Papillate Hairs Research Articles

Studies on the gametophytic development, mating behaviour and reproductive biology of Macrothelypteris torresiana (Gaudich.) Ching (Thelypteridaceae)

Macrothelypteris torresiana is a terrestrial fern belongs to the family Thelypteridaceae. It is very imperative to know the germination and growth pattern of this fern to make strategy for ex- situ conservation. In the present study germination of spore, developmental pattern of prothallium with particular emphasis on emergence of antheridia as well as archegonia, their fertilization and development of sporophytes were studied. The spores were spheroidal or reniform with broadly winged fimbriate perispore having average size of 48 ± 3.6 × 39 ± 4.2 μm. The spores started germinating just after 6 days of plating and percentage of germination was 94%. The germination pattern of spore was Vittaria type and development of gametophyte was Aspidium type. After 27 days of plating, a very distinct cordate-shaped adult gametophyte with deep apical notch and unicellular papillate hairs throughout the gametophyte was developed. The rhizoids appeared away from the apical notch of the gametophyte. The gametophyte first developed archegonia on 32nd day, whereas antheridia were developed on 42nd day. In isolate culture the gametophytes did not develop any sporophyte whereas in composite culture juvenile sporophytes were emerged on 77th day. This suggests the plant has ability to reproduce only through inter-gametophytic selfing and crossing, hence decreasing the plant’s capacity for colonization in a particular locality.

The morphology of the stigma surface of Petunia hybrida hort. superbissima as seen in scanning electron microscopy

The ultrastructure of stigma surface in allotetraploid petunias was analyzed by scanning electron microscopy. The stigma forms a bilobed structure with. a distinct central depression. The stigma surface is covered with numerous. papillate hairs of ununiform sizes and shapes.

Reproductive Biology ofAglaomorpha cornucopia(Copel.) M.C. Roos, a Rare and Endemic Fern from the Philippines

Aglaomorpha cornucopia (Copel.) M.C. Roos is an endemic and rare epiphytic fern from the Philippines. Ex situ germplasm storage and growth are important complementary tools for conserving this rare fern. This study was conducted to document the reproductive biology of this species. Mature sporophylls of A. cornucopia were collected in May, 2012 from Mt. Apo, the Philippines. Each sporangium bore 64 yellow, monolete spores. The average spore size was 49.3±3.7 µm. Fresh spores germinated 100% within one week of sowing (mean germination time (MGT) <1 week). Air-dried mature spores remained completely viable even after one year of storage at 3°C, although mean germination time was somewhat delayed (MGT = 1.4 weeks). Spore germination was of the Vittaria-type, whereas gametophyte development was of the Drynaria-type. Adult gametophytes were cordiform-annual and gametangia were of the leptosporangiate type. Unicellular papillate hairs appeared on marginal, dorsal, and ventral surfaces of the gametophytes. Gametophytes first produced antheridia and archegonia after seven weeks of culture. Gametophytes began to sexually produce sporophytes after 13 weeks of culture. The rate of sporophyte production reached 64% after 26 weeks culture. Results of this study suggest that cold temperature spore storage and in vitro culture offer reliable techniques for conserving this rare fern.

Reproductive biology of Pittosporum dasycaulon Miq., (Family Pittosporaceae) a rare medicinal tree endemic to Western Ghats.

