Stamens Research Articles

Two new species, Begonia minhaniae and B. dieuanhiae (sect. Platycentrum, Begoniaceae), from northwestern Vietnam

Two novel species in Begonia sect. Platycentrum from northwestern Vietnam, B. minhaniae and B. dieuanhiae, are described and illustrated. Both species superficially resemble B. phouchomvoyensis in their rhizomatous habit, plain green ovary and leaves, 4-tepaled staminate flowers and 3-locular ovaries, but they can be clearly distinguished from the latter by several morphological characters such as morphology of vestiture, fewer anthers (those of B. minhaniae are ca. 15 vs. ca. 45 in B. phouchomvoyensis) and more tepals of pistillate flower (5 tepals in B. dieuanhiae vs. 3 tepals in B. phouchomvoyensis). These two novel discoveries highlight the growing body of research showing the rich and varied biodiversity of Begonia in the flora of Vietnam.

Pollination Effectiveness of the Hoverfly Eristalinus aeneus (Scopoli, 1763) in Diploid and Triploid Associated Watermelon Crop.

Watermelon (Citrullus lanatus) is an important crop worldwide. Pollination of this crop is carried out by insects, with honey bees (Apis spp.) and bumble bees (Bombus spp.) as the most used in greenhouse production. Nevertheless, due to the extreme conditions in closed enclosures, these hymenopterans suffer management and behavior problems leading to insufficient pollination. The effectiveness of three release densities (15, 30, and 45 individuals/m2) of Eristalinus aeneus was compared in diploid- and triploid-associated watermelon varieties under protected cultivation. Floral visits, pollen-pistil interaction after pollen transport, yield, and fruit quality were evaluated. The number of floral visits increased with release density in both pistillate and staminate flowers. No significant differences were observed, however, among release densities or between flower types in the duration of the visits. Floral preferences were not found in the behavior of E. aeneus in watermelon. High and medium release densities increased pollen deposition onto the stigma, and consequently the yield of the triploid variety compared to low release density, by 23.8 to 41.8% in 2020 and by 36.3 to 46.7% in 2021. The results of this trial demonstrate the potential of E. aeneus as a managed pollinator in protected cultivation of triploid watermelon.

Combining Ability Analysis for Fruit Yield in Bottle Gourd [Lagenaria siceraria (Mol.) Standl

Present investigation was carried out during Zaid season 2019-2020 in (Y1) and Zaid 2020-2021 in (Y2) at the Main Experimental Station (MES), Department of Vegetable Science, Acharya Narendra Deva University of Agriculture & Technology, Narendra Nagar, Kumarganj, Ayodhya (U.P) with 21 genotypes with six parental line and their fifteen F1 hybrids of bottle gourd by using diallel (excluding reciprocal) mating fashion. Experiment was laid out in RBD include three replication having each experimental unit with rows space at 3 (m) apart with a plant to plant spacing of 0.50 (m). Significant variances over seasons were found for general as well as sca for all the 17 traits studied during over season pooled which suggested that both additive and non-additive gene action were most important in the expression of all the traits. Pooled combining ability analysis revealed that parents viz., P4, P6 and P2 were good general combiner for fruit yield per plant. An attempt to identify desirable parents based on gca effect as well per se performance of the most of the character studied. Among the 15 F1 crosses P3 x P4, P2 x P6 and P2 x P5 have found good specific combiners for total fruit yield per plant along with most of the other yield contributing characters follow days to first staminate flower anthesis, days to first pistillate flower anthesis, fruit length and average fruit weight.

