Inferior Ovary Research Articles

Peliosanthes epigynica (Asparagaceae, Convallarioideae), a new species from southeastern Vietnam

Peliosanthes epigynica, a new species occurring in a dry coastal forest in southeastern Vietnam (Ninh Thuan Province) is described and illustrated. It is distinguishable from any other Peliosanthes by a combination of the following character states: comparatively small elliptic leaf blades, drooping narrowly campanulate purple/violet flowers, and a nearly flat-topped, perfectly inferior ovary with a short straight (non-tortuous) conoid style. Besides data on morphological and ecological aspects, we provide notes on its taxonomic relationships to some other species similarly sharing completely epigynous flowers.

Peliosanthes thachii (Asparagaceae), a new species from Vietnam

Peliosanthes thachii is described and illustrated as a new species endemic to southern Vietnam. This is the fifth species found for the Neolourya group as it has a slender tortuous style with the stigma positioned above the level of anthers and an inferior ovary. The new species is morphologically closest to P. curviandra but it is distinguishable from all the others of the group by having smaller dimension leaves and floral parts, spherical and hardly open perianth, short and strongly tortous style and purple ovules. The data on phenology, distribution, and provisional assessment of conservation status of the new taxon are provided.

A reversal to hypogyny in Campanula alpina and its impact on capsule dehiscence: evidence from morpho-anatomy of the fruiting ovary

Introduction. Campanula alpina is a perennial herbaceous bellflower grown in the Eastern Alps, Carpathians, and Balkans. Fruit in Campanula species opens by the hippocrepiform slits in the fruit wall, which are formed by axicorns, elongated structures inside the ovary composed of lignified parenchyma cells. Our objectives were to reveal the fruit structure and dehiscence mode in C. alpina and compare it with C. latifolia, a type species of the genus Campanula. Materials and methods. Flowers and fruits at different stages of morphogenesis of C. alpina subsp. alpina were examined. Plant materials were sampled in two plots in the Chornohora massif of the Ukrainian Carpathians. Results. Contrary to other Campanula species, in C. alpina only the basal part of the ovary is fused with the calyx forming the flattened ovary base. The placentation is axile, the fruit wall and septas are parenchymatous, only axicorns are lignified. Dehiscence of the hanged fruit proceeds by the curving of axicorns outside by drying. In the dehiscent capsule viewed from above, hollow openings in the horizontal ovary base are exposed, and the curved axicorns attached to the crumpled fragments of the ovary wall are visible inside the ovary. Discussion. The dehiscence of the fruit in C. alpina proceeds through septifragal and hippocrepiform slits like in C. latifolia. The main differences are that the ovary is mostly superior, openings are located on the horizontal ovary base, and valves together with axicorns curve inside the ovary. The semi-inferior or nearly superior ovary insertion could be traced in illustrations in digital databases and researches for some taxa of Campanula section Medium. No issues have been made on the evolution of the ovary position in Campanuleae, since only the inferior ovary was referred for this tribe before the present article. The functional implications of shifts in the ovary position in C. alpina could be a result of selection of the pollination mechanism, or dissemination mode. Conclusions. The peculiarity of the fruit in C. alpina is the axicorns curving inside the ovary during the dehiscence. It is expected that deviation from the inferior ovary will be confirmed in other related species of the Campanula with pendent fruits. No argumentation about the evolution of secondary hypogyny in Campanula has been proposed so far.