BackgroundFor successful cultivation and conservation of plants a detailed knowledge of their reproductive biology is required. The reproductive features of trees are important to determine the diversity patterns and community structure of tropical forests. The present study on reproductive biology of Pittosporum dasycaulon, a rare medicinal tree, was conducted in the shola forests of Vaghamon hills, one of the foot hills of Southern Western Ghats of India from 2008–2011.ResultsThe plant flowers profusely during February to April. Inflorescence is a raceme and the total number of flowers per inflorescence varies from 96–217. The flowers are comparatively small, hermaphrodite, short pedicellate, complete, zygomorphic, pentamerous, polypetalous, hypogynous and light cream in colour with an average length of 1.14 cm. Anthesis started at 08.30 h and the flowers were completely opened at approximately 09.30 h followed by anther deshiscence at 10.00-11.30 h. The pollen grains were trizonocolpate with 45 ± 5.6 μm in size. Acetocarmine staining showed 66 ± 6% fertile pollen at the time of anther dehiscence. The number of pollen grains in an anther is 5246 ± 845 and per flower is 26230 ± 1021. The stigma is wet, non-papillate, capitate and contains a thin film of exudates under the light microscope. The superior ovary is densely covered with papillate hairs and containing 3–8 ovules. The important floral visitors include bees and butterflies. The plant is self-incompatible and an out crosser. Fruit set under open-pollination was poor (24%) with 58.3% fruits having seeds inside. There was no fruit set in manually self pollinated flowers while over 57% of the cross pollinated flowers set fruits.ConclusionsOur study presents a detailed account on reproductive biology of this medicinal tree which may help in the conservation and genetic improvement of this particular taxa.Electronic supplementary materialThe online version of this article (doi:10.1186/1999-3110-55-15) contains supplementary material, which is available to authorized users.

Gametophyte Morphology in Three Mexican Species of Bolbitis (Lomariopsidaceae)

The development of gametophytes in Bolbitis bernoullii, B. portoricensis and B. umbrosa (Lomariopsidaceae) is described and compared. Spores are monolete, ellipsoid with prominent winged perispore. Germination is of the Vittaria type and the prothallial development is of the Drynaria type. Collenchyma-like thickenings at the corners of the wing cells were not observed. Adult gametophytes are cordate with scarce marginal hairs near the shallow notch. Gametangia are of the common type found in homosporous leptosporangiate ferns. Bolbitis portoricensis develops the first leaf of the sporophyte after 6 to 8 months, with polocytic stomata. In B. portoricensis, vegetative propagation is present in old thalli 6 to 8 months after cultivation. The genus Bolbitis is a terrestrial or hemiepiphyitic fern, with dimorphic leaves and simple or pinnate blades. Some species have laminar buds, and all have fertile leaves with acrostichoid sori, and reticulate venation with or without included veinlets. Its spores are monolete, non-chlorophyllous, and winged (Mickel and Smith, 2004; Moran, 1995; Tryon and Tryon, 1982; Tryon and Lugardon, 1991). The genus contains about 45 species, a third of which are found in the New World; seven occur in the southeastern part of Mexico. These seven species grow between 0-1300 masl in very wet rainforests. Except for B. portoricensis (Spreng.) Hennipman, all species are uncommon or rare in Mexico. The gametophyte morphologies are known for several Indian species: Bolbitis semicordata (Moore) Ching, B. quoyana (Gaud.) Ching, B. subcrenata (Hook. et Grev.) Ching in C. Chr. (Nayar, 1960; Nayar and Kaur, 1964a, 1964b, 1965a, 1965b, 1965c, 1971); and for Old Word species such as B. angustipinna (Hayata) Ito, B. heteroclita (Presl) Ching and B. repanda (Bl.) Schott (Hennip- man 1970, 1977). In general terms, the mature prothallus of Bolbitis is cordate- thalloid, wider than long, with a dense, 6 to 8-celled thick cushion, and wide flat wings. Collenchyma-like thickenings are present in the corners of wing cells of some Indian species. Gametophytes of Bolbitis can be morphologically different. For instance, the prothallus in B. repanda is cordate, with pluricellular branched hairs and, when old, has a lobed thallus. In B. cladorrhizans (Spreng.) Ching, the gametophyte is glabrous and ribbon-shaped or lobed. Other species such as B. heteroclita have cordiform-spatulate prothalli, with unicellular, secretory and papillate hairs sparsely distributed along the margin of the adult gametophyte. In species such as B. semicordata, B. quoyana and B. subcrenata, the adult cordate thallus is usually branched but may be un-branched and has club-

Experimental studies of the attachment of the parasitic angiospermAgalinis purpurea to a host

