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The pollen of Trigonostemon and the related genera Dimorphocalyx, Ostodes, Tritaxis and Jatropha (outgroup) has been studied with light microscopy, and scanning and transmission electron microscopy. The two major pollen types within Trigonostemon correlate well with macromorphological characters. Species belonging to the Trigonostemon reidioides type have pollen with 'croton pattern' ornamentation, a pistil with deeply divided stigmas (to at least half the length of the stigma arm) and stamens with a protruding appendage on the connective, while species of the Trigonostemon verrucosus type have verrucate (to almost gemmate) pollen, stigmas that are shortly cleft and stamens without an appendage on the connective. Dimorphocalyx, Ostodes, Tritaxis and Jatropha (outgroup) have similar pollen morphology, while Trigonostemon deviates from these genera in the absence of the 'vertically' striate ornamentation on the subunits. Therefore, when compared with an existing phylogeny of the Euphorbiaceae, the pollen characters of Trigonostemon appear to be derived. Moreover, because the 'croton pattern' ornamentation itself is widely shared by the 'inaperturate crotonoids', the loss of that structure in the Trigonostemon verrucosus type pollen is considered a further apomorphy. [ABSTRACT FROM AUTHOR]

Heterostyly is a genetic polymorphism of anther and stigma heights, which are reciprocally placed among morphs. The maintenance of heterostyly has often been ascribed to disassortative mating, but alternative explanations are also possible, which can be examined by analyzing mating patterns. However, parental analysis with genetic markers has only been applied to a limited number of taxa, despite the phylogenetic diversity of heterostylous species. Here, we examined the mating patterns of a distylous primrose, Primula kisoana (Primulaceae), in its natural habitat, using 11 microsatellite markers. We also examined other fitness components. We found no differences in seed production, vegetative growth, or survival between morphs. However, the siring success of thrum fathers was much higher than that of pin fathers; outcrossing occurred unilaterally between thrum fathers and pin mothers, and selfing was more frequent in thrum plants than in pin plants. These findings are consistent with the explanation that distyly in this species is maintained either by overdominance due to previously reported recessive lethal effects of the thrum allele or by effectively dioecious mating if inbreeding depression is strong. We built a mathematical model of the overdominance hypothesis to confirm that it is logically sound. These results warrant further investigations into the possible roles of overdominance and dioecy in the maintenance of heterostyly. [ABSTRACT FROM AUTHOR]

Purpose The purpose of the study is to identify the high valuable compounds which are crocin, crocetin and zeaxanthin in the stigmas and stamens of Crocus sativus grown under controlled environment in Malaysia.Design/methodology/approach Spectrophotometry and high-performance liquid chromatography (HPLC) analysis were used to identify and measure crocin, crocetin and zeaxanthin content qualitatively and quantitatively in the stigmas and stamens of C. sativus grown under controlled environment in Malaysia.Findings The results of this study showed that crocin, crocetin and zeaxanthin were detected in the stigmas. However, among those three compounds, only crocetin was detected in the stamens. In the stigmas, the detectable level of crocin was high compared to crocetin and zeaxanthin. It was also found that crocetin was higher in the stamens compared to in the stigmas.Originality/value This is the first attempt in Malaysia that the stigmas and stamens were directly purified from the natural sources by means of no addition of preservatives as C. sativus has never been grown here before. Furthermore, limited reports are available regarding the identification of compounds in saffron stamens. [ABSTRACT FROM AUTHOR]

The family Malpighiaceae, particularly in the Neotropic, shows a similar floral morphology. Although floral attraction and rewards to pollinators are alike, stigmas and styles show more diversity. The stigmas were described covered with a thin and impermeable cuticle that needs to be ruptured by the mechanical action of the pollinators. However, this characteristic was only mentioned for a few species and the anatomy and ultrastructure of the stigmas were not explored. In this work, we analyze the morphology, anatomy, and ultrastructure of the stigma and style of Callaeum psilophyllum. Moreover, we identify the potential pollinators in order to evaluate how the disposition of the stigmas is related with their size and its role in the exposure of the receptive stigmatic surface. Our observations indicate that Centris flavifrons, C. fuscata, C. tarsata, and C. trigonoides are probably efficient pollinators of C. psilophyllum. The three stigmas are covered by a cuticle that remained intact in bagged flowers. The flowers exposed to visitors show the cuticle broken, more secretion in the intercellular spaces between sub-stigmatic cells and abundant electron-dense components inside vacuoles in stigmatic papillae. This indicates that the stigmas prepares in similar ways to receive pollen grains, but the pollinator action is required to break the cuticle, and once pollen tubes start growing, stigmatic and sub-stigmatic cells release more secretion by a granulocrine process. [ABSTRACT FROM AUTHOR]

The stigma plays several roles such as pollen hydration and selection, and pollen tube nutrition. In the Ficus -fig wasp mutualism, stigmata have an additional, almost unknown, function by representing a physical interface for both plant and wasp reproduction. We used light and electron microscopy to compare the detailed morphology of the stigmata of nine Ficus species of different sections and with different pollination modes and sexual expressions. Figs were collected at the stage when the stigmata were receptive for pollination. Stigmata in actively pollinated monoecious species have well developed papillae concentrated on the adaxial surface exposed towards the fig cavity. Conversely, the passively pollinated monoecious species have the whole surface of the stigmata covered by somewhat smaller papillae. In both actively and passively pollinated monoecious species these features are consistent, irrespective of style length. In all actively pollinated gynodioecious species, the stigmata of pistillate flowers were tubular or infundibuliform whereas in almost all actively pollinated monoecious species (except F. racemosa ) the stigmata were filiform, with one branch or two asymmetric branches. In gynodioecious species the short-styled flowers in “male” figs show a limited receptive surface with small papillae, while the stigmata of long-styled flowers in “female” figs are covered by papillae that extend down the sides of the style, increasing the stigmatic surface. In actively pollinated species, stigmata are cohesive, forming a common surface for pollen tube germination (= synstigma). The synstigma arrangement was quite variable: lax, cohesive or very cohesive, with entanglement by stigmatic papillae and stylar trichomes. Entanglement by stylar trichomes is common in gynodioecious species. The synstigma arrangement did not correlate with phylogeny or breeding system. This study is the first to report a very loose synstigma in actively pollinated monoecious Ficus species. Our analyses revealed that, in Ficus , the synstigma is functionally analogous to an extra-gynoecial compitum. Comparative studies will be required to test further hypotheses about the evolutionary determinants of such variation. [ABSTRACT FROM AUTHOR]

