Economic importance of pteridophytes,several ferns such as angiopteris, asplenium, marattia, microsorium, nephrolepis, phymatodes, etc. The pteridophytes reproduce both by the vegetative and sexual methods. Comparative morphology, reproduction and phylogeny of. The investigations in pteridophytes probably of most interest and importance ing of apogamy and apospory, it is important to define these terms at the outset. Reproductive systems and evolution in vascular plants pnas. Ecology of life cycle known as apogamy, in which fertilization is bypassed. Themorphologof pteridophytes biologicalsciences professorh. Prothallus gives rise to sporophyte without fertilization. Pteridophyta living in water are known as hydrophyte, sticking in other plants are called epiphyte and living in residue or waste of other plants are known as saprophyte. Apospory in pteridophytes pdf the investigations in pteridophytes probably of most interest and importance ing of apogamy and apospory, it is important to.
The printed version, however, was effectively published on 6 june 20. Observations on the inheritance of apospory and alternations of generations. The homosporous pteridophytes constitute the lowest sub kingdom of. Firstly all the botanists divided the plant kingdom into two large groups cryptogamia and phanerogamia, linnaeus 1754 used the term cryptogams for the first time for those plants which did not possess visible sex organs. It is also advantageous since it can produce large number of individuals which are genetically identical too. Pteridophytes biology encyclopedia plant, body, different. Theoretical considerations reproductive biology of the pteridophyta. Apogamy, apospory, and parthenogenesis in the pteridophytes w. Formation of sporophyte from a vegetative portion of prothallus without sexual fusion is called apogamy apospory apomixis apocarpy. The sporophyte is the conspicuous and familiar plant body.
Jan 23, 2017 reproduction the sporophytes reproduce by spores which are produced within sporangia. But trust me the first thing that you notice is the abundant foliage of fern plants. This life cycle is also believed to foster quick reproduction in connection with brief damp periods. A concept based exclusive material pteridophytes, gymnosperms. Most pteridophytes are terrestrial and grows in moist and shady places while some flourish well in open dry places. Apospory is the development of a gametophyte directly from a sporophyte without the occurrence of meiosis or spore formation. Pteridophytes may represent the closest living relatives sister group to the seed plants. Apogamy, apospory, and parthenogenesis in the pteridophytes. Common between bryophytes and pteridophytes is a absence of sporophyte b gametophyte dependent on sporophyte c sporophyte dependent on gametophyte d multicellular sex organs with sterile jacket. Thus, these characteristics make them horticulturally important plants. Phytochemical studies in brazilian pteridophytes soeder 1985 reported a large inventory of papers that appeared between 1966 and 1984 on the chemical constituents of pteridophytes.
The first vascular plants rapidly diversified to cover the earth. Extant pteridophytes are cosmopolitan but are much better represented in the humid tropics, with only a few families e. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Pteridophyta is the most highly evolved group among the cryptogams. Similar to the life cycle of seed plants, the pteridophytes also involves the alternation of generations in its life cycle. It helps to increase the number of population under unfavourable conditions also.
In some pteridophytes the sporangia develop on stems i. The cryptogamia was further divided into thallophyta. Maheshwari used the following simple classification of types of apomixis in flowering plants. The different species of selaginella are grown as the garden plants. Eichler 1883 divided the plant kingdom into cryptogamia and phanerogamia. Pteridophytes introduction, authors and addresses, systematic list, glossary, and key to tribes. Altmetric apogamy, apospory, and parthenogenesis in the. In vitro induction of apospory and apogamy, and direct field establishment of aposporous gametophytes and subsequent sporophyte development has been. Ferns can be used to illustrate the life cycle stages common to all pteridophytes. Sumita, assistant professor, department of botany, pggc11, chandigarh. Nonetheless, manton 11 cites examples from at least seven genera of ferns and points out that it has been known for more than a century that apogamy can be experimentally induced in many. Natural apogamy is common in ferns like dryopteris, adiantum, osmunda, pteris etc. Pteridophyta characteristics, life cycle, classification.
The pteridophytes reproduce both by the vegetative and sexual methods vegetative reproduction. Pteridophyte definition of pteridophyte by merriamwebster. Howev er, the gametophytes of some apogamous ferns. Furthermore, in hymenophyllous ferns, the sporophyte is. Triploidy in equisetum subgenus hippochaete equisetaceae. Biosystematic studies on equisetum subgenus hippochaete revealed evidence that triploids occur in nature. Later, apogamy has been described in many pteridophytes e. However, the pteridophytes differ from mosses and seed plants in that both generations are independent and freeliving.