Agalinis purpurea (L.) Raf. (Scrophulariaceae) is a facultative rootparasite. Haustoria, the organs specialized for host attachment and penetration, develop rapidly after exposure of the parasite's roots to host root exudate or specific haustoria-inducing molecules. Haustoria are competent to attach as early as 6–12 hours post-induction and reach a maximal level of attachment by 36 hours. Developing haustoria which have not contacted a host by 60–72 hours of development fail to attach when contact is established. However, this time course of attachment competency is extended for haustoria which have previously been attached to a host. Attachment is a nondiscriminatory event and induced haustoria will adhere to a variety of biological and non-biological substrates. Adhesion is mediated through specialized haustorial hairs whose surface is covered with a papillate network. The papillae represent the cement which attaches the haustorium to its host. The proportion of papillate hairs on haustoria parallels the attachment competency.

On the morphology ofSphaerostephanos subtruncata (Bory) Holttum with a discussion of the genusSphaerostephanos J. Sm

Morphology of the sporophyte ofSphaerostephanos subtruncata (Bory) Holttum, the only species of the genus occurring in India, is described. It is found chiefly in the Western Ghats of S. India. The genusSphaerostephanos shows similarity in many features withCyclosorus, but differs in possessing antrorse, acicular, multicellular hairs on the costae and in the absence of unicellular, papillate hairs, which are common inCyclosorus either on the paleae or on the surface of the rhizome.

Morphology of some polystichoid ferns

The morphology of the spores and prothalli of Arachniodes aristata, A. assamica, Cyrtomium caryotideum, C. falcatum and 10 species of Polystichum is described. The spores are bilateral with a smooth exine and the perine smooth in Cyrtomium and granulose to spinulose in the others. Spore germination is of the Vittaria type and prothallial development is of the Aspidium type. The adult prothallus of Arachniodes and Polystichum is cordate, with profuse papillate hairs. Sex organs are of the common leptosporangiate type. The antheridium dehisces by a pore-like opening in the cap cell in Polystichum, whereas the cap cell collapses at dehiscence in Arachniodes. Both species of Cyrtomium are apogamous; the thallus becomes irregular in shape in C. caryotideum but is cordate in C. falcatum.

The Gametophytes of the Victorian Blechnaceae. II. Doodia aspera R. Br., D. media R. Br., and D. caudata R. Br.: A comparison with three extra-Australian Genera, Brainea, Sadleria, and Woodwardia

An account is given of the spores, germination, and vegetative and reproductive features of the gametophytes of eight species of Blechnaceae. The close resemblance between the prothalli of Doodia aspera, D. media, and D. caudata and those of three Woodwardia species, Sadleria cyatheoides, and Brainea insignis is described. Minor differences in morphological and developmental features of the gametophytes were noted between all species but these were no greater between genera than they were between individual species of a genus. Unlike Blechnum nudum, but like many other Blechnum species and other higher ferns the cordate prothalli bore unicellular papillate hairs. There was no evidence that the terminal cell of the primary filament ended in a hair or became quiescent with subsequent development of the wedge-shaped meristematic cell from a subterminal cell, a feature reported by others to be common in some species of Blechnaceae. The meristematic cell almost invariably appeared to be a product of the terminal cell of the filament although there was considerable variation in the sequence of divisions contributing to plate formation. The antheridia were normally of the advanced type with three wall cells and showed similar variations in shape to those of B. nudum. Abnormal development of hairs on the wall cells of antheridia and the neck cells of archegonia is reported for the Doodia species. Various concepts concerning development of the cap cell of the antheridium are discussed. Antheridia were induced in W. japonica and were formed on prothalli of two or three cells, occasionally on the basal cell itself. No archegonia were formed on prothalli of W. martinezii and this species was apogamous. Other species formed normal sporophytes. Juvenile leaves on young sporophytes of W. orientalis were slow to develop a dissected lamina, and pinnate venation and costal areolae were initiated before this occurred. In the Doodia species, however, early dissection of the blade occurred and no anastomoses between veins were observed on juvenile fronds with several pinnae.

