Phlebodium Aureum Research Articles

The Mating Systems of Some Epiphytic Polypodiaceae

Genetic loads, estimated from sporophyte production by isolated gametophyte cultures, indicate mating systems of intragametophytic selfing in Campyloneurum angustifolium (in part), C. phyllitidis, Phlebodium aureum and Phymatosorus scolopendria, and intergametophytic mating in C. angustifolium (in part), Microgramma heterophylla and Polypodium pellucidum. Polyploidy characterizes the intragametophytic-selfing species, whereas the intergametophytic-mating taxa are diploid. The duplicated loci of polyploid taxa may mitigate the expression of recessive lethal alleles caused by intragametophytic selfing, whereas genetic load probably maintains the mating systems of the intergametophytically mating taxa. Enzyme electrophoretic patterns of fixed heterozygosity support allopolyploid origins of C. phyllitidis and P. aureum and confirm their intragametophytic mating systems. Antheridiogens, present in both groups, may promote intergametophytic mating in diploids through promotion of the early development of male plants in gametophyte populations and bisexuality in isolated gametophytes of polyploids if these gametophytes delay or do not attain insensitivity to their own antheridiogen. In the polyploids, antheridiogens may also alleviate low genetic variability through promotion of occasional outcrossing. The perennial, clone-forming habit of epiphytic Polypodiaceae increases the duration and the physical space occupied by derivatives of a single spore, thus expanding the chance of interaction with a later migrant. Genetic load, duplicated genes, and antheridiogens, together with a perennial and clone-forming gametophyte growth habit, interact to produce successful breeding strategies of these epiphytic species.

Cryopreservation of in vitro Grown Fern Gametophytes

Cryopreservation of in vitro Grown Fern Gametophytes

Ontogeny of the Sporangia of Sphaeropteris cooperi

Ontogeny of the Sporangia of Sphaeropteris cooperi

Antheridiogen production and response in Polypodiaceae species

Antheridiogen chemicals secreted by living fern gametophytes have been shown to influence production of male gametangia and thus mating systems in a large number of terrestrial fern species. Antheridiogens have not previously been thought to be prevalent in the Polypodiaceae, a large family composed mostly of tropical epiphytes. This study presents bioassay methods more sensitive than previously used to detect antheridiogen and demonstrates that antheridiogens are also operative in the Polypodiaceae and in epiphytic species. Seven species in six genera (Campyloneurum angustifolium, C. phyllitidis, Lepisorus thunbergianus, Microgramma heterophylla, Phlebodium aureum, Phymatosorus scolopendria, and Polypodium pellucidum) were tested for the presence of an antheridiogen system. All species tested except P. aureum were induced to produce antheridia precociously by their own antheridiogen and by that of Pteridium aquilinum (APt). Phlebodium aureum responded to APt and promoted antheridium formation in Onoclea sensibilis but did not respond to its own antheridiogen. Spores of all species except P. aureum were induced to germinate in darkness by antheridiogen of the same species and by APt and to form antheridia in the dark, further enhancing the possibility of intergametophytic mating.

Purification and Characterization of a Novel (R)-Mandelonitrile Lyase from the Fern Phlebodium aureum.

Using high-performance liquid chromatography and nuclear magnetic resonance we identified vicianin as the cyanogenic compound of Phlebodium aureum. The (R)-hydroxynitrile lyase involved during cyanogenesis in the catabolism of the aglycon ([R]-mandelonitrile) was purified to apparent homogeneity. The purified holoenzyme is a homomultimer with subunits of Mr = 20,000. At least three isoforms of the enzyme exist. In contrast to other hydroxynitrile lyases, mandelonitrile lyase (MDL) from P. aureum was not inhibited by sulfhydryl- or hydroxyl-modifying reagents, suggesting a different catalytic mechanism. The enzyme is active over a broad temperature range, with maximum activity between 35 and 50[deg]C, and a pH optimum at 6.5. In contrast to (R)-MDLs isolated from several species of the Rosaceae family, (R)-MDL from P. aureum is not a flavoprotein. The substrate specificity was investigated using immobilized enzyme and diisopropyl ether as solvent. The addition of cyanide to aromatic and heterocyclic carbonyls is catalyzed by this (R)-MDL, whereas aliphatic carbonyls are poorly converted.

