Which plant diseases are caused by viral, bacterial, and fungal pathogens?

SouravNovember 12, 2024

Answered step-by-step

Plant diseases can be caused by various pathogens, including viruses, bacteria, and fungi. Each type of pathogen is responsible for specific diseases, exhibiting distinct symptoms and effects on host plants. Here’s an overview of common diseases associated with each type of pathogen:

Viral Diseases

Viruses affect a wide range of plants and can cause symptoms such as stunted growth, leaf discoloration, and distortion. Common viral diseases include:

• Tobacco Mosaic Virus (TMV): Causes mottled leaves and stunted growth in tobacco and many other plants.
• Cucumber Mosaic