White Flowers Research Articles

A newly recorded species \(\textit{Zingiber densissimum}\) (sect. \(\textit{Cryptanthium}\)) for the flora of Vietnam

During our floristic expedition in South Vietnam, a wild taxon Zingiber densissimum (sect. Cryptanthium) was recognized as a newly recorded species for the flora of Vietnam. The taxonomic treatment with a description is provided, along with photographs, distribution, ecology, a conservation assessment, and morphological comparison with its alliance species. It is similar to Zingiber orbiculatum and Zingiber mioga in having whitish flowers and bright yellow anthers but differs in many aspects of vegetative and reproductive characteristics. Moreover, a taxonomic key for all species of sect. Cryptanthium in Vietnam is included.

Study of carotenoids and chlorophylls content in Thymus L. essential oils genus species at the reproductive period

The genus Thymus (Thymus L., Lamiaceae L.) is polymorphic, containing various races and forms with minor morphological differences. Up to 200 species have been identified in the world, of which up to 50 are found in Ukraine.
 Widespread wild essential oil species of the genus Thymus L. in Ukraine are: creeping thyme, Crimean thyme, Dnieper thyme, Marshall's thyme, flea thyme, Pallas's thyme. Successfully cultivated: common thyme, Spanish white thin thyme, Spanish white flowering thyme, creeping thyme, lemon thyme.
 Thyme is known for its rich chemical composition. Carotenoids and chlorophylls contribute to the accumulation of essential oil, polyphenolic compounds, antioxidant, detoxification and radioprotective effects.
 For the standardization of raw materials of Thymus L. species, it is advisable to determine the accumulation of carotenoids and chlorophylls during the reproductive period.
 The purpose of the work is to identify and determine the quantitative content of carotenoids and chlorophylls during the reproductive period in the herb species of the genus Thymus L. of the flora of Ukraine.
 Raw materials were collected in steppe biocenoses and specialized farms of southeastern Ukraine during the reproductive period (May–September 2018–2023) according to generally accepted methods. They were dried at 35 ºС to a moisture content of no more than 10%. n-Hexane extracts (1:100) were used to identify substances and establish their quantitative content. The determination was made by thin-layer chromatography (TLC) followed by densitometry and spectrophotometry.
 By the methods of thin-layer chromatography and spectrophotometry in n-hexane extracts from grass species of the genus Thymus L. of flora of Ukraine 4 carotenoids and 2 chlorophylls were identified. Cultivated species had the highest content: Th. vulgaris L. and Th. x citriodorus (Pers.) Schreb. var. «Silver Queen».
 The accumulation of carotenoids and chlorophylls in the raw materials of the genus Thymus L. during the reproductive period was studied. The results indicate the expediency of standardization of the studied raw materials according to the accumulation of carotenoids and chlorophylls.

A Phylogenetic Analysis of Marcetia (Melastomataceae, Marcetieae) and Three New Sprawling Species from Bahia, Brazil

Abstract— Three new species of the Neotropical genus Marcetia are described and illustrated: Marcetia barbadensis, Marcetia minima, and Marcetia serratifolia. The three species are known from small isolated populations in mountains of the Chapada Diamantina, Bahia, Brazil. The recognition of Marcetia barbadensis and Marcetia serratifolia is confirmed with an updated molecular phylogeny of the tribe Marcetieae (based on ETS, ITS, accD-psaI, atpF-atpH, trnS-trnG, psbK-psbL, ndhF and rbcL), and by morphological and morphometric studies. In turn, the recognition of Marcetia minima, a new species known only from the type gathering collected about 30 yr ago, is based on analyses of leaf and anther connective shape, as well as linear measurements of vegetative and reproductive structures. Based on the new phylogenetic hypothesis for Marcetieae, we reconstructed the evolution of habit and petal color in the tribe, and showed that prostrate plants and white flowers evolved repeatedly from ancestors with an erect habit and pink to magenta petals. We also provide notes on the intergeneric relationships and phylogeny of Marcetia and evaluate the generic placement of the recently described Acisanthera saxatilis.

