the α-bisabolol biosynthesis pathway in German chamomile, especially the transcription factors (TFs) related to the regulation of α-bisabolol synthesis. In this study, we identified MrFPS and MrBBS and investigated their functions by prokaryotic expression and expression in hairy root cells of German chamomile. The results suggest that MrFPS is the key enzyme in the production of sesquiterpenoids, and MrBBS catalyzes the reaction that produces α-bisabolol. Subcellular localization analysis showed that both MrFPS and MrBBS proteins were located in the cytosol. The expression levels of both MrFPS and MrBBS were highest in the extension period of ray florets. Furthermore, we cloned and analyzed the promoters of MrFPS and MrBBS. A large number of cis-acting elements related to light responsiveness, hormone response elements, and cis-regulatory elements that serve as putative binding sites for specific TFs in response to various biotic and abiotic stresses were identified. We identified and studied TFs related to MrFPS and MrBBS, including WRKY, AP2, and MYB. Our findings reveal the biosynthesis and regulation of α-bisabolol in German chamomile and provide novel insights for the production of α-bisabolol using synthetic biology methods.

Valorization of Bioactive Compounds from By-Products of Matricaria recutita White Ray Florets

In this research, we have reported the valorization possibilities of Matricaria recutita white ray florets using supercritical fluid extraction (SFE) with CO2. Experiments were conducted at temperatures of 35-55 °C and separation pressures of 5-9 MPa to evaluate their impact on the chemical composition and biological activity of the extracts. The total obtained extraction yields varied from 9.76 to 18.21 g 100 g-1 DW input. The greatest extraction yield obtained was at 9 MPa separation pressure and 55 °C in the separation tank. In all obtained extracts, the contents of total phenols, flavonoids, tannins, and sugars were determined. The influence of the supercritical CO2 extraction conditions on the extract antioxidant capacity was evaluated using the quenching activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH). The chemical composition of the extracts was identified using both gas and liquid chromatography-mass spectrometry methods, whereas analyses of major and minor elements as well as heavy metals by microwave plasma atomic emission spectrometer were provided. Moreover, extracts were compared with respect to their antimicrobial activity, as well as the cytotoxicity and phototoxicity of the extracts. The results revealed a considerable diversity in the phytochemical classes among all extracts investigated in the present study and showed that the Matricaria recutita white ray floret by-product possesses cytotoxic and proliferation-reducing activity in immortalized cell lines, as well as antimicrobial activity. To the best of our knowledge, this is the first paper presenting such comprehensive data on the chemical profile, antioxidant properties, and biological properties of SFE derived from Matricaria recutita white ray florets. For the first time, these effects have been studied in processing by-products, and the results generated in this study provide valuable preconditions for further studies in specific test systems to fully elucidate the mechanisms of action and potential applications, such as potential use in cosmetic formulations.

Assessment of Doable Technologies for enhancing the yield potentials in Sunflower (Helianthus annuus L.) under Rainfed Conditions

Cluster FLDs were organized by AICRP on sunflower scheme, Regional Agricultural Research Station, Nandyal during three consecutive years of 2018-19, 2019-20 and 2020-21 in an area of 50 ha at 66 locations. At every demonstration site improved management practices viz improved sunflower hybrid with high oil content (Prabhath), thinning at 10 days after sowing boron spray @0.2% at ray floret stage and need based plant protection measures were demonstrated against viz., farmer’s practice of sunflower cultivation. The sunflower yields under demonstration practice higher than farmer practice in all the three years. The percentage increase over farmers practice was lowest 13.3% during 2020-21 and highest 25.6 during 2018- 19 with an average increase of 20.7 per cent observed in demonstration practice. The average gross returns of three years were Rs. 92477/- per hectare in demo practice which is 19.7 per cent higher than the farmers practice (Rs. 72262/- per ha.). The net returns of Rs.65393/- per hectare was recorded under demonstration practice and it was 26.9 per cent higher than the farmer practice (Rs. 51528/- per ha.). The mean benefit cost ratio of three years of demonstration practice higher (1:3.2) than farmer practice (1:2.96).

