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A sporangium (from Late Latin, from Ancient Greek σπορά (sporá) 'seed' and ἀγγεῖον (angeîon) 'vessel'); pl.: sporangia) [1] is an enclosure in which spores are formed. [2] It can be composed of a single cell or can be multicellular .
The sporangiospores are asexual mitospores (formed via mitosis), produced inside sporangia (thousands of spores) or sporangioles (single or few spores).They are released when mature by the disintegration of the sporangium wall, or as a whole sporangiole that separates from the sporangiophore.
Spores develop on sides and edges of wall; Spores: The spores are round or oval globules individually attached to stalks sprouting from sporangia. Spores vary in size (8-13 μm in diameter). The spore walls are thin and transparent. Spores appear grainy and may have some vacuoles which are often near the perimeter or surrounding the nucleus.
A walled spore produced within a sporangium. [358] sporangium. pl. sporangia. A sac-like structure that produces spores endogenously. From Gr. angeion, vessel. [359] spore A reproductive structure in fungi. Can result from both sexual and asexual processes. [360] spore wall The layered wall defining a spore. Considered to have five layers.
The fungus produces a thick walled structure known as a winter sporangium. It is 25-75 μm in diameter and contains 200-300 spores. Sporangia are clustered into thin-walled sori. The motile life stage, zoospore is about 0,5 μm in diameter and has one posterior flagellum.
These specialized hyphae usually show negative gravitropism and positive phototropism allowing good spore dispersal. The sporangia wall is thin and is easily destroyed by mechanical stimuli (e.g. falling raindrops, passing animals), leading to the dispersal of the ripe mitospores. The walls of these spores contain sporopollenin in some species ...
Some markings represent apertures, places where the tough outer coat of the spore can be penetrated when germination occurs. Spores can be categorized based on the position and number of these markings and apertures. Alete spores show no lines. In monolete spores, there is a single narrow line (laesura) on the spore. [8]
The germinated zygote produces a diploid thallus with two types of sporangia: thin-walled zoosporangia and thick walled resting spores (or sporangia). The thin walled sporangia release diploid zoospores. The resting spore serves as a means of enduring unfavorable conditions. When conditions are favorable again, meiosis occurs and haploid ...