Cytological characteristics of blueberry fruit development

Using the blueberry cultivar "Powderblue" after pollination, fruits at different developmental stages were collected for study. The transverse and longitudinal diameters, individual fruit weight, and fruit water content were measured during their development. Employing tissue sectioning and microscopy techniques, we systematically studied the morphological features and anatomical structures of the fruits and seeds at various developmental stages, aiming to elucidate the cytological patterns during blueberry fruit development. The results of our study revealed that the "Powderblue" blueberry fruit growth and development followed a double "S" curve. Mature "Powderblue" blueberries were blue-black in color, elliptical in shape, with five locules, an inferior ovary, and an average fruit weight of 1.73 ± 0.17 g, and a moisture content of 78.865 ± 0.9%. Blueberry fruit flesh cells were densely arranged with no apparent intercellular spaces, and mesocarp cells accounted for 52.06 ± 7.4% of fruit cells. In the early fruit development stages, the fruit flesh cells were rapidly dividing, significantly increasing in number but without greatly affecting the fruit's morphological characteristics. During the later stages of fruit development, the expansion of the fruit flesh cells became prominent, resulting in a noticeable increase in the fruit's dimensions. Except for the epidermal cells, cells in all fruit tissues showed varying degrees of rupture as fruit development progressed, with the extent of cell rupture increasing, becoming increasingly apparent as the fruit gradually softened. Additionally, numerous brachysclereids (stone cells) appeared in the fruit flesh cells. Stone cells are mostly present individually in the fruit flesh tissue, while in the placental tissue, they often group together. The "Powderblue" blueberry seeds were light brown, 4.13 ± 0.42 mm long, 2.2 ± 0.14 mm wide, with each fruit containing 50–60 seeds. The "Powderblue" seeds mainly consisted of the seed coat, endosperm, and embryo. The embryo was located at the chalazal end in the center of the endosperm and was spatially separated. The endosperm, occupying the vast majority of the seed volume, comprised both the chalazal and outer endosperm, and the endosperm developed and matured before the embryo. As the seed developed, the seed coat was gradually lignified and consisted of palisade-like stone cells externally and epidermal layer cells internally.

Identification and functional characterization of conserved cis-regulatory elements responsible for early fruit development in cucurbit crops.

A number of cis-regulatory elements (CREs) conserved during evolution have been found to be responsible for phenotypic novelty and variation. Cucurbit crops such as cucumber (Cucumis sativus), watermelon (Citrullus lanatus), melon (Cucumis melo), and squash (Cucurbita maxima) develop fruits from an inferior ovary and share some similar biological processes during fruit development. Whether conserved regulatory sequences play critical roles in fruit development of cucurbit crops remains to be explored. In six well-studied cucurbit species, we identified 392,438 conserved noncoding sequences (CNSs), including 82,756 that are specific to cucurbits, by comparative genomics. Genome-wide profiling of accessible chromatin regions (ACRs) and gene expression patterns mapped 20,865 to 43,204 ACRs and their potential target genes for two fruit tissues at two key developmental stages in six cucurbits. Integrated analysis of CNSs and ACRs revealed 4,431 syntenic orthologous CNSs, including 1,687 cucurbit-specific CNSs that overlap with ACRs that are present in all six cucurbit crops and that may regulate the expression of 757 adjacent orthologous genes. CRISPR mutations targeting two CNSs present in the 1,687 cucurbit-specific sequences resulted in substantially altered fruit shape and gene expression patterns of adjacent NAC1 (NAM, ATAF1/2, and CUC2) and EXT-like (EXTENSIN-like) genes, validating the regulatory roles of these CNSs in fruit development. These results not only provide a number of target CREs for cucurbit crop improvement, but also provide insight into the roles of CREs in plant biology and during evolution.

Exploring floral morphoanatomy and embryology in wild populations of Chrysolaena flexuosa (Vernonia, Asteraceae): a contribution to understanding its ornamental potential.

Chrysolaena flexuosa (Sims.) H. Rob. is a South American species in the tribe Vernonieae, with potential ornamental value: it has attractive inflorescences, is suitable for pot cultivation, and its cypselae are useful for dried flower arrangements. Apart from studies on the growth dynamics of this species under cultivation, chromosome number, DNA content, ploidy level, size, pollen viability, and the characterization of phenotypic and genetic variability, it is noteworthy that other aspects regarding the floral architecture, reproductive mode, and gametophyte formation of C. flexuosa have not yet been studied. For this reason, our study encompasses a floral morphoanatomical survey and a comprehensive assessment of gametophyte development in the species. As a result of this study, we report new floral morphotypes, confirming that the morphological variability of the species might be greater than speculated. The morphoanatomy of the androecium and gynoecium and the male and female gametophyte developmental characteristics are uniform in all the populations studied despite the different ploidy levels. Chrysolaena flexuosa has five tetrasporangiate stamens of the dicotyledonous type of development; all the populations studied displayed a unilocular inferior ovary with a single anatropous, unitegumented, and tenuinucellar ovule. Given that all the embryo sacs observed were of the Polygonum-type development regardless of the ploidy level, we infer that the populations analyzed are fertile and undergo sexual reproduction. Our results not only contribute further research in the field of breeding systems and propagation of this species, but also promote the successful introduction of C. flexuosa to the plant ornamental market.

A long noncoding RNA functions in pumpkin fruit development through S-adenosyl-L-methionine synthetase.