Contributions to the morphology of the fern genus Oleandra

The rhizome of Oleandra pistillaris and 0. wallichii is elongated (erect in the former, creeping in the latter), cylindrical, clothed with peltate, non-glandular, hairy paleae and bearing leaves in small clusters separated by long leafless portions. The ground tissue of the rhizome is composed of thick-walled parenchyma, and there is a peripheral sclerenchymatous sheath as well as a few scattered slender sclerenchyma strands in the pith close to the vascular cylinder. The vascular cylinder is dissected into a loose reticulum of slender meristeles by crowded, spirally arranged leaf gaps. In the ‘leafless’ portions of the rhizome these leaf gaps are associated with a solitary vestigial leaf trace: where well-developed leaves occur, each gap is associated with two or three leaf trace bundles. In 0. pistillaris, well developed leaves are in whorls at regular intervals; in 0. wallichii they are in small well-separated groups, each group consisting of two to six leaves in two irregular rows on the dorsal surface (i.e. leaves all along the ventral surface are suppressed). Leaves in both the species are simple with an entire, free-veined lamina and with an articulated stipe, the articulation being towards (but not at) the base and formed of an abscission pad. Branches of the rhizome are borne in pairs and each branch trace is a solitary cylindrical vascular strand, unaccompanied by any branch gap in the stelar cylinder. Sporangia are in circular sori placed in a row close to the midrib and protected by reniform indusia. The sporangial stalk bears glandular hairs, and is two cells thick except at the capsule base, where a short third row is developed secondarily during sporangial development as a protrusion from a lateral wall cell of the capsule base. The spores are of the bilateral type provided with a loose wrinkled perine: spinose excrescences occur over the exine as well as the perine. The prothallus is of the cordate type, bearing unicellular papillate hairs profusely on the surfaces and margin. It develops from a uniseriate germ-filament which develops into a prothallial plate by longitudinal divisions in the anterior cells. The terminal cell of the germ filament ends in a hair either prior to or immediately after the initiation of plate formation. A meristematic cell is formed early, either as a daughter cell of the terminal cell or of the penultimate cell. On the basis of morphological comparisons it is suggested that Oleandra is probably allied to the Aspidioid rather than to the Dennstaedtioid or Lindsaeoid groups of ferns.

Morphological studies on some species of Blechnum, Doodia, Woodwardia and Stenochlaena

Morphological studies on some species of Blechnum, Doodia, Woodwardia and Stenochlaena

Gametophytes and Juvenile Leaves of Drynarioid Ferns

Spores of the six genera (10 spp.) of the drynarioid ferns (Polypodiaceae) studied are monolete, with the exine either granulose, areolate, spinulose, or verrucate. On germination an elongated germ filament is produced; its anterior cells divide longitudinally to form an ameristic prothallial plate. Later an obconical apical meristematic cell is defferentiated. The germ filament of Merinthosorus ends in a hair and the penultimate cells form the prothallial plate; in this a meristematic cell is differentiated laterally. The prothalli develop a cordate apex in which a multicellular meristem replaces the meristematic cell within 4-6 weeks after spore germination. A prothallus attains maturity in about 3 months and at this stage is cordate, usually with a light midrib and broad unruffled wings. The walls of the wing cells in most species show collenchyma-like thickenings. Unicellular papillate hairs are produced on the margin and lower surface of the prothallus, starting with the spatulate or cordate stage of development. In addition, club-shaped hairs, two to four cells long, occur on the mature prothallus of all genera except Drynaria. In Aglaomorpha and Photinopteris unbranched club-shaped hairs are borne marginally also. Sex organs are of the type common in advanced ferns. Antheridia are small and often produce only 4-12 sperms. The first leaf is simple with a medianly placed vascular bundle and bears branched hairs. A midrib with pinnate lateral veins is found in the third to eighth leaves and a reticulate venation pattern occurs in leaves produced by plants over 5 months old. The leaf lamina is simple and lanceolate until the plants are over 3 years old.