Croton nagaoi, a new species of Euphorbiaceae from southern Laos

Croton nagaoi (Euphorbiaceae) is described based on a specimen collected from the basin of the Bolaven Plateau, southern Laos. It is most similar to Croton thorelii Gagnep. of Laos, Cambodia, Thailand and Vietnam in size and shape of lamina, short petioles less than 1 cm long, and basal glands lateral on the abaxial midrib base, but different in having densely stellate hairy lower leaf surface (vs. very sparsely pubescent and glabrescent in C. thorelii), smaller sepals and petals of staminate flowers (sepals and petals ca. 2.2 mm long vs. 3 mm long and 2.5 mm long, respectively), and the presence of petals in pistillate flowers (vs. absent). Morphological descriptions, photographs, vernacular name, and preliminary conservation status are provided for C. nagaoi.

First report of staminate flowers of Calatola (Metteniusales: Metteniusaceae) from the Miocene Mexican amber

Metteniusaceae is a small family with ca. 11 genera that are distributed in the Neotropical and Paleotropical regions. The genus Calatola represents the northern limit of the family in the Neotropics. In this work, we describe a new fossil species of Calatola (Metteniusaceae) from the Miocene Chiapas amber, Southern Mexico, based on several staminate flowers. Calatola verae Estrada-Ruiz, Hernández-Urban, Rodríguez-Reyes, Ortega-Flores et Hernández-Damián sp. nov. is characterized by several actinomorphic unisexual flowers belonging to an inflorescence. It has four petals with adaxially raised midveins, pubescence on both sides of petals, an androecium composed of four stamens, each one of the stamens alternate and adnate to the petals at their base, and with anthers dithecal and oblong. This new fossil species of Calatola represents the first macrofossil record of the genus discovered in Mexico and based on its fossil flowers or inflorescence, provides evidence for a more extensive distribution of the genus in low latitudes in North America during the Miocene.

Phyllanthus longipetiolatus (Phyllanthaceae), a new species from São Paulo State, Brazil

During a taxonomic revision of Phyllanthus sect. Phyllanthus subsect. Phyllanthus, a new species was found and is being described and illustrated here. Phyllanthus longipetiolatus, known from the state of São Paulo (Brazil), belongs to the previously mentioned section and is morphologically similar to P. niruri. However, the new species differs from the latter by its leaves with long petioles (1.4–1.9 mm long), staminate inflorescences in cincinni, staminate and pistillate flowers with long pedicels (3.8–4 mm long and 6.7–8 mm long, respectively), staminate disk and smooth seeds. Its distribution, habitat, phenology, and informal conservation status are presented.

Begonia tuanii (sect. Platycentrum, Begoniaceae), a new species from Lao Cai Province, North Vietnam

Begonia tuanii from Lao Cai Province of Vietnam is described and illustrated. The habit of B. tuanii is mostly similar with B. fordii, but it can be distinguished by its bracts glabrous (vs. pilose) abaxial surface, larger outer tepals of staminate flower by 25–40 × 24–35 mm (vs. 6–8 × 5–77 mm) that are whole glabrous (vs. abaxially hairy), inner ones 20–35 × 10–20 mm (vs. 5.6–7.5 × 3–4 mm) and glabrous (vs. pilose) ovary. Referring to the IUCN of Nature criteria, B. tuanii is proposed to be Endangered (EN D).

Two New Species of Phyllanthus (Phyllanthaceae) from Southeastern Brazil

Abstract— Two new species, Phyllanthus lilliputianus and Phyllanthus sobralii are described for the Atlantic Forest of Southeastern Brazil, for the states of Espírito Santo and Minas Gerais, respectively. The presence of deeply emarginate anthers and four-colporate pollen grains with reticulate and microreticulate exine indicate that both species belong to Phyllanthus sect. Phyllanthus subsect. Claussenianii. Phyllanthus lilliputianus is an erect and small herb, with mucilaginous-hyaline branchlets, stipules, and petiole, an elliptical leaf blade that is membranaceous and sparsely mucilaginous-hyaline, staminate flowers with 5 sepals rhombic to widely obovate, and pistillate flowers with 5 slightly unguiculate sepals. P. sobralii is characterized by an herbaceous habit, with cylindrical branchlets that are glabrous, fractiflex and pinnatiform, leaf blades broadly elliptical to oval-elliptical, turquoise with prominent ribs on both surfaces, staminate and pistillate flowers with 5 sepals, with an accentuated central strip. Detailed description, colored plates, line drawing, notes on distribution, and conservation assessment are provided below.