Integrated metabolome and transcriptome analyses of anthocyanin biosynthesis reveal key candidate genes involved in colour variation of Scutellaria baicalensis flowers

BackgroundBright flower colour assists plants attract insects to complete pollination and provides distinct ornamental values. In some medicinal plants, diverse flower colour variations usually imply differences in active ingredients. Compared to the common bluish purple of Scutellaria baicalensis flower (SB), the natural variants present rose red (SR) and white (SW) flowers were screened out under the same growing conditions in the genuine producing area Shandong Province, China. However, the mechanism of flower colour variation in S. baicalensis was remain unclear. In the present study, we conducted integrated transcriptome and metabolome analyses to uncover the metabolic difference and regulation mechanism in three S. baicalensis flowers.ResultsThe results showed that 9 anthocyanins were identified. Among which, 4 delphinidin-based anthocyanins were only detected in SB, 4 cyanidin-based anthocyanins (without cyanidin-3-O-glucoside) mainly accumulated in SR, and no anthocyanin but high level of flavanone, naringenin, was detected in SW. The gene expression profile indicated that the key structural genes in the flavonoid and anthocyanin biosynthesis pathway differentially expressed in flowers with different colours. Compared to SB, the down-regulated expression of F3’5’H, ANS, and 3GT gene in SR might influence the anthocyanin composition. Especially the InDel site with deletion of 7 nucleotides (AATAGAG) in F3’5’H in SR might be the determinant for lack of delphinidin-based anthocyanins in rose red flowers. In SW, the lower expression levels of DFR and two F3H genes might reduce the anthocyanin accumulation. Notably the SNP site of G > A mutation in the splicing site of DFR in SW might block anthocyanin biosynthesis from flavanones and thus cause white flowers. In addition, several key transcription factors, including MYB, bHLH, and NAC, which highly correlated with structural gene expression and anthocyanin contents were also identified.ConclusionsThese results provide clues to uncover the molecular regulatory mechanism of flower colour variation in S. baicalensis and promote novel insights into understanding the anthocyanin biosynthesis and regulation.

Moraea saxatilis (Iridaceae: Iridoideae), a new montane species from the Groot Winterhoek Wilderness Area of the Cape Floristic Region, South Africa

The new species Moraea saxatilis Goldblatt & J.C.Manning (Iridaceae: Iridoideae) is a narrow endemic of the Kliphuisvlakte above Porterville in Western Cape, South Africa. First recorded in September 2019, M. saxatilis is restricted to shallow, seasonally waterlogged soils on sandstone sheets. This diminutive species has unusual terete leaves with a median dorsal translucent line, and distinctive pale lilac flowers irregularly speckled or streaked with dark blue towards the centre, with the filaments ±free or connate only in the basal third. The acaulescent habit and ±campanulate flowers with subequal tepals connate below in a solid perianth tube and reduced style crests place the species in subg. Galaxia (Thunb.) Goldblatt & J.C.Manning. Within the subgenus, the fringed style branches of M. saxatilis place it in ser. Galaxia, which currently includes nine species, all with white or yellow flowers. Among these, only M. luteoalba has ±free filaments but it differs considerably from M. saxatilis in having plane, ovate to elliptic leaves and larger yellow flowers sometimes creamy white distally.

Medicinal potential and health benefits of torch ginger (Etlingera elatior)

Indo-Pacific Region has a rich diversity of medicinal and aromatic plants. Torch ginger (Etlingera elatior) from the Zingiberaceae family in exemplary, is one of the valuable sources for condiment, ornamental and medicinal purposes. This perennial herb can be found growing in clumps of aromatic rhizomes with their distinctive inflorescences, borne on erect stalks and showy bracts. Their torch-like flowers are edible, usually appeared during the second year of cultivation and continuous harvesting is feasible for the flower production. The varieties of torch ginger with pink-color flowers are often cultivated compared to white and red flower varieties due to the market demand. Interestingly, almost every part of this herb produces certain percentages of beneficial phytochemicals. In this review, the botanical aspects of torch ginger as well as their progresses in usage and properties in different forms as fresh, extract and essential oils have been conversing with respect to their plant parts. Major compounds found in torch ginger are phenols, polyphenols, flavonoids and terpenoids. Those compounds correlate with the significant health benefits of torch ginger such as antioxidant, antimicrobial, antitumor, antihyperuricemic, antiallergic, cytotoxicity, antidiabetic as well as their cosmeceutical potential in skin care application. Moreover, the prominent pharmacological activities of this herb with particular attention to the chemical composition also have been uncovered, suggesting the substantial medicinal benefits of torch ginger.

