Definition

Noun A species of oomycete (water mold) in the family Peronosporaceae. It is an obligate parasite that causes a serious and destructive disease in tobacco plants, characterized by the growth of bluish-grey, downy mildew on the undersides of the leaves.

Usage

This term is used specifically in the fields of plant pathology, mycology, and agriculture. It refers to the pathogenic organism itself, not the disease it causes (which is called blue mold or downy mildew of tobacco).

Examples

• The rapid spread of devastated the tobacco crop.
• Researchers are studying the life cycle of to develop resistant plant varieties.
• The identification of was confirmed under the microscope by its distinctive sporangiophores.

Advanced Usage

• The genus name is often italicized in scientific writing, while the species epithet is always lowercase.
• In taxonomic contexts, the author citation may be included: Adam.

Variants and Related Words

• Blue mold (of tobacco): The common name for the disease caused by .
• Downy mildew (of tobacco): Another name for the same disease, describing the symptom.
• Oomycete: The broader biological class to which this pathogen belongs, distinct from true fungi.
• Peronosporaceae: The family name.

Synonyms

• Tobacco blue mold pathogen (descriptive synonym, not a scientific name).

Notes

Peronospora tabacina is not a true fungus but an oomycete, though it was historically classified and is often discussed within mycology. It is a subject of quarantine and significant management efforts in tobacco-producing regions.

Noun

1. fungus causing a serious disease in tobacco plants characterized by bluish-grey mildew on undersides of leaves