The sporangia and spores of ferns, found inMiniature leafIn pteridophytes, the sporangium is solitary in the sporophyllParaxial planeleaf axilOr the base of a leaf, usually many sporophylls gather closely or loosely at the top of a branch to form a ball or spike, calledSporophyll(strobilus）Or sporophyllspilte, such as Lycopodium and Equisetum.Large leafOfFernNot formingSporophyllSpike,SporangiumIt is not only in the leaf axils, but also formed by many sporangia with different shapesSporangiumOr sorus, on the back or edge of the sporophyll.Sporangialcell wallIt is composed of single-layer (thin cyst fern) or multi-layer (thick cyst fern) cells, with uneven thickening on the cell wallAnnular band(anulus). There are various forms of zonal attachment, such as terminal zonal attachment, transverse central zonal attachment, oblique zonal attachment, and longitudinal zonal attachment, which play an important role in spore dispersal.SporangiumThe wall is composed of multiple layers of cells（Hypercystis）Or a layer of cells（Leptocystis）The walls of some of the cells in the sporangium wall are often unevenly thickened, and they are arranged in a band, called a ring band.The ring belt has the types of terminal, horizontal middle, oblique and vertical.mostFernThe spores produced are the same in shape and size, calledSporotype(isospore）, a few ferns such asSelaginellaAnd aquaticFilicinae The spores ofMegaspore(macroscore) andmicrospore(microscore) is calledSporotype(Heterospore)。The cystic structure that produces megaspores is calledMegasporangiumMegasporangiumMicrospore sac(mirosl orangium), the female gametophyte is formed after the germination of the megaspore, and the male gametophyte is formed after the germination of the microspore.
Eulaliopsis binata is apomixis somatic apospory
Microspore
The sporangia often gather to form sporangia groups (stacks).There are many types of sporangia, the original type is born on the specialized sporophyll at the top of the branch and forms spike or cone shaped sporangia spikes. The evolutionary types are: marginal sporangia, which refers to the sporangia that is born on the edge of the feather, and terminal sporangia, which is born on the top of the feather;Telangial sporangiaVeinletsThe apex, vein dorsal sporangia group, is born in the middle of the veinlets, and the sporangia group is born in the cave formed by the pinna, and some are distributed on the back of the leaf.Some sporangia have a lid, others have no lid.The sporangia group has various shapes, such as round, kidney shaped, and strip shaped.
shape
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Spore structure
The spores are usually double faced, tetrahedral or spherical tetrahedral in shape, with smooth outer walls or ridges and spiny processes orElastic silk。The spores of most species are monotypic, and a few species are heterotypic (e.gSelaginella）, that is, largemicrosporePoints.FernThere are about 12000 species, and about 2600 species in China,medicinal plantMore.
Sporangium formationSporangium(sporangium).The sporangia is formed by the enlargement of the top of the sporangial stem.Cyst spores have cell walls, no flagella, and can fly with the wind after release.
Produced from the differentiation of hyphaeConidiophore(conidiophore）Upper, terminal, lateral or stringy, various in shape and size, unicellular or multicellular, colorless or colored, and mature fromSporopodiumFalling off.The conidia and conidiophores of some fungi are still attached to the conidia.RobeThere are two main types of fruit, namely, subglobose, perforatedConidia(pycnidium) and cup-shaped or discoidConidial disc(acervulus)。
Sexual reproduction
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Sporogenesis
FungusGrowth and developmentAt a certain period (usually later)Sexual reproduction。Sexual reproduction is the combination of two sexual cellsnucleusconductMeiosisA mode of reproduction that produces spores.Most fungi are produced by hypha differentiationSexual organNamely gametophyte, which is formed by the combination of male and female gametophytesSexual spore。The whole process can be divided intoQuality matching、Nuclear allocationAnd meiosis.The first stage is quality matching, that is, after the fusion of two personality cellscytoplasmCombine with the nucleus (N) in the same cell to form a binucleate phase (N+N).The second stage is nuclear fusion, that is, twohaploidA diploid nucleus (2N) was synthesized from the nucleus of.The third stage is meiosis. The diploid nucleus undergoes two successive divisions to form four haploid nuclei (N), thus returning to the original haploid stage.After sexual reproduction, fungi can produce four types of sexual spores.
OomycetesSexual spores of.It is composed of two heterogametes——Male organandOvipositorAfter contact, the cytoplasm and nucleus of the male organInsemination tubeIt enters the egg storage apparatus and is mated with the egg ball. The fertilized egg ball finally develops intoThick wallA diploid oospore.
ZygoteSexual spores of.It is formed by the fusion of two gametophytic vesicles into one cell in the way of combining gametophytic vesicles, and the formation of cytoplasm and nucleus in this cellChlamydospore。
AscomycetesSexual spores of.It is usually composed of two heterogametes, male organ andSacculusHaploid spores formed by cytoplasmic, nuclear and meiotic processes.Ascospores are born in colorless, transparent, rod shaped or oval saclike structures, namely ascus.8 ascospores are generally formed in each ascus.The ascus is usually produced in the envelopedAscocarpInside.There are generally four types of ascocarp, that is, globular without orificeObturator capsule(cletothecium), bottle shaped or spherical, with realShell wallAnd fixing orificeAscus shell(peithiecium), which is formed due to the dissolution of the base and has no real shell wall and fixed orificeAscus cavity(location), and dish or cup shapedAscus disc(9pothecium)。
BasidiomycetesSexual spores of.It is usually formed directly by the combination of "+" and "-" hyphaeBinucleate hyphae, later binucleate hyphalApical cellA stretcher that expands into a stick（basidium)。The dinucleate in the basidium undergoes karyogamy and meiosis, and finally produces four exogenous haploid basidiospores on the basidium.