Glochidion malingheense (Phyllanthaceae), a new species from Guizhou, China

Glochidion malingheense, a new species from southwestern Guizhou, China, is described. Morphologically, the new species is most similar to G. oblatum Hook. f. in having angled branchlets, leathery leaves, and thick pericarp of capsules that become lignified to some extent when dry, but clearly differs from the latter by its long pedicelled pistillate flowers that are with oblong sepals, short cylindrical styles, depressed globose ovary, subcircular to broadly ellipticum sepals of staminate flowers, 3 stamens and smaller fruits.

Begonia yentuensis and B. khaucaensis (Begoniaceae), two new species from northern Vietnam

Two new species of Begonia from northern Vietnam, B. yentuensis and B. khaucaensis, are described. The first new species, B. yentuensis, is similar to B. asperifolia Irmsch., the two species share several characters such as tuberous habit, subsymmetric foliage, 4-tepaled staminate flowers and pistillate flowers with 5 tepals, but B. yentuensis is different in its shorter petioles up to 7 (vs. to 20) cm long and leaves nearly appressed to the substrate (vs. not appressed to substrate), filaments fused at base (vs. fused at base into a column ca. 2 mm long), anthers apex rounded (vs. acute to mucronate) and placentae unilamellate (vs. bilamellate). Moreover, B. asperifolia is found only at high elevations (1,500–3,400 m), while B. yentuensis was collected at a low elevation (ca. 500 m). The other new species, B. khaucaensis resembles B. jubar V.T.Pham & C.W.Lin in its rhizomatous habit, number of tepals of both staminate and pistillate flowers, ovary 3-loculed and placenta bilamellate, but differs from the latter for having hairy (vs. glabrous) stipules and petiole, suborbicular to reniform leaves (vs. ovate to widely ovate leaves, slightly polygonal in outline), bracts margin entire (vs. denticulate to serrate with very short soft hairs) and ovary wings crescent-shaped (vs. triangular).

Integrated transcriptome and hormone analyses provide insights into silver thiosulfate-induced "maleness" responses in the floral sex differentiation of pumpkin (Cucurbita moschata D.).

The perfect mating of male and female flowers is the key to successful pollination. The regulation of ethylene with chemicals is a good option for inducing staminate or female flowers. Silver thiosulfate is often used to induce the formation of male flowers in subgynoecious and gynoecious crops, which is important to maintain their progenies. However, its effects on flower sex differentiation in pumpkin (Cucurbita moschata Duch.) and the underlying mechanism remain unclear. In this study, the application of silver thiosulfate to pumpkin seedlings significantly delayed the occurrence of the first female flower and increased the number of male flowers. We next investigated the underlying mechanism by employing transcriptome and endogenous hormone analyses of the treated plants. In total, 1,304 annotated differentially expressed genes (DEGs)were identified by comparing silver thiosulfate-treated and control plants. Among these genes, 835 were upregulated and 469 were downregulated. The DEGs were mainly enriched in the phenylpropanoid biosynthesis and metabolism pathways (phenylalanine ammonia-lyase, peroxidase) and plant hormone signal transduction pathways (auxin signaling, indole-3-acetic acid-amido synthetase, ethylene response factor). Silver thiosulfate significantly reduced the levels of 2-oxindole-3-acetic acid, para-topolin riboside, dihydrozeatin-O-glucoside riboside, and jasmonoyl-l-isoleucine but increased the levels of trans-zeatin-O-glucoside, cis-zeatin riboside, and salicylic acid 2-O-β-glucoside. The levels of auxin and jasmonic acid were decreased, whereas those of salicylic acid were increased. Different trends were observed for different types of cytokinins. We concluded that silver thiosulfate treatment not only affects the expression of auxin synthesis and signaling genes but also that of ethylene response factor genes and regulates the levels of auxin, salicylic acid, jasmonic acid, and cytokinins, which together might contribute to the maleness of pumpkin. This study provides useful information for understanding the mechanism underlying the effect of silver thiosulfate on floral sex differentiation in pumpkin, a widely cultivated vegetable crop worldwide, and gives a production guidance for the induction of maleness using STS for the reproduction of gynoecious lines of Cucurbitaceae crops.

