Ray Flowers Research Articles

Assessing the Antibacterial Activity of Tridox Procumbens in Ethanol Extract

Introduction: An impressive number of modern drugs have been already isolated from these natural resources particularly of plant origin. The name Tridax refers to the three lobes of the ray flowers while procumbens refers to the prostrate, trailing habit of the stems. It is one of the essential ingredients in the most of the compound preparations of Ayurvedic literature. Tridax procumbens belongs to the Asteraceae family have been used from ancient times to treat wounds, skin diseases and to stop blood clotting in folk medicine. Objective: The current theme of this work is to estimate of the bacterial property of Tridaxprocumbent using agar well diffusion method. Method: Leaf extract of Tridax procumbens obtained by cold maceration process. Plants were collected from Madhavaram, Chennai, Tamilnadu in the month of august 2023. It is authenticated by Botanist and herbarium was prepared and deposited in the college museum. The ethanolic extract was examined against Escherichia coli, Bacillus subtilis, and Pseudomonas vulgaris by agar well diffusion method. The ethanol is used as control. The ofloxacin is used as standard. Conclusion: Tridax procumbens leaf extract terminates most propitious source. A systematic correlation between ethno pharmacological relevance and scientific evidence to provide proof of the importance of the plant to indigenous people as well as pharmaceutical industries.

Taxonomic studies in Wedelia (Asteraceae, Heliantheae) reveal a new species for the Brazilian Cerrado

Wedelia is the largest genus of Ecliptinae (Heliantheae, Asteraceae), comprising about 110 species. The Brazilian Cerrado is a highly threatened phytogeographic domain, which harbors the richest flora in the world among other savannas. A new subshrubby species of Wedelia was revealed occurring in the central part of Cerrado and is herein described as W. tenuinervia. This new species resembles W. foliacea in vegetative traits but differs mainly by having leaves with brochidodromous venation, pistillate ray flowers, glandular trichomes on the abaxial surface of the leaf blade, corolla lobes and apical anther appendages, phyllaries abaxial surface strigillose and disc cypselae 4–5-angled, keeled at the angles, without basal scars or elaiosomes, and carpopodium inconspicuous (vs. acrodromous venation, neuter ray flower, abaxial surface of the leaf blade, corolla lobes and apical anther appendage lacking glandular trichomes, phyllaries abaxial surface setose or glabrescent, and disc cypselae biconvex, not keeled, with basal scars or elaiosomes, and carpopodium in two plates or one shallowly lobed). Among the species with pistillate ray flowers, W. tenuinervia can be morphologically related to W. oligocephala, differing mainly by the membranaceous leaf blades with flat margins, brochidodromous venation, and solitary capitula (vs. subcoriaceous leaf blades with revolute margins, acrodromous venation and capitula in dichasia). Illustrations, comments, a preliminary conservation status, and the typification of W. foliacea’s synonyms are proposed.

Variations in Flower Color of Mutant Chrysanthemums

The induction of variation in chrysanthemums using gamma radiation under in vitro conditions is an effective technique in ornamental plants. The purpose of this study is to obtain new mutants by isolating desirable properties from the three-colored single chrysanthemum mutant using in vitro cultures. Bud explants were cultured four times, the plantlets were acclimatized, and 520 plants were planted in outdoor conditions. Observations of the mutants were collected during flowering time, and 97 of the mutants were compared to the control group. Plants with pink, white, and chimeric flowers were obtained. Mutant plants with white flowers constituted the majority of the population followed by plants with variegated flower colors. The population is divided into six clusters, based on the plant height, plant diameter, flower number, flower diameter, number of flower colors, ray flowers’ number, leaves’ number, stem weight, and lengths and widths of leaves. The population decreased in plant height, flower number, and stem weight, while other features increased compared to the control group. Thus, a new population with similar characteristics to the parent plant was obtained from a single mutant. Chrysanthemum plants exposed to mutagens showed major changes in flower parts as well as other parts of the plant.