SIEVE‐PORE DEVELOPMENT IN SOME LEPTOSPORANGIATE FERNS

Sieve‐pore development was examined in four species of leptosporangiate ferns: Phlebodium aureum, Platycerium bifurcatum, Pityrogramma calomelanos, and Regnellidium diphyllum. In all four species, sieve‐pore development is initiated with the formation of a barrel‐shaped periplasmodesmatal region—bounded by a narrow, electron‐dense band—around the prepore plasmodesma. This phase is followed by the deposition of callose, or of a calloselike substance, around the prepore plasmodesma. With deposition of this substance, the periplasmodesmatal region is no longer discernible, but an electron‐dense band continues to border the pore site. Perforation of the pore site involves removal of the calloselike substance and widening of the plasmodesmatal canal, both processes occurring more or less uniformly along the entire length of the pore site. During widening of the plasmodesmatal canal, numerous membranous elements appear within the pore. The number of membranous elements within the pore appears to decrease with increasing age of the sieve element. The location of feeding aphid (Myzus persicae) mouth‐parts indicates that the conducting sieve elements in Pellaea viridis are mature cells interconnected by membrane‐containing, callose‐free sieve pores.

Sieve-Pore Development in Some Leptosporangiate Ferns

Sieve-pore development was examined in four species of leptosporangiate ferns: Phlebodium aureum, Platycerium bifurcatum, Pityrogramma calomelanos, and Regnellidium diphyllum. In all four species, sieve-pore development is initiated with the formation of a barrel-shaped periplasmodesmatal region—bounded by a narrow, electron-dense band—around the prepore plasmodesma. This phase is followed by the deposition of callose, or of a calloselike substance, around the prepore plasmodesma. With deposition of this substance, the periplasmodesmatal region is no longer discernible, but an electron-dense band continues to border the pore site. Perforation of the pore site involves removal of the calloselike substance and widening of the plasmodesmatal canal, both processes occurring more or less uniformly along the entire length of the pore site. During widening of the plasmodesmatal canal, numerous membranous elements appear within the pore. The number of membranous elements within the pore appears to decrease with increasing age of the sieve element. The location of feeding aphid (Myzus persicae) mouth-parts indicates that the conducting sieve elements in Pellaea viridis are mature cells interconnected by membrane-containing, callose-free sieve pores.

Observations on the Structure and Function of Hydathodes in Blechnum lehmannii

The fronds of many ferns in the Polypodiaceae (Ogura, 1972) and Cyatheaceae (Weiler, cited in Lippmann, 1925) possess swollen vein endings associated with specialized adaxial epidermal cells. Their structure is similar in all ferns (Gardiner, 1883; Potonie, 1892; Poirault, 1893; Goebel, 1930; Guttenburg, 1934), including Blechnum lehmannii Hieron. (Figs. 1-3). The depressed epidermis (Fig. 3) suggested the term Wassergriibchen for the vein endings to European anatomists of the nineteenth century (e.g., Potonie, 1892). Vein endings on developing fronds secrete water (Fig. 1) when conditions reduce or stop transpiration (Mettenius, 1856; Haberlandt, 1894a; Goebel, 1926, 1930). In some species, the secreted water contains salts in solution which form scales after the water has evaporated (Mettenius, 1856; Potonie, 1892; Lippmann, 1925). Most sources report that water secretion is dependent on the metabolic activity of the specialized epidermal cells adaxial to the vein ending (Fig. 3, e); it is thus regarded as an active, or glandular, process (Gardiner, 1883; Haberlandt, 1894a, 1914; Lepeshkin, 1906; Stocking, 1956; Fahn, 1979). This conclusion is reflected in various references to the vein endings as water glands, salt glands, or chalk glands. There is, however, very little evidence to support any conclusions on the mechanism of secretion. All work on the subject was performed in the last century, and the results obtained are questionable due to the bias in experimental design which prevented testing of alternative hypotheses and to the possibility of artifacts in technique (see comments in Spanjer, 1898; Haberlandt, 1898; Lepeshkin, 1923). Moreover, the results are contradictory, since they have been interpreted as supporting either an active (Gardiner, 1883; Haberlandt, 1894a, 1914) or a passive (Spanjer, 1898) mechanism of secretion. Finally, all experiments were performed on a single species, Polypodium aureum L., and need not represent the situation in other ferns. Because the mechanism of secretion from vein terminations is unknown, they will be referred to in this paper by the term which, as originally defined by Haberlandt (1894b), did not presuppose a mechanism of secretion. Haberlandt used his term to refer to structures on above-ground portions of the plant, particularly foliage leaves, which function in water transfer to and from the plant surface. Previous work on the mechanism of hydathode secretion in ferns neglected important aspects of the problem. Despite the fact that root pressure could play a significant role in the secretion process, the relationship of root pressure to secretion in intact plants was not studied. In fact, there is no well documented account of root pressure in ferns. In addition, investigators could not analyze secretion from a structural standpoint because anatomical studies were confined to the mature, non-secreting hydathodes; the structure of the secreting hydathodes on developing leaves was unknown. In this study, the relationship of root pressure to secretion as well as developmental changes in hydathode structure were investigated in B.