Long noncoding RNAs (lncRNAs) play important roles in various biological processes. However, the regulatory roles of lncRNAs underlying fruit development have not been extensively studied. The pumpkin (Cucurbita spp.) is a preferred model for understanding the molecular mechanisms regulating fruit development because of its variable shape and size and large inferior ovary. Here, we performed strand-specific transcriptome sequencing on pumpkin (Cucurbita maxima "Rimu") fruits at 6 developmental stages and identified 5,425 reliably expressed lncRNAs. Among the 332 lncRNAs that were differentially expressed during fruit development, the lncRNA MSTRG.44863.1 was identified as a negative regulator of pumpkin fruit development. MSTRG.44863.1 showed a relatively high expression level and an obvious period-specific expression pattern. Transient overexpression and silencing of MSTRG.44863.1 significantly increased and decreased the content of 1-aminocyclopropane carboxylic acid (a precursor of ethylene) and ethylene production, respectively. RNA pull-down and microscale thermophoresis assays further revealed that MSTRG.44863.1 can interact with S-adenosyl-L-methionine synthetase (SAMS), an enzyme in the ethylene synthesis pathway. Considering that ethylene negatively regulates fruit development, these results indicate that MSTRG.44863.1 plays an important role in the regulation of pumpkin fruit development, possibly through interacting with SAMS and affecting ethylene synthesis. Overall, our findings provide a rich resource for further study of fruit-related lncRNAs while offering insights into the regulation of fruit development in plants.

Comparative analysis of floral transition and floral organ formation in two contrasting species: Disocactus speciosus and D. eichlamii (Cactaceae)

Key messageContrasting morphologies in Disocactus are the result of differential development of the vegetative and floral tissue where intercalary growth is involved, resulting in a complex structure, the floral axis.Species from the Cactaceae bear adaptations related with their growth in environments under hydric stress. These adaptations have translated into the reduction and modification of various structures such as leaves, stems, lateral branches, roots and the structuring of flowers in a so-called flower-shoot. While cacti flowers and fruits have a consistent structure with showy hermaphrodite or unisexual flowers that produce a fruit called cactidium, the developmental dynamics of vegetative and reproductive tissues comprising the reproductive unit have only been inferred through the analysis of pre-anthetic buds. Here we present a comparative analysis of two developmental series covering the early stages of flower formation and organ differentiation in Disocactus speciosus and Disocactus eichlamii, which have contrasting floral morphologies. We observe that within the areole, a shoot apical meristem commences to grow upward, producing lateral leaves with a spiral arrangement, rapidly transitioning to a floral meristem. The floral meristem produces tepal primordia and a staminal ring meristem from which numerous or few stamens develop in a centrifugal manner in D. speciosus and D. eichlamii, respectively. Also, the inferior ovary derives from the floral meristem flattening and an upward growth of the surrounding tissue of the underlying stem, producing the pericarpel. This structure is novel to cacti and lacks a clear anatomical delimitation with the carpel wall. Here, we present a first study that documents the early processes taking place during initial meristem determination related to pericarpel development and early floral organ formation in cacti until the establishment of mature floral organs.

Some remarks on the taxonomic significance of the floral structure in several Miconia (Melastomataceae) species

The structural features of vegetative organs have been used in the identification of species de Miconia, Melastomataceae, but the data available are inconsistent because they are commonly subject to environmental variations. In the present work we have attempted to point out floral characters that can be employed in the taxonomy of the genus. Floral buds and flowers were obtained from herbarium vouchers, and plants that occur in natural environments of Brazilian state parks, embedded in historesin, and analyzed in light microscope. Flowers consist of perianth with homogeneous parenchymatous mesophyll, the inferior or semi-inferior ovary with collenchyma and/or parenchyma, anatropous or hemi-anatropous ovules, a single strand of transmitting tissue in the style, hypanthium with collenchyma and parenchyma, and poricidal anthers. Associated floral characters have value at the specific level, viz. perigynous hypanthium structure, filament structure, anther type, ovary position and number of carpels/locules, placentation, wall of the inferior ovary, vascular supply of the ovary, ovule type, and style structure. These structural characteristics of the flower can be useful at the specific and generic level.