A Promising Coriander (Coriandrum sativum L.) Genotype WFPS 48-1 for High Yield and Quality for South Eastern Rajasthan, India

Coriander (Coriandrum sativum L.), a major seed spice crop of India and Rajasthan is valued for seed and leaf, used for flavouring and seasoning of food and food products. A promising coriander (Coriandrum sativum L.) genotype WFPS 48-1 has been identified for high yield and essential oil, on the basis of multilocation testing across the coriander growing states and specifically for Zone V of Rajasthan state. It bears white flowers and recorded average yield of 1933 kg/ha with around 11, 19 and 25 percent superiority over the zonal, state and national checks viz., RKD 18, RCr 436 and Hisar Anand, respectively. Its seeds contain higher essential oil content of >0.55% showing an advantage of 6 and 18 percent, respectively over the national checks RCr 728 and Hisar Anand. The genotype WFPS 48-1 could be further used in crop improvement programmes to provide a suitable replacement of the existing varieties to increase coriander production and productivity.

Effect of Spraying with Different Concentrations of Organic Fertilizer Nutrigreen and Salicylic Acid on the Vegetative Growth of Two Cultivars of Gladiolus hybrid L.

The experiment was carried out inside the wooden canopy of the Department of Horticulture and Landscaping / College of Agriculture and Forestry / University of Mosul during the period from 17 March to 10 October 2022 in order to evaluate the response of two varieties of Gladiolus X hortulanus L. They are: White Prosperity with white flowers and Plumtart with flowers Purple for treatment with Nutrigreen organic fertilizer in three concentrations: zero, 1000- and 2000-ml. L-1, as well as treatment with salicylic acid in three concentrations, 500 and 1000 mg. L-1 sprayed on the shoots three times. In the implementation of the experiment, the factorial experiment with a randomized complete block design (RCBD) was used in split plots (Factorial Experiment with in split plot) with three replications and 7 treatment plants. The results indicated that the white cultivar recorded the largest plant height 136.596 cm, while the purple cultivar plants recorded the largest values for the leaf length per plant 86.312 cm and the number of leaves per plant 8.206 leaves. Plant-1, the leaf area of the plant was 484.472 (cm2), and the dry weight of the leaves was 16.559 (g).

Effect of edible dyes on value addition and post-harvest life of tuberose spikes

Tuberose is one of the most imperative bulbous crops with white fragrant florets, used for loose as well as cut flowers. All the commercial varieties have white colour flower only which is limiting factor in its popularity and marketing. By using edible dyes this issue may be solved for getting higher price in market as well as consumers satisfaction. An investigation was carried out to study the effect of food dyes on value addition and post harvest life of cut spikes of tuberose cv. Local Double in completely randomized design with factorial concept consisting thirty-six treatment combinations and one absolute control. Different treatments of food dyes and immersion time considerably induced colour in tuberose spikes without affecting postharvest life. The results revealed that 4% lemon yellow food dye with one hour immersion of tuberose cut spikes was found best in improving vase life (6.02 days), floret diameter (3.29 cm), opening of florets (49.66%) and visual appearance with minimum physiological loss in weight (16.91 % and 34.04 % at second and fourth day, respectively). Tinted tuberose cut spikes aids higher net return than white flowers, which will benefit farmers in fetching good prices.

Micropropagation of Lisianthus [Eustoma grandiflorum (Raf.) Shinn.] Leaf Explants and Single Nodes in Response to Plant Growth Regulators

