Discover the essential role of microsporangium in plant embryology.
Microsporangium: A Closer Look at Structure
Microsporangium is really the pollen sac or polllen chamber found inside the anther. Microsporangium has sporogenous tissue with in it. These sporogenous tissues produce microspores or Pollen grains latter in the process called microsporogenesis.
Microsporangium or Pollen chamber or Pollen sac is covered by four layers of anther walls. The anther walls surrounding the microsporangium are called epidermis, endothecium, multilayer middle layer and the innermost important nutritive layer called tapetum.
In a transverse section of a typical young anther you will find four microsporangia. So each typical young anther is called the tetrasporangiate in nature.
Events Within the Microsporangium: From Meiosis to Pollen Formation
Microsporangium or Pollen sac is the real reproductive area in the anther. Each microsporangium or pollen sac has hundreds of spore mother cells which are also called as microspore mother cells. All these reproductive microspore mother cells separately undergo reductional division or meiotic division to produce huge number of Microspores or pollen grains.
Microspore or pollen grain is the first gametophytic stage of the plant. The pollen grain is the first male gametophyte which latter develops by two mitotic divisions. Each Pollen grain develops to produce matured 3 celled male gametophyte.’
The Pollen Grain during its development inside the Pollen sac collects the nourishment and all necessary nutrients from the innermost tapetum layer of anther. The tapetum layer provides nutrients to the developing pollen grains and also provides the chemical called sporopollenin to form the outer exine part of pollen grain.
Tapetum is also glandular in nature. It secretes the lipid derivative sticky substance called Pollen kitt which forms the outermost layer of insect pollinated pollen grain.
The Role of the Microsporangium in Plant Reproduction
Microsporangium is the essential male reproductive site that plays major role in producing finally male gametophytes for sexual reproduction.
conclusion
Thus we can’t imagine sexual reproduction without microsporangium.
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