The dried stigmas of Crocus sativus constitute the saffron, which is considered to be the costliest spice of the world. Saffron is valuable for its constituents, which are mainly apocarotenoids. In order to enhance the production of apocarotenoids, it is imperative to understand the regulation of apocarotenoid biosynthetic pathway. In C. sativus, although the pathway has been elucidated, the information regarding the regulation of the pathwaygenes is scanty. During the present investigation, the characterization of promoters regulating the expression of two important genes i.e. CsPSY and CsUGT was performed. We successfully cloned the promoters of both the genes, which were functionally characterized in Crocus sativus and Nicotiana tabaccum. In silico analysis of the promoters demonstrated the presence of several important cis regulatory elements responding tolight, hormonesand interaction with transcription factors (TFs). Further analysis suggested the regulation of CsPSY promoter by Abscisic acid (ABA) and that of CsUGT by Gibberellic acid (GA). In addition, we also observed ABA and GA mediated modulation in the expression of significant TFs and CsPSY and CsUGT transcripts. Overall, the study addresses issues related to regulation of key genes of apocarotenoid pathway in C.sativus. [ABSTRACT FROM AUTHOR]

Plant stigmas and bee pollinators are competitors for pollen. Pollen placed on a pollinator's body can be picked up by conspecific stigmas or it can be collected by the pollinator as food. Hypothetically, one solution is for pollen to be placed on 'safe sites' on the pollinator's body, sites where the pollinator cannot easily remove it, leaving the pollen for stigmas. We compared 14 sites on the bumblebee body in terms of the ability of the bee to groom off fluorescent power, a dust that may be thought of as analogous to pollen. The safest sites were along the midline of the dorsal thorax, the dorsal abdomen, and the ventral abdomen. Next, we counted how much pollen is borne on the 14 sites by bees visiting one nectariferous and three nectarless Pedicularis species. In the four species, only 7, 26, 28, and 30% of pollen found on the bees were on safe sites. Finally, we observed that the 14 sites were contacted by stigmas of the four Pedicularis species; none of the most contacted sites were safe sites. Across all four Pedicularis species, pollen is mainly positioned on sites of the bee body that were beneficial for both the plant and the bee, not on sites detrimental to either of them. Our analysis showed that the conflict of interest between flowers and bees can be solved by cooperation. Pedicularis pollen is placed where it strengthens the mutualism between plants and pollinators. [ABSTRACT FROM AUTHOR]

Saffron is one of the most highly priced agricultural products in the world. Its prize can reach 20,000 €/kg retail and this is due both to the high demand and to the great cultivation and production costs. Several studies have demonstrated that differences in saffron quality are mainly due to the methodology followed in the processing of stigmas, and environmental conditions independent of the origin. Some authors found phenotypic variations within cultivated saffron, but very limited genetic diversity. The reason for the very limited genetic diversity in cultivated saffron is explained by its asexual mode of reproduction (propagation). The aim of this study was to assess the antimicrobial activity of stigma saffron, which were tested against different bacteria strains. The results obtained from the antimicrobial activity study indicate that stigmas of C. sativus have some antimicrobial effect. [ABSTRACT FROM AUTHOR]

Bervillé et al. express concern about the existence of the diallelic self-incompatibility ( DSI) system in Olea europaea, mainly because our model does not account for results from previous studies from their group that claimed to have documented asymmetry of the incompatibility response in reciprocal crosses. In this answer to their comment, we present original results based on reciprocal stigma tests that contradict conclusions from these studies. We show that, in our hands, not a single case of asymmetry was confirmed, endorsing that symmetry of incompatibility reactions seems to be the rule in Olive. We discuss three important aspects that were not taken into account in the studies cited in their comments and that can explain the discrepancy: (i) the vast uncertainty around the actual genetic identity of vernacular varieties, (ii) the risk of massive contamination associated with the pollination protocols that they used and (iii) the importance of checking for stigma receptivity in controlled crosses. These studies were thus poorly genetically controlled, and we stand by our original conclusion that Olive tree exhibits DSI. [ABSTRACT FROM AUTHOR]

Flower-visiting bees collect large quantities of pollen to feed their offspring. Pollen deposited in the bees’ transport organs is lost for the flowers’ pollination. It has been hypothesised that specific body areas, bees cannot groom, serve as ‘safe sites’ for pollen transfer between flowers. For the first time, we experimentally demonstrated the position, area and pollen amount of safe sites at the examples of Apis mellifera and Bombus terrestris by combining artificial contamination of the bees’ body with pine or sunflower pollen and the subsequent bees’ incomplete grooming. We found safe sites on the forehead, the dorsal thorax and waist, and on the dorsal and ventral abdomen of the bees. These areas were less groomed by the bees’ legs. The largest amount of pollen was found on the waist, followed by the dorsal areas of thorax and abdomen. At the example of Salvia pratensis, S. officinalis and Borago officinalis, we experimentally demonstrated with fluorescent dye that the flowers’ pollen-sacs and stigma contact identical safe sites. These results confirm that pollen deposition on the bees’ safe sites improves pollen transfer to stigmas of conspecific flowers sti. Future research will demonstrate the importance of safe sites for plant pollination under field conditions. [ABSTRACT FROM AUTHOR]

Clerodendrum indicum (Lamiaceae) is a medicinally important shrub. We have studied the details of its pollination ecology which was hitherto unknown. The work was done during three consecutive years 2012-2014, based on 118 plants occurring in three widely separated wild populations in West Bengal, India, together with 25 individuals grown in an experimental plot. Details of flower structure and dynamics of floral events, pollen production and pollen dispersal, visitors and pollinators, floral attractants and floral rewards and pollen transfer mechanism have been worked out by standard methodologies with a 10x high resolution hand lens (IRL), a Leica WILD M3B Stereo-binocular microscope (Switzerland) and a Leica DMLB compound bright field light microscope (Germany). The tubular flower of four-day longevity attracts its visitors by visual cues. Flowers are visited regularly by ten species of insects. On the basis of the visitor behaviour, these can be classified into three distinct categories, viz., visitors belonging to Category-I act on cushion and trichome nectaries of calyx and corolla respectively, those of Category-II act on the dehisced anthers and trichome nectaries of corolla while those of Category-III act on dehisced anthers as well as receptive stigma. Majority of the visitors belong to either Category-I or Category-II. They visit only the 2nd day flowers and never visit a 3rd day flower when the stigma assumes receptivity. Therefore, they are not regarded as pollinators but, act as pollen and/or nectar robbers. Those are discriminated by offering secretions from extra-nuptial nectaries of the flower. Visitor species of Category-III, represented by a species of Trigona, constitute the legitimate pollinator of the plant and thereby, making the plant monophilic. Pollen presentation from the bisexual, dichogamous and protandrous flower takes place on the 2nd day, while the stigma assumes its receptivity on the 3rd day of flower opening. Pollen transfer to the body of the pollinator by a 2nd day flower in its male phase is achieved by offering edible pollen grains. On the other hand, a 3rd day flower at its female phase is devoid of the reward (pollen grain). The yellow shiny receptive stigma of such a flower strikingly mimics the freshly dehisced anthers and the pollinators being lured by such a stigma inadvertently transfer pollen onto it. C. indicum is so far the only known species of flowering plants where deceit pollination occurs by anther-mimicking stigma in a bisexual flower. [ABSTRACT FROM AUTHOR]

