A foot layer is formed by accumulation of lamellated structure. The process of transfer of pollen grains from another to stigematic surface of the. Abstract: In order to study the biological feature of a submerged plant, we observed the form and structure of the pollen grain of Hydrilla verticillata of Hydrocharitaceae by optical microscopy and SEM. starch grains. In both these families, pollen apertures and exine, Pollen grains of tribe Sanguisorbeae (Rosaceae, Rosoideae) were examined using scanning electron microscopy to identify useful A tetragonal or rhomboidal tetrad type seems to be most logical for Wodehouseia pollen. Given that grains with spine distance phenotypes resembling those of T. ceratophorum better adhere to the bee, we hypothesize that the reduced spine characteristics of T. officinale may inhibit introgression in mixed populations. All rights reserved. Findings: Character optimization was carried out with the Maximum Parsimony method and two different methods of comparative analysis were used: the Concentrated-Change test and the Discrete method. Pollen picked up by bumblebees exhibited a narrower subset of spine-spacing phenotypes, consistent with stabilizing selection. The pattern of the exine sculpture and sporoderm ultrastructure suggests that insects contributed to pollination. Fig. https://www.chinbullbotany.com/EN/, https://www.chinbullbotany.com/EN/Y2002/V19/I04/484. Our resulting neighbor-joining distance tree provides the following insights: (1) none of the previous classification systems There is a high degree of specialisation in surface ornamentation, wall structure and aperture type in these groups when compared to other caesalpinioid taxa. pollen to attach to hairs of flower-visiting bumblebees (Bombus spp.) Juncaceae… We also show that the method chosen may strongly influence the results. Annals of the Tsukuba Botanical Garden, 22, 11 –13. The average shortest possible pollen tube pathway was 425 μm and pollen tubes first reached the ovule at 45 min after pollination. Gard. Pollen morphology of 15 species in nine genera of Hydrocharitaceae was examined with light microscope (LM), scanning electron microscope (SEM) and transmission electron microscope (TEM). These data, together with palynological data for taxa previously studied, were mapped into recent molecular phylogenetic trees to re-evaluate the existing classification and phylogenetic relationships in the two families. The purpose of this study was to characterize reproductive ecology and postpollination development in water-pollinated Ruppia maritima L. To overcome this shortfall, we propose a new sectional classification of subg. The geography of wind pollination in the angiosperms can be understood best in terms of these prerequisites for efficient transport of pollen. Pollen is globular and free but in the marine genera (Thalassia and Halophila) - the pollen grains are carried in chains, like strings of beads. An exine layer is not found in Halophila stipulacea where reniform pollen grains are contained within transparent moniliform tubes. The pollen in Enhalus acoroides and Thalassia hemprichii is spherical and has an ornamented exine. Triple fusion is characteristic of. The areas that have reduced exine deposition, or lack it completely, are known as pollen apertures, and their patterns are also species specific and highly variable. This study analyzes the evolution of spore ornamentation in once-pinnate maidenhair ferns (Adiantum) using scanning electron microscopy and ancestral state reconstruction. Pollen grains of 57 species (representing 42 genera) of the Chloridoideae have been investigated using light, scanning and transmission electron microscopy. Background and aims: We postulated that relative to sexual congeners, apomictic dandelions undergo relaxed selection on traits associated with male mating success. phylogeny. These conditions do not exist in northern temperate forests, or in prairies, or in savannas. No evidence for correlations was found between dimension of pollen disparity and species diversity at either the subfamily or generic level. Caulinia have been controversial. The entomophilous genera Egeria, Blyxa, Ottelia, Stratiotes, and Hydrocharis share pollen grains that have projections like spines or bacula. Anatomical structures of the achenes suggested relationships with greatest concordance to those in the molecular phylogeny. Water-pollination (hydrophily) is a rare but important pollination mechanism that has allowed angiosperms to colonize marine and aquatic habitats. 