Morpho-anatomy and habitat characteristics of Xanthostemon verdugonianus Náves ex Fern.-Vill. (Myrtaceae), a threatened and endemic species in the Philippines

A study provided insights on morphoanatomy of Xanthostemon verdugonianus, an endemic and vulnerable species in the Philippines. Sampling was conducted in its natural habitat with presence of dominant vegetation and rehabilitated sites of the species. In a purposive manner, quadrats were established to collect samples and describe the morpho-anatomy, associated species, and soil particle characteristics. The leaf is opposite with a distinct reddish color when young in shoot terminal. The leaf cuticle is distinctly thick, hypostomatic with presence of paracytic stomata, and the compact spongy layer could be an adaptation to xeric conditions. The stem and roots contain tissues manifesting secondary growth having secondary xylem and formation of outer bark. Inflorescence is corymb, complete flower is bright red, with prominent cup-shaped hypanthium, persistent lobe-shaped calyx, and inferior ovary. Fruit is globular capsule round-ovoid in shape with a woody texture. Placental seeds are visible upon splitting of matured fruits which are flattened and deltoid to semicircular shape. A total of 31 species under 18 flora families are associated with X. verdugonianus with the mean abundance of 8 species per plot. Ultramafic substrate was dominantly composed of medium sand particles, and the reddish color indicating oxidation of metallic elements in the soil. Analyzing the morpho-anatomical features can help to explain its endemicity, survival in the wild, and adaptation to climate change.

Merianthera calyptrata sp. nov. (Melastomataceae, Myrtales), a new candelabriform species from Minas Gerais, Brazil

Merianthera is a genus of flowering plants with up to now seven species occurring in eastern Brazil, in the states of Bahia, Espírito Santo, and Minas Gerais. It belongs to the tribe Pyramieae (Melastomataceae), and can be recognized by its shrubby or treelet habit with caducous leaves, 5-merous flowers with a strongly zygomorphic androecium, the latter with dimorphic stamens bearing complex dorsal connective appendages, as well as an inferior ovary and capsular fruits. We describe here a new species of Merianthera from two collections and a photographic record, all from the same locality, an inselberg in the Municipality of Jacinto, in northeastern Minas Gerais. Its candelabriform habit, with a fistulose stem, and solitary, axillary or cauliflorous flowers are only shared with M. burlemarxii. However, M. calyptrata R.Goldenb., Bochorny & Fraga sp. nov. has at least three characters that are absent in M. burlemarxii and all other species in the genus: the total absence of both a peduncle and bracteoles, the calyptrate calyx and the fruits developing from inferior ovaries and dehiscing through longitudinal slits. The first character appears to be unknown in other species in the family.

The Complete Chloroplast Genomes of Gynostemma Reveal the Phylogenetic Relationships of Species within the Genus.

Gynostemma is an important medicinal and food plant of the Cucurbitaceae family. The phylogenetic position of the genus Gynostemma in the Cucurbitaceae family has been determined by morphology and phylogenetics, but the evolutionary relationships within the genus Gynostemma remain to be explored. The chloroplast genomes of seven species of the genus Gynostemma were sequenced and annotated, of which the genomes of Gynostemma simplicifolium, Gynostemma guangxiense and Gynostemma laxum were sequenced and annotated for the first time. The chloroplast genomes ranged from 157,419 bp (Gynostemma compressum) to 157,840 bp (G. simplicifolium) in length, including 133 identical genes: 87 protein-coding genes, 37 tRNA genes, eight rRNA genes and one pseudogene. Phylogenetic analysis showed that the genus Gynostemma is divided into three primary taxonomic clusters, which differs from the traditional morphological classification of the genus Gynostemma into the subgenus Gynostemma and Trirostellum. The highly variable regions of atpH-atpL, rpl32-trnL, and ccsA-ndhD, the repeat unilts of AAG/CTT and ATC/ATG in simple sequence repeats (SSRs) and the length of overlapping regions between rps19 and inverted repeats(IRb) and between ycf1 and small single-copy (SSC) were found to be consistent with the phylogeny. Observations of fruit morphology of the genus Gynostemma revealed that transitional state species have independent morphological characteristics, such as oblate fruit and inferior ovaries. In conclusion, both molecular and morphological results showed consistency with those of phylogenetic analysis.

