Ray Florets Research Articles

Morphological and molecular characterization of some Chrysanthemum (Dendranthema grandiflora) cultivars

The diversity and genetic relationships among seven commercial chrysanthemum cultivars were analyzed using morphological and molecular markers. Vegetative growth, flowering, flower yield, and flower quality parameters were evaluated to assess genetic variability across the cultivars. Cultivars Crystal Red, Kodiack, and Crystal White exhibited superior vegetative growth, while Abrun, Crystal Red, and Kodiack displayed better flowering characteristics, particularly in terms of the number of inflorescences per plant and mass of colored flowering. Crystal White, Coca Bleach, and Crystal Red cultivars demonstrated the highest inflorescence stalk length, while cvs. Crystal Red, Crystal Yellow, Crystal Pink, and Kodiack Yellow recorded the maximum number of ray floret inflorescences. Other quality parameters such as inflorescence diameter and ray floret length were found to be optimal in Kodiack, Crystal White, Crystal Pink, Coca Bleach, and Crystal Yellow cultivars. Simple Sequence Repeat (SSR) markers were employed to distinguish and identify standard-type chrysanthemum cultivars, utilizing twelve SSR markers from the chrysanthemum SSR database. The results suggest that these SSR markers hold promise for identifying additional chrysanthemum cultivar types and assessing genetic relationships among them. Association studies combining morphological and molecular data offer a valuable approach to identifying informative markers for plant breeding purposes.

Pollen morphology and fruit anatomy of the enigmatic monotypic genus Dicranocarpus (Coreopsideae, Asteraceae)

Dicranocarpus is a monotypic genus endemic to the Chihuahuan Desert with atypical attributes among species of tribe Coreopsideae. Phylogenetic position of Dicranocarpus parviflorus has been controversial. A molecular phylogeny showed that the taxon was closely related to Dahlia; however, further analyses with a wider sampling of Dahlia, also including Hidalgoa, identified the genus in a more distant clade. The objective of this study is to gather anatomical attributes from the cypselae as well as palynological characters along with macromorphology to determine whether Dicranocarpus shares characters with these genera in Coreopsideae. Our results show that although the pollen of D. parviflorus does not possess attributes that distinguish it from the rest of the tribe Coreopsideae, they were useful to confirm its membership in the tribe. The cypselae anatomy identified that D. parviflorus has characters of taxonomic value that differentiate this species from the rest of the Coreopsideae. The three most significant novel characters in Dicranocarpus were in the outer mesocarp, consisting of tracheoidal-like cells forming irregular rows up to 250 μm in length, an aerenchyma in the middle mesocarp, and the lack of phytomelanin and calcium oxalate crystals. Furthermore, the results of the phytomelanin patterns in the studied taxa highlight the need for further anatomical studies of the cypselae to fully understand the evolution of phytomelanin deposition in the tribe Coreopsideae and even in the Heliantheae Alliance. Macromorphological, palynological and anatomical attributes of the cypsela in Dicranocarpus were not shared with Dahlia. Moreover, the sexual condition of the disc and ray florets shared with Hidalgoa has evolved independently in lineages of Asteraceae.

Effect of Pinching on Growth, Yield, and Quality of African Marigold (Tagetes erecta L.) cv. Pusa Narangi Gainda

Marigold is a very common and a hardy flower crop cultivated throughout the world. Pinching is an important intercultural practice commonly followed in cultivation of marigold however, this needs to be standardized for getting higher yields in commercial cultivation. Hence, the present investigation was conducted at Rajasthan Agricultural Research Institute, Durgapura, Jaipur, Division of Horticulture, during 2020-21 and 2021-22 to standardize the commercial pinching practice for getting higher productivity. Three levels of pinching (no pinching, single at 20 days and double at 20 and 40 days after transplanting) were used in the course of the research arranged using a factorial randomized block layout with three replications applied to African marigold variety Pusa Narangi Gainda. The results revealed that treatment P0 (No pinching) was discovered to be the finest in increment in height of plant, early flower bud initiation flower opening and treatment P2 (Double pinching) in boosting spread of plant, primary branches, length of leaf, leaf width, leaf area, plant fresh weight, plant dry weight, total biomass, root- shoot ratio, 50% flowering, flower diameter, stalk and ray floret length, fresh and dry flower weight, mass and number of flower per plant, flower yield additionally improved quality characteristics like chlorophyll and xanthophyll content in marigold. Hence, it might be concluded that application of double pinching can be helpful and recommended in improving yield as well as quality characteristics in commercial cultivation of marigold.