Effect of Combined Application of Non–Nano and Nano Fertilizers on the Growth, Yield and Oil Content of Sunflower under Semi-arid Conditions

Field experiment was conducted at International Crops Research Institute for the Semi-Arid Tropics, Hyderabad during early summer season in 2021 and 2022 to study the “Effect of integrated use of Nano and Non–Nano fertilizers on the growth and yield of sunflower under semi-arid conditions”. The experiment was carried out using randomized block design with 3 replications and comprised of 12 treatments. The averages of all study indicators were compared according to L.S.D test at a probability level of 0.05. Results revealed that application of conventional fertilizers as per recommended dose (75:90:30 kg/ha) along with foliar application of nano (19:19:19) N P K at 0.2% at 30 DAS and 60 DAS + nano boron at 0.2 % at ray floret opening stage (T7) recorded highest plant height (195,197 and196 cm), number of leaves (27.43, 28.12 and 27.78), leaf area (7632, 7665 and 7649 cm2 plant-1), leaf area index (LAI) (4.24 4.25 and 4.25), and dry matter production (98.96, 97.64 and 98.30 g/plant) at 90 DAS in both the years and on mean basis. However, treatment T7 was statistically on par with the treatment T9 - Conventional fertilizers 50% as per recommended dose + nano (19:19:19) N P K at 0.2% as foliar spray at 30 DAS and 60 DAS and nano boron at ray floret opening stage. Seed yield (1961,1915 and 1938 kg/ha), stalk yield (4193, 3918 and 4055 kg/ha) were also significantly influenced during both the years respectively with the treatment (T7) was statistically on par with the treatment T9. Lowest seed yield (758, 710 and 734 kg/ ha) and stalk yield (1684, 1702 and 1693 kg/ ha) and oil content (40.73 %, 39.67% & 40.20) was recorded with the control in both the years and on mean basis.

GENETIC ASSESSMENT AND ESTIMATION OF COMBINING ABILITY FOR OIL AND YIELD RELATED TRAITS IN SUNFLOWER (HELIANTHUS ANNUUS L.)

Pakistan is inadequate in vegetable oil, and an enormous amount is spent on its import. This is due to the lack of local varieties of oilseed crops in the country. Sunflower (Helianthus annuus L.) is used as a supreme oilseed crop due to its higher oil content. Its hybrids are popular due to its cross-pollinated mode. The present study was conducted for the evaluation of crosses that were better in oil and yield-related traits. For this purpose, 8 parental genotypes were collected, including 5 female and 3 male parents. The subsequent Line × Tester breeding scheme crossed these parental genotypes. Fifteen crosses and eight parental lines were evaluated in Randomized Complete Block Design by using three repetitions. At maturity, data was collected for the following traits such as head diameter, time to bud formation, time to flower initiation, time to maturity, leaf area, plant height, no. of leaves per plant, no. of ray florets per head, 1000 achene weight, achene yield per plant, protein contents and oil contents. Crosses having better yield were selected. Among parents, lines 3-A, 11-A, and 23-A, while testers 79-R and 20-R were the best general combiners for head diameter, time to bud formation, time to flower initiation, time to maturity, leaf area, plant height, number of leaves/plants, 1000 achene weight, achene yield/plant and oil contents. SCA effects showed that cross combination of 12-A × 20-R, 11-A × 78-R, and 20-A × 79-R was best for time to bud formation, the number of leaves per plant, 1000 achene weight, plant height, time to flower initiation and oil contents, respectively. The information obtained from the hybrids can be used in further breeding programs.

Evaluating Sustainable and Environment Friendly Growing Media Composition for Pot Mum (Chrysanthemum morifolium Ramat.)