Fossil Leaves and Fruits of Tetramelaceae (Curcurbitales) from the Eocene of the Rocky Mountain Region, USA, and Their Biogeographic Significance

Premise of research. Eocene sediments of Colorado, Utah, and Wyoming contain fossil leaves and infructescences that appear to represent Tetramelaceae (Cucurbitales). Today, this family consists of two genera (Tetrameles and Octomeles) of towering rain forest trees native to India, Southeast Asia, and Australia.Methodology. We examined the fruit, seed, and leaf morphology of extant Tetramelaceae as a basis for recognizing fossil representatives. Fossils were studied from localities in the Parachute Creek Member of the Green River Formation in Utah and Colorado and in the Bridger and Aycross Formations of western Wyoming. Extant and extinct material was studied by light microscopy and micro–computed tomography (micro-CT) scanning.Pivotal results. Infructescences of Parvaspicula lepidioidea (Cockerell) comb. nov. conform to Tetramelaceae in their spicate arrangement of helically arranged, capsular, ribbed fruits with inferior ovaries and parietal placentation. Each fruit typically has four styles and dehisces apically between the styles, reminiscent of extant Tetrameles, but they share an apical disk and the bulbous stigmas of extant Octomeles. Leaves of Punctaphyllum glandulosum (Brown) comb. nov. conform to Tetramelaceae in their long petioles, basal marginal and intramarginal veins, and regularly spaced circular laminar glands. These glands are small and cover the laminae or are larger and concentrated in a single file row along the lamina margin. Punctaphyllum glandulosum varies in its base shape, lobe number, and margin type, matching the variation seen in extant Octomeles leaves.Conclusions. The repeated co-occurrence of Parvaspicula and Punctaphyllum and the morphological similarities of both of these organs with extant Tetramelaceae lead us to infer that they represent parts of the same extinct plant. These records serve as the first documented leaf and infructescence fossils of Tetramelaceae and suggest that the family once lived in North America, indicating broader biogeographic distribution than previously recognized.

Еволюційна й екологічна інтерпретація структури плодів однодольних рослин флори України

Background. Monocot plants in the flora of Ukraine embrace about 1000 species. The members of this group have various fruit types and ways of dissemination. In this review, the results of the evolutionary-morphological analysis of fruits in monocot plants of the flora of Ukraine and their structural adaptations to dispersal are presented. Gynoecium structure and morphogenetic fruit types in monocots. The features of the inner gynoecium structure and the relation between gynoecium and fruit structure were analyzed, and the main problems of fruit classification were detected. It was revealed that apocarpous fruits are often polymerous or oligomerous, composed of 3–6 one-seeded fruitlets. The species with inferior ovary often develop capsular fruits. One-seeded fruits represent the most reduced variant of the gynoecium structure and fruit wall anatomy, providing few structural traits for analysis. Ecological and functional features of fruits in monocots. The characteristics of dehiscent and indehiscent fruits, as well as adaptations to various ways of dispersal: myrmeco-, endozoo-, epizoo-, anemo-, hydro- and autochory are presented. Dehiscent fruits (follicle and capsule) reveal ventral, dorsal or double, dorsoventral dehiscence. One-seeded fruits and fruitlets are often adapted to hydrochory or anemochory. Trends of evolutionary changes of fruits in monocots. The most diverse fruits are found in low-species taxa of early monocots. Within the monocots, we can observe certain evolutionary trends: incomplete carpel fusion, the occurrence of superior one-seeded fruits and inferior many-seeded fruits. Each of these trends may be evoked by adaptations for pollination in gynoecium at the flowering stage. Conclusions. The present evolutionary morphological and ecological studies of fruits in monocot plants of the flora of Ukraine are impeded by controversial structural types of the gynoecium in some species and a scarcity of data on ways of dispersal of fruits and seeds. The precise carpological and carpoecological investigations of the monocots are desirable for many plants of the flora of Ukraine.

Monopyleglutinosa (Gesneriaceae), a new species from the western slopes of the Ecuadorian Andes.

Exploratory field expeditions to the western slopes of the Ecuadorian Andes resulted in the discovery of a new species of Monopyle (Gesneriaceae). Monopyleglutinosa J.L.Clark & Keene, sp. nov. is described as a narrow endemic from lowland forests along the border of the Reserva Ecológica Los Illinizas in the Province of Cotopaxi. The new species is unique for the presence of glutinous or sticky trichomes on the calyx lobes and outer surface of the inferior ovary. Based on IUCN guidelines, a preliminary conservation status is assigned as Critically Endangered (CR).

A Novel Early Cretaceous Flower and Its Implications on Flower Derivation.