The fungus Monilinia vaccinii-corymbosi infects open blueberry flowers via stigma and style, causing mummy berry disease. Management of flower infection in this pathosystem relies on multiple fungicide applications during bloom. However, flowers that open between spray applications may remain prone to infection because the stigmatic surface (infection court) is not exposed to active ingredient, unless there is systemic movement in the pistil and/or eradicant activity in the ovary. To quantify and compare pre- and post-infection fungicidal activity in flowers, we examine here the ability of two systemic fungicides to prevent flower infection and subsequent fruit colonization by M. vaccinii-corymbosi . The fungicides were applied before or after anthesis (first day of open bloom) in an experimental system where flower development stages and inoculation timing were monitored and controlled precisely. In greenhouse experiments with potted rabbiteye blueberry plants, treatment with fenbuconazole, triforine, or water was made when sufficient numbers of flower clusters at anthesis and earlier pre-anthesis stages were present simultaneously. Treated flowers ( n = 10,992) were tagged, observed daily, and individual flowers were pollinated and inoculated 1 day after opening. Fruit from treated flowers were assessed for incidence and severity of mummification. Both fungicides provided excellent protection to newly opened flowers that were at the anthesis stage during fungicide application, but differed in their activity in unopened flowers at pre-anthesis stages during application. Fenbuconazole suppressed infection in unopened flowers that were on average 2.5 days pre-anthesis at the time of application, whereas triforine provided substantial protection to earlier flower stages up to 6.5 days pre-anthesis. In a separate experiment to quantify post-infection activity ( n = 13,068 flowers), fenbuconazole and triforine significantly suppressed fruit mummification when applied within 2 and 5 days after anthesis, respectively (with inoculation and pollination 1 day after anthesis). Thus, the total window of activity of fenbuconazole in blueberry flowers was 4.5 days, whereas that of triforine was at least 11.5 days. Prevention of ovary colonization by eradicant activity appeared to be the predominant mode for superior activity of triforine against M. vaccinii-corymbosi in flowers. To better manage flower infection by this pathogen, active ingredients such as triforine with superior activity in floral tissues need to be identified and characterized. [ABSTRACT FROM AUTHOR]

This study was aimed at the identification and quantification of the protein components of the pollen grains in parallel with the distal stigmatic tissue of tetraploid cultivars. Proteomes were analyzed using iTRAQ 4plex labeling, peptides separation by online RP-nano-LC and analysis by ESI–MS/MS. Protein identification and quantification were made using the Asparagales database as a reference. A total of 524,037 MS/MS spectra were produced from pollen and stigma samples. From these, a total of 8368 peptides wereidentified corresponding to 994 unique peptides and 432 protein groups. Among them, 128 differentially expressed proteins were retained for further analysis. In absence of the daylily genome availability, we exploited numerous databases and bioinformatics resources to exploring the putative biological functions of these proteins. The profile of differentially expressed proteins suggests an important representation of functions associated to the signalling and response against endogenous and environmental stresses, including several enzymes implicated in the biosynthesis of antibiotics. The abundance in stigma of several structural proteins of the ribosomal sub-units as well as of the core histones suggest that the translation processes and the regulation of gene expression in stigma is a more active mechanism than in pollen. In addition, pollen prioritizes the synthesis of fructose and glucose as opposed to sucrose in stigma as a source of energy. Finally, the modulated proteins in Hemerocallis point to several pathways that give potential clues concerning the molecular mechanisms underlying the functions of the pollen and the stigmatic fluid in daylily reproduction. [ABSTRACT FROM AUTHOR]

The reproductive characteristics of Erodium somanum (Geraniaceae), a critically endangered endemic species, were investigated in order to evaluate the main factors that affect its reproductive success and to evaluate their importance on its conservation. The estimated pollen/ovule ratio was calculated as 1187. Pollen viability and stigma receptivity experiments showed that stigma receptivity and pollen viability were high and synchronous throughout the anthesis. E. somanum is a strictly dioecious species and pollinated by insects. Flower visitors in the studied populations were mostly beetles and ants. The average percentage of fruit formation for each plant was determined as 46%. Capacity of seed production for each plant was 36%. Seed viability and germination success were determined as 81% and 80%, respectively. When combined, the capacity of viable and germinative seed production for each plant was determined as 29%. The factor that most affects the reproductive success is thought to be the low density of pollinators. With the direct and indirect effects, population viability seems considerable. [ABSTRACT FROM AUTHOR]

Gentian ovary ring-spot virus (GORV) infected gentian plants by pollination with GORV-infected gentian pollen grains, but the virus was not horizontally transmitted to gentian plants by transfer of pollen from GORV-infected Nicotiana benthamiana plants. However, N. benthamiana plants were infected with the virus by pollination with infected gentian pollen as well as by pollination with infected N. benthamiana pollen. When infected gentian pollen grains were placed on N. benthamiana stigmas, germinating pollen tubes penetrated into the stigmas and the styles (stigma-style). Virus infection occurred during penetration of the stigma-style, and the virus subsequently spread systemically to the mother plant. On the other hand, most infected N. benthamiana pollen grains failed to germinate on gentian stigmas, and virus infections were not detected in the stigma-style. [ABSTRACT FROM AUTHOR]

Apocarpy is regarded as an original feature obtained during the evolution of angiosperms. Compared with syncarpous plants, apocarpous plants have some adaptive disadvantages in apocarpous plants, for example, the number of offspring is lower under conditions of uneven pollen-tube distribution. However, in some apocarpous species, extra-gynoecial pollen-tube growth (EGPG) may remedy this disadvantage. We conducted micro-observations and field studies of Sagittaria trifolia, to investigate the gynoecium structure and the pathway of pollen-tube growth in the entire gynoecium. In a single-carpel pollination experiment, we found that the extra-gynoecial pollen tubes from a carpel of S. trifolia were able to fertilize approximately 13 carpels. Simulated EGPG in the entire gynoecium of S. trifolia revealed that its effect on the seed set could be divided into two stages: stage of low/high-level stigmas pollination, in which the cutoff point was about 0.1. The seed set would be markedly improved during the low-level stigmas pollination stage by EGPG when the maximum distance of extra-gynoecial pollen tubes could span three carpels, as in the present experiment. Our simulation also showed that the high pollen load could enhance the effect of EGPG on the seed set, and if the number of germinating pollen is triple the carpel number in the gynoecium, a 100% seed set rate would be obtained when approximately 50% of the stigmas are pollinated. [ABSTRACT FROM AUTHOR]

In entomogamous plants, the presence and function of floral secretory structures, whose main role is to attract pollinators, is strictly associated with the pollination ecology and hence the reproductive success of the plant. The aims of the present paper were to analyse the micromorphology and anatomy of flower nectaries and stigmas in Viburnum opulus and V. lantana and to determine the function and microstructure of inflorescence trichomes in both taxa using light and scanning electron microscopy as well as histochemical assays. It was found that stigmas were formed by papillae, which contained lipids, polysaccharides, tannins, and pigments. Stigmatic secretion proceeded via cuticular pores. Floral nectaries formed a thick layer around the styles, and nectar was secreted through numerous nectarostomata. There were no traces of vascular bundles penetrating the nectary tissue. In turn, numerous tannin deposits were observed in the cells of the glandular parenchyma. Pedicels, hypanthia, and bracts had mainly peltate and capitate glandular trichomes as well as stellate non-glandular trichomes (in V. lantana). The trichomes were shown to contain lipids, mucilage, and tannins. Many similarities in the flower and nectaries microstructure and considerable heterogeneity were observed in the examined Viburnum species. Knowledge of the microstructural characteristics of flowers, nectaries, and trichomes may be important for the phylogenesis and taxonomy of the genus Viburnum and the family Adoxaceae. Additionally, floral and nectaries features are helpful in assessment of the relatedness between taxa and provide better understanding of the floral biology and pollination ecology. [ABSTRACT FROM AUTHOR]