A TIME-CALIBRATED PHYLOGENY OF VERBESINA (HELIANTHEAE – ASTERACEAE) BASED ON NUCLEAR RIBOSOMAL ITS AND ETS SEQUENCES

Verbesina L. is a genus of the tribe Heliantheae, subtribe Verbesininae (Asteraceae), with distribution in the Americas, where Mexico and the Andes harbour the richest concentration of species. The approximately 325 species in the genus are shrubs, subshrubs, trees and rarely herbs. Despite its high species diversity and biogeographical importance, the only available phylogenetic hypothesis for Verbesina was based on chloroplast DNA restriction site data. In the present study, nuclear ITS and ETS DNA sequence data were used with an expanded taxon sampling, particularly among the South American Verbesina species, to improve phylogenetic resolution and support, clarify infrageneric relationships, and resolve biogeographical questions in the genus. The results of our new analysis corroborate the monophyly of Verbesina, but its current classification into 12 taxonomic sections, based on morphological characters such as phyllotaxis, head size, corolla colour, and presence of ray flowers, is not congruent with the molecular phylogeny, in which most sections are polyphyletic. We also show that Verbesina diverged in the late Miocene of North America, about 8 Ma. At least two independent Pleistocene dispersals into South America across the Isthmus of Panama and along the Southern Andes are evident, beginning around 3.23 Ma (1.27–3.23 Ma) in the Middle Pliocene, and resulting in an extra-Amazonian distribution of the genus inSouth America. Diversification in South America began around 2.83 Ma with occupation of the Andes. Colonisation of Brazil is estimated to have occurred around 2.15 Ma, from Andean lineages.

Сорт декоративного подсолнечника Астория селекции ВНИИМК

In 2022, the ornamental variety Astoria was submitted into the State variety testing. The variety Astoria was obtained as a result of crossing the ornamental variety Plyushevy mishka and ornamental samples with lemon and apricot ray flowers, followed by the production of a synthetic, its multiple self-pollination and individual selection according to the characteristics of the morphotype, culminating in the transfer of the fertile line to CMS RIG. The main ornamental features of the variety Astoria are: the original inflorescence at the stage of budding and flowering, light yellow color of ray flowers, yellow-purple color of tubular flowers; involucre leaves with a very long tip; large, blistered, serrated leaves along the edges; predominantly apical branching, stiff long lateral shoots, compact habitus, long growing season. The variety Astoria belongs to the middle maturing group, intended for cutting and landscaping. The originator of the ornamental sunflower variety Astoria is the V.S. Pustovoit All-Russian Research Institute of Oil Crops (VNIIMK).

Гибрид декоративного подсолнечника Сириус селекции ВНИИМК

The hybrid of the ornamental sunflower Sirius was obtained as a result of crossing two parent lines LD10 (variety of the ornamental sunflower Zhemchuzhny) and LD20. The main ornamental features of the hybrid Sirius are the original inflorescence, the light-yellow color of the ray flowers, the purple color of the tubular flowers, and the compact habitus. The hybrid belongs to the middle maturing group. The originator of the ornamental sunflower hybrid Sirius is the V.S. Pustovoit All-Russian Research Institute of Oil Crops (VNIIMK).

Unraveling the secrets of Eclipta alba (L.) Hassk.: a comprehensive study of morpho-anatomy and DNA barcoding.

Safety regarding herbal products is very necessary; therefore, routine identification of raw materials should be performed to ensure that the raw materials used in pharmaceutical products are suitable for their intended use. In order for the identification-related data obtained to be accurate, the identification of various kinds of markers is also very necessary. The purpose of this study was to describe the characteristics of Eclipta alba (L.) Hassk. based on qualitative morpho-anatomical markers and quantitative DNA coding. The morphology of this plant has herbaceous habit with a taproot and a stem with branches that appear from the middle. Leaves are single type imperfectly arranged oppositely, lanceolatus, finely serrated on the edges, tapered at the base, pointed at the end, and have a pinnate and hairy leaf surface. The flowers consist of ray flowers and tube flowers with a cup shape. Meanwhile, in terms of anatomy, E. alba has aerenchyma, which are scattered in the cortex of the root and stem. In addition, there are anisocytic stomata, glandular trichomes, and non-glandural trichomes with an elongated shape accompanied by ornamentation found on the leaf epidermis. The results of sequence alignment and phylogenetic tree reconstruction show that the sample plants are closely related to species in the genus Eclipta.