Marigold (Tagetes erecta) MADS-Box Genes: A Systematic Analysis and Their Implications for Floral Organ Development

Marigold (Tagetes erecta) has a capitulum with two floret types: sterile ray florets and fertile disc florets. This distinction makes marigold a valuable model for studying floral organ development in Asteraceae, where MADS-box transcription factors play crucial roles. Here, 65 MADS-box genes were identified in the marigold genome, distributed across all 12 chromosomes. These genes were classified into type I (13 genes) and type II (52 genes) according to phylogenetic relationships. The gene structure of type I was simpler than that of type II, with fewer conserved motifs. Type I was further divided into three subclasses, Mα (8 genes), Mβ (2 genes), and Mγ (3 genes), while type II was divided into two groups: MIKCC (50 genes) and MIKC* (2 genes), with MIKCC comprising 13 subfamilies. Many type II MADS-box genes had evolutionarily conserved functions in marigold. Expression analysis of type II genes across different organs revealed organ-specific patterns, identifying 34 genes related to flower organ development. Given the distinct characteristics of the two floret types, four genes were specifically expressed only in the petals of one floret type, while twenty genes were expressed in the stamens of disc florets. These genes might have been related to the formation of different floret types. Our research provided a comprehensive and systematic analysis of the marigold MADS-box genes and laid the foundation for further studies on the roles of MADS-box genes in floral organ development in Asteraceae.

Chrysanthemum lavandulifolium homolog ClCYCA2;1 modulates cell division in ray florets.

Morphology of ray florets in chrysanthemums is tightly associated with cell division and cell expansion, both of which require proper cell cycle progression. Here we identified a Chrysanthemum lavandulifolium homolog ClCYCA2;1, whose expression in ray florets is negatively correlated with petal width in C. lavandulifolium. Two TCP transcription factors in CYCLOIDEA2 (CYC2) family, ClCYC2a interacts with and stabilizes ClCYC2b and the latter can bind to the promoter of ClCYCA2;1 to activate its transcription. Overexpression of ClCYCA2;1 in C. lavandulifolium reduces the size of capitula and ray florets. Cytological analysis reveals that ClCYCA2;1 overexpression inhibits both cell division and cell expansion via repressing mitotic cell cycle in ray florets whose latitudinal development was more negatively influenced leading to increased ratios of petal length to width at later developmental stages. Yeast two hybrid library screening reveals multiple ClCYCA2;1 interacting proteins including ARP7, and silencing ClARP7 inhibits the development of ray florets. Co-immunoprecipitation assays confirm that ClCYCA2;1 can induce the degradation of ClARP7 to inhibit the development of ray florets. Taken together, our study constitutes a regulatory network containing ClCYC2b-ClCYCA2;1-ClARP7 in ray floret development via governing mitosis, which may facilitate breeding efforts targeted for novel ornamental traits of chrysanthemums.

HaMADS3, HaMADS7, and HaMADS8 are involved in petal prolongation and floret symmetry establishment in sunflower (Helianthus annuus L.).

The development of floral organs, crucial for the establishment of floral symmetry and morphology in higher plants, is regulated by MADS-box genes. In sunflower, the capitulum is comprised of ray and disc florets with various floral organs. In the sunflower long petal mutant (lpm), the abnormal disc (ray-like) floret possesses prolongated petals and degenerated stamens, resulting in a transformation from zygomorphic to actinomorphic symmetry. In this study, we investigated the effect of MADS-box genes on floral organs, particularly on petals, using WT and lpm plants as materials. Based on our RNA-seq data, 29 MADS-box candidate genes were identified, and their roles on floral organ development, especially in petals, were explored, by analyzing the expression levels in various tissues in WT and lpm plants through RNA-sequencing and qPCR. The results suggested that HaMADS3, HaMADS7, and HaMADS8 could regulate petal development in sunflower. High levels of HaMADS3 that relieved the inhibition of cell proliferation, together with low levels of HaMADS7 and HaMADS8, promoted petal prolongation and maintained the morphology of ray florets. In contrast, low levels of HaMADS3 and high levels of HaMADS7 and HaMADS8 repressed petal extension and maintained the morphology of disc florets. Their coordination may contribute to the differentiation of disc and ray florets in sunflower and maintain the balance between attracting pollinators and producing offspring. Meanwhile, Pearson correlation analysis between petal length and expression levels of MADS-box genes further indicated their involvement in petal prolongation. Additionally, the analysis of cis-acting elements indicated that these three MADS-box genes may regulate petal development and floral symmetry establishment by regulating the expression activity of HaCYC2c. Our findings can provide some new understanding of the molecular regulatory network of petal development and floral morphology formation, as well as the differentiation of disc and ray florets in sunflower.