Primulina maciejewskii F. Wen, R.L. Zhang & A.Q. Dong, a new species of Primulina (Gesneriaceae) from Guangdong, China, is described and illustrated. It is similar to P. lobulata and P. danxiaensis in leaf and flower shape, but can be distinguished by bract shape, peduncle, pedicel, and bract size, filament and anther indumentum, and number of bracts, staminodes and stigma. [ABSTRACT FROM AUTHOR]

Background Crocus sativus L. (saffron) belongs to Iridaceae family which is commonly cultivated in Asia, Europe and America. The commercial product and use of saffron comes from the dried stigmas which gives a yellow color, bitter taste and intense aroma. This spice has been used since ancient times because of its aromatic, flavor and coloring properties along with its functional characteristics. Saffron is applied in many food products as well as being utilized in medical treatments. Scope and approach Lately, scholars have focused on using herbal medicine for the healing of various diseases such as, tumor and heart-related disorders, along with functions such as antitussive, antioxidant, anti-inflammatory and antinociceptive, antidepressing, memory enhancing and treatment of Alzheimer's disease. The main purpose of this review is to highlight the recent advances of experimental in vitro and in vivo investigations focused on the stigmas and tepals of saffron, chemical composition, and application of its principal ingredients (crocin, picrocrocin and saffranal) in treatment of different diseases. Key findings and conclusions Despite the main usage of saffron is for culinary purposes, it also has significant applications in pharmaceutical and clinical fields. Saffron contains a number of bioactive components which are believed to be largely responsible for its health promoting properties including treating various disorders like asthma, atherosclerosis, painful menstrual periods and even depression; its role as an antioxidant with anti-cancerous and memory enhancing properties; its effectiveness at treating mild to moderate depression; and its high efficiency in lowering the levels of cholesterol and triglycerides in the blood of people suffering from cardiovascular diseases. The clinical findings suggest that saffron is a safe and effective plant. In the last decade, saffron has been studied for its unique properties to be employed within medical fields to treat many diseases. [ABSTRACT FROM AUTHOR]

Distylous species have two floral morphs with reciprocal positions of sexual whorls, functioning to promote cross-pollination. Additionally, most distylous species have an incompatibility system linked to the discrete variation of anthers and stigmas. Here we provide new data on heterostyly, reproductive biology and pollination in four Psychotria spp. from the Cerrado Region (Brazil). Psychotria deflexa, P. nitidula and P. trichophoroides fitted the distylous morphological syndrome, whereas P. prunifolia was monomorphic and self-compatible. Reciprocity varied across species, with the upper whorl of anthers and stigmas being more reciprocal than the lower whorl. Psychotria nitidula has a heteromorphic incompatibility system, whereas P. deflexa and P. trichophoroides showed partial self-compatibility. Psychotria prunifolia and P. trichophoroides were visited by large bees and exhibited lower reproductive efficacy than P. nitidula and P. deflexa, which are visited by wasps and small bees. Our results provide new evidence that the morphological distylous syndrome does not always co-occur with heteromorphic incompatibility and additional mechanisms (e.g. disassortative pollen transfer) may operate to maintain the polymorphism and isoplethy of species with different incompatibility system. [ABSTRACT FROM AUTHOR]

Context:Zea maysL. (Poaceae)Stigma maydisis an underutilized product of corn cultivation finding therapeutic applications in oxidative stress-related disorders. Objectives:This study investigated its aqueous extract against acetaminophen (APAP)-perturbed oxidative insults in rat hepatocytes. Materials and methods:Hepatotoxic rats were orally pre- and post-treated with the extract (at 200 and 400 mg/kg body weight) and vitamin C (200 mg/kg body weight), respectively, for 14 days. Liver function, antioxidative and histological analyses were thereafter evaluated. Results:The APAP-induced marked (p < 0.05) increases in the activities of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, gamma glutamyl transferase and the concentrations of bilirubin, oxidized glutathione, protein carbonyls, malondialdehyde, conjugated dienes, lipid hydroperoxides and fragmented DNA were dose-dependently extenuated in the extract-treated animals. The extract also significantly (p < 0.05) improved the reduced activities of superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase as well as total protein, albumin and glutathione concentrations in the hepatotoxic rats. These improvements may be attributed to the bioactive constituents as revealed by the gas chromatography–mass spectrometric chromatogram of the extract. The observed effects compared favourably with vitamin C and are informative of hepatoprotective and antioxidative attributes of the extract and were further supported by the histological analysis. Conclusion:The data from the present findings suggest thatStigma maydisaqueous extract is capable of preventing and ameliorating APAP-mediated oxidative hepatic damage via enhancement of antioxidant defence systems. [ABSTRACT FROM AUTHOR]

The stigma, the specialized apex of the Brassicaceae gynoecium, plays a role in pollen capture, discrimination, hydration, germination, and guidance. Despite this crucial role in reproduction, the global proteome underlying Brassicaceae stigma development and function remains largely unknown. As a contribution towards the characterization of the Brassicaceae dry stigma global proteome, more than 2500 Brassica napus mature stigma proteins were identified using three different gel-based proteomics approaches. Most stigma proteins participated in Metabolic Processes, Responses to Stimulus or Stress, Cellular or Developmental Processes, and Transport. The stigma was found to express a wide variety of proteins with demonstrated roles in cellular and organ development including proteins known to be involved in cellular expansion and morphogenesis, embryo development, as well as gynoecium and stigma development. Comparisons to a corresponding proteome from a very morphologically different Poaceae dry stigma showed a very similar distribution of proteins among different functional categories, but also revealed evident distinctions in protein composition especially in glucosinolate and carotenoid metabolism, photosynthesis, and self-incompatibility. To our knowledge, this study reports the largest Brassicaceae stigma protein dataset described to date. [ABSTRACT FROM AUTHOR]

Accumulation of reactive oxygen species (ROS) in the stigma of several plant species has been investigated. Four developmental stages (unopened flower buds, recently opened flowers, dehiscent anthers, and flowers after fertilization) were analyzed by confocal laser scanning microscopy using the ROS-specific probe DCFH2-DA. In all plants scrutinized, the presence of ROS in the stigmas was detected at higher levels during those developmental phases considered "receptive" to pollen interaction. In addition, these molecules were also present at early (unopened flower) or later (post-fertilization) stages, by following differential patterns depending on the different species. The biological significance of the presence ROS may differ between these stages, including defense functions, signaling and senescence. Pollen-stigma signaling is likely involved in the different mechanisms of self-incompatibility in these plants. The study also register a general decrease in the presence of ROS in the stigmas upon pollination, when NO is supposedly produced in an active manner by pollen grains. Finally, the distribution of ROS in primitive Angiosperms of the genus Magnolia was determined. The production of such chemical species in these plants was several orders of magnitude higher than in the remaining species evoking a massive displacement toward the defense function. This might indicate that signaling functions of ROS/NO in the stigma evolved later, as fine tune likely involved in specialized interactions like self-incompatibility. [ABSTRACT FROM AUTHOR]