The use of different growing media offers a valuable alternative to the conventional use of soil for quality flower production due to their good water holding capacity, aeration and nutrient status. The experiment was conducted in a Completely Randomised Design with three replications in the years 2021–2022 to study the influence of different compositions of growing media [Soil, Sand, Vermicompost, Cocopeat, Vermiculite, Perlite and Leaf mould] in different ratios on the growth and development of pot mum (Chrysanthemum morifolium Ramat.).The growing media compositions of cocopeat, vermicompost and leaf moulds improve the water retention and aeration of media. The results revealed vegetative growth with maximum plant height at first bud appearance, plant height at harvesting stage, number of primary branches per plant, number of secondary branches per plant, number of leaves per plant, leaf biomass, average fresh weight of leaf, dry weight of root and flowering parameters with maximum flower longevity, flower diameter, number of flowers per plant, number of ray florets, average fresh weight of flower, flower yield per plant and vase life of flower in case of media composition of Cocopeat + Vermicompost + Leaf mould (2:1:1) among all the growing media compositions. The combination of cocopeat with vermicompost and leaf mould (2:1:1 v/v/v) was found best for lighter media weight, better plant morphological development and sustained quality flower production of pot mum.

Molecular and phenotypic characteristics of T1 transgenic yellow cosmos (Cosmos sulphureus) carrying neomycin phosphotransferase II gene

Abstract. Irsyadi MB, Sawitri WD, Purwantoro A. 2022. Molecular and phenotypic characteristics of T1 transgenic yellow cosmos (Cosmos sulphureus) carrying neomycin phosphotransferase II gene. Biodiversitas 23: 6097-6105. Yellow cosmos (Cosmos sulphureus) is a tropical ornamental flower that contains secondary metabolites useful fornatural pesticide application. Plant genetic transformation is one genetic engineering method used to increase secondary metabolite accumulation. However, published reports on this issue have yet to be made available. This is the first report of genetic transformation in transgenic yellow cosmos using neomycin phosphotransferase II (nptII) encoding gene. This study aimed to determine the efficiency transformation and phenotypic character of the T1 yellow cosmos transgenic nptII. This genetic transformation was carried out by the floral dip method mediated with Agrobacterium tumefaciens and characterized based on quantitative and qualitative observations, as well as a cluster analysis of transgenic plants. The T1 transgenic yellow cosmos was confirmed using PCR with a transformation efficiency of 73.33% based on the total plants resistant to Kanamycin and 10.57% based on the total seeds transformed. The presence of the nptII encoding gene was shown in transgenic plant samples with a size of 550 bp. In general, the introduction of the nptII gene generated no novel traits except the resistance to the kanamycin antibiotic. However, there was a decrease and increase in the number of stomata and the size of stomata in transgenic plants, respectively. In addition, there was a change in the type of ray floret to a mixture of ligulate and tubular, indicating that the nptII gene affected the phenotype of yellow cosmos. The result revealed that the nptII gene was inserted fairly randomly into the plant genome.

CmHY5 functions in apigenin biosynthesis by regulating flavone synthase II expression in chrysanthemum flowers

The predominant flavones in the ray florets of chrysanthemum flowers are apigenin and its derivatives. CmHY5 participates in apigenin biosynthesis by directly regulating the expression of FNSII-1 in chrysanthemum. Chrysanthemum (Chrysanthemum morifolium) flowers have been used for centuries as functional food and in herbal tea and traditional medicine. The chrysanthemum flower contains significant amounts of the biologically active compound flavones, which has medicinal properties. However, the mechanism regulating flavones biosynthesis in chrysanthemum flowers organs is still unclear. Here, we compared the transcriptomes and metabolomes of different floral organs between two cultivars with contrasting flavone levels in their flowers. We identified 186 flavonoids by metabolome analysis. The predominant flavones in the ray florets of chrysanthemum flowers are apigenin and its derivatives, of which the contents are highly correlated with the expression of flavones synthase II gene CmFNSII-1. We also determined that CmHY5 is a direct upstream regulator of CmFNSII-1 transcription. We showed that CmHY5 RNAi interference lines in chrysanthemum have lower contents of apigenin compared to wild-type chrysanthemum. Our results demonstrated that CmHY5 participates in flavone biosynthesis by directly regulating the expression of FNSII-1 in chrysanthemum.