Breyniahiemalis (Phyllanthaceae, Phyllantheae), a new species from Yunnan, south-west China.

Breyniahiemalis Huan C. Wang & Feng Yang (Phyllanthaceae), of sect. Cryptogynium (Müll.Arg.) Welzen & Pruesapan in subg. Breynia, is described from Yunnan, south-west China. It is known from only a single locality in the valley of the Yuanjiang River, and usually occurs in the understory of the savanna vegetation. It is characterized by its broadly elliptic to orbicular leaf blades, shallowly plate-like calyces of the staminate flowers, ovaries with clearly erose rim and urceolate capsules. Morphological comparisons with similar species are also presented.

Taxonomy of the genus Begonia (Begoniaceae) in Mindanao, Philippines IV: Begonia bangsamoro subsp. bagasa (Begonia section Petermannia), a new subspecies from Zamboanga del Sur

A subspecies new to science, Begonia bangsamoro subsp. bagasa Naive (section Petermannia) discovered in Zamboanga del Sur, Western Mindanao, Philippines is herewith described and illustrated. The new subspecies differs significantly from the type subspecies in having staminate and pistillate flowers with very narrow tepals. A colour plate, notes on its distribution, habitat, phenology, proposed conservation assessment based on IUCN criteria as well as a checklist of Begonia species present in Zamboanga Peninsula are provided. With this discovery, Zamboanga Peninsula now holds a total of 17 Begonia taxa, and the very first subspecies described for the Philippine archipelago.

BEGONIA HEMICARDIA (SECT. PETERMANNIA, BEGONIACEAE), A RESURRECTED HETEROTYPIC SYNONYM AND NOMEN NUDUM

The nomen nudum Begonia hemicardia Elmer ex Merr. (Begonia sect. Petermannia) was coined by A.D.E. Elmer in 1915. He annotated one of his collections (14366 from Mount Bulusan, Luzon) in the PNH herbarium with the name but did not formally publish it. E.D. Merrill in 1923 recognised the name as a synonym of Begonia binuangensis Merr. After thorough studies of living and preserved specimens and the relevant literature, we found Begonia hemicardia to be different from B. binuangensis. Begonia hemicardia is allied to a group of climbing Begonia in the Philippines with axillary inflorescences and numerous, subsymmetrical, ovate to lanceolate-ovate leaves, namely B. aequata A.Gray, B. binuangensis, B. edanoii Merr., B. gracilipes Merr., B. lagunensis Elmer, B. megacarpa Merr., B. sarmentosa L.B.Sm. & Wassh. and B. wenzelii Merr. However, a combination of characters such as long internodes, large persistent stipules, serrate leaf margins, and long inflorescence with staminate flowers borne on a jointed rachis readily distinguish Begonia hemicardia from these other species, and we validly describe the new species here.