Species integrity relies on the maintenance of reproductive isolation, particularly between closely related species. Further, it has been hypothesized that the presence of heterospecific pollen on flower stigmas adversely affects plant reproduction with increasing effect in closely related species. Using two pairs of co-occurring buzz-pollinated Thysanotus spp. in the Mediterranean climate region of Perth, Western Australia, we quantified the effect of heterospecific pollen on fruit and seed set. We first determined the mating systems of the two focal species using selfand outcross pollen, followed by separate treatments with heterospecific pollen within each species pair. Of the two species receiving pollen, Thysanotus triandrus had a mixed mating system, but with significantly lower fruit and seed set from self-pollen relative to outcross pollen. Thysanotus tenellus was autogamous with no difference in fruit or seed set between autogamous, self- or outcross pollinations. Heterospecific pollen had no effect on fruit or seed set of either focal species. These outcomes point to post-pollination reproductive isolation, consistent with a floral morphology that causes low specificity of pollen placement and thus a poor capacity for pre-pollination discrimination. Negative effects of heterospecific pollen, therefore, do not appear to play a role in the reproduction in this group of buzz-pollinated flowers. [ABSTRACT FROM AUTHOR]

A clambering bamboo endemic to the Lam Vien plateau, southern Vietnam and representing a new monotypic endemic genus, Yersinochloa H. N. Nguyen & V. T. Tran (Gramineae -Bambusoideae -Bambusinae), is described and illustrated. It has an indeterminate inflorescence, terminate leafy branches, pseudo-spikelets with only one perfect floret, unkeeled palea, three lodicules, six stamens with free filaments, anther apices with tiny spines, glabrous ovary with a long style, 3 plumose stigmas, and an oblong caryopsis with a relatively thin pericarp. [ABSTRACT FROM AUTHOR]

Information about the relative importance of competitive or facilitative pollinator-mediated interactions in a multi-species context is limited. We studied interspecific pollen transfer ( IPT) networks to evaluate quantity and quality effects of pollinator sharing among plant species on three high-Andean communities at 1600, 1800 and 2000 m a.s.l. To estimate the sign of the effects (positive, neutral or negative), the relation between conspecific and heterospecific pollen deposited on stigmas was analysed with GLMMs. Network analyses showed that communities were characterised by the presence of pollen hub-donors and receptors. We inferred that facilitative and neutral pollinator-mediated interactions among plants prevailed over competition. Thus, the benefits from pollinator sharing seem to outweigh the costs (i.e. heterospecific deposition and conspecific pollen loss). The largest proportion of facilitated species was found at the highest elevation community, suggesting that under unfavourable conditions for the pollination service and at lower plant densities facilitation can be more common. [ABSTRACT FROM AUTHOR]

The fate of male gametophytes after pollen reaches stigmas links pollination to ovule fertilisation, governing subsequent siring success and seed production. Although male gametophyte performance primarily involves cellular processes, an ecological analogy may expose insights into the nature and implications of male gametophyte success. We elaborate this analogy theoretically and present empirical examples that illustrate associated insights. Specifically, we consider pollen loads on stigmas as localised populations subject to density-independent mortality and density-dependent processes as they traverse complex stylar environments. Different combinations of the timing of pollen-tube access to limiting stylar resources (simultaneous or sequential), the tube distribution among resources (repulsed or random) and the timing of density-independent mortality relative to competition (before or after) create signature relations of mean pollen-tube success and its variation among pistils to pollen receipt. Using novel nonlinear regression analyses (two-moment regression), we illustrate contrasting relations for two species, demonstrating that variety in these relations is a feature of reproductive diversity among angiosperms, rather than merely a theoretical curiosity. Thus, the details of male gametophyte ecology should shape sporophyte reproductive success and hence the dynamics and structure of angiosperm populations. [ABSTRACT FROM AUTHOR]