Indução de mutagênese em crisântemo

Abstract Crop genetic diversity has a significant role in improving new plants through breeding. The chrysanthemum contains the most mutant varieties, making mutation breeding one of the most widely utilized breeding procedures for ornamental plants. The goal of this research is to use gamma irradiation to induce genetic variation and mutation breeding to improve chrysanthemum features. In vitro bud explants of the white ‘Bacardi’ type were treated with gamma rays at 20 Gy on this scope. The explants were subcultured until M1V4 growing period occurred, and observations were made during blooming on this time. Variable flower head widths, distinction on plant heights and widths, numerous flower numbers, color and size variations of ray florets were among the mutagenic changes observed in plants and flowers. Ray florets varied in length, width, number of rows, and color. The mutation frequency of the population was estimated 1.1% and yellow-colored florets were developed whereas the control group remained white. The dendrogram was grouped into five groups with 1, 28, 31, and 41 mutants in each based on the plant height and width, plant stem height and width, number of shoots and flowers per plant, flower head width, ray florets’ number- height- color, number of leaves, leaf length and width, and weight of flowering stems. The yellow-colored mutants were located in the first, second, and fourth groups. The advantageous mutations could result in improving new varieties. Gamma radiation is an effective mutagen for creating new chrysanthemum types when applied to in vitro bud explants.

Genetic analysis of anemone-type and single-type inflorescences in chrysanthemum using genotyping-by-sequencing

Flower shape is a key trait of ornamental and commercial importance in breeding programs for chrysanthemum (Chrysanthemum morifolium Ramat.). Understanding the genetic basis of the phenotypic variation seen in inflorescence-related traits will contribute to genetic improvement and to the development of new varieties. In this study, we investigated the genetic determinants of inflorescence traits using an F1 segregating population derived from a cross between two cultivars with different inflorescence types, ‘Puma White’ (anemone-shaped inflorescence) and ‘Dancer’ (single-type inflorescence). Genotyping-by-sequencing identified 26,847 single-nucleotide polymorphisms (SNPs) between 182 F1 progenies and their parents. A genome-wide association study highlighted 17 SNPs mapping to 15 GBS-tags as being significantly associated with three inflorescence traits: flower type, number of ray florets, and disk flower diameter. No single SNP was associated with flower diameter. These SNP-harboring sequences defined ten candidate genes associated with inflorescence traits. We explored the transcript levels for nine of these in flower buds, disk florets and ray florets using publicly available genome and transcriptome data. These results will provide the genetic and genomic foundation to harness important horticultural traits and explore new avenues in chrysanthemum breeding.

Whole-transcriptome profiles of Chrysanthemum seticuspe improve genome annotation and shed new light on mRNA–miRNA–lncRNA networks in ray florets and disc florets

BackgroundChrysanthemum seticuspe has emerged as a model plant species of cultivated chrysanthemums, especially for studies involving diploid and self-compatible pure lines (Gojo-0). Its genome was sequenced and assembled into chromosomes. However, the genome annotation of C. seticuspe still needs to be improved to elucidate the complex regulatory networks in this species.ResultsIn addition to the 74,259 mRNAs annotated in the C. seticuspe genome, we identified 18,265 novel mRNAs, 51,425 novel lncRNAs, 501 novel miRNAs and 22,065 novel siRNAs. Two C-class genes and YABBY family genes were highly expressed in disc florets, while B-class genes were highly expressed in ray florets. A WGCNA was performed to identify the hub lncRNAs and mRNAs in ray floret- and disc floret-specific modules, and CDM19, BBX22, HTH, HSP70 and several lncRNAs were identified. ceRNA and lncNAT networks related to flower development were also constructed, and we found a latent functional lncNAT–mRNA combination, LXLOC_026470 and MIF2.ConclusionsThe annotations of mRNAs, lncRNAs and small RNAs in the C. seticuspe genome have been improved. The expression profiles of flower development-related genes, ceRNA networks and lncNAT networks were identified, laying a foundation for elucidating the regulatory mechanisms underlying disc floret and ray floret formation.