Piecing together the taxonomic puzzle: Generic delimitation in the Stoebe clade of Cape daisies (Asteraceae: Gnaphalieae) and a synopsis of the species

The Stoebe clade is a Cape-centred lineage comprising ca. 70 species, currently in eight genera. Despite recent generic taxonomic changes, many generic characters are ambiguous, and generic circumscription is likely to remain unstable in the absence of a robust species-level phylogeny. Here, we present a hypothesis of species relationships in the clade, based on parsimony and Bayesian analyses of DNA sequence and morphological characters, in order to assess generic monophyly. The trees based on morphology alone and plastid sequences alone are poorly resolved, with few well-supported nodes, while those based on nuclear sequences alone are better resolved. There is no evidence of phylogenetic conflict, and concatenation of all three data sources produces a well-resolved tree with many highly-supported nodes. We show that none of the currently-accepted genera are monophyletic, with the exception of Muscosomorphe, which is supported as monospecific. Amphiglossa species are recovered in two separate clades, requiring the resurrection of the genus Pterothrix to house ten of the twelve species. All the characters used to circumscribe the remaining genera, such as the possession of ray florets, are shown to be homoplasious. As a result, these remaining genera (Dicerothamnus, Disparago, Elytropappus, Myrovernix, Seriphium, and Stoebe) are here synonymised with Stoebe. The main morphological synapomorphy for this enlarged concept of Stoebe is the aggregation of the tiny capitula into conflorescences with varying degrees of complexity and congestion. The proposed taxonomy for the Stoebe clade comprises just four genera: Amphiglossa, Muscosomorphe, Pterothrix, and Stoebe. We present the new combinations, keys and generic descriptions, as well as keys to the species.

Complex petal spot formation in the Beetle Daisy (Gorteria diffusa) relies on spot-specific accumulation of malonylated anthocyanin regulated by paralogous GdMYBSG6 transcription factors.

Gorteria diffusa has elaborate petal spots that attract pollinators through sexual deception, but how G. diffusa controls spot development is largely unknown. Here, we investigate how pigmentation is regulated during spot formation. We determined the anthocyanin composition of G. diffusa petals and combined gene expression analysis with protein interaction assays to characterise R2R3-MYBs that likely regulate pigment production in G. diffusa petal spots. We found that cyanidin 3-glucoside pigments G. diffusa ray floret petals. Unlike other petal regions, spots contain a high proportion of malonylated anthocyanin. We identified three subgroup 6 R2R3-MYB transcription factors (GdMYBSG6-1,2,3) that likely activate the production of spot pigmentation. These genes are upregulated in developing spots and induce ectopic anthocyanin production upon heterologous expression in tobacco. Interaction assays suggest that these transcription factors regulate genes encoding three anthocyanin synthesis enzymes. We demonstrate that the elaboration of complex spots in G. diffusa begins with the accumulation of malonylated pigments at the base of ray floret petals, positively regulated by three paralogous R2R3-MYB transcription factors. Our results indicate that the functional diversification of these GdMYBSG6s involved changes in the spatial control of their transcription, and modification of the duration of GdMYBSG6 gene expression contributes towards floral variation within the species.