The genus Dendromyza (Amphorogynaceae) comprises approximately 21 species with a distribution from the Malay Archipelago to southern Australia. Two new hemiparasitic species in this genus: D. hiepkoana from Irian Jaya and D. staufferi from Papua New Guinea are here described, illustrated and compared. Dendromyza hiepkoiana is similar to members of the genus Phacellaria (Benth.) where the leaves are very small and bract-like, but differs in its separate stigmas and chambered fruits that possess a crown of fibers on the endocarp. Dendromyza staufferi is allied to D. reinwardtiana (Bl. ex Korth.) Danser but differs from this species by broader, ovate rather than narrower, spathulate leaves and sessile inflorescences. Dendromyza staufferi also has an ovoid rather than elliptical endocarp and the crown of fibres at the apex of the endocarp are pilose. Due to their hemiparasitic nature and aerial habitat, species of Dendromyza are generally considered to be vulnerable in terms of conservation status. Based on the information available to us, however, the species described here are categorised as locally common or near threatened. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: Coflowering plants often share pollinators and may receive mixed species pollen loads. Although detrimental effects of heterospecific pollen receipt have been documented, trait-based modifiers of interactions on the stigma remain largely unknown. Chemicals that mediate interactions between sporophytes could also influence pollen-pollen or pollen-style interactions. We test for the first time whether nickel (Ni) accumulation in pollen can lead to "elemental allelopathy" and intensify the fitness consequences of heterospecific pollen receipt. METHODS: We grew Ni-hyperaccumulator Streptanthus polygaloides in soils augmented with three concentrations of Ni, measured pollen Ni concentration, and hand-pollinated non-Ni hyperaccumulator Mimulus guttatus. We assayed pollen germination, tube gro th and seeds of M. guttatus after pure and mixed species pollinations. KEY RESULTS: Streptanthus polygaloides pollen accumulated Ni in proportion to soil availability and at levels significantly greater than M. guttatus pollen. Altho ug h receipt of 5. polygaloides pollen increased M. guttatus pollen germination, it decreased the proportion of pollen tubes reaching the ovary and seed number. Increased Ni in pollen, however, did not significantly intensify the e ffect of S. polygaloides pollen receipt on M. guttatus seed production. CONCLUSIONS: Different levels of Ni in the pollen of S. polygaloides achieved in the greenhouse did not significantly reduce the fitness of M. guttatus. Stigma tolerance to Ni may also have contributed to the lack of response to increased Ni in heterospecific pollen. This study paves the way for additional tests in other metal hyperaccumulators and recipients, and to identify mechanisms of interactions on the stigma. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: Pollen size varies greatly among flowering plant species and has been shown to influence the delivery of sperm cells to the eggs. Relatively little is known, however, about the functional significance of within-species genetic variation in pollen size. This study tests whether pollen size influences the relative siring success of a pollen donor during in vivo pollen competition experiments. METHODS: We used two groups of ipomoea purpurea plants genetically divergent in their pollen sizes and applied equal number of pollen grains from one large-pollen and one small-pollen donor onto the same stigma. Using microsatellite genetic markers, we identified the pollen parent of each of the resulting progeny to determine the relative siring success of the competing donors. Competitions between donors of equal-sized pollen served as a control. KEY RESULTS: Differences in pollen size significantly affected the relative siring success of a pollen donor; larger-grained individuals outcompeted smallergrained competitors but not equal-sized competitors. Relative siring success, however, sometimes varied across different pollen recipients. CONCLUSIONS: Pollen size can influence the relative siring success of different individuals competing on the same stigma during postpollination processes. However, other factors, such as pollen-pistil interaction and environmental conditions, are likely to influence these competitions as well. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: Pollen grains are subject 10 intense dehydration before dispersal. They rehydrate after landing on a stigma or when placed in humid environment by absorbing water from the stigma or surroundings. Resulting fluctuations in water content cause pollen grains to undergo significant changes in volume. Thus, morphological or structural adaptations might exist to help pollen adjust to sudden volume changes, though little Is known about the correlation between pollen morphology and its ability to accommodate volume changes. We studied the effect of one morphological feature of pollen grains, the aperture number, on pollen wall resistance to water inflow in Arabidopsts thaliana. METHODS: We used three Atabidopsis thaliana mutants that differ in the number of apertures in their pollen (zero, four, or a mix of four to eight, respectively) and the wild type with pollen with three apertures. We tested pollen survival in solutions with various mannitol concentrations. KEY RESULTS: The number of intact pollen grains increased with increasing mannitol concentration for all pollen morphs tested. At a given mannitol concentration, however, an increase in aperture number was associated with an increase in pollen breakage. CONCLUSIONS: Aperture patterns, i.e., number, shape, and position, influence the capacity to accommodate volume variations in pollen grains. When subjected to water inflow, pollen grains with few apertures survive better than pollen with many apertures. Trade-offs between survival and germination are likely to be involved in the evolution of pollen morphology. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: One proposed function of long styles is to intensify selection among male gametophytes relative to short styles. If so, given sufficient competition, longer styles will have higher rates of pollen tube attritin (failure to reach the style base) with in the style than shorter ones. Alternatively, style length may influence pollen receipt, which itself may affect attrition rates. METHODS: We tested these predictions by collecting senescing styles from wild populations of two insect-pollinated Clarkia species. We examined the number of pollen grains adhering to the stigma, length of styles, and rates of attrition from the stigma surface to the stigma-style junction (SSJ), from the SSJ to the style base, and from the stigma surface to the style base. Multivariate analyses estimated the independent effects of pollen grains per stigma, the number of pollen tubes at the SSJ, and style length on attrition. KEY RESULTS: Style length was generally positively correlated w ith pollen receipt, and the number of pollen grains per stigma was positively correlated with all three attrition rates. In neither species was any attrition rate affected by style length independent of the number of pollen grains per stigma. CONCLUSIONS: Pollen attrition was mediated by style length, but the function of style length was primarily to increase the number of germinating pollen grains, which affected attrition rates either through stigma clogging or pollen-pollen interactions. Style length may have a direct effect on pollen receipt due to the stigma's position relative to pollinator body parts, but traits correlated with style length may also directly affect pollen receipt. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: Changes in the pollinator communities of marginal plant populations can affect their pollination quantity or quality. Geographic variation in pollination success can alter the reproductive advantage that female plants require to persist within gynodioecious populations. Particularly valuable is determining the pollination success at the prezygotic stage in self-compatible gynodioecious species whose females do not exhibit enhanced seed production. METHODS: In core and marginal populations of Daphne laureola, we analyzed the differences between hermaphrodites and females in the proportion of flowers visited, the stigma pollen loads, and the quantity of pollen tubes in styles. We also examined the relationship between the number of pollen tubes in styles vs. the number of pollen grains on stigmas using piecewise regression and binomial generalized linear mixed models. KEY RESULTS: Pollinators deposited larger pollen loads on flowers in marginal populations. In marginal populations, female flowers received more pollinator visits and more pollen grains on their stigmas, and they had more pollen tubes in their styles than did female flowers in core populations. Both piecewise regression and binomial GLMM analyses showed that females in marginal populations had a lower proportion of grains that developed tubes than females in the core populations, which suggests decreased pollination quality. CONCLUSIONS: More efficient pollination services in marginal populations decreased the overall differences in the prezygotic pollination success between the sex morphs. Our results also suggest that pollination quality is lower in females of marginal populations, which could be counteracting the increased pollination in females in marginal populations. [ABSTRACT FROM AUTHOR]

Background and Aims Floral traits are essential for ensuring successful pollination and reproduction in flowering plants. In particular, style and anther positions are key for pollination accuracy and efficiency. Variation in these traits among individuals has been well studied, but less is known about variation within flowers and plants and its effect on pollination and reproductive success. Methods Style deflexion is responsible for herkogamy and important for pollen deposition in Passiflora incarnata. The degree of deflexion may vary among stigmas within flowers as well as among flowers. We measured the variability of style deflexion at both the flower and the plant level. The fitness consequences of the mean and variation of style deflexion were then evaluated under natural pollination by determining their relationship to pollen deposition, seed production and average seed weight using structural equation modelling. In addition, the relationship between style deflexion and self-pollen deposition was estimated in a greenhouse experiment. Key Results We found greater variation in style deflexion within flowers and plants than among plants. Variation of style deflexion at the flower and plant level was positively correlated, suggesting that variability in style deflexion may be a distinct trait in P. incarnata. Lower deflexion and reduced variation in that deflexion increased pollen deposition, which in turn increased seed number. However, lower styles also increased self-pollen deposition. In contrast, higher deflexion and greater variability of that deflexion increased variation in pollen deposition, which resulted in heavier seeds. Conclusions Variability of style deflexion and therefore stigma placement, independent from the mean, appears to be a property of individual P. incarnata plants. The mean and variability of style deflexion in P. incarnata affected seed number and seed weight in contrasting ways, through the quantity and potentially quality of pollen deposition. This antagonistic selection via different fitness components may maintain diverse style phenotypes.. [ABSTRACT FROM AUTHOR]

Agricultural land management modify environments in such a way that ecosystem functions are impaired. The establishment of exotic plants, favoured by agricultural land management, may alter the foraging behaviour of native floral visitors and consequently the pollination service they provide. To determine whether agricultural land management affects the pollination service provided by floral visitors for the most abundant plant species in a Pampean grassland ecosystem, we compared the pollination service of native and exotic entomophilous plants in landscape fragments with or without current agricultural usage. Both the quantity (number of conspecific pollen grains deposited on stigmas) and quality (proportion of heterospecific pollen grains deposited on stigmas) of the pollination service was estimated for three to nine entomophilous plants in each landscape fragment. Agricultural land management reduced the quality of the pollination service due to an increase in the deposition of heterospecific pollen on stigmas. [ABSTRACT FROM AUTHOR]

