Megaspore

Megaspore (megaspore) Spore The size of the type two form called megaspore. In Megasporangia In. stay Fern Large, spore germination after degradation of the female Prothallus . In addition, Angiosperm and Gymnosperms The Embryo sac cells , and fern Botany The female prothalli the same embryo sac It is also known as megaspore.
Megaspore

Megaspore Late Paleozoic megaspore research has made new progress

Megaspore (megaspore) is the individual two types of spores produced by plants in different from larger, and finally developed into the female gametophyte (female prothalli) a class of spore. Due to the large spores larger, easy to place preservation, and the number is less, and the relationship between the parent plant is more clear, more convenient for quantitative statistical analysis, so in recent years the spores are more used in Paleoclimate and paleovegetation in reconstruction of the face. Compared with foreign countries, China's late Paleozoic dispersed megaspores of a late start, some of the existing research results still stays in the genus description and stratum age comparison, for the study of megaspore and paleoecology and paleovegetation relationship is relatively weak. To solve this problem, I Liu Feng, assistant professor and researcher Zhu Huaicheng made a detailed analysis and sample selection of nearly 400 samples from Shanxi and Baode in the late Paleozoic strata, found a total of 13 genera and 20 species of spores, the system description and classification, enrich China Permian Carboniferous megaspore research content the classification system of China in the late Paleozoic megaspore to further improve. At the same time, through comparative study and quantitative analysis of megaspore and the parent plant, reveals the coal environment of North China in Late Carboniferous Early Permian in the seal wood is main coal plants, but in the non coal environment in Selaginella Lycopod herb is a common type of plant. The study found that, from the beginning in Early Permian, Baode section in coal seam gradually disappear, the emergence of a large number of red beds, at the same time the megaspore assemblage also changed significantly, probably has a close relationship with the arid climate in North china.

Megaspore The megaspore mother cell

embryo sac Mother cell Embryosac mother cell Seed plant The The megaspore mother cell . Is immediately under the skin Nucellus Organization cell differentiation From this, cells than the surrounding cells, abundant cytoplasm, nuclear can produce large archesporial cells, some can directly into the embryo sac mother cell, some can become covered with cells and embryo sac mother cell. Sympetalous flower plants do not produce Plumb cells (Lanxue cover - aginales, Convolvulaceae Several exceptions of Convolvulaceae), located in the nucellar embryo sac mother cells under the epidermis. Gymnosperms , Rubiaceae (Rubiaceae), Compositae (Compositae) produced several embryo sac mother cell. Did not originate in the archesporial cell, but originated in the cell and embryo sac mother has the same effect, known to have integument cells (Solanum Solanum, Nymphoides peltatum The genus Nymphoides (Orchidaceae), nucellar epidermal cells Orchidaceae Larkspur orchid genus Oncidium) etc..
 The megaspore SEM and transmitted light photographs The megaspore SEM and transmitted light photographs
 Stratigraphic age distribution Stratigraphic age distribution
 The megaspore SEM and transmitted light photographs The megaspore SEM and transmitted light photographs
 Stratigraphic age distribution Stratigraphic age distribution