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There are around 64 spores in a leptosporangium. Scanning electron micrograph of fern leptosporangia. In a eusporangium, characteristic of all other vascular plants and some primitive ferns, the initials are in a layer (i.e., more than one). A eusporangium is larger (hence contain more spores), and its wall is multi-layered.
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]
Rain can wash spores into the soil where they infect young tubers, and the spores can also travel long distances on the wind. The early stages of blight are easily missed. Symptoms include the appearance of dark blotches on leaf tips and plant stems. White mold will appear under the leaves in humid conditions and the whole plant may quickly ...
Sori occur on the sporophyte generation, the sporangia within producing haploid meiospores. As the sporangia mature, the indusium shrivels so that spore release is unimpeded. The sporangia then burst and release the spores.
Leaf spot disease occurs when the following factors are all present: favourable environmental conditions, a pathogenic agent, and susceptible host. [2] Different types of pathogens, including fungal, bacterial and viral agents have unique ways to suppress and attack the host plant's immune system, thereby resulting in the progression of leaf ...
Cladosporium cladosporioides occurs outdoor environments year-round with peak spore concentration in the air occurring in summer where levels can range from 2,000 spores up to 50,000 spores per cubic meter of air. [16] It is among the most common of all outdoor airborne fungi, [16] colonizing plant materials and soil. [14]
Guttation is the exudation of drops of xylem and phloem sap on the tips or edges of leaves of some vascular plants, such as grasses, and also a number of fungi. Ancient Latin gutta means "a drop of fluid", whence modern botany formed the word guttation to designate that a plant exudes drops of fluid onto the outer surface of the plant, when the ...
The sporophyll of a fern. It is a fertile leaf bearing reproductive structures. In botany, a sporophyll is a leaf that bears sporangia.Both microphylls and megaphylls can be sporophylls.