Segregation analysis and floral phenotype of T2 transgenic yellow cosmos (Cosmos sulphureus Cav.) carrying neomycin phosphotransferase II gene in second generation

Abstract. Muchyiddin MGAA, Sawitri WD, Irsyadi MB, Swandari T, Purwantoro A. 2024. Segregation analysis and floral phenotype of T2 transgenic yellow cosmos (Cosmos sulphureus Cav.) carrying neomycin phosphotransferase II gene in second generation. Biodiversitas 25: 1711-1717. The seed of transgenic yellow cosmos (Cosmos sulphureus Cav.) lines harbouring neomycin phosphotranferase II (nptII) gene have been obtained from our previous studies. The nptII selectable marker gene is commonly used for developing a method to estimate the number of targeted gene integrated into the genome. In order to produce successful clones, it is important to ensure that transgenes are inherited sexually as the dominant trait in T2 progeny. This study aimed to obtain the segregation patterns of nptII gene in two populations derived from open- and self-pollinated and evaluated floral phenotypic of T2 transgenic yellow cosmos. The molecular analysis of transgenic yellow cosmos was conducted by PCR and the obtained data was analyzed using a Chi-Square test. The results showed that transgenes were inherited in 1:1 for transgenic and wild-type in both self- and open-pollinated populations. Therefore, it indicated that T2 transgenic plants were still unstable and evolved continuously to segregate independently in the over generation. Surprisingly, the morphological changes were detected in transgenic plants. The mixture of ligulate and tubular types in ray floret was found in some of the flower types in T2 yellow cosmos. In this case, nptII gene may diverge in apparently random genome insertion. This insertion would induce morphological changes in the ray floret type of flower since recombination estimates varied among transformation events.

Identification of two 6'-deoxychalcone 4'-glucosyltransferase genes in dahlia (Dahlia variabilis).

Two glycosyltransferase genes belonging to UGT88 family were identified to have 6'-deoxychalcone 4'-glucosyltransferase activity in dahlia. 6'-Deoxychalcones (isoliquiritigenin and butein) are important pigments for yellow and orange to red flower color. 6'-Deoxychalcones are glucosylated at the 4'-position in vivo, but the genes encoding 6'-deoxychalcone 4'-glucosyltransferase have not yet been identified. In our previous study, it was indicated that snapdragon (Antirrhinum majus) chalcone 4'-O-glucosyltransferase (Am4'CGT) has isoliquiritigenin 4'-glucosylation activity. Therefore, to identify genes encoding 6'-deoxychalcone 4'-glucosyltransferase in dahlia (Dahlia variabilis), genes expressed in ray florets that shared high homology with Am4'CGT were explored. As a result, c34671_g1_i1 and c35662_g1_i1 were selected as candidate genes for 6'-deoxychalcone 4'-glucosyltransferases in dahlia. We conducted transient co-overexpression of three genes (c34671_g1_i1 or c35662_g1_i1, dahlia aldo-keto reductase1 (DvAKR1) or soybean (Glycine max) chalcone reductase5 (GmCHR5), and chili pepper (Capsicum annuum) MYB transcription factor (CaMYBA)) in Nicotiana benthamiana by agroinfiltration. Transient overexpression of c34671_g1_i1, DvAKR1, and CaMYBA resulted in increase in the accumulation of isoliquiritigenin 4'-glucosides, isoliquiritigenin 4'-O-glucoside, and isoliquiritigenin 4'-O-[6-O-(malonyl)-glucoside]. However, transient overexpression of c35662_g1_i1, DvAKR1, and CaMYBA did not increase accumulation of isoliquiritigenin 4'-glucosides. Using GmCHR5 instead of DvAKR1 showed similar results suggesting that c34671_g1_i1 has isoliquiritigenin 4'-glucosyltransferase activity. In addition, we conducted co-overexpression of four genes (c34671_g1_i1, c35662_g1_i1 or Am4'CGT, DvAKR1 or GmCHR5, CaMYBA, and chalcone 3-hydroxylase from dahlia). Accumulation of butein 4'-O-glucoside and butein 4'-O-[6-O-(malonyl)-glucoside] was detected for c35662_g1_i1, suggesting that c35662_g1_i1 has butein 4'-glucosyltransferase activity. Recombinant enzyme analysis also supported butein 4'-glucosyltransferases activity of c35662_g1_i1. Therefore, our results suggested that both c34671_g1_i1 and c35662_g1_i1 are 6'-deoxychalcone 4'-glucosyltransferases but with different substrate preference.