Studies on the fern genera Bolbitis and Egenolfia

SUMMARY An account of the spore-morphology, development and structure of the prothalli and morphology of the juvenile sporophytes of 19 spp. (12 of Bolhitis and 7 of Egenolfia) is given. The spores are monolete, with a smooth exine and enveloped by a granulose (rarely smooth) or reticulate perine which is characteristically folded. The average spore-size is 22–34 32–40 22–34 μ. in Bolbitis, and 28–36 36–49 26–37μ in Egenolfia. On spore germination, a 3–6-cells long filament is formed and develops into a prothallial plate by longitudinal divisions in the anterior cells. Generally an obconical apical meristematic cell is developed from one of the anterior marginal cells, either soon after plate formation or a little later. The anterior region of the thallus expands, later becoming cordate, and a multicellular meristem replaces the apical cell in the usual way. An apical cell stage is sometimes omitted, more frequently in Egenolfia than in Bolbitis. A midrib is developed when the thalli are about 2 months old. Prothalli reach maturity in 6–8 months in most species (3–4 months in B. presliana). The mature prothallus is of the cordate type, with a tendency, in most species, to elongate slightly with age: the midrib is 6–8 cells thick and the wings are spread out. Collenchyma-like thickenings of wing cells are found in some species of Bolbitis. The prothalli, in most species, are naked: towards maturity, sparse, marginal hairs are developed in B. heteroclita and B. presliana, and club-shaped, marginal, multicellular hairs in B. semicordata, B. subcrenata and E. sinensis. The early juvenile leaves are simple with a lobed lamina and supplied by a solitary, vascular strand forked 2 or 3 times. A midrib is found from the 5th-7th leaf onwards: the lamina is pinnately dissected and the venation is free and pinnate. As the size of the successive juvenile leaves increases, the lamina becomes bipinnate with small ultimate lobes. The protostelic vascular cylinder of the juvenile rhizome becomes dorsally grooved and later gutter-like, with the leaves supplied by paired leaf traces originating from either margin of the gutter. Soon the vascular cylinder becomes siphonostelic by the margins of the gutter coming together, and later, the leaves are borne in 2 alternating rows as in the adult plants. The leaves on the siphonostelic rhizome are markedly larger and simply pinnate as in the adult plants, the transition being rather sudden. Branching associated with leaf insertions occurs only after the simply pinnate condition is attained. Unicellular papillate hairs are found on the lamina of all the juvenile leaves. Uniseriate club-like hairs are found towards the bases of the earlier leaves, and later, spread over the main veins. Large acicular hairs are found on the lamina from the 3rd or 4th juvenile leaf onwards, and persist till the adult simply pinnate form is attained. Bolbitis and Egenolfia are closely related genera, allied to Elaphoglossum on the one hand and Lomariopsis and Teratophyllum on the other: the group appears to be more or less an isolated one, but may be remotely related to the Rumohra-Polystichum line of evolution of the ‘Aspidiaceae’.

Development of Sorus and Prothallium of Acrophorus stipellatus

1. The sorus of Acrophorus stipellatus is not terminal on a vein but is borne on a short branch arising near the vein ending. 2. The sorus originates close to the leaf margin, but the marginal initial cell is never involved in sorus construction. The sorus is zygomorphic from its first appearance. Sporangia arise at first in gradate but soon in mixed sequence. 3. The first segmentation of the sporangial initial may be either transverse or oblique. The sporangial stalk consists of three cell rows and sometimes bears a curved hair. The annulus is vertical and incomplete, with an unequal number of cells in the two faces of the capsule. 4. Prothallia are of the usual polypod type and bear unicellular papillate hairs. The antheridial "funnel cell" has the form of a solid cylinder. The lid cell is extruded intact at maturity. 5. The soral development and structure of Acrophorus bear striking resemblances to those of Cystopteris. Acrophorus appears to form a link between the more advanced of the Woodsioideae and Dryopteris.