Lisianthus has long-lasting, white, blue-purple, velvet or pink flowers. Varieties that can be used in pots, outdoors, or cut flowers are widely used and it is essential to develop new varieties to increase their commercial value. Breeding studies with classical methods can take a long time in lisianthus. Techniques to create variation in these plants and facilitate their reproduction always contribute to shortening the breeding period and one of the best known of these methods is plant tissue culture. This study aimed to investigate the micropropagation possibilities in lisianthus and examine the effects of auxin and cytokinin applications and doses on shoot reproduction. Supplemented with 10 different plant growth regulators in Murashige and Skoog (MS) medium, leaf explants from lisianthus plants that were germinated under in vitro conditions (seedlings) were cultivated. 6-benzyl aminopurine (BAP) was utilized in 5 doses (0.5, 1.0, 2.0, 3.0, and 4.0 mg L-1) alone in the first 5 groups. Naphthalene acetic acid (NAA) was also added to the BAP mediums at a concentration of 0.5 mg L-1. Shoot formation, shoot lengths, the number of shoots longer and shorter than 1 cm, and regeneration of new shoots after subcultures were determined. According to the results, MS mediums containing 3.0 and 4.0 mg L-1 BAP could be good starting mediums for regenerating new lisianthus shoots from leaf explants. These treatments got the highest values both in shoot formation and the number of shoots longer than 1 cm. It has been determined that 3.0 mg L-1 BAP alone can be used for both organogenesis from leaf explants and shoot proliferation in single node culture. In vitro shoots of the lisianthus species were easily rooted and both PGR-free MS or ½ MS mediums. Lisianthus shoots propagated under in vitro conditions can be rooted under ex vitro conditions both in the float hydroculture and in the soil mixture. The acclimatization stage was optimized also successfully.

Transcriptome analysis of Lantana camara flower petals reveals candidate anthocyanin biosynthesis genes mediating red flower color development.

Flower color plays a crucial role in the appeal and selection of ornamental plants, directly influencing breeding strategies and the broader horticulture industry. Lantana camara, a widely favored flowering shrub, presents a rich palette of flower colors. Yet, the intricate molecular mechanisms governing this color variation in the species have remained largely unidentified. With the aim of filling this gap, this study embarked on a comprehensive de novo transcriptome assembly and differential gene expression analysis across 3 distinct lantana accessions, each showcasing a unique flower color. By harnessing the capabilities of both PacBio and Illumina sequencing platforms, a robust transcriptome assembly, encompassing 123,492 gene clusters and boasting 94.2% BUSCO completeness, was developed. The differential expression analysis unveiled 72,862 unique gene clusters that exhibited varied expression across different flower stages. A pronounced upregulation of 8 candidate core anthocyanin biosynthesis genes in the red-flowered accession was uncovered. This was further complemented by an upregulation of candidate MYB75 (PAP1) and bHLH42 (TT8) transcription factors. A candidate carotenoid cleavage dioxygenase (CCD4a) gene cluster also manifested a marked upregulation in white flowers. The study unveils the molecular groundwork of lantana's flower color variation, offering insights for future research and potential applications in breeding ornamental plants with desired color traits.

Tirpitzia meiguensis (Linaceae), a new species from southwest Sichuan (China)

Tirpitzia meiguensis, a new species from Meigu County, Sichuan Province, China, is herein described and illustrated. Although its herb-like semi-shrub habit, toothed leaf margins, and seeds without a membranous wing are not characteristics that are seen in the three formerly-reported Tirpitzia species, other characteristics are morphologically related to T. sinensis; these include white flowers, terminal cymes, a four-loculed ovary with two ovules per locule, and a four-valvate capsule. Furthermore, phylogenetical analysis based on the internal transcribed spacer sequences of nuclear genes confirmed that this new species is clearly a member of Tirpitzia.

Genetic analysis and characterisation of Cmowf, a gene controlling the white petal colour phenotype in pumpkin (Cucurbita moschata D)

