Which of the following is true about Pythium?

Pythium is a significant plant pathogen commonly associated with seedling diseases, especially in wet and poorly drained soils. This organism is classified as a water mold, belonging to the group known as oomycetes, which distinguishes it from true fungi. The statement that Pythium is a water mold fungus is accurate because it highlights its unique classification within the broader category of microorganisms that affect plants.

In addition to being a water mold, Pythium is well-known for its role as a soilborne pathogen. It typically thrives in moist conditions and can infect plant roots and seedlings, leading to damping-off disease, which is particularly devastating in agricultural settings. The characterization of Pythium as a common soilborne pathogen reflects its prevalence in various soils and its potential to cause significant damage to crops.

Therefore, the choice that states both aspects—Pythium being a water mold fungus and a common soilborne pathogen—is entirely correct, aligning with established plant pathology knowledge.