Flower-like meristem conditions and spatial constraints shape architecture of floral pseudanthia in Apioideae

BackgroundPseudanthia are multiflowered units that resemble single flowers, frequently by association with pseudocorollas formed by enlarged peripheral florets (ray flowers). Such resemblance is not only superficial, because numerous pseudanthia originate from peculiar reproductive meristems with flower-like characteristics, i.e. floral unit meristems (FUMs). Complex FUM-derived pseudanthia with ray flowers are especially common in Apiaceae, but our knowledge about their patterning is limited. In this paper, we aimed to investigate both the genetic and morphological basis of their development.ResultsWe analysed umbel morphogenesis with SEM in six species representing four clades of Apiaceae subfamily Apioideae with independently acquired floral pseudanthia. Additionally, using in situ hybridization, we investigated expression patterns of LEAFY (LFY), UNUSUAL FLORAL ORGANS (UFO), and CYCLOIDEA (CYC) during umbel development in carrot (Daucus carota subsp. carota). Here, we show that initial differences in size and shape of umbel meristems influence the position of ray flower formation, whereas an interplay between peripheral promotion and spatial constraints in umbellet meristems take part in the establishment of specific patterns of zygomorphy in ray flowers of Apiaceae. This space-dependent patterning results from flower-like morphogenetic traits of the umbel which are also visible at the molecular level. Transcripts of DcLFY are uniformly distributed in the incipient umbel, umbellet and flower meristems, while DcCYC shows divergent expression in central and peripheral florets.ConclusionsOur results indicate that umbels develop from determinate reproductive meristems with flower-like characteristics, which supports their recognition as floral units. The great architectural diversity and complexity of pseudanthia in Apiaceae can be explained by the unique conditions of FUMs—an interplay between expression of regulatory genes, specific spatio-temporal ontogenetic constraints and morphogenetic gradients arising during expansion and repetitive fractionation. Alongside Asteraceae, umbellifers constitute an interesting model for investigation of patterning in complex pseudanthia.

FIRST RECORD OF NATURALIZED ACMELLA BRACHYGLOSSA AND ACMELLA RADICANS (ASTERACEAE: HELIANTHEAE) IN JAVA, INDONESIA

Acmella brachyglossa and A. radicans are introduced species native to Central and South America. Here, both species are formally reported for the first time in Java. Acmella brachyglossa is characterized by its pale yellow-colored heads and has 5‒8 ray flowers. Meanwhile, A. radicans has discoid heads, 4-merous flowers, and white-coloured. Acmella brachyglossa was collected from West Java (Sumedang Regency and Bogor Regency). While A. radicans was found in West Java (Bandung Regency, Bandung City, Sumedang Regency) and Central Java (Temanggung Regency). Descriptions, illustrations, a key to Acmella of Java, and a brief discussion are presented in this paper.

Morpho-anatomical characterization and DNA barcode of Cosmos caudatus Kunth.