AbstractFlower colour, as an important morphological marker, plays an essential role in improving the identification efficiency of the purity seed in hybrid production. However, the molecular mechanism of white‐flower trait has not been reported in pumpkin (Cucurbita moschata D.). In this study, we obtained a white‐flower mutant (wf) through the ethyl methane sulfonate (EMS) mutagenesis of inbred line N87 (yellow flower). F2 populations were then constructed by crossing wf mutant and N87 plant to fine map the genes controlling white‐flower trait in pumpkin. Phenotypic identification revealed that carotenoid content significantly decreased in the petals of wf mutants compared with N87 plants. Genetic analysis indicated that the white flower mutant trait was controlled by a single recessive gene, Cmowf. Using bulked segregant analysis and KASP phenotyping, Cmowf was mapped to a 762 kb region on chromosome 14 containing three annotated genes. Among them, a nonsynonymous single‐nucleotide polymorphisms mutation was identified only in CmoCh14G005820 gene, which encoded a DUF1997 family protein. Compared with CmoDUF1997 amino acid sequences between the wf mutants and N87 plants, the critical amino acid mutations (early termination of amino acids) occurred in wf mutants, so CmoCh14G005820 was predicted as a potential candidate for controlling the white‐flower trait. RNA‐sequencing analysis revealed that the expression of CmoCh14G005820 and most genes involved in carotenoid biosynthesis was significantly downregulated in wf mutants, whereas the expression of several genes responsible for carotenoid degradation was upregulated in wf mutants. This finding suggested that carotenoid metabolism may participate in the formation of flower colour in pumpkin. Overall, our results provided a theoretical basis for understanding the genetic mechanisms underlying white‐flower formation in pumpkin.

Micromorphological and phytochemical profiling of Delphinium suave Huth. from Hindukush range, Lower Dir Khyber Pakhtunkhwa Pakistan.

This is a very first attempt to study various parameters of a medicinal plant, Delphinium suave Huth. The plant is erect, geophytic, herbaceous, with tuberous root, trifid in a palmatipartite, strigose cuneate leaf and white spurred zygomorphic flower. The root was isodiametric phellem with single non-glandular trichomes. The stem revealed single-layered cuticle, multiseriate epidermis, cortex, pith ray and uniserate bowed non-glandular trichomes. The leaf was amphistomatic, showed tapering trichomes, prismatic crystals and ranunculaceous stomata with circumference 144.66-182.67 μm. Pollen grains in Light Microscopy (LM), were prolate, spheroidal trizonocolpate, isopolar, radiosymmetric, scabrate, elliptic and monads. Scanning Electron Microscope (SEM) pollen surface was scabrate, monad, size varied from 18.06 to 16.67 μm, colpus to inaperturate, tricolpate, ornamented, echinus, isopolar, isodiametric and circular. SEM roots showed sclerenchymatic tissues, stellate, glandular, non-glandular trichomes and crystals. The stem showed scalariform, pitted vessels, warty protuberances, unicellular, silicified, non-glandular trichomes. Leaves powder revealed, simple, unicellular, tapered headed, uniseriate, sessile, capitate, unbranched glandular, non-glandular, trichomes with crystals. Capitate, stellate, circular, unicellular, branchy trichomes were observed for the first time through SEM. Powder drug study of root, stem leaves through LM revealed different tissues. Preliminary phytochemical revealed alkaloids, anthocyanins, anthraquinones, coumarins, flavones, mucilages, saponins, steroids, terpenoids, volatile oils and proteins. GC/MS showed 36 compounds in roots, 33 in stem while 40 in leaves. Fluorescence analysis of roots, stem and leaves showed variations in color when treated with chemicals. This study will assist pharmacognostic exploration, authentication from adulterants/allied species for consistent quality, resulting in safe use, preservation and efficacy. RESEARCH HIGHLIGHTS: This was first attempt on pharmacognostic study on D. suave Huth. which could be used as a foundation for identifying and authenticating the specie from other allied species by these morphological, anatomical, GC/MS profiling, phytochemical analysis and fluorescence analysis.

Island area, isolation and climate effects upon flower traits in a megadiverse archipelago

AbstractAimFlower traits are critical to the mutualistic networks that underpin ecosystem function. However, the broad‐scale drivers of flower traits are unclear. Using the megadiverse islands of Malesia, we test three hypotheses: (1) Flower size, openness and colourfulness (i.e. the trend from white to colourful flowers) will decrease with increasing temperature, but not with increasing precipitation seasonality. (2) Flower size, openness and colourfulness will increase with island area, and decrease with isolation. (3) Models parameterised by climate, rather than non‐climatic island characteristics will have the greatest predictive capacity as climate affects both pollinator communities and energetic/physiological constraints upon flower traits.LocationFourteen Malesian islands.TaxonAngiosperms.MethodsWe applied Bayesian phylogenetic models of occurrence for >2500 species in 400 m elevation bands, across islands, as a function of flower trait interactions with either climatic variables or islands characteristics. We compare predictive capacity of models based on climate versus island characteristics using Leave One Out‐Cross Validation.ResultsAll six flower traits examined varied with at least temperature, precipitation seasonality, island area and isolation. Flowers are larger in cold environments. The lowland tropics are mostly inhabited by white flowered species. At cold high elevations, red and pink flowered species are more frequent whereas green and purple flowered species increase in the drought‐prone seasonally dry tropics. Flower openness declined with precipitation seasonality and increased with isolation. Models parameterised by climate performed best for perianth length, red and white flowers, whereas pink flowers and flower openness were better predicted using island characteristics.Main ConclusionsThere are relationships between flower traits and climatic gradients within Malesia. However, island characteristics have also left a legacy upon current flower trait distributions. These island biogeographical impacts are likely key for the eco‐evolutionary drivers of flower traits.