In its farina it produces the cytotoxic and anticancer compound dihydrochalcone. Pteridophytes gymnosperms and angiosperms groups are distinguished from algae by reproduction life cycle that involves the development of a multicellular embryo attached to the mother plant for its protection and nourishment. In this lesson, well discover the characteristics, classification, and life cycle of the group pteridophyta, which includes plant species like ferns and horsetails. In contrast, apogamy is the development of 1n sporophytes without gametes and syngamy from vegetative cells of the gametophyte. This is made apparent by the phenomena of apogamy and apospory, cases of which have been recorded many times in pteridophytes since they were first observed in 1874.
Apospory is the development of 2n gametophytes, without meiosis and spores, from vegetative, or nonreproductive, cells of the sporophyte. The phenomena of apogamy and apospory have always been regarded as short cuts in the life history of ferns, and the fact that apparently either generation. Life cycles of lycopodium, selaginella, equisetum, adiantum and marsilea. Pteridophytes constitute a significant and important group in the plant kingdom. Bright green indicates diploid, pale green, haploid. Seed habit originated in algae fungi bryophytes pteridophytes. Pteridophyta do not produce seeds but they produce spores. These ferns, in biological terms, are nothing but the pteridophytes, belonging to the division pteridophyta of the plant kingdom. The new embryo may then arise either from the egg haploid parthenogenesis or from some other cell of the gametophyte haploid apogamy. Even today, many tribal communities and rural populations are dependent heavily upon the natural resources obtained from the surrounding forest regions for treatment of various ailments and diseases. Apospory in pteridophytes pdf the investigations in pteridophytes probably of most interest and importance ing of apogamy. Apogamy is a type of plant reproduction in which sporophyte diploid phase is produced from the gametophyte haploid phase without fertilization. Rudimentary seed habit occurs in a selaginella b lycopodium c psilotum.
Affinities of pteridophyte with bryophyte and algae. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as cryptogams, meaning that their means of reproduction is hidden. A few pteridophytes are aquatic while still others are epiphytes. The vegetative reproduction is also a common type of reproduction in the pteridophytes. At one point, pteridophyta was considered its own phylum, although now they are considered a group of disparate. India abstract pteridophytic flora is the extinct members of plants groups used medicinally by aboriginals. Apogamy formation of a sporophyte by the gametophyte without fertilization and apospory formation of a gametophyte by the sporophyte without the function of meiospores have been alleged as evidence for the homologous theory of alternating generations, since in some cases gametophyte and sporophyte seem interconvertible. Modified 17 199 embryophytes bryophytes rhynia fossil lycopodiophyta. Multiple choice quiz on pteridophytes biology multiple. Some of the most important characters of pteridophytes are as follows. As in seed plants, the greatest diversity of pteridophytes is found in the tropics, with only about six hundred species adapted for life in temperate climates. Some of the characters of pteridophytes are as follows. Download scientific diagram 2 comparison of apogamy in ferns with apomixis in angiosperms. Abstract background and aims the genus equisetum is cytologically uniform, having a base chromosome number of x 108.
Pteridophytes or pteridophyta, in the broad interpretation of the term, are vascular plants plants with xylem and phloem that reproduce and disperse via spores. Apogamous diploids are considered to originate from the hybridisation of two sexual diploid species followed by acquired apogamy or from genetic change of a sexual diploid species. A pteridophyte is a vascular plant with xylem and phloem that disperses spores. Apospory and apogamy in pteridophytes biology discussion.
One piece of evidence indicating apogamy is the lack of archegonia in the gametophyte knobloch, 1966. The plant body can be divided into a true root, stem, and leaves. What is apogamy and apospory biology plant growth and. This pdf version does not have an isbn or issn and is not therefore effectively published melbourne code, art. Some pteridophytes are aquatic and some are epiphytes.
Unlike the bryophytes, these plants are in the mainstream of land plant evolution and eventually gave rise to the seed plants. Classification of pteridophytes for a long time the division pteridophyta includedthe ferns, lycopods and horsetails. Both apospory and apogamy are considered as the abnormalities of plant life cycle. Apospory in pteridophytes pdf the investigations in pteridophytes probably of most interest and importance ing of apogamy and apospory, it is important to define these terms at the. The sexuality of pteridophytic gametophytes can be classified as follows. Useful notes on the classification of pteridophytes. In 1880, the cryptogams of the plant kingdom were divided. On the basis of their anatomy jeffrey in 1902 divided the vascular plants into two types or stocks. In addition, in pteridophytes, the gametophyte is often very thin and can be unistratose, especially at the margins yatskievych, 2003.