Crassothonna moniliformis (Asteraceae, Senecioneae), a new species from the Albany Centre of floristic endemism, South Africa

Crassothonna moniliformis is described as a new species from the Eastern Cape province, South Africa. The species is a prostrate, succulent-leaved perennial herb distinguished from Crassothonna capensis in having slender, weak, trailing, distantly branched stems, with nodal adventitious roots developing precociously, forming diffuse patches to ±50 cm diam., with erect to ascending, usually red-purple, globose-obovoid to obovoid to subclavate leaves 10–25 mm long, and a more slender synflorescence bearing fewer capitula (1–4 per flowering shoot) with fewer ray florets (7–9) and functionally staminate peripheral disc florets. The species is geographically localised, with the known Extent of Occurrence and Area of Occupancy <10 km2, and is habitat-restricted, growing in shallow sandy sediments overlying exposed sandstone pavements among coastal thicket. The single known population is threatened by sand mining and informal housing encroachment. Based on the IUCN Red List categories and criteria, a conservation assessment of Vulnerable (VU – D2) is recommended.

A GASA Protein Family Gene, CmGEG, Inhibits Petal Growth in Chrysanthemum.

The diversity in the petal morphology of chrysanthemums makes this species an excellent model for investigating the regulation mechanisms of petal size. However, our understanding of the molecular regulation of petal growth in chrysanthemums remains limited. The GASA (gibberellic acid [GA]-stimulated Arabidopsis) protein plays a significant role in various aspects of plant growth and development. Previous studies have indicated that GEG (a gerbera homolog of the gibberellin-stimulated transcript 1 [GAST1] from tomato) is involved in regulating ray petal growth by inhibiting cell expansion in gerberas. In this study, we successfully cloned the GASA family gene from chrysanthemums, naming it CmGEG, which shares 81.4% homology with GEG. Our spatiotemporal expression analysis revealed that CmGEG is expressed in all tissues, with the highest expression levels observed in the ray florets, particularly during the later stages of development. Through transformation experiments, we demonstrated that CmGEG inhibits petal elongation in chrysanthemums. Further observations indicated that CmGEG restricts cell elongation in the top, middle, and basal regions of the petals. To investigate the relationship between CmGEG and GA in petal growth, we conducted a hormone treatment assay using detached chrysanthemum petals. Our results showed that GA promotes petal elongation while downregulating CmGEG expression. In conclusion, the constrained growth of chrysanthemum petals may be attributed to the inhibition of cell elongation by CmGEG, a process regulated by GA.

Evaluation of the growth, flower quality, yield and vase life of gerbera (Gerbera jamesonii L.) cultivars under open ventilated saw-tooth type polyhouse

Cultivation of crops under protected conditions can enhance the yield and quality of agricultural produce. Gerbera is one of the high-value cut flowers which can be commercially cultivated under greenhouse conditions in tropical and subtropical regions. The choice of commercially viable cultivars is essential for obtaining its marketability. Moreover, cultivars of gerbera should be highly productive. Considering the above facts, the present study was conducted in 2020-2022 in the Protected Cultivation Unit of the Centurion University of Technology and Management where 10 cultivars were chosen as treatments. They were Intense, White house, Stanza, Dune, Dana-ellen, Artist, Sunway, Silvester, Pre-intenzz and Ankur. The experiment was laid out in a randomized complete block design and replicated three times. The data collected on the growth parameters, quality, yield, and vase life revealed that among all the cultivars of gerbera, Dana-ellen showed its superiority over others in terms of plant height and number of leaves (49.3 cm and 31.0 at 120 days after sowing respectively), days to first flowering (84.3), flower stalk length (64.8 cm), flower stalk girth (67.2 cm), ray floret length (8.7 mm) and suckers per plant (3.4); however, it remained on par with Dune, Intense, and Silvester in expression of most of the crop parameters. Similarly, the same variety Dana-ellen registered the highest yields (27.3, 33.7 and 34.7 flowers per plant during first, second and third years of the study respectively) among all the cultivars. Moreover, the variety Dune recorded the maximum vase life of 8.4 days and 9.2 days with citric acid and sucrose solutions, respectively. The study concluded that the cultivation of Dana-ellen, Dune, Silvester, and Artist under open-ventilated saw-tooth polyhouse conditions can be commercially viable for achieving higher flower quality and yield.