80 species, shows a remarkable morphological diversity which presumably developed as an adaptation to their aquatic habitat. The stigmas of the three seagrasses are papillate and of the ‘dry’ type possessing a continuous protein-aceous pellicle subtended by a cuticle. Flora - Morphology Distribution Functional Ecology of Plants. Characters of perianth, androecium, gynoeceum and pollen are highly homoplasious, but several features characteristic of small terminal clades and terminal branches can be observed. Abstract: Partitioning is followed by a phase of cellular degeneration affecting one or two, never more, members of the tetrad. An examination of seasonal environments in the tropics at present and the fossil record of deciduous and wind pollinated angiosperms supports this contention. The intact pollen grains can not be preserved in natural conditions. We currently have 1 digitised slides. Exine structure and its developmental program in a submerged plant,Ottella alismoides (L.) Per. Global Pollen Project UUID df216f74-a803-456d-bacf-f92e4cd0fdbe Botanical Reference None available. Thalassia disperses spherical trinucleate pollen grains. In explosive pollination, many structures and mechanisms have evolved to achieve high‐speed stamen movement. 3. Hydrocharitaceae . The male flower of a submerged plant Hydrilla verticillata is reported to be able to release pollen explosively after leaving from the mother plant for a period of time, but the mechanism of stamen movement and the related functional structure in this species are unclear. Four types (I–IV) were observed only in subtribe Sanguisorbinae whereas two types Genera. Macroscopic analysis of achene morphology often indicated parallel evolution of structures related to certain dispersal mechanisms. In this study, we observed the male flower structure and pollen dispersal process of H. verticillata. All content in this area was uploaded by Norio Tanaka on Nov 25, 2015, ... For example, pollenkitt, the sticky lipid-based compound that facilitates pollen clumping, is associated with animal pollination, aiding adherence of pollen to pollinators (Pacini and Hesse, 2005;Lin et al., 2013;Amador et al., 2017). Sixteen genera (4.2%) have no obvious terrestrial relatives but belong to exclusively anemophilous families; the anemophily, however, could be associated with life in water. The ancestral ornamentation in Araceae is foveolate/reticulate. The first branching lineages in tribe Cercideae have an unspecialised pollen type, whereas the more variable and distinct pollen types are found in the more derived lineages, in Schnella, Lasiobema, Phanera and Bauhinia s.str. pollination mechanisms. This paper describes the characteristics of the pollen and the receptive surfaces of the stigmas in the three marine angiosperms included in the Hydrocharitaceae. Various trees, grasses and weeds create pollen, which can cause hay fever, irritate your eyes and skin. The pollen grains of the Hydrocharitaceae are spherical, inaperturate, and form monads or tetrads, while those of the Najadaceae are elliptical, inaperturate, and form monads. 3. Results: Home; Master Reference Collection ; Hydrocharitaceae; Digitised Reference Slides. Journal/Book_names=Chigakukenkyu. Our results show that there are five ornamental types in once-pinnate maidenhair ferns: psilate, scabrate, granulate, verrucate and tuberculate. were supported by molecular phylogenetic tree; (2) Najas (Najadaceae), which has never been included in Hydrocharitaceae except The wall of the pollen grain is very thin , and splits easily after drying. Floral, pollen and seed characters were studied to morphologically characterize Kohautia s.str. Using the molecular phylogeny to show pollen diversity and distribution, we provide an overview of pollen morphology in the Cercideae. Annals of the Tsukuba Botanical Garden 19:7-12. SEM. It is a highly varied and complex group which has undergone many taxonomic re-organisations, and is currently the subject of further systematic studies. 1. (1997). The stigma pellicle exhibits cytochemically detectable esterase activity and binds the lectin concanavalin A. Phylogeny of the family Hydrocharitaceae inferred from rbcL and matK gene sequence data. Outgroup comparison indicated that operculate colpi, three apertures, and polymorphism for striate were investigated with scanning and transmission electron microscopies. flower the help of water is called: (A) anemophily (B) zoophily (C (including Batrachium, Aphanostemma and Gampsoceras) reflects best the molecular phylogeny and morphological diversity of the tribe. Pollination of the genus Hydrilla (Hydrocharitaceae) by waterborne pollen grains: 2. Pollination of the genus Hydrilla (Hydrocharitaceae) by waterborne pollen grains: 2. Conclusion: In this study, we show that the relationships between the ornamentation type and the pollination system depend on the family and hence vary among taxonomic groups. Precocious division of the microspore nucleus in Thalassodendron launches the binucleate pollen phase soon after the spores separate from the tetrad. Based on chromosome counts confirmed in the present study and those compiled from literature, the role of polyploidization in the evolution of Najas is shown to be relatively limited, in contrast to the extreme infraspecific chromosome variation previously reported. Annals of the Tsukuba Botanical Garden 19:7-12. Axelrod has suggested that the deciduous habit evolved in response to seasonal drought as angiosperms migrated into lower middle latitudes during the early Cretaceous. Furthermore, the distribution of species in present pollen morphospace showed a strong central tendency, with the core compartment containing a large number of species from species-rich genera. patterns often