Study of the Earliest Symptoms of Plum Pox in the Sofia Valley and Vratsa Region

Since ancient times, the fruits of the plum have occupied an important place on the table of the Bulgarians. To obtain high and stable yields an important condition is the proper organization and conduct of plant protection activities and the fast, the correct and accurate diagnosis of PPV - Stoneware. In our climate, Plum pattern manifests symptoms first on the first spring leaves. The described symptoms of flowers in different stone species are few and scarce, so we conducted the present study in two following years 2019 and 2020 to describe, differentiate and compare visual symptoms of flowering with the results of DAS-ELISA tests on the leaves of the studied stone species. From the surveyed PPV host species in two orchards 12 mather trees with color symptoms were selected and described in two regions of Bulgaria - the Sofia field (Vrajdebna (1,2 ha) and the Vratsa region (Roman Orchard Nursery (0,4 ha). In a total of 9 samples, PPV infection was confirmed. The established deviations were found only in fruit crops that bloom with white flowers. Based on the results and conclusions, the present study will contribute to the timely detection of the causative agent of pox virus in the earliest symptoms in nurseries and gardens and will provide the right and quick direction to overcome the damage through proper plant protection activities

Identification of volatile organic compounds in purple and white soybean flowers by HS-SPME/GC-MS

This study aimed to establish a method for the extraction, enrichment, and identification of volatile organic compounds (VOCs) released by the flowers of purple (BRS 399) and white (DONMARIO 6563) soybean varieties. We tested the Static Headspace (HS) and Solid Phase Microextraction (SPME) methods using various fibre types: PDMS (Polydimethylsiloxane), PDMS/DVB (Divinylbenzene), and PDMS/DVB/CAR (Carboxen). We employed gas chromatography–mass spectrometry (GC–MS) to identify the VOCs. The SPME method with PDMS/DVB and PDMS/DVB/CAR fibres yielded the highest number of extracted compounds for both soybean cultivars. Notably, 67 compounds were detected in Glycine max. L for the first time. Using the developed method, we were able to detect 52 and 57 VOCs in the purple and white soybean varieties, respectively, including ketones, alcohols, aldehydes and benzenoids. In conclusion, the method we developed effectively identified VOCs in soybean flowers, thus enriching our understanding of the interactions between soybean flowers and their pollinators.

The Flower Colour Influences Spontaneous Nectaring in Butterflies: a Case Study with Twenty Subtropical Butterflies.

Butterflies have a wide spectrum of colour vision, and changes in flower colour influence both the visiting and nectaring (the act of feeding on flower nectar) events of them. However, the spontaneous behavioural response of butterflies while foraging on real flowers is less characterised in wild conditions. Hence, this study intends to investigate flower colour affinity in wild butterflies in relation to nectaring frequency (NF) and nectaring duration (ND). Six distinct flower colours were used to study spontaneous nectaring behaviour in 20 species of subtropical butterflies. Both NF and ND greatly varied in the flower colours they offered. Yellow flowers were frequently imbibed by butterflies for longer durations, followed by orange, while red, pink, white and violet flowers were occasionally nectared in shorter bouts. Though butterflies have a general tendency to nectar on multiple flower colours, the Nymphalids were more biased towards nectaring on yellow flowers, but Papilionids preferred both yellow and orange, while the Pierids were likely to display an equal affinity for yellow, orange and violet flowers as their first order of preference. Even if the blooms are associated with higher nectar concentrations or a significant grade reward, the butterfly may prefer to visit different-coloured flowers instead. Flower colour choice appears to be a generalist phenomenon for butterflies, but their specialist visiting nature was also significant. Nymphalid representatives responded to a wider variety of floral colour affinities than Pierid and Papilionid species. The colour preference of butterflies aids in the identification of flowers during foraging and influences subsequent foraging decisions, which ultimately benefits pollination success. The current information will support the preservation and conservation of butterflies in their natural habitats.

