What is the primary host range of late blight of potato?

The primary host range of late blight of potato is indeed potatoes and tomatoes. Late blight is caused by the oomycete pathogen Phytophthora infestans, which primarily affects the Solanaceae family—this includes the potato (Solanum tuberosum) and the tomato (Solanum lycopersicum). Both plants are highly susceptible to this pathogen, making them critical hosts in its life cycle.

Phytophthora infestans thrives under specific environmental conditions that are also favorable for the growth of these crops, often leading to devastating outbreaks in potato and tomato fields. Understanding this host specificity is crucial for managing the disease effectively, such as through crop rotation and careful monitoring of susceptible crops within agricultural systems.

The other options consist of crops that do not belong to the same family as potatoes and tomatoes, making them unconnected to the late blight pathogen. Crops like wheat, corn, rice, barley, cucumber, and squash do not serve as hosts for Phytophthora infestans, which is why they are not considered part of the primary host range.