Embryology of Ficus tuerckheimii (subg. Spherosuke, Moraceae) and its relevance in interactions with its pollinator wasps, Pegoscapus sp. (Agaonidae)

• Ficus tuerckheimii has two female floral morphs with dimorphic stigmas. • Both floral morphs form showed cohesive synstigmas. • Wet stigmas are described for the first time within the genus Ficus. • The development of the anther wall in male flowers is a basic type. • Several evidence suggest that F. tuerckheimii is actively pollinated. Species in the Ficus (Moraceae) genus carry an inflorescence called syconium, formed by a fleshy, urn-shaped receptacle. This study aims to i) describe the embryology of Ficus tuerckheimii flowers at different developmental stages and ii) determine whether this species is pollinated actively or passively. The species is monoecious, with protogynous syconia and diclinous flowers. The syconia contain two pistillate floral morphs: one sessile with a long style and a symmetrically bilobed stigma, the other pedicellate with a short style and asymmetrical stigmatic lobes. The ovule of each flower type can develop into a seed or a (parasitic or pollinator) wasp. The gynoecium is pseudomonomerous; the flowers form a cohesive synstigma due to the proximity of the stigmatic papillae, which facilitates pollen concentration and pollen tubes growth in neighboring flowers. The staminate flowers are pedicellate and unistaminate. The anther dehiscence is longitudinal, rotating horizontally to open and release bicellular pollen grains. The syconium includes three different trichome types whose functions remain unknown. The drupelet fruit has a pericarp conformed of a tanniferous exocarp, a parenchymatic mesocarp, and a schlerenchymatic endocarp. We detected the following embryological characteristics that were previously undescribed for the genus and are potentially informative for the systematics of the family: i) wet stigmas, ii) a basic anther wall with a non-persistent epidermis and a multiplicative middle layer, iii) pollen grains that can germinate within the anther, iv) a profuse nucellus that later forms a perisperm, and v) a persistent perisperm. Altogether, the synstigma, the low anther-to-ovule ratio (0.12 SD ± 0.031), the smooth pollen ornamentation, and the specialized pollen collection and transport structures (corbiculae) of its pollinator wasps ( Pegoscapus sp., Agaonidae) suggest that F. tuerckheimii is actively pollinated.

Response to Selection for the Quantitative Traits in Bottle Gourd [Lagenaria siceraria (Mol.) Standl.

Present investigations were carried out in bottle gourd to assess the heritability and genetic advance for yield and quality traits. Fifteen hybrids of bottle gourd generated along with their six parents evaluated in a randomized complete block design with three replication at the Main Experiment Station, Department of Vegetable Science A.N.D. University of Agriculture & Technology, Narendra Nagar, Kumarganj, Ayodhya during the season of Zaid 2020 and Zaid 2021. High heritability was observed for number of primary branch per plant, days to first pistillate flower anthesis, days to first fruit harvest, days to first staminate flower anthesis and vine length during in Y1, days to first staminate flower anthesis, node number to first pistillate flower appearance, days to first fruit harvest, days to first pistillate flower anthesis and non-reducing sugar during in Y2, days to first pistillate flower anthesis, days to first staminate flower anthesis, days to first fruit harvest and non-reducing sugar during in pooled. High genetic advance as percent of mean was observed for average fruit weight, number of fruit per plant, fruit yield per plant and reducing sugar during seasons Y1 and Y2. The results indicated that these traits had additive gene effect and therefore, these are more reliable for effective selection for their further improvement.

НОВЫЙ ВИД РОГОЗА (TYPHA L., TYPHACEAE) С ЮЖНОГО САХАЛИНА

The results of a comparative morphological analysis of Typha sakhalinica Krasnova et Efremov are pre-sented. It was found that the morphological characters of the reproductive organs do not correspond to T. latifolia from the European part of Russia. The species is distinguished by staminate flowers with narrow membran-ous anthers, large and solitary pollen, degraded flowers in bunches of three. Plants are smaller, cauline leaves with axils and membranous auricles directed downwards. It is believed T. sakhalinica is a Pleistocene species that emerged from the isolation of Sakhalin Island from the mainland North-Eastern Asia.