Generic concepts and species diversity within the Gynoxyoid clade (Senecioneae, Compositae).

The Gynoxyoid clade of the Senecioneae (Asteraceae) until now included the five genera Aequatorium, Gynoxys, Nordenstamia, Paracalia and Paragynoxys as diagnosed using selected morphological characters. In their pre-phylogenetic circumscription, the genera Aequatorium and Paragynoxys were considered to inhabit the northern Andes in contrast to Nordenstamia and Paracalia that occur in the central Andes. The most species-rich genus, Gynoxys, was believed to be distributed throughout the Andes. We use a recently established plastid phylogenomic framework that rendered Gynoxys paraphyletic to further evaluate the delimitation of genera in the Gynoxyoid clade. We examine the morphological variation of all members of the Gynoxyoid to identify characters potentially informative at genus level. This results in a matrix of eleven, mostly multistate characters, including those originally used to diagnose these genera. The ancestral character state inference displays a high level of homoplasy, but nevertheless supports the recognition of four genera. Aequatorium is characterised by white radiate capitula. Paracalia and Paragynoxys share white flowers and floral characteristics, such as flower opening and length of disc flowers lobes, as plesiomorphic states, but differ in habit (scandent shrubs vs. trees). Paracalia also retained white flowers, but its two species are characterised by the absence of outer phyllaries. The genera Gynoxys and Nordenstamia comprise species with yellow capitula which appear to be a derived feature in the Gynoxyoids. The genus Nordenstamia, with eight species, is synonymised under Gynoxys since molecular evidence shows its species nested within various parts of the Gynoxys subclade and the morphological variation of Nordenstamia falls well within that of Gynoxys. With the goal to assign all species to four genera (Aequatorium, Gynoxys, Paracalia and Paragynoxys), we assess the states for the eleven characters for all members of the Gynoxyoids and generate new ETS and ITS sequences for 171 specimens belonging to 49 species to further support their generic placement. We provide a taxonomic treatment for the four genera recognised here including amended diagnoses and morphological descriptions. Furthermore, a species-level taxonomic backbone is elaborated for all genera using electronic tools that list 158 currently accepted names and synonyms (209 names in total) with the respective protologue and type information, as well as notes on the current understanding of species limits. Eleven names are newly synonymised, two are lectotypified and eight are newly transferred to other genera.

Agronomic and hormonal approaches for enhancing flowering intensity in white Guinea yam (Dioscorea rotundata Poir.).

Developing novel white Guinea yam (Dioscorea rotundata) varieties is constrained by the sparse, erratic, and irregular flowering behavior of most genotypes. We tested the effectiveness of nine agronomic and hormonal treatments to enhance flowering on D. rotundata under field conditions. Genotypes responded differently to flower-inducing treatments (p<0.001). Of the test treatments, pruning and silver thiosulfate (STS) were effective in increasing the number of spikes per plant and the flowering intensity on both sparse flowering and monoecious cultivars. STS and tuber removal treatments promoted female flowers on the monoecious variety while pruning and most treatments involving pruning favored male flowers. None of the treatments induced flowering on Danacha, a non-flowering yam landrace. Flower-enhancing treatments had no significant effect on flower fertility translated by the fruit set, since most treatments recorded fruit sets above the species' average crossability rate. Flower-enhancing techniques significantly influenced number of tubers per plant (p = 0.024) and tuber dry matter content (DMC, p = 0.0018) but did not significantly affect plant tuber yield. Nevertheless, treatments that could enhance substantially flowering intensity, such as pruning and STS, reduced tuber yield. DMC had negative associations with all flowering-related traits. This study provided insights into white yam flower induction and suggests promising treatments that can be optimized and used routinely to increase flowering in yam crop, without significantly affecting flower fertility and tuber yield.