A new species of Encelia (Compositae, Heliantheae, Enceliinae) from the southern Baja California Peninsula.

Here, we describe and illustrate Enceliabalandra sp. nov., a new species of Compositae from the Baja California Peninsula. It is rare and known only from the rocky hills around Puerto Balandra and Pichilingüe, inside the bay of La Paz, in the State of Baja California Sur, Mexico. We determine that this new species has affinities with Encelia, based on its suffruticose woody habit, neuter ray florets and compressed disc cypselae with a cleft apex. The taxonomic placement within Encelia is supported by nuclear ribosomal sequence data from two regions, ITS and ETS. We also present detailed photographs, a conservation assessment and a dichotomous key to the Encelia of the southern Baja California Peninsula. Finally, we discuss the uniqueness of Enceliabalandra amongst peninsular Encelia and its potential significance for understanding the enigmatic biogeography of this ecologically important genus.

Senecio namibensis (Asteraceae: Senecioneae), a new species from Namibia

Senecio namibensis is described as a new species known only from the northern part of the Namib Desert in northwestern Namibia. It is a range-restricted species near-endemic to the Kaokoveld Centre of Endemism. These dwarf shrubs grow on rocky outcrops under harsh desert conditions. Diagnostic characters for Senecio namibensis include the annual or perennial habit, succulent leaves, and radiate capitula with 3–6 yellow ray florets. A comparison of some of the more prominent morphological features to differentiate between S. namibensis and its possible nearest relatives, S. englerianus and S. flavus, is provided. All three species have superficially similar looking succulent leaves, but an obvious difference is that the capitula in S. englerianus are discoid and in S. flavus disciform or obscurely radiate. Based on IUCN Red List categories and criteria, a conservation assessment of Least Concern (LC) is recommended for the new species.

Morphological characters variation of Indonesian accession Echinacea purpurea in response to gamma-ray irradiation

Abstract. Cahyaningsih AP, Etikawati N, Yunus A. 2022. Morphological characters variation of Indonesian accession Echinacea purpurea in response to gamma-ray irradiation. Biodiversitas 23: 5351-5359. Indonesia was one of the countries that introduced E. purpurea as a medicinal plant. Accessions of E. purpurea that have been successfully cultivated in Indonesia have narrow genetic diversity, lack accession variation, and have almost uniform tillers. This study was conducted to determine the effect of different doses of gamma-ray irradiation on morphological characteristics of E. purpurea accession B2P2TOOT. The experimental design was a Randomized Block Design with three replications, and six doses of gamma-ray irradiation (0, 15 Gy, 20 Gy, 25 Gy, 40 Gy, and 60 Gy) were used. The qualitative morphological data were presented descriptively; quantitative data were analyzed using ANOVA followed by a DMRT test at a 5% level with SPSS 16.0 application. The Dice similarity algorithm analyzed the similarity index, group analysis, and dendrogram construction using the UPGMA method with the NTSYS 2.02 application. Gamma-ray irradiation treatment increased the survival rate of E. purpurea plants grown in tropical lowlands. A dose of 15-60 Gy gamma irradiation did not affect the qualitative morphology of E. purpurea roots, stems, and leaves. Irradiation at doses of 40 Gy and 60 Gy resulted in flowers with more variation in color, overall flower shape, and arrangement of ray floret. Gamma irradiation significantly affected plant height, leaf length, leaf area, flower angle, and the first day of flowering. The 40 and 60 Gy doses resulted in longer leaves with wider leaf surfaces. The dendrogram revealed that E. purpurea irradiation resulted in two main groups, with doses of 40 and 60 Gy forming their groups and increasing morphological variation by 30% compared to controls.