Reciprocal Allelopathy between the Gametophytes of Osmunda cinnamomea and Dryopteris intermedia

Of the four interactions, gametophytes acting on gametophytes of different species permits study of the weakest link hypothesis in an experimental design where interspecific competition is minimal. Fern gametophytes were selected as experimental organisms because they are easily cultured and amenable to the experiments' requirements of control, replication, manipulation, and minimization of competition. Six fern species usually found growing in similar natural habitats were selected for the initial survey experiment which was conducted to determine if allelopathic effects were detectable between any of the species. By similar natural habitats we mean that, among the species selected, there is some overlap between their respective ecological amplitudes so that it is possible that they would be in competition for the same space. The literature on fern allelopathy is limited but increasing. Froeschel (1953) reported that water extracts of Polypodium aureum and Lycopodium clavatum

COMPARATIVE LEAF STRUCTURE OF SEVERAL SPECIES OF HOMOSPOROUS LEPTOSPORANGIATE FERNS

The structure of the mature leaves of 13 species from 9 families of homosporous leptosporangiate ferns was examined by light and electron microscopy. In 11 species (Adiantum pedatum L., Athyrium angustum Roth., Cyathea dregei Sm., Lygodium palmatum Sw., Mohria caffrorum (L.) Desv., Oleandra distenta Kuntae, Pellaea calomelanos (Sw.) Link, Pityrogramma calomelanos (L.) Link var. austro‐americana (Domn.) Farw., Trichomanes melanotrichum Schlechtend., Vittaria guineensis Desv., and Woodwardia orientalis Sw.) the lamina veins are collateral; in two (Phlebodium aureum and Platycerium bifurcatum), bicollateral as well as collateral veins are present. The vascular bundles in the midribs of C. dregei and those in the petioles and midribs of Phlebodium and Platycerium are concentric. All of the vascular bundles in the homosporous leptosporangiate ferns studied are delimited by a tightly arranged cylinder of endodermal cells with Casparian strips. Within the veins without parenchymatic xylem sheaths, some sieve elements commonly abut tracheary elements with hydrolyzed primary walls. The majority of vascular parenchyma cells contact both sieve elements and tracheary elements, although some parenchyma cells are associated with only one type of conducting cell. Transfer cells (parenchyma cells with wall ingrowths) occur in the veins of 6 species examined. Most of the vascular parenchyma cells, however, have no distinctive structural characteristics. The sieve elements of the homosporous leptosporangiate ferns are very similar structurally and each consists of a plasmalemma, a parietal, anastomosing network of smooth endoplasmic reticulum (ER), and variable numbers of refractive spherules, plastids and mitochondria. The sieve elements of L. palmatum also contain plasmalemma tubules. The parenchymatic cells of the leaf (mesophyll, endodermal and vascular parenchyma cells) are united by desmotubule‐containing plasmodesmata. The sieve elements are connected to each other by sieve pores and to parenchymatic cells by pore‐plasmodesma connections. The sieve‐area pores contain variable amounts of membranous material, apparently ER membranes, but do not occlude them. These membranes commonly are found in continuity with the parietal ER of the lumen. Based upon the relative frequencies of cytoplasmic connections between cell types, the photosynthates may move from the mesophyll to the site of phloem loading via somewhat different pathways in different species of homosporous leptosporangiate ferns.

Photocontrol of Germination of Spores of the Fern Polypodium aureum

Although Polypodium aureum produces spores throughout the year when grown indoors, these spores show a seasonal germination response which may be due to phytochrome levels induced in spores as they form. The maximum germination obtained with 5 days of R during October-January was 24%, but it increased to 79% during January-April. Germination induced by R is reversed by FR; longer periods of FR were no more effective in inhibiting germination than 1 day of FR. Kinetin, GA, IAA or cAMP did not induce germination in darkness, but kinetin and GA together with 1 day of R increased germination over that induced by 1 day of R alone. Cyclic AMP had a slight stimulatory effect with R, and IAA inhibited germination. Kinetin, GA, and cAMP were effective in preventing FR reversal of R-induced germination. Blue light alone did not induce germination. Germination was reduced if blue light followed 1 day of R, but blue light had no effect if 3 or 5 days of R had been given. Blue light followed by 1, 3, or 5 days of R increased the germination effect of R alone.