Marigold Like Structure from Methionine Mediated Growth of Positively Charged Gold Nanorod

AbstractDuring morphological evolution of gold nanoparticles, amino acids play a vital role in tuning shape, introducing chirality and inducing facet selective reactivity. Herein, we report the synthesis of unique marigold like structure (MGS) via growth reaction of methionine (Met) incubated positively charged anisotropic gold nanorod (GNR). Varying three important parameters such as growth time, concentration of Met and Au3+ reveals the combination of freshly generated small nucleated particles (fNPs) and GNR towards fabricating the unique MGS containing disk and ray floret parts. Strong interaction between Met and (111) plane of Au0 controls the orientation of (111) plane parallel to the direction of growth. This preferential interaction directs the assembly of gold nanostructures through Au (200) plane and results in merging of fNPs with concave GNR (cGNR) to fabricate the external arrangement of ray floret structure. The structural selectivity is attributed to the electron donating capacity of thioether functional group of Met(S) to Au+, generated prior to secondary nucleation. As confirmed by XPS and ζ‐potential analysis, the above interaction controls the Met concentration dependent inhibition of further Au+→Au0 reduction. The growth strategy of GNR has been further validated with a Met enriched peptide to produce disk and ray florets.

Cla-miR164-NO APICAL MERISTEM (ClNAM) regulates the inflorescence architecture development of Chrysanthemum lavandulifolium.

Chrysanthemum × morifolium has great ornamental and economic value on account of its exquisite capitulum. However, previous studies have mainly focused on the corolla morphology of the capitulum. Such an approach cannot explain the variable inflorescence architecture of the chrysanthemum. Previous research from our group has shown that NO APICAL MERISTEM (ClNAM) is likely to function as a hub gene in capitulum architecture in the early development stage. In the present study, ClNAM was used to investigate the function of these boundary genes in the capitulum architecture of Chrysanthemum lavandulifolium, a closely related species of C. × morifolium in the genus. Modification of ClNAM in C. lavandulifolium resulted in an advanced initiation of the floral primordium at the capitulum. As a result, the receptacle morphology was altered and the number of florets decreased. The ray floret corolla was shortened, but the disc floret was elongated. The number of capitula increased significantly, arranged in more densely compounded corymbose synflorescences. The yeast and luciferase reporter system revealed that ClAP1, ClRCD2, and ClLBD18 target and activate ClNAM. Subsequently, ClNAM targets and activates ClCUC2a/c, which regulates the initiation of floral and inflorescence in C. lavandulifolium. ClNAM was also targeted and cleaved by cla-miR164 in this process. In conclusion, this study established a boundary gene regulatory network with cla-miR164-ClNAM as the hub. This network not only influences the architecture of capitulum, but also affects compound corymbose synflorescences of the C. lavandulifolium. These results provide new insights into the mechanisms regulating inflorescence architecture in chrysanthemum.

Senecio sisparensis (Asteraceae), a new species from southern Western Ghats, India

A new species of Senecio (Asteraceae), S. sisparensis, has been collected from Silent Valley National Park, Palakkad, Kerala, India. It is morphologically close to the species grouped in cluster 24 by Jeffrey et al., most closely similar to S. griffithii; however, it differs in its habit, leaves, capitula, bracts, ray florets and achene characters. Therefore, this new species is described with a detailed description, phenology and conservation status, along with a photographic plate to facilitate easy identification.

Assessing Amounts of Genetic Variability in Key Horticultural Traits Underlying Core Korean Breeding Lines of Cut Chrysanthemums.

The cut chrysanthemum holds one of the most substantial segments of the global floriculture market, particularly in Korea. We conducted a detailed assessment of the genetic structures across the cut chrysanthemum breeding lines in Korea. Using standard and spray chrysanthemum breeding lines from leading Korean research institutes, we first compared the variability of 12 horticultural traits, revealing a wide range of variation for most traits. We found that the overall flower diameter (OFD) and ray floret length (RFL) showed a solid positive relationship, regardless of the type. From a multivariate approach, OFD, RFL, and ray floret width (RFW) show consistently high association. Genotypic and phenotypic coefficients of variation analyses further indicated the significant genetic control over most traits. However, certain traits, like the volume of flowers (VF) in standard types, are more influenced by environments. Lastly, our analysis demonstrated substantial variability in broad-sense heritability (H); plant height (PH) consistently showed high H in both types. But the number of side branches (NOSB) and VF exhibited inconsistent H scores. These findings highlight the need for type-specific breeding strategies and modulating environmental management to optimize the trait expressions depending on the H scores, which offers significant implications for future breeding strategies.