A comparative approach reveals diversity of floral developmental processes in Urticaceae

Abstract Most species of Urticaceae, the nettle family, have small and inconspicuous, diclinous flowers, in which the perianth, androecium and gynoecium tend to vary in number. Our objective was to study the morphology of the developing flowers of seven species of Urticaceae to understand the pathways that lead to the different patterns of floral reduction and the complex development of pseudomonomerous gynoecia. Buds and flowers were prepared for electron and light microscopy. Vascularization was studied via high resolution X-ray computed tomography micro-CT. Only one whorl of perianth organs is initiated, except for Phenax sonneratii, the flower of which is achlamydeous; variation in perianth merosity results from absence of organs from inception; dicliny results from the absence of stamens from inception (pistillate flowers) and from pistil abortion at intermediate developmental stages (staminate flowers). The gynoecium results from a primordium that divides partially forming two congenitally united primordia (most species) or from a single primordium that apparently does not divide. The gynoecium is served by a single (four species), or two vascular bundles. This second condition is expected for a pseudomonomerous gynoecium. Pistillode or rudimentary carpels occur in staminate flowers. The comparison among species shows that the developmental processes acting in the floral construction in Urticaceae is diverse.

Integrative Analyses of Transcriptomics and Metabolomics in Sex Differentiation of Mulberry Flowers.

Sex determination and sex differentiation of plants are important physiological processes of plant development. Mulberry (Morus indica L.) is an important economic tree being cultivated in sericulture countries, and mulberry leaf is commonly used for sericulture. The transcriptomic and metabolomic differences between the staminate flowers (SFs) and pistillate flowers (PFs) of mulberry were investigated by RNA sequencing and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Overall, we uncovered 4,230 genes and 209 metabolites are significantly differentially expressed between the SFs and PFs of mulberry. The combined transcriptomic and metabolomic analysis revealed these differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs) are involved in flavonoid biosynthesis, galactose metabolism, plant–pathogen interaction, and starch and sucrose metabolism, and these detected DEGs and DEMs may be associated with sex differentiation of mulberry through the regulation of the enrichment pathways, such as the MAPK pathway, flavonoid biosynthesis, galactose metabolism, plant–pathogen interaction, and starch and sucrose metabolism. This study will provide a rich source for the analysis of the molecular mechanism of mulberry sex differentiation processes.

Inflorescence and floral development of Dipteronia sinensis (Sapindaceae): Demonstration of developmental constraints in the shaping of the flower

The inflorescence, floral structure and ontogeny, and breeding system of the relict woody species Dipteronia sinensis was investigated to understand the developmental basis for its floral Bauplan, more particularly the octandrous androecium, dimerous gynoecium and the occurring flower symmetry in comparison with Sapindaceae.The functionally unisexual flowers arise in thyrses. Structural floral dimorphism was clearly observed in the different lengths of style and filaments and in the presence or absence of fructifications. Functionally pistillate flowers are found in a terminal position of each cincinnus maturing before the functionally staminate flowers. Petals are initiated unidirectionally and there is a time overlap with stamens. No common petal-stamen primordium was observed. There are two empty stamen positions, always opposite the first initiated petal, between sepals 1 and 3, and opposite the second petal between sepals 2 and 4; subsequently stamens are displaced to accommodate to the available space. Two median carpels are almost apocarpous in early stages and produce two parallel ovules each that become later superposed. Floral dimorphism develops as a late event when pollen and ovules are formed.Empty stamen positions are inversely correlated with the sequence of initiation and delayed growth of the petals, suggesting that a subtle heterochronic shift is responsible for the balance between petal and stamen initiation. Although the flower is initially polysymmetric to weakly monosymmetric, the bicarpellate gynoecium causes a shift to disymmetry during the mid-developmental stage as in the sister genus Acer, differently from tricarpellate Sapindaceae. Floral development demonstrates the flexibility in building symmetry in Sapindaceae, which is linked with available space and subtle changes in the sequence of initiation, rate of development and reduction of floral organs. This study underlines the importance of analyzing developmental constraints responsible for the floral diversity of Sapindaceae and provides further support for a monosymmetric ancestry in Sapindaceae.