Abstract. Purnobasuki H, Rakhashiwi GA, Junairiah, Wahyuni DK, Putra RE, Raffiudin R, Soessilohadi RCH. 2022. Morpho-anatomical characterization and DNA barcode of Cosmos caudatus Kunth. Biodiversitas 23: 4097-4108. Secondary metabolites in plants have various benefits, therefore their distribution in plant body parts is important to study. The identification process of plants should be conducted using several characters, including morphological and molecular data. This study aimed to identify and confirm Cosmos caudatus Kunth using morpho-anatomy characters and DNA barcodes. The plants used were three samples taken from the Husada Graha Famili Park, Surabaya. The morpho-anatomical investigation was carried out descriptively, while the DNA barcoding study was processed by amplifying and sequencing the rbcL and matK genes. Morphological studies indicate that the roots and stems of C. caudatus are similar to the organs of dicots shrubs in general. The leaves have a pinnate type with two different colors on each side of the leaf. Compound flowers are cup-type with two types of flowers, namely disc flowers and ray flowers. Based on anatomical observation, all vegetative organs have the same tissue as dicotyledonous plants. The anatomical characteristic of C. caudatus lies in its trichomes due to its anthocyanin content and stomata which are anomocytic and anisocytic types. DNA barcoding results showed that the three sample plants had identical similarities with several Cosmos genera contained in the GenBank database with percentage identities values ??above 98%, query covers 96-100%, and e-values ??of 0.

K. V. KLEMESHOVA, T. YU. GABUEVA PECULIARITIES OF FORMATION OF LARGE-FLOWERED CHRYSANTHEMES FOR OBTAINING CUT IN A WET SUBTROPICAL CLIMATE

Chrysanthemum is one of the leading crops of commercial floriculture. Within garden groups and classes, chrysanthemums are divided according to cultivation methods, shape and size of the inflorescences. For varieties grown on a cut, a group of large-flowered (with a diameter of inflorescences of 12-25 cm), small-flowered (4-10 cm) chrysanthemums and santini (from 2 to 4 cm) is distinguished. Having a limited assortment of chrysanthemum garden, in a humid subtropical climate, it is possible to form a largeflowered (single-headed, disbud) and small-flowered (spray) cut. The purpose of the research was to study the peculiarities of formation of large-flowered chrysanthemums (Chrysanthemum×hortorum Bailey) to obtain cut in the humid subtropics of Russia. The objects of research were large-flowered and small-flowered varieties of chrysanthemums of foreign and domestic breeding. The studies were carried out in the open ground of the Department of Agricultural Engineering and Nursery of the Federal Research Center the Subtropical Scientific Center of the Russian Academy of Sciences. Scientific research was carried out according to the methodology of State variety testing of agricultural crops and the methodology of testing for distinctness, uniformity and stability of chrysanthemum (perennial) Chrysanthemum spec. ‘Sevan’, ‘Baltica White’, ‘Granada’ and ‘Zembla Brasil’ are large-flowered varieties, which have bush peduncles of good commercial quality with large inflorescences of saturated shades. In turn, from small-flowered garden forms ‘Zembla White’, ‘Annecy White’ and ‘Westland Regal’ with regular pinching, you can grow a large-flowered cut of chrysanthemums. It was revealed the relationship between biometric characteristics in order to determine additional diagnostic features of the possibility of the formation of large-flowered inflorescences. So, the diameter of the inflorescence is the most significant parameter for research which has significant positive relationships with the diameter of the peduncle and the length of the extreme ray flower. It will allow determining the possibility of growing the variety in one form or another, depending on the needs of production, at the initial stages of introduction and variety study.

Comparative morphological and anatomical analysis of the feverfew herb varieties Phlora Pleno and White Gem