Simple SummaryMany people are fascinated by beautiful flowers. Botanists have been intensively studying flowers to decipher their history. Various hypotheses have been advanced to account for the evolution of flowers. Unfortunately, most hypotheses are based on the understanding of modern flowers. Magnolia and related plants were once thought to bear the greatest resemblance to ancestral flowers. Naturally, botanists have been frequently surprised by new finds in the past century. A new flower named Lingyuananthus from the Early Cretaceous (about 125 million years ago) in China is the latest surprise for botanists. Distinct from all previously reported fossil flowers of similar ages, Lingyuananthus has an inferior ovary, syncarpy, and hypanthium. All three features were thought to be highly derived in angiosperms. Considering its Early Cretaceous age (the currently widely accepted earliest age of angiosperms and flowers), Lingyuananthus is a black swan that illustrates how astray botanists may have gone previously. Unable to account for the fossil flower diversity in the Early Cretaceous, botanical theories face a crisis. Among existing hypotheses, Zimmermann’s hypothesis, a long-time unfavored hypothesis, stands out like a black swan: it provides a better explanation for the origin and evolution of Lingyuananthus.Background: The origin and early evolution of angiosperms, by far the most important plant group for human beings, are questions demanding answers, mainly due to a lack of related fossils. The Yixian Formation (Lower Cretaceous) is famous for its fossils of early angiosperms, and several Early Cretaceous angiosperms with apocarpous gynoecia have been documented. However, a hypanthium and an inferior ovary are lacking in these fossil angiosperms. Methods: The specimen was collected from the outcrop of the Yixian Formation in Dawangzhangzi in the suburb of Lingyuan, Liaoning, China. The specimen was photographed using a Nikon D200 digital camera, and its details were photographed using a Nikon SMZ1500 stereomicroscope and a MAIA3 TESCAN SEM. Results: A fossil angiosperm, Lingyuananthus inexpectus gen. et sp. nov, is reported from the Lower Cretaceous of China. Differing from those documented previously, Lingyuananthus has a hypanthium, an inferior ovary, and ovules inside its ovary. Such a character assemblage indicates its angiospermous affinity, although not expected by any existing leading angiosperm evolutionary theory. Conclusions: New fossil material with a unique character assemblage falls beyond the expectation of the currently widely accepted theories of angiosperm evolution. Together with independently documented fossils of early angiosperms, Lingyuananthus suggests that at least some early angiosperms’ flowers can be derived in a way that has been ignored previously.

Refined Interpretation of the Pistillate Flower in Ceratophyllum Sheds Fresh Light on Gynoecium Evolution in Angiosperms.

Molecular phylogenetic analyses have revealed a superclade of mesangiosperms with five extant lineages: monocots, eudicots, magnoliids, Ceratophyllum and Chloranthaceae. Both Ceratophyllum and Chloranthaceae are ancient lineages with a long fossil record; their precise placement within mesangiosperms is uncertain. Morphological studies have suggested that they form a clade together with some Cretaceous fossils, including Canrightia, Montsechia and Pseudoasterophyllites. Apart from Canrightia, members of this clade share unilocular gynoecia commonly interpreted as monomerous with ascidiate carpels. Alternatively, the gynoecium of Ceratophyllum has also been interpreted as syncarpous with a single fertile carpel (pseudomonomerous). We investigate patterns of morphological, anatomical and developmental variation in gynoecia of three Ceratophyllum species to explore the controversial interpretation of its gynoecium as either monomerous or pseudomonomerous. We use an angiosperm-wide morphological data set and contrasting tree topologies to estimate the ancestral gynoecium type in both Ceratophyllum and mesangiosperms. Gynoecia of all three Ceratophyllum species possess a small (sometimes vestigial) glandular appendage on the abaxial side and an occasionally bifurcating apex. The ovary is usually unilocular with two procambium strands, but sometimes bilocular and/or with three strands in C. demersum. None of the possible phylogenetic placements strongly suggest apocarpy in the stem lineage of Ceratophyllum. Rescoring Ceratophyllum as having two united carpels affects broader-scale reconstructions of the ancestral gynoecium in mesangiosperms. Our interpretation of the glandular appendage as a tepal or staminode homologue makes the Ceratophyllum ovary inferior, thus resembling (semi)inferior ovaries of most Chloranthaceae and potentially related fossils Canrightia and Zlatkocarpus. The entire structure of the flower of Ceratophyllum suggests strong reduction following a long and complex evolutionary history. The widely accepted notion that apocarpy is ancestral in mesangiosperms (and angiosperms) lacks robust support, regardless of which modes of carpel fusion are considered. Our study highlights the crucial importance of incorporating fossils into large-scale analyses to understand character evolution.