Synopsis of Calea subgen. Teucriifoliae (Asteraceae: Neurolaeneae), a new subgenus endemic to the Cerrado

Calea comprises 159 species characterized by striate phyllaries, pistillate ray florets, yellow corolla, and pappus elements as scales. The “Calea teucriifolia complex” is an informal group of 15 species. Molecular phylogenetic inference recognized the polyphyly of this group, but also supports the recognition of a monophyletic subgenus when considering a more restrict set of species. Thus, the aim of this study is to morphologically circumscribe the group at subgeneric rank and provide an updated nomenclatural and taxonomic synopsis. As defined here, C. subgen. Teucriifoliae comprises eight species (C. ferruginea, C. hymenolepis, C. hypericifolia, C. microphylla, C. ramosissima, C. senecioides, C. teucriifolia and C. villosa). The new subgenus is endemic to the Cerrado tropical savanna and is characterized by cylindrical involucres, reddish phyllaries, and pappus scales shorter than 1 mm. Seven lectotypes are designated and data on type specimens is clarified including localities, dates of collection, and collector. In addition, we record new state level occurrences for four species and provide a key for species identification.

Ligularialushuiensis (Asteraceae, Senecioneae), a new species from northwestern Yunnan, China.

Ligularialushuiensis, a new species from northwestern Yunnan, China, is described and illustrated. It was tentatively placed in L.sect.Ligulariaser.Ligularia on the basis of the pinnate-palmate leaf venation, racemose synflorescence and pappus which is as long as tubular corolla. Within the series, it appeared somewhat close to both L.lamarum and L.pseudolamarum. However, L.lushuiensis can be easily distinguished from the latter two species by, among other characters, the leaf margin, bract size, involucre shape and size, and number and width of ray florets. Morphologically, L.lushuiensis is also superficially similar to L.secunda but differs readily by having distally shortly yellowish and brownish puberulent stems, palmately-pinnately veined leaves regularly dentate at margin, scarious, brown and larger bracts, and larger ray laminae. In addition, a distribution map and a diagnostic key to Chinese species of L.ser.Ligularia are also provided.

Integrated transcriptome and small RNA sequencing revealing miRNA-mediated regulatory network of bicolour pattern formation in Pericallis hybrida ray florets

Flower spots of plants are of evolutionary importance and ornamental value, but research on regulatory mechanisms is still limited. Cineraria (Pericallis hybrida) is an important ornamental plant with various bicolour cultivars. In this study, we performed transcriptome and small RNA sequencing to investigate the regulatory network of bicolour pattern formation in P. hybrida ray florets. Through transcriptome sequencing, we mainly focused on differentially expressed genes (DEGs) involved in flavonoid biosynthesis. Gene expression analysis showed that PhLAR (Unigene0092951), PhMYB8 (Unigene0068595) and PhbHLH137 (Unigene0091507) were up-regulated in the colourless region. Additionally, we identified 234 known miRNAs and 280 novel miRNAs by sRNA sequencing, and 49 differentially expressed miRNAs (DEmiRs) were screened. Integrated analysis of RNA-seq and sRNA-seq data revealed that miR172-AP2 and miR156-SPL modules were crucial in regulating bicolour pattern formation. When PhAP2 was transiently silenced in cineraria capitulum by virus-induced gene silencing (VIGS), the colourless region of ray florets increased and the coloured region changed from carmine to pink. Meanwhile, PhCHS2, PhDFR3 and PhANS were down-regulated, while PhLAR was up-regulated significantly. It was hypothesized that PhAP2 functions as an inhibitor of bicolour pattern appearance and could influence flavonoid biosynthesis. Overall, our study revealed a possible regulatory network of miRNA-mediated bicolour pattern appearance in P. hybrida, which could enrich the post-transcriptional regulatory mechanisms of flower spots formation in ornamental plants.