Which of the following best describes bacterial canker?

Bacterial canker is best defined as a bacterial infection that leads to the development of lesions on various plant tissues, including fruit. This condition is commonly seen in a range of plants and can result in significant damage due to the formation of dark, necrotic lesions that compromise fruit quality and yield. The presence of these lesions can also create entry points for secondary infections, exacerbating the issue for the affected plants.

The other options describe conditions that are associated with different types of plant diseases. For instance, wilting is typically a symptom of root or vascular issues rather than specifically associated with bacterial canker. Diseases affecting root systems tend to involve pathogens that target root structures directly, which is distinct from the fruit lesions seen in bacterial canker. Lastly, fungal infections are responsible for various symptoms, including leaf discoloration, but they are not described by the term "bacterial canker," which specifically refers to bacterial agents causing those characteristic fruit lesions. Thus, focusing on the specific impact of bacterial canker allows for a clearer understanding of its symptoms and management within plant pathology.