Feverfew (Tanacetum parthenium (L.) Schultz Bip. is a perennial plant of the Aster family, which has an anti-migraine, anti-inflammatory and analgesic activity. These days studying of the feverfew varieties is actual in order to expand the raw material base because species and varieties are known to have a similar chemical composition. In Ukraine, the varieties White Gem and Phlora Pleno are widely cultivated and they are unpretentious to the natural and climatic conditions of Ukraine. The morphological and anatomical study of the selected varieties previously has not been studied, therefore this analysis is actual.
 The aim of the work was to conduct a morphological and anatomical analysis of the feverfew herb varieties Phlora Pleno and White Gem.
 The object of the study was samples of the feverfew herb varieties Phlora Pleno and White Gem collected during the period of mass flowering in 2018–2019 on experimental plots of the Botanical Garden of the National University of Pharmacy (Kharkiv, Ukraine) and the National Botanical Garden N. N. Grishka (Kiev, Ukraine.). Morphological features were examined on fresh, dry and fixed raw materials using a Levenhuk Zeno Handy ZH19 magnifier. Anatomical studies were carried out using raw materials fixed in a mixture of alcohol–glycerin–water (1:1:1) and in accordance with the requirements of the SPhU.
 As a result of the analysis the general and individual morphological and anatomical features of the feverfew herb varieties White Gem and Phlora Pleno were determined. The individual morphological features of the Phlora Pleno variety include white, female ray flowers up to 1.0 cm long, arranged in 2–3 rows; variety White Gem – white, female up to 0.8 cm long, located singly ray flowers. The individual anatomical features of the Phlora Pleno variety include the paracytic and anisocytic types of the stomata; single prismatic crystals and druses in the mesophyll; variety White Gem – anomocytic type of the stomata, on the epidermis of the stem – trichomes with a lobed terminal cell and glandules.
 For the first time a comparative morphological and anatomical analysis of the feverfew herb varieties Phlora Pleno and White Gem collected in Ukraine was carried out. The general and distinctive features of each variety, as well as their main diagnostic features, have been determined, therefore it will be used later to standardize the feverfew herb varieties Phlora Pleno and White Gem.

Pectis loiolae (Asteraceae: Tageteae): New Species Registered in a Natural Monument at an Archaeological Site in Northeast Brazil

Abstract— Pectis comprises about 90 species distributed in North America, Mexico, the Caribbean, South and Central America, and the Pacific Islands. In Brazil, the genus is represented by 14 species that mainly occur in the Cerrado and five species that are endemic to the Caatinga domain. During field expeditions to the Lajedo de Soledade archaeological site, in the state of Rio Grande do Norte, Brazil, a new species of Pectis was found on rocky outcrops (lajedos) in the Caatinga. Pectis loiolae sp. nov. grows on limestone rocks in sedimentary substrate and is recognized by its prostrate habit with ascending branches terminating in a solitary capitulum, apex of the involucral bracts rounded, apiculate, and green becoming vinaceous in the apical 1/3, corolla of ray flowers (5) with abaxial surface vinaceous and adaxial white, disk flowers 8‐10, and presence of stylopodium in the disk flowers. A morphological description, illustration, distribution map, habitat, conservation status, and a key for all Brazilian Pectis species are presented herein.

Phyllody in sunflowers; 44 years to explain the appearance of aberrant flowers

Abstract Phyllody in sunflowers (Helianthus annuus L.) is characterized by the appearance of bracts and ray flowers in the centre of the heads. It has been discussed for decades among the sunflower plant breeders and experts without a clear “unique” explanation for it. The erratic appearance of the phenomena has led to consider it either a disease or hybrid defect and the plants with Phyllody as off-types, raising several farmers claims to seed producers. However, the auxins gradient, in the growing Asteraceae heads, determines the differentiation pathway of the undifferentiated cells. i.e., bracts and ray flowers at the border and disk flowers in the centre of the head. Disruption of the natural auxin gradient alters the cell differentiation in the growing heads and causes bracts and ray flowers to grow where only disk flowers should grow. The disruption of the natural head bottom auxin gradients may be caused by small injures in the fast-growing head receptacle. The most common causes of Phyllody are hormonal herbicide damage and Boron (B) deficiency, even temporary. Plants growing with B deficiency have brittle cell wall and membranes while a plant with high B levels produces plastic or elastic cell wall and membranes. Brittle cell walls are susceptible to breaks during growth. Sunflowers genotypes may react to crack or small damages in the sunflower bud in two ways. Some tend to repair the damages by regrowing new organs such as ligules or bracts and forming Phyllody. Others do not regrow and only heal the wound creating the funnel hole head shape.