Aspidistra cylindrica, a new species from southern Vietnam (Kon Tum province), is described and illustrated. The new species possesses a unique combination of cylindrical shape of pistil and shoot system with foliage leaves crowded in groups and not divided into petiole and lamina. Aspidistra cylindrica resembles A. muricata but differs in longer leaves, shorter and wider perigone, shorter pistil, shape and colour of perigone lobes, anther position, and stigma shape. The conservation status of A. cylindrica is assessed. A key for species of Aspidistra in southern Vietnam is provided. [ABSTRACT FROM AUTHOR]

A new species, Cryptocoryne joshanii Naive & Villanueva, from the island of Basilan, Philippines, is herein described and illustrated. It is comparable to C. usteriana, but differs significantly in having lanceolate leaves, acicular, outwardly recurved, purplish red stigmas and an erect spathe limb. Information on the geographical distribution, ecological data, phenology and conservation status as well as an identification key to the Philippine Crytocoryne species are provided. [ABSTRACT FROM AUTHOR]

Amorphophallus ravenii V. D. Nguyen & Hett., a new species of Araceae, is described from material collected in Vang Vieng District, Vientiane Province, Laos. This species is similar to A. khammouanensis A. Galloway and A. croatii Hett. & A. Galloway, but differs by having an appendix about half the length of the male zone, stigmas about 1.5 times as broad, unwinged rachises of the decompound leaf blade, and a subglobose tuber. [ABSTRACT FROM AUTHOR]

This study aimed to assess the acute toxicity and safety of flavonoid-rich extract from Maydis stigma (FMS) in mice. The in vitro antioxidant activity of FMS was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethyl-benzthiazoline-6-sulphonate) (ABTS) scavenging assays. Furthermore, the in vivo antioxidant of FMS against ethanol-induced oxidative damage in mice was determined by analysis of the serum total superoxide dismutase (T-SOD) activity, malondialdehyde (MDA) content, liver tissue glutathione (GSH) content, and protein carbonyl (PC) content in liver tissue. The oral administration of FMS at doses of 30 g/kg did not cause death in mice, and there were no significant biologically adverse effects in mice. These results indicated that the median lethal dose (LD50) is higher than this dose. The IC50 values of FMS for the DPPH and ABTS scavenging activity were 50.73 and 0.23 mg/mL, respectively. Meanwhile, FMS could significantly enhance T-SOD activity, reduce MDA content in the serum, increase GSH content, and decrease PC content in the liver tissue at the tested doses (25, 50, 100, 200 mg/kg· day). These results indicate that FMS can be generally regarded as safe and used potentially as a bioactive source of natural antioxidants. [ABSTRACT FROM AUTHOR]

Initial pollen-pistil interactions in the Brassicaceae are regulated by rapid communication between pollen grains and stigmatic papillae and are fundamentally important, as they are the first step toward successful fertilization. The goal of this study was to examine the requirement of exocyst subunits, which function in docking secretory vesicles to sites of polarized secretion, in the context of pollen-pistil interactions. One of the exocyst subunit genes, EXO70A1, was previously identified as an essential factor in the stigma for the acceptance of compatible pollen in Arabidopsis (Arabidopsis thaliana) and Brassica napus. We hypothesized that EXO70A1, along with other exocyst subunits, functions in the Brassicaceae dry stigma to deliver cargo-bearing secretory vesicles to the stigmatic papillar plasma membrane, under the pollen attachment site, for pollen hydration and pollen tube entry. Here, we investigated the functions of exocyst complex genes encoding the remaining seven subunits, SECRETORY3 (SEC3), SEC5, SEC6, SEC8, SEC10, SEC15, and EXO84, in Arabidopsis stigmas following compatible pollinations. Stigma-specific RNAsilencing constructs were used to suppress the expression of each exocyst subunit individually. The early postpollination stages of pollen grain adhesion, pollen hydration, pollen tube penetration, seed set, and overall fertility were analyzed in the transgenic lines to evaluate the requirement of each exocyst subunit. Our findings provide comprehensive evidence that all eight exocyst subunits are necessary in the stigma for the acceptance of compatible pollen. Thus, this work implicates a fully functional exocyst complex as a component of the compatible pollen response pathway to promote pollen acceptance. [ABSTRACT FROM AUTHOR]

Premise of research. Comparative studies of variation in the ecology and genetics of natural plant populations located at the limits and in the center of a species range provide fundamental insights into the historical formation of species distribution patterns. Methodology. In this study, we quantify variation in the ecological niche and the expression of a floral polymorphism across the range of the Mediterranean geophyte Narcissus dubius Gouan. An exhaustive data set of known locations was compiled to distinguish groups of geographically central and peripheral populations in both Spain and France. These occur across a double climatic gradient. First, there is a gradient from a hot and dry Mediterranean climatic regime in eastern Spain to a milder Mediterranean climatic regime in southern France (lower maximum temperature and shorter summer drought). Second, there is a shift to a more continental climate in peripheral populations in inland Spain. We also modeled the current climatic niche and produced historical projections of potential glacial refugia for this species. Pivotal results. Peripheral populations showed consistent patterns of ecological niche differences with a less rupicolous ecology, more bare soil, and a higher cover of annual species. The ecological niche was more variable among peripheral populations than among central populations. Peripheral populations showed a repeated pattern of loss of stigma-height polymorphism and floral traits indicative of a reproductive strategy based on within-morph mating (probably selfing to assure seed set). Climate models indicate that contemporary peripheral populations (particularly in Spain) occur in areas that were least likely to have served as glacial refugia. Conclusions. Historical isolation and recolonization may have shaped contemporary patterns of ecological niche and reproductive trait variation among central and peripheral populations. [ABSTRACT FROM AUTHOR]

Stigma exertion is one of the key factors for improving the outcrossing ability of wheat thermo-photo sensitive genic male sterile (TPSGMS) line. A DH population derived from K239S/K92S was constructed to investigate the inheritance of stigma exertion. K239S and K92S are TPSGMS lines with higher and lower stigma exertion rates (SER), respectively. The SERs of parents, reciprocal crosses and the DH population were evaluated for two consecutive years. The results showed that no significant difference was observed in SER between F1s of K239S/K92S and K92S/K239S, implying that stigma exertion was a trait controlled by nuclear gene (s). In the DH population, the segregation of low and high SERs fitted to a ratio of 3:1 by Chisquare test, suggesting that the stigma exertion of K239S was controlled by one pair of recessive genes. In addition, the effects of temperature and humidity on the expression of stigma exertion were also discussed. [ABSTRACT FROM AUTHOR]

