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. Some of the most important characters of Pteridophytes are as follows: Apogamy and Apospory: Sometimes deviation in the regular alternation if generations. Apogamy, apospory and parthenogenesis in the Pteridophytes II Steil, W.N.. Bot Rev: This is a supplement to the review which appeared in Bot.
|Published (Last):||19 November 2004|
|PDF File Size:||1.81 Mb|
|ePub File Size:||7.81 Mb|
|Price:||Free* [*Free Regsitration Required]|
A Case Study from Polystichoid Ferns. Ultrastructural aspects of apospory and apogamy. An introduction to the embryology of the angiosperms. Embryologie und Fortpflanzungsbiologie der Angiospermen: For similar processes in animals and Oomycetes, see Parthenogenesis.
13 Important Characters of Pteridophytes – Explained!
You do not currently have access to this article. For androgenetic alopecia, see Pattern hair loss. Illuminating the systematics of the Spiranthes sinensis species complex Orchidaceae: In some cases sporophylls for compact structures called cones or strobili e. Pteridopjytes with petiole, excised from aseptically raised plants from excised cultured buds, also aposspory apospory, while no success was achieved with the excised leaves of the parent plantS.
The gametophytes develop sex organs like antheridia male sex organs and archegonia female sex organs.
In adventitious embryony sporophytic apomixisan embryo is formed directly not from a gametophyte from nucellus or integument tissue see nucellar embryony. Because apomictic plants are ln identical from one generation to the next, each lineage has some of the characters of a true speciesmaintaining distinctions from other apomictic lineages within the same genuswhile having much smaller differences than is normal between species of most genera.
In the presence of sucrose, calli responded like prothalli, while in the presence of 2,4-D, differentiation was delayed or completely inhibited. In Embryology of angiosperms. Meaning, General Characters and Affinities.
In flowering plants, the term “apomixis” is commonly used in a restricted pteridoophytes to mean agamospermyi. Bot Gaz 3: Although agamospermy could theoretically occur in gymnospermsit appears to be absent in that group. For English speakers, Maheshwari  is very influential. This article is about plants. Efficient induction of apospory and apogamy in vitro in silver fern Pityrogramma calomelanos L.
Views Read Edit View history.
Apogamy, apospory, and parthenogenesis in the Pteridophytes. International Botanical Congress Abstracts As Jens Clausen put it : Plant Cell Reports 25 In plants with independent gametophytes notably fernsthe term is still used interchangeably with “apomixis”, and both refer to the formation of sporophytes by pteridophyres of gametophyte cells.
In botanyapomixis was defined by Hans Winkler as replacement of the normal sexual reproduction by asexual reproductionwithout fertilization. Rivera Nava; Julien B. But Psilopsids are rootless plants having rhizoids. In vitro studies on apogamy, apospory and controlled pterdophytes of rhizome segments of the fern, Ampelopteris prolifera Retz.
Selaginella, Marsilea, Azolla etc. Cytology of apogamy and apospory in Osmunda javanica Bl. Oxford University Press is a aposppory of the University of Oxford. Answer Now and help others. The central cell of the megagametophyte may require fertilization to form the endospermpseudogamous gametophytic apomixisor in autonomous gametophytic apomixis fertilization is not required.
Annals of Forest Science.
Gametophytic apomixis in flowering plants develops in several different ways. Journal of the Hattori Botanical Laboratory: The genetic control of apomixis can involve a single genetic change that affects all the major developmental components, formation of the megagametophyte, parthenogenesis of the egg cell, and endosperm development. Botanical Journal of the Linnean Society 62 4: German speakers might prefer to consult Rutishauser In gametophytic apomixisthe embryo arises from an unfertilized egg cell i.
Thus “normal asexual reproduction ” of plants, such as propagation from cuttings or leaves, has never been considered to be apomixis, but replacement of the seed by a plantlet or replacement of the flower by bulbils were categorized as types of apomixis.
Apogamy was induced in the fern Ampelopteris prolifera by culturing the gametophytes on mineral nutrients supplemented with various concentrations of aospory.
Apospory | botany |
Occurrence of apogamy and apospory from the capsules of Funaria hygrometrica Hedw. In vitro production of apogamy and apospory in bryophytes and their significance. Apogamy is a related term that has had various meanings over time. Apogamy, apospory and parthenogenesis in the Pteridophytes II.