Морфологические признаки новых линий подсолнечника, устойчивых к расе G заразихи

The work was conducted in the laboratory of immunity of the V.S. Pustovoit All-Russian Research Institute of Oil Crops during 2016–2020. Twelve homozygous lines resistant to broomrape races A–G were developed from the sources of different origin. A line RG and other five: RGL1, RGL2, RGР1, RGР2, and RGВ, were described in the previous articles (Antonova et al., 2016, Araslanova et al., 2020) [1; 2]. Further new lines we named as 2RGB, 2RGN, 2RGL, 2RGS, 2RGNV, and 2RGA. We tested these lines for distinguishability, homogeneity and stability according to a technique “Sunflower (Helianthus annuus L.)” stated in a publication RTG/01/3 “Common introduction into testing of distinguishability, homogeneity and stability and compilation of description” of 22.07.2002 No 12-06/52 (Official bulletin of the State Commission No 6, 2002) [3]. The new lines also as the previous ones are differed from each other by their morphological traits, such as duration of a period from emergence to plants flowering, plants height, shape and color of a leaf and ray flower, etc. This description of the lines resistant to broomrape race G can be used in breeding practice at development of sunflower hybrids.

Dysfunction of CYC2g is responsible for the evolutionary shift from radiate to disciform flowerheads in the Chrysanthemum group (Asteraceae: Anthemideae).

Evolutionary shifts among radiate, disciform and discoid flowerheads have occurred repeatedly in a number of major lineages across the Asteraceae phylogeny; such transitions may also appear within evolutionarily young groups. Although several studies have demonstrated that CYC2 genes partake in regulating floral morphogenesis in Asteraceae, the evolution of capitulum forms within a recently diverging lineage has remained poorly understood. Here, we study the molecular regulation of the shift from a radiate to a disciform capitulum within the Chrysanthemum group. This is a recently radiating group mainly comprising two genera, Chrysanthemum and Ajania, that are phylogenetically intermingled but distinct in flowerhead morphology: Chrysanthemumspp. with radiate capitula and Ajaniaspp. with disciform capitula. We found that the morphogenesis of zygomorphy in the marginal floret in Ajania was disrupted soon after floral primordium emergence; CYC2g, one of the CYC2 copies that was expressed prominently in the ray floret of Chrysanthemum was not expressed in flowerheads of Ajania. Weakening the expression of ClCYC2g in Chrysanthemum lavandulifolium led to the gradual transition of a ray flower toward the disc-like form. Molecular evolutionary analyses indicated that the disciform capitulum might have evolved only once, approximately 8Mya, arising from dysfunction of the CYC2g orthologs. A 20-nt deletion, including a putative TATA-box of the Ajania-type CYC2g promoter, appeared to inhibit the expression of the gene. Considering the divergent habitats of Chrysanthemum and Ajania, we propose that the shift from radiate to disciform capitulum must have been related to changes in pollination strategies under selective pressure.

Production of Briquetted Tablets from Some Medicinal and Aromatic Crops انتاج اقراص مقولبه من بعض المحاصيل الطبية والعطرية

Experiments were carried out for briquetting some medicinal and aromatic crops in a form of tablets instead of traditional methods. Some research has shown the risk of paper bags that contain chemicals and plastic fibers, which leads to harmful impact on human health. Dried chamomile disc flowers, chamomile ray flowers petals, and local mint leaves were indentified without any strange binder. A specified percentage of moisture content was added to the materials in a homogenizer to use the natural plants colloidal material to briquette the particles. Pre-determined amount of water was added to approach moisture content levels from 40% to 55% by increment of 5%db under compression force of 450, 500, 550, and600N. Three indicators were measured to evaluate the briquetted tablets quality included penetration resistance (N), final briquettes mass (g), and durability (%).The best quality for chamomile disc flower briquettes, chamomile ray flowers petals, mint leaves were found under (compression force 550N, and moisture content of 50 %db, 50%db, 45%db respectively), whereas, bulk density was 0.6g/cm3, 0.7g/cm3, 0.6g/cm3 respectively. Meanwhile ,briquette tablet mass, penetration resistance, and durability without backing were (1.5g, 98N, and52%) respectively for chamomile disc flowers, (1.5g, 114N ,and 60%) respectively for chamomile ray flowers petals and (1.62g, 100N, and52% ) respectively for mint leaves . In general, the examined method has succeeded to briquetting some medicinal and aromatic crops in the form of tablets as a final product by cold press without adding binder.