An investigation of a questionable orchid led to the discovery of a new genus and species Thuniopsis cleistogama, endemic to Yunnan province, China. It is characterized by having a subglobose corm, a spike-like (racemose) inflorescence, half opened and spurless flowers, a collar-shaped stigma and subglobose capsules. Based on DNA sequence data from three gene regions (nuclear ribosomal ITS, chloroplast matK and trnL), we investigated its phylogenetic position within the tribe Arethuseae. Phylogenies using maximum likelihood and Bayesian inference support the recognition of Thuniopsis as a distinct genus, and suggest its close relationship to the genera Bletilla, Dilochia, and Thunia. The new genus is circumscribed and a description and illustrations of the new species are provided. The phylogenetic relationships among the genera in Arethuseae are accessed. Moreover, our phylogeny also shed light on the phylogenetic positions of several genera which, to date, remain uncertain. [ABSTRACT FROM AUTHOR]

Saffron is the commercial name of the dried stigmas ofCrocus sativusL. flower. Due to the high cost of saffron, adulteration sometimes occurs in the local market. In this study, the aroma fingerprints of saffron, saffron with yellow styles, safflower, and dyed corn stigma were detected by an electronic nose system. The features of the obtained signals from electronic nose system were extracted and used for data analysis. In this work, principal component analysis was used and the results were confirmed by back propagation artificial neural networks. The results revealed that the system can recognize the saffron adulteration satisfactorily. As a conclusion, it was found that the electronic nose could provide good separation of the saffron and adulterated one (safflower and other adulteration) as 100 and 86.87% classification accuracy, respectively, by means of artificial neural networks. The electronic nose was able to differentiate non-adulterated and adulterated saffron at higher than 10% adulteration level successfully. [ABSTRACT FROM PUBLISHER]

Dasylarynx anomalus is described as a new genus and species, based on two flowers preserved in Mid-Tertiary amber from the Dominican Republic. The fossil is hypothesized as being adapted for pollination by hummingbirds or long-tongued insects, with a slender perianth tube formed of 3 fused petals. The flower is bisexual, the stamens being positioned at the base of the corolla tube together with a single stipitate pistil. The tube is densely hirsute within, bearing trichomes from base to apex. The trichomes, although appearing stiff, were evidently flexible enough to allow the bills or mouthparts of visiting pollinators to reach the source of food. Only part of the androecium is visible. The fertile stamens are club-shaped, with introrse dehiscence. They are accompanied by several lattice-like staminodes that are perforated by numerous openings of various sizes. The combination of unique androecial characteristics, together with a tubular, non-lobed corolla, makes it difficult to place the fossil in any modern family of monocotyledons. [ABSTRACT FROM AUTHOR]

In many gynodioecious species, gender differences have been documented. Previous studies on populations of Lobelia spicata consistently documented hermaphrodites having larger corollas than females, but inconsistencies as to whether females had higher fruit set or not. In this study we expanded the data set on floral morphology, and to relate morphological differences to potential reproductive output we recorded stigma pollen loads and pollen tube growth to the ovary for both genders from four populations. Also, individuals were bagged to determine if and how much self-pollen deposition occurred on stigmas. Because this species is self-compatible but protandrous, it was thought unlikely to be able to self-fertilize through autogamy. Hermaphroditic flowers were larger than female flowers in four out of the six flower traits analyzed. Overall, hermaphroditic flowers had larger corollas and stigma-nectary distance, but female flowers had longer and wider stigmas and more ovules. Open-pollinated hermaphroditic flowers received more pollen grains on the stigma than female flowers. Positive correlations were found between floral morphological traits and stigma pollen load, but only for hermaphrodites. Pollen was found on the stigmas of all hermaphroditic bagged individuals and on a few female bagged individuals, though pollen tube growth was quite limited. Lastly, population differences were found. This study has identified several floral morphological traits and pollen grain/tube differences between genders and among populations for Lobelia spicata, supporting overall patterns identified in other gynodioecious species and adding a more detailed description of differences between the reproductive biology of each gender for this particular species. [ABSTRACT FROM AUTHOR]

Systematic investigations and phylogenetic analyses have indicated that Astelia, as currently circumscribed, is paraphyletic, with Collospermum nested within it. Further, A. subgenus Astelia is polyphyletic, and A. subgenera Asteliopsis and Tricella are paraphyletic, as currently circumscribed. Revision of the subgeneric classification of Astelia is warranted to ensure classification accurately reflects the evolutionary history of these taxa. Collospermum is relegated to synonymy within Astelia. Astelia is dioecious or polygamodioecious, with a superior ovary, anthers dorsi- or basifixed, pistillodes or pistils that have a single short or poorly defined style, a 3 lobed stigma, and fleshy uni- or trilocular fruit with funicular hairs that are poorly to well developed. Astelia subgenus Collospermum (Skottsb.) Birch is described. A key to Astelia sections is provided. Astelia hastata Colenso, A. montana Seem., and A. microsperma Colenso pro parte are resurrected and the new combination A. samoense (Skottsb.) Birch, comb. nov. is made. [ABSTRACT FROM AUTHOR]

Local and international information on sunflower pollination indicate that crop yield may be limited by the quality of the pollination service. This work focuses on the response of commercially-grown sunflower hybrids to variations in the amount and quality of the pollen delivered to stigmas, measured in terms of grain set, unit grain weight, grain oil concentration, and oil yield per plant as a way to assess the importance of entomophilous pollination for this crop. Three consecutive experiments including 2–8 experimental treatments each were conducted between 2004 and 2007 in Argentina. The results (a) demonstrate for the first time that the pollen amount and pollen quality that arrive to the stigma have a joint effect on sunflower grain set, (b) suggest that some yield crop components could be sensitive to this joint effect, and (c) remark the probable positive effect of the pollen redistribution across the head. Overall, results underline the importance of pollinators for the crop, and point out to possible mechanisms that explain their beneficial effect. [ABSTRACT FROM AUTHOR]

Sensitive stigma has been recognized to facilitate outcrossing. We hypothesized that species with different levels of sensitivity might have corresponding differences in components of their breeding system. In this study, three Mazus species with bilobed stigmas were used to test the hypothesis. We explored stigma behaviors of the species in reaction time, recovery time, permanent closing time, and the minimum pollen load causing permanent closure. We investigated floral traits, pollinator type and behavior, pollination intensity, and natural schedule of pollen deposition on stigma. Moreover, we evaluated the mating system of the species by checking seed set after controlled pollination treatments, namely, natural flowers with open pollination, enclosed flowers without pollination, and enclosed flowers with self and outcross hand pollination. Results indicated that stigma of M. pumilus (N. L. Burman) Steenis was not sensitive, whereas stigmas of M. miquelii Makino and M. stachydifolius (Turcz.) Maxim. closed and reopened quickly in response to pollination. Accordingly, hand pollination treatments revealed that seed set of self-spontaneous pollination in M. pumilus was similar to the other treatments. For M. miquelii, outcross pollen resulted in significantly higher seed set than self-pollen. Mazus stachydifolius was self-incompatible. Additionally, the corresponding characteristics in other components of the breeding system for each species were found. Our study indicated that the sensitivity of bilobed stigma might be linked with floral traits and the mating system in a given species. Sensitive stigma should be regarded as an evolutionary mechanism for enhancement of outcrossing. [ABSTRACT FROM AUTHOR]