Reproductive biology of two Lagenaria (Curcubitaceae) species

The genus Lagenaria (Cucurbitaceae) members are underutilised, neglected and on the verge of being threatened to extinction. An investigation of their reproductive biology will serve as the basis for effective strategic planning towards their conservation. The plant materials used for this study were collected from Osun, Ekiti and Niger States in Nigeria. Reproductive parameters, including seed germination, phenology and pollination mechanism, were documented. The highest seed germination rate was observed in the accession of Lagenaria siceraria from Ekiti Bowl. The male flowers appeared first, followed by female flowers’ emergence 14–28 days later, on the secondary shoots. The female flowers of each accession had unique inferior ovary shapes, which developed into different fruit shapes with distinct seed morphology. This study showed that the members of Lagenaria performed better as climbers than as trailers, and the number of fruits produced per accession depends on the size or weight of the fruit. Chrysomelidae and Coryna apicicornis beetles were the primary pollinators observed. Furthermore, the pollens were predominantly monad, spheroidal and tricolporate, and pollen stainability ranged between 81% and 91% in all the accessions studied. Therefore, the fruit and seed morphology were diagnostic for each accession, and the flowers were pollinated mainly by beetles

Micromorphology and Anatomy of the Flowers in Clivia spp. and Scadoxus multiflorus (Haemantheae, Amaryllidaceae)

Abstract The general morphology, micromorphology, and anatomy of the flowers of Clivia miniata , Clivia nobilis , and Scadoxus multiflorus were studied using light microscopy. The studied species have large syntepalous and trimerous flowers, short floral tubes with adnate stamens, and inferior ovaries that develop baccate fruit. The gynoecium in the studied species consists of synascidiate, symplicate, and hemisymplicate zones. The style is composed of postgenitally fused carpels. The few ovules are located in a locule in the synascidiate and symplicate zones in C. miniata and C. nobilis , whereas in S. multiflorus , solitary ovules occupy the synascidiate zone in each locule. The septal nectaries are located in the hemisymplicate zone and occupy the uppermost 29% to 56% of the ovary height. Septal nectaries are of the nonlabyrinthine lilioid-type, covered with secretory tissue only in its lower portion. Nectary channels are apical or subapical and open near the style base. A common pattern of the venation of the floral parts was observed in all species: Tepal traces and stamen traces were fused in the ovary wall, the style was supplied by dorsal carpellary bundles, and ovules were supplied by ventral carpellary bundles entering the ovary from the bottom. The observed gynoecium inner structure provides adaptations for the development of fleshy fruit, with thickened parenchymous ovary wall, ovary base, and ovary roof, and numerous branched vascular bundles in the ovary wall around locules.

Comparative anatomy and genetic bases of fruit development in selected Rubiaceae (Gentianales).

PremiseThe Rubiaceae are ideal for studying the diversity of fruits that develop from flowers with inferior ovary. We aimed to identify morpho‐anatomical changes during fruit development that distinguish those derived from the carpel versus the extra‐carpellary tissues. In addition, we present the fruit genetic core regulatory network in selected Rubiaceae species and compare it in terms of copy number and expression patterns to model core eudicots in the Brassicaceae and the Solanaceae.MethodsWe used light microscopy to follow morphoanatomical changes in four selected species with different fruit types. We generated reference transcriptomes for seven selected Rubiaceae species and isolated homologs of major transcription factors involved in fruit development histogenesis, assessed their homology, identified conserved and new protein motifs, and evaluated their expression in three species with different fruit types.ResultsOur studies revealed ovary‐derived pericarp tissues versus floral‐cup‐derived epicarp tissues. Gene evolution analyses of FRUITFULL, SHATTERPROOF, ALCATRAZ, INDEHISCENT and REPLUMLESS homologs suggest that the gene complement in Rubiaceae is simpler compared to that in Brassicaceae or Solanaceae. Expression patterns of targeted genes vary in response to the fruit type and the developmental stage evaluated.ConclusionsMorphologically similar fruits can have different anatomies as a result of convergent tissues developed from the epicarps covering the anatomical changes from the pericarps. Expression analyses suggest that the fruit patterning regulatory network established in model core eudicots cannot be extrapolated to asterids with inferior ovaries.