Diversity of pteridophytes in india and their migration to land. Most pteridophytes are terrestrial and grow in moist and shady places while some flourish well in open, dry places especially in xeric conditions. Apogamy is the development of a sporophyte directly from the gametophyte without the intermediate formation and fertilization of gametes. The group pteridophyta, the wing plants, is a diverse bunch of related plants. Apogamous triploids could derive from a cross between sexual diploid and tetraploid species or. All pteridophytes have a true alternation of generations, in which a dominant sporophyte generation produces spores through meiosis, and a freeliving gametophyte generation forms gametes egg and sperm by mitosis. Pteridophyta mcq multiple choice question and answer pteridophyta mcq with detailed explanation for interview, entrance and competitive exams.
Stelar evolution of pteridophytes sporangial organization. Pteridophytes do not have seeds or flowers either, instead they also reproduce via spores. Phytochemical studies in pteridophytes growing in brazil. Ebook an introduction to pteridophyta as pdf download. A first checklist of the pteridophytes of togo west africa. Neet biology diversity in living world pteridophytes mcq. Buy isbn9781403930309 at 16% discount by macmillian india ltdnew delhi. Thus, free water is not required for swimming sperm. Apogamy is development of an embryo without fertilization. Pteridophytes were dominant land plants during the carboniferous era and a major source of todays coal and oil. Engler 1909 included the bryophyta and pteridophyta. Download scientific diagram apogamous fern life cycle.
Classification of pteridophytes short classification of the ferns pdf. When you think of forests and woods, you can picture trees, abundant lush green ferns, and other plants. Reproductive systems and evolution in vascular plants. It is speculated that life began in the oceans, and through millions of years of evolution, life slowly adapted on to dry land. Engler 1909 included the bryophyta and pteridophyta under embryophyta. A, apogamous alternation of generations in ferns n. Apogamy is the development of an unusual haploid sporophyte from the gametophyte without the fusion of gametes. Some of the species belonging to this division have small leaves called as the microphylls. Read the introductory remarks and list of characteristics of the bryophytes p. In this article we will discuss about the classification of pteridophytes. Pteridophyte reproduction christian brothers university.
Apospory definition of apospory by the free dictionary. Ferns, horsetails often treated as ferns, and lycophytes clubmosses, spikemosses, and quillworts are all pteridophytes. This author lists a total of 671 references, but only one work had been carried out in brazil miraglia et al. In this type the megaspore mother cell undergoes the usual meiotic divisions and a haploid embryo sac megagametophyte is formed.
Pteridophytes ferns and fern allies the plant list. Apospory is the development of gametophyte directly from sporophyte without formation of spores. Megasporophyll of pteridophytes is comparable to which structure of angiosperms stamens ovule carpel microsporophyll. An introduction to pteridophyta top results of your surfing an introduction to pteridophyta start download portable document format pdf and ebooks electronic books free online rating news 20162017 is books that can provide inspiration, insight, knowledge to the reader. Pteridophyte definition is any of a division pteridophyta of vascular plants such as a fern that have roots, stems, and leaves but lack flowers or seeds. Apospory is the development of unusual diploid gametophyte from the vegetative parts of sporophyte and not from the spores. Ethnomedicinal uses of pteridophytes of vindhyan region m. Many studies address the relationships between diversity or. Sporophylls the leaves that bear sporangia are known as sporophylls. The sporophyte was the dominant phase of the life cycle of these early pteridophytes. As they produce neither flowers nor seeds, they are referred to as cryptogams.
A few pteridophytes are aquatic while still others are. Apogamy, apospory and parthenogenesis in the pteridophytes. Pteridophyte definition of pteridophyte by the free dictionary. Professor farmer and miss digby have published the results of their studies of apogamy and apospory in ferns. And among the first of the plants to truly live on land were the pteridophytes. Pteridophyta in the broad interpretation of the term are. Apogamy is found in 39% of all cytotypes and 28% of polyploids figure 3. Sometimes deviation in the regular alternation if generations. Any of numerous vascular plants that reproduce by means of spores rather than seeds, including the ferns and related plants such as horsetails, and. The taxonomic distribution of apogamy in pteridophytes is not well known because of the technical difficulties associated with studying spore development. There are also some purely aquatic ferns such as water fern or water velvet salvinia molesta and mosquito ferns azolla species.
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