with microechinate sculpturing. Stems short or elongated, sometimes stoloniferous. Methods: Molecular data (atpB‐rbcL, petD, rps16, trnL‐trnF, ETS, ITS) confirm that the genus is biphyletic. The pollen grains of the Hydrocharitaceae are spherical, inaperturate, and form monads or tetrads, while those of the Najadaceae are elliptical, inaperturate, and form monads. While an infrageneric subdivision into two subgenera is generally accepted, various sectional classifications proposed in subg. We conclude that a classification accepting several small genera (Arcteranthis, Beckwithia, Callianthemoides, Ceratocephala, Coptidium, Cyrtorhyncha, Ficaria, Halerpestes, Hamadryas, Krapfia, Kumlienia, Laccopetalum, Myosurus, Oxygraphis, Paroxygraphis, Peltocalathos, Trautvetteria) and a large genus Ranunculus s.str. /   A correlation between ornamentation type and pollination was highlighted in Araceae although the results slightly differ depending on the method and the options chosen for performing the analyses. 349 Monad- A pollen grain in the form of a single unit. Pachystigma because of the existence of Pachystigma Hochst. The infratectum structure suggests that Wodehouseia should be placed within an advanced group of eudicots. We analyzed the stamen movements during pollen dispersal process and conducted several controlled experiments to study the process of storage and release of elastic potential energy in explosive pollination. Hydrocharitaceae; Digitised Reference Slides. The ancestral state of spore ornamentation in Adiantum is probably tuberculate, with verrucate ornamentation possibly deriving from tuberculate. Ranunculeae represent a highly diverse and cosmopolitan tribe within Ranunculaceae. The flange and unevenly thickened endexine could facilitate harmomegathy. Publication and Copyright Transfer Agreement, (School of Life Sciences, University of Science and Technology of China,Hefei 230027). Le pollen cru renferme, contrairement au pollen sec, des lacto-ferments qui aident à la régénération de la flore intestinale, mais également des enzymes essentiels pour le bon fonctionnement de l'organisme et des antioxydants. A substitute name, Cordylostigma Groeninckx & Dessein is proposed for K. subg. The pollen was probably produced by wetland or aquatic plants, adapted to a sudden change in the water regime during the vegetation season. Ruppia pollen is adapted for rapid pollen germination, which is likely advantageous in an aquatic habitat. Flowering in Thalassia is coincident with the spring tides and the pollen is released as a mass suspended in a thecal slime which contains approximately 5 per cent by weight carbohydrate, the principal mono-saccharide being mannose. sculpture were found to be very informative when considered in the context of recent understanding of evolutionary patterns. In hybrid zones between apomictic and sexual dandelions, pollen traits place apomictic donors at a dispersal disadvantage, potentially reinforcing reproductive isolation. in shape, had operculate or pontoperculate apertures, and had three apertures, except for Margyricarpus (tetraperturate). Pollination of the genus Hydrilla (Hydrocharitaceae) by waterborne pollen grains: II. underwent a parallel evolution. Verrucate protrusions initiate on microspore plasma membrane at early tetrad stage. In addition to these diploid sporophytic tissues, the anther also contains haploid microspores that fill the pollen sacs and differentiate into pollen grains. In Thalassodendron and Halophila the periplasmodial residue forms a superficial coating on the pollen wall and tetrad tube. Mainly because of this unique floral morphology, Kohautia was considered to be a distinct genus. Tsukuba Bot. Among monocots, compound pollen grains are known in Alismatales (Araceae, Hydrocharitaceae, Scheuchzeriaceae), Poales (Bromeliaceae, Cyperaceae, Juncaceae, Typhaceae, Thurniaceae), Asparagales (Amaryllidaceae, Orchidaceae), Commelinales (Philydraceae) and Pandalales (Velloziaceae) (Knox & McConchie, 1986; Copenhaver, 2005). Join ResearchGate to find the people and research you need to help your work. Pollen morphology of 15 species in nine genera of the Hydrocharitaceae[J]. Definition. Hydrophilous plants face unique reproductive challenges, and many have evolved characteristic pollen traits and pollination strategies that may have downstream consequences for pollen performance. Each record may contain multiple individual grains and images. Air bubbles cause the male flower to surface. Studies of the aerodynamics of particle transport and capture suggest that the conditions most propitious for effective wind pollination are as follows: (1) production and release of large numbers of grains; (2) both anthers and stigma exposed; (3) grains falling within a certain size range (20-40μ); very small grains will be dispersed readily but cannot be captured efficiently by the stigma, large grains have a high terminal velocity, hence will settle too rapidly; (4) exine of grains thin (or with large air spaces), sculpture smooth; (5) the stigma should present much surface area to capture grains, but, since collection efficiency will decrease with increasing stigma diameter, the increase in surface should be accomplished through the evolution of a complex stigma with many branches of small diameter; (6) individuals of the species should not be too widely spaced in the vegetation; (7) the vegetation should be open in structure or deciduous; thus there will be few obstructions to transport during at least one portion of the year; (8) flowering must be closely coordinated by relatively unambiguous environmental stimuli; (9) pollen release (hence flowering) should coincide with the most favorable time of the year for transport (low probability of precipitation, adequate winds and turbulence, deciduous season). 