Polypodoaurein, a new phytoecdysone from Polypodium aureum L.

A new phytoecdysone was isolated from Polypodium aureum L. and its structure determined as 25- O-methylecdysterone.

Sieve-element ultrastructure in Platycerium bifurcatum and some other polypodiaceous ferns: The nucleus

Sieve elements of various ages were examined in Platycerium bifurcatum (Cav.) C. Chr. and Phlebodium aureum (L.) J. Sm., only older ones in Polypodium schraderi Mett. and Microgramma lycopodioides (L.) Copel. Early in sieve-element differentiation small crystalloids arise in the matrix of the sieve-element nuclei in Platycerium. As differentiation continues, the crystalloids increase in size and eventually may occupy up to a third of the cross-sectional area of the nucleus and extend almost its entire length. At the time of nuclear degeneration the crystalloids are liberated into the cytoplasm. Nuclear degeneration during sieve-element development in Phlebodium is essentially similar to that in Platycerium, with the exception that no nuclear inclusions exist in the sieve-element nuclei in Phlebodium. Stacking of endoplasmic reticulum against the nuclear envelope occurs in both Platycerium and Phlebodium. In the final stages of degeneration, the nuclear envelope ruptures and the contents of the nucleus mix with the cytoplasm. At maturity the sieve elements of all four species are devoid of nuclei, although occasional remnants of chromatin persist along the walls of some mature cells.

Sieve-element ultrastructure in Platycerium bifurcatum and some other polypodiaceous ferns: The refractive spherules

Sieve elements of various ages of Platycerium bifurcatum (Cav.) C. Chr. and Phlebodium aureum (L.) J. Sm. and older ones of Polypodium schraderi Mett. and Microgramma lycopodioides (L.) Copel. were examined with the electron microscope. Evidence was obtained which implicated the Golgi apparatus with the formation of refractive spherules in Platycerium and Phlebodium. In all four species the delimiting membranes of the refractive spherules eventually fuse with the plasmalemma in mature sieve elements, and the material comprising the spherules is liberated into the region of the wall.

New Evidence on the Organization of the Root Apex in Leptosporangiate Ferns

SUMMARYDNA cytophotometry and DNA labelling with 3H-thymidine were used to study the apical cell in lateral root primordia of Marsilea strigosa and in root apices of Marsilea strigosa, Blechnum brasiliense, B. gibbum, Polypodium aureum and Ceratopteris thalictroides.The initial cell of the lateral root in Marsilea makes a series of divisions which lead to a primordium with a tetrahedral apical cell. At different stages of development of the primordium, the apical cell becomes « quiescent »; that is, it divides rarely, if at all, whilst mitotic activity is retained by the mass of cells surrounding the apical. This situation is kept in the apex of adult roots in Marsilea and the other species investigated. Quiescence of the apical cell is due to a permanent, or long-lasting, block in the G2 phase without any interference with further DNA synthesis up to 8–16C intermediate DNA contents. From time to time, the apical cell enters mitosis with either 4C (diploid) or — more rarely — 8C (tetraploid) DNA content. ...

Polypodium aureum in Florida and Georgia

looking for plant material in connection with extensive poisonous plant studies which were in progress. The common trees on the island were Quercus virginiana, Sabal palmetto, Juniperus virginiana, and Ilex vomitoria. Growing from among the leaf bases of a Sabal palmetto we saw a large plant of Polypodium aureum. After removing some of the lower persistent leaf bases with an axe Mr. Hardin was able to climb the tree and

