PV in biology typically refers to pathovar, which is a designation used in bacterial nomenclature.
A pathovar (abbreviated as pv.) is a subdivision below the species level used to classify bacteria, particularly plant-pathogenic bacteria. It denotes a strain or group of strains within a bacterial species that are distinguishable by their specific pathogenicity to one or more plant hosts. In simpler terms, a pathovar represents a group of bacteria that can cause disease in a particular set of plants, but not necessarily in others, even within the same plant family or genus.
Here's a breakdown:
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Strain specificity: Pathovars highlight the specialized relationship between a bacterial strain and its plant host. Different pathovars of the same bacterial species can infect different plants.
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Pathogenicity: This refers to the ability of the bacteria to cause disease in a host plant. The pathovar classification indicates that the bacteria have been confirmed to cause disease in specific plant species.
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Nomenclature: The pathovar name is typically added to the species name, abbreviated as "pv.", and followed by the specific name that describes the plant host or a characteristic of the disease. For example, Pseudomonas syringae pv. tomato is a pathovar of Pseudomonas syringae that specifically infects tomato plants.
Example:
Consider the bacterial species Xanthomonas campestris. This species contains numerous pathovars, each causing disease on different crops. Some examples include:
- Xanthomonas campestris pv. campestris: Causes black rot in cruciferous plants like cabbage and broccoli.
- Xanthomonas campestris pv. oryzae: Causes bacterial leaf blight in rice.
Key Characteristics Summarized:
| Feature | Description |
|---|---|
| Level | Subdivision within a bacterial species |
| Primary Criterion | Host specificity (pathogenicity to particular plant(s)) |
| Application | Classification of plant-pathogenic bacteria |
| Example | Pseudomonas syringae pv. tomato (infects tomato) |
In conclusion, "PV" in the context of biology, particularly microbiology and plant pathology, most commonly refers to pathovar, a designation for bacterial strains exhibiting specific host-pathogen interactions leading to disease in certain plant species.