Transcriptome analysis reveals chrysanthemum flower discoloration under high-temperature stress.

Temperature is an important environmental factor affecting plant anthocyanin synthesis. High temperatures are associated with decreased anthocyanin pigmentation in chrysanthemum. To reveal the effects of high temperature on anthocyanin biosynthesis in chrysanthemum, ray florets of the heat-sensitive cultivar “Nannong Ziyunying” (ZYY) were subjected to RNA sequencing. A total of 18,286 unigenes were differentially expressed between the control and treatment groups. Functional annotation and enrichment analyses of these unigenes revealed that the heat shock response and flavonoid pathways were significantly enriched, suggesting that the expression of these genes in response to high temperature is associated with the fading of chrysanthemum flower color. In addition, genes related to anthocyanin synthesis and heat shock response were differentially expressed under high-temperature stress. Finally, to further investigate the molecular mechanism of discoloration under high-temperature stress and facilitate the use of marker-assisted breeding for developing novel heat-tolerant cultivars, these results were used to mine candidate genes by analyzing changes in their transcription levels in chrysanthemum.

Germplasm Innovation and Establishment of Comprehensive Evaluation System for Hedgerow Garden Chrysanthemum

Garden chrysanthemums are a group of chrysanthemums (Chrysanthemum morifolium) that are mostly used in garden landscape collocations. Because most garden chrysanthemum varieties have low plants and poor space effects, they have certain limitations in garden landscape applications. In this study, we selected seven garden chrysanthemum varieties with excellent characteristics for artificial hybridization and intercross parentage to obtain new varieties with good traits we need. The phenotypic characteristics of the F1 offspring in terms of plant height, crown width, crown height ratio, number of main branches, branching intensity, plant form, inflorescence diameter, number of flowers per plant, number of ray florets, flower color, and days from planting period to coloring period were analyzed and systematically evaluated. Subsequently, a comprehensive evaluation system was established using the analytic hierarchy process (AHP) and k-means clustering method. We built a comprehensive analysis model, calculated the weighting of each evaluation factor, and multiplied the weight value by the score of the evaluation index standard of each factor to obtain the comprehensive score of each plant. All F1 plants were divided into four grades: excellent grade accounting for 13%, good grade accounting for 28%, medium grade accounting for 36%, and poor grade accounting for 23%. Then, we analyzed the differences of some quantitative traits between Group E (hybrids in excellent grade) and Group O (hybrids in good, medium, and poor grades). There were significant differences in plant height, crown height ratio, and the number of main branches but no significant difference in crown width. Combining with comprehensive score showed that Group E performed well overall. Finally, we selected five hybrid offspring with the highest overall scores in Group E as excellent variety materials of garden chrysanthemum for hedgerow. They were CH22, YQ73, HY08, CQ80, and HY07, respectively. We also found that plant height, lodging resistance, crown height ratio, plant form, crown width, and the number of main branches could be the main indicators in the AHP, which can be effectively applied to the comprehensive evaluation and breeding of garden chrysanthemums for hedgerows.

Co-option of a carotenoid cleavage dioxygenase gene (CCD4a) into the floral symmetry gene regulatory network contributes to the polymorphic floral shape-color combinations in Chrysanthemum sensu lato.