Experimental Control of Development in the Embryo of the Fern, Phlebodium aureum

American Journal of BotanyVolume 41, Issue 5 p. 428-434 Article EXPERIMENTAL CONTROL OF DEVELOPMENT IN THE EMBRYO OF THE FERN, PHLEBODIUM AUREUM Max Ward and R. H. Wetmore, Max Ward and R. H. Wetmore Glenville State College, Glenville, West Virginia The Biological Laboratories, Harvard University, Cambridge, MassachusettsSearch for more papers by this author Max Ward and R. H. Wetmore, Max Ward and R. H. Wetmore Glenville State College, Glenville, West Virginia The Biological Laboratories, Harvard University, Cambridge, MassachusettsSearch for more papers by this author First published: 01 May 1954 https://doi.org/10.1002/j.1537-2197.1954.tb14359.xCitations: 16AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume41, Issue5May 1954Pages 428-434 RelatedInformation

Some Mutations in Polypodium aureum

Polypodium aureum L. has been grown in the Marquette University greenhouse, mainly for class use, the past 25 years and during this long period of time a number of leaf mutations have been observed in the plant. This fern is known to be variable, since frequently it produces different forms of leaves, some of which, although rarely, have been observed by the writer to form more or less distinctly serrate margins. Occasionally parts of the leaves are laciniate. Hence, these resemble somewhat the leaves of Polypodium Mandaianum, its well known mutant, discovered by W. A. Manda of South Orange, New Jersey, some time before 1912, when the fern had already been introduced in the markets and exhibited at flower shows in this country and in Chelsea, England. Two years ago, one of the P. aureurn plants in the greenhouse formed, in addition to the typical leaves, a fertile leaf similar in all respects to that of Polypodium Mandaianum. The fern and its mutant are similar in

Permanent Changes of Chloroplasts Induced by X Rays in the Gametophyte of Polypodium aureum

1. The spores of Polypodium aureum may be treated with calcium hypochlorite up to 50 minutes at least, with no deleterious effect on germination and growth. 2. Irradiation of spores with dosages as high as 30,000 r units is without effect on the percentage of germination. With higher dosages the percentage of spores germinating decreases. The growth rate is decreased with dosages as low as 10,000 r units, and progressively decreases with increased dosage. 3. From seventy-two cultures in which were sown nearly 300,000 spores, fifty-one prothallia having abnormal chloroplasts were isolated. Twenty-seven prothallia survived. These have been classified according to the characteristics of the chloroplasts. Including the normal, eleven types were noted. These prothallia have been propagated vegetatively during a period of 7 years. The plastid types persist. 4. Certain types are transmitted to the sporophyte as a result of sexual reproduction and retransmitted to the new generation of the gametophyte. 5. The grouping of the plastids (type B) disappears in the adult leaves of the sporophyte and does not reappear in the new gametophyte generation. 6. On theoretical grounds it is suggested that the plastid changes may be independent of any genic changes, and that certain plant mutations may be due solely to plastid changes.

REGENERATION AND INDUCED POLYPLOIDY IN FERNS

Induced apospory, or the regeneration of prothalli from the young leaves of ferns, has been known since I908, when Goebel (8) described the appearance of prothallial tissue on the detached primary leaves of members of the Polypodiaceae and the Cyatheaceae. Pteris longifolia regenerated prothalli from the surface of the leaf and from the petiole. Rhizoids and sex organs were present on the prothalli, but sporophytes never appeared. Ceratopteris thalictroides produced prothallus-like structures which bore rhizoids and antheridia, and also stomata near the antheridia. Some leaves of this same fern developed buds on the petioles from which there arose structures intermediate between leaves and prothalli. Gymnogramme chrysophylla also produced prothallus-like outgrowths which contained stomata. When the primary leaves of Polypodium aureum were cut off, sporophytes grew from the buds produced on the epidermal cells. Alsophila van Gertii produced adventitious buds on the leaves, typical prothalli, and intermediate structures such as prothalli containing stomata. Later Goebel (9) described regeneration from a third family. Primary leaves of Osmunda regalis developed typical prothalli bearing rhizoids. Woronin (25) made similar experiments with the leaves of some apogamous ferns as well as with some which reproduced sexually. Trichomanes Kraussii of the Hymenophyllaceae was apogamous and its leaves developed prothalli by apospory, especially if they were cut off and kept growing on a suitable substratum. The apospory could go still further in that the border cells of the leaves produced antheridia. This condition was termed apoprothallia. Two species of Pellaea, both of which were apogamous, were capable of regenerating. Pellaea nivea produced filamentous prothallus-like outgrowths from the surface cells of detached leaves. Only the primary leaves of Pellaea flavens regenerated; but sometimes the secondary leaves 1 Papers from the Department of Botany of the University of Michigan No. 365. [The Journal for March (I9' 205-30I) was issued March 25, I932.] 303