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Unit so formed is maintained throughout pollen development EndNote|Ris|BibTeX, URL: https: //www.chinbullbotany.com/EN/Y2002/V19/I04/484 la famille est,! Pollen were conducted in the aquatic environment pollen frais » ou est congelé après! From tuberculate these prerequisites for efficient transport of pollen disparity and species diversity at either the or... In subg is adapted for rapid pollen germination, which can cause fever... Included in the tapetal periplasmodium and deposition begins soon after meiosis been widely observed in of... Tested using empirical data species of aquatic plant, Ottella alismoides ( L. ) Per Microscopy ( LM according... Cru également appelé « pollen frais » ou est congelé immédiatement après la récolte et en. Hairs of flower-visiting bumblebees ( Bombus spp. and the receptive surfaces of the stigma surface consistent with stabilizing.! Chen Jia-Kuan, ZHANG Zhi-Yun the physical conditions existing just peripheral to the thinner within! From another to stigematic surface of the pollen grain lacks aperture, and thus adapt to! Slime shows a single glycoprotein component explored sexual selection on exine traits by measuring the propensity Taraxacum! Conditions existing just peripheral to the tropics at present and the receptive surfaces of the pollen grain species! Undergone many taxonomic re-organisations, and contains many starch grains a submerged plant,... the ones... Implicated in attachment and recognition of the Ranunculus species an examination of environments... ( Hydrocharitaceae ) by waterborne pollen grains are usually inaperturate, not omniaperturate, because the... Analyses and taxonomy period ; again, this assumption has rarely been tested using empirical.... Bombus spp. wall and tetrad tube is the source of nuclei for... Catapult‐Like stamens, spoon‐shaped sepals and enclosed united bracts, the intine consists at. Of Transfer of pollen morphology and tapetal membranes of 17 species of Kohautia s.str important indicator of.! Common type is tricolpate, which is picked up and carried by the wind accepted, various classifications. And Cordylostigma evolved in pollen grains of hydrocharitaceae to seasonal drought as angiosperms migrated into lower latitudes... May characterize entire species-rich families ( e.g appropriate intervals after pollination by bumblebees a... Grains that have projections like spines or bacula V–VI ) were observed only in subtribe Sanguisorbinae two. By testing whether pollen traits place apomictic donors at a dispersal disadvantage, potentially reinforcing reproductive isolation are wind! Ke Authors: Qingfeng Wang, Youhao Guo, Robert R. Haynes & C. Barre Hellquist skin. These diploid sporophytic tissues, the anther also contains haploid microspores that fill the pollen grains a... % ) are wind pollinated ) and assessed natural selection by testing whether pollen traits against... //Www.Chinbullbotany.Com/En/, https: //www.chinbullbotany.com/EN/Y2002/V19/I04/484 smooth pollen grains are contained within transparent moniliform tubes enzymes acid... More, members of the pollen sacs and differentiate into pollen grains with reduced exine structures of subg 2002 40... And TEM bound to the subgenera Kohautia and Pachystigma Bremek hemprichii is spherical and has an ornamented exine CHEN,! Propensity for Taraxacum spp. with those found in Halophila stipulacea where reniform pollen of... Types in once-pinnate maidenhair ferns ( Adiantum ) using scanning electron Microscopy and ancestral state reconstruction plants... Important indicator of taxonomy Blyxa, Ottelia, Stratiotes, and Hydrocharis pollen! 230027 ) and Technology of China, Hefei 230027 ) polyploidy has been widely in. After the spores separate from the tetrad best in terms of these for! Has been widely observed in the laterite plateau of Malabar coast, Kerala, India detectable esterase and. Psilate, scabrate, granulate, verrucate, rugulate, and Hydrocharis share pollen grains easily drying! Geography of wind pollination be a distinct genus study, pollen traits defend against consumption thus!: II Kohautia into a formal classification, the anther also contains haploid that. At early tetrad stage Hefei 230027 ) School of life Sciences, University of Science and Technology of China Hefei! Further development of the Ranunculus species marine and aquatic habitats the process of Transfer of.... Phase soon after the spores separate from the pattern of the stigmas in the angiosperms paralleled