Morphological novelties, including formation of trait combinations, may result from de novo gene origination and/or co-option of existing genes into other developmental contexts. A variety of shape-color combinations of capitular florets occur in Chrysanthemum and its allies. We hypothesized that co-option of a carotenoid cleavage dioxygenase gene into the floral symmetry gene network would generate a white zygomorphic ray floret. We tested this hypothesis in an evolutionary context using species in Chrysanthemum sensu lato, a monophyletic group with diverse floral shape-color combinations, based on morphological investigation, interspecific crossing, molecular interaction and transgenic experiments. Our results showed that white color was significantly associated with floret zygomorphy. Specific expression of the carotenoid cleavage dioxygenase gene CCD4a in marginal florets resulted in white color. Crossing experiments between Chrysanthemum lavandulifolium and Ajania pacifica indicated that expression of CCD4a is trans-regulated. The floral symmetry regulator CYC2g can activate expression of CCD4a with a dependence on TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING (TCP) binding element 8 on the CCD4a promoter. Based on all experimental findings, we propose that gene co-option of carotenoid degradation into floral symmetry regulation, and the subsequent dysfunction or loss of either CYC2g or CCD4a, may have led to evolution of capitular shape-color patterning in Chrysanthemum sensu lato.

Integrative Analysis of miRNAs and Their Targets Involved in Ray Floret Growth in Gerbera hybrida.

MicroRNAs (miRNAs) are involved in regulating many aspects of plant growth and development at the post-transcriptional level. Gerbera (Gerbera hybrida) is an important ornamental crop. However, the role of miRNAs in the growth and development of gerbera is still unclear. In this study, we used high-throughput sequencing to analyze the expression profiles of miRNAs in ray floret during inflorescence opening. A total of 164 miRNAs were obtained, comprising 24 conserved miRNAs and 140 novel miRNAs. Ten conserved and 15 novel miRNAs were differentially expressed during ray floret growth, and 607 differentially expressed target genes of these differentially expressed miRNAs were identified using psRNATarget. We performed a comprehensive analysis of the expression profiles of the miRNAs and their targets. The changes in expression of five miRNAs (ghy-miR156, ghy-miR164, ghy-miRn24, ghy-miRn75 and ghy-miRn133) were inversely correlated with the changes in expression of their eight target genes. The miRNA cleavage sites in candidate target gene mRNAs were determined using 5′-RLM-RACE. Several miRNA-mRNA pairs were predicted to regulate ray floret growth and anthocyanin biosynthesis. In conclusion, the results of small RNA sequencing provide valuable information to reveal the mechanisms of miRNA-mediated ray floret growth and anthocyanin accumulation in gerbera.

Intergeneric hybridization of marguerite (Argyranthemum frutescens (L.) Sch. Bip.) and Roman chamomile (Chamaemelum nobile (L.) All.) using ovule culture and confirmation of hybridity.

To introduce useful characteristics such as fragrance into Argyranthemum frutescens (L.) and to expand the variation, we conducted crosses using A. frutescens as the seed parent and Chamaemelum nobile (L.) All. as the pollen parent. All the tested cross combinations between the three strains of A. frutescens and one strain of C. nobile produced embryos, and healthy plants were obtained by ovule culture. The obtained plantlets had a white ray floret, and the leaf shape was intermediate to those of the parents. The individuals obtained from this cross were subjected to two methods to determine hybridity: flow cytometry analyses and cleaved amplified polymorphic sequence (CAPS) markers. For the CAPS marker, we selected the internal transcribed spacer (ITS) region, which is highly variable among the genera, as the region to be amplified. We selected restriction enzymes BmgT120 I and Afl II, which selectively cut common sequences in the genus Argyranthemum, based on the sequence analysis of one parent strain each of A. frutescens and C. nobile and alignment with known sequences of related species. Flow cytometry analyses and CAPS markers revealed that the individuals obtained from the cross between A. frutescens and C. nobile are intergeneric hybrids. In addition, these established methods were capable of quickly and reliably identifying hybrids between A. frutescens and C. nobile. This report shows for the first time that crossbreeding between A. frutescens (seed parent) and C. nobile (pollen parent) is possible, and further development of Argyranthemum breeding, such as the expansion of variation by intergeneric crosses, is expected.