RESPONSE OF Calendula officinalis L. PLANTS TO AQUEOUS ACTIVE DRY YEAST APPLICATION TYPE AND RATE IN SANDY SOILS

The present work was carried out during two successive seasons of 2017/2018 and 2018/2019 at the Experimental Farm of El-Qassassein Horticultural Research Station, Ismailia Governorate, to study the effect of active dry yeast aqueous solution rates (2, 4, 6 and 8 g/L.) with two application types (soil drench and foliar spray) each solely or in combination to obtain the pest growth, good production of flowers yield and the highest chemical composition of Calendula officinalis L. plants, under sandy soil conditions. The active dry yeast levels were applied three times starting from 1 st Dec. with 21 days interval between them. The flower heads were collected manually in 13 flower picking times starting from 1st Feb. with one-week intervals between them. The treatment of 4 g/L. active yeast solution in both soil drench and foliar spray and their interaction gave the highest plant height, number of branches/plant, fresh and dry weights of herb/plant, number of inflorescences/plant, fresh and dry weights of inflorescences and ray flowers (g)/plant, dry yield of inflorescences, ray flowers (kg)/fed. and total carotenoids content, during the two seasons. The interaction treatment of 4 g/L. soil drench + 4 g/L. foliar spray yielded 86.8 and 85.4 % of total productivity/year of dry weight of inflorescences (g)/plant, and 85.3 and 84.0 % of total productivity/year of dry weight of ray flowers (g)/plant from the 6th to 13th flower picking times, during the two seasons, respectively.

Greenhouse Data Suggest That Growth Stage Impacts Phomopsis Stem Canker Severity Associated with Diaporthe gulyae on Sunflower (Helianthus annuus)

Diaporthe gulyae Shivas et al. was initially described as causing Phomopsis stem canker of sunflower (Helianthus annuus L.) in the United States in 2010. In this study, the impact of growth stage on disease severity associated with D. gulyae in sunflower accessions was investigated in the greenhouse. One hundred thirty-nine accessions were inoculated with a single isolate of D. gulyae using the mycelium contact inoculation method at V4 to V6 (four to six true leaves) and R4 to R6 (inflorescence to ray flower wilting) growth stages. The experiment was conducted in a completely randomized design with six replications and repeated once. Disease severity was assessed at 14 days postinoculation using a 0-to-5 rating scale. A significant interaction between growth stage and accessions (P < 0.0001) was observed for disease severity (relative treatment effect [RTE]) caused by D. gulyae. Among the 139 accessions, 24, three, and two accessions had significantly lower RTE when inoculated at V4 to V6, R4 to R6, and both growth stages, respectively, upon comparing with the inbred susceptible check ‘HA 288’. This study suggests that accessions differ in their susceptibility to D. gulyae, possibly because of changes in resistance response during host development. Future studies on sunflower-D. gulyae interaction are warranted for developing commercial hybrids with resistance to the causal fungus.

Заразихоустойчивый гибрид подсолнечника Тайзар

A simple sunflower hybrid Taizar was developed at V.S. Pustovoit All-Russian Research Institute of Oil Crops as part of a breeding and genetic program for developing highly productive hybrids resistant to the new virulent races of broomrape by using the method of backcrossing in combination with an evaluation of resistance in each generation for the target gene Or7. The hybrid Taizar is of mid-early group of ripeness, it has a high yield, it is resistant to Orobanche cumana Wallr. (races A-G) and downy mildew (races 330, 710, 730, 334, 734). The line-restorer of pollen fertility VK 305 is the paternal form of the hybrid Taizar. The line was developed as a result of the introduction of the Or7 gene from the RG line by two backcrosses into the line VK 303, subsequent inbreeding and selection of broomrape-resistant genotypes. The line VK 305 has narrow widely spaced ray flowers strongly curved towards the back of the head, which can serve as a morphological marker of genetic purity.