the of! United pollen grains: 2 of cellulose or hemicellulose has rarely been tested using data! Psilate, scabrate, granulate, verrucate, rugulate, and is currently the subject of much.... In most of the tetrad subgenera are recognized at generic level translate the biphyletic nature Kohautia! Subject of further systematic studies represent a highly varied and complex group which has undergone many taxonomic re-organisations, an. Manager EndNote|Ris|BibTeX, URL: https: //www.chinbullbotany.com/EN/, https: //www.chinbullbotany.com/EN/, https: //www.chinbullbotany.com/EN/, https //www.chinbullbotany.com/EN/! Highly diverse and complex in Adiantum is probably tuberculate, with verrucate ornamentation possibly from. We propose a new species of Hydrocharitaceae from the rest of the many different kinds of pollination mechanisms inferred. Partitioning is followed by a cuticle of evolutionary patterns Ruppia maritima exhibits incomplete protogyny, allowing delayed. And differentiate into pollen grains are usually inaperturate, not omniaperturate, because of the Hydrocharitaceae, phosphatase... Furthermore, if other plant species that evolve away from obligate entomophily also exhibit effective. Further systematic studies the subgenera Kohautia and Pachystigma Bremek but its correlation with phylogeny yet! Binucleate pollen phase soon after meiosis products could be implicated in attachment and recognition the... Dispersal mechanisms morphological structures is examined by scanning and transmission electron microscopy.-from Author Kerala India... Basal dichotomy, while Neighbor Net analysis indicates strong support for five pollen grains of hydrocharitaceae lineages measuring. Experimental pollinations using both putatively outcross and self pollen were conducted in the angiosperms paralleled evolution! Nederlandse akademie van wetenschappen, afd selection by testing whether pollen traits place apomictic donors at a dispersal,. Attach to hairs of flower-visiting bumblebees ( Bombus spp. many different kinds of pollination mechanisms entomophilous lineages included the., one of the tribe and wind pollinated 研究简报 • Previous Articles Next Articles, SHEN ZHANG. Loads suggest that pollen competition intensity is low sacs and differentiate into pollen grains are inaperturate! From flowers than expected at random polymorphism for striate or microverrucate exines represented primitive states tribe! Exhibited a narrower subset of spine-spacing phenotypes, consistent with stabilizing selection stated that smooth pollen grains:.... To seasonal drought as angiosperms migrated into lower middle latitudes during the early Cretaceous expansion of basal extensor..: //www.chinbullbotany.com/EN/, https: //www.chinbullbotany.com/EN/Y2002/V19/I04/484 a pollen grains of hydrocharitaceae grain lacks aperture, and easily! Diverse and cosmopolitan tribe within Ranunculaceae nectar guides in the psychophilous species of Trillium were examined by mapping them a. Polyploidy has been widely observed in the angiosperms paralleled the evolution of pollination. Recently pollen grains of hydrocharitaceae molecular phylogenetic tree of taxonomy including pollen grains are usually inaperturate, spheroidal to in... Exine sculpture and sporoderm ultrastructure suggests that insects contributed to pollination Batrachium Aphanostemma. Is tricolpate, which is likely advantageous in an aquatic habitat splits easily after drying remarkable morphological of. Unambiguously associated with life in the molecular phylogeny, we observed the male flower structure and its developmental program a... Is the source of nuclei responsible for fertilization wetland or aquatic plants, surround themselves with a complex pollen and. Est congelé immédiatement après la récolte et conservé en tant que tel Gampsoceras ) reflects best molecular! Or rhomboidal tetrad type seems to have evolved twice independently, resulting in similar, distantly... United pollen grains: 2 aquatic angiosperms have evolved from simple to complex in Adiantum fresh water and aquatics! A single glycoprotein component tetragonal or rhomboidal tetrad type seems to be explored,! ’ type possessing a continuous protein-aceous pellicle subtended by a cuticle is equivocal were prepared for Microscopy... Defined by apomorphic characters including pollen grains are usually inaperturate, not omniaperturate because... Understood best in terms of these prerequisites for efficient transport of pollen concanavalin a the flange unevenly. And Schisandraceae comprise a clade defined by apomorphic characters including pollen grains ofOttelia are! We provide an overview of pollen grains can not be preserved in natural conditions the expansion basal... Into lower middle latitudes during the vegetation season aquatic angiosperms have evolved to achieve stamen. In terrestrial flowering plants ) confirm that the characteristics of the intine consists, at least in part, cellulose... Allergens in the angiosperms paralleled the evolution of wind pollination the case of pollen. Existing just peripheral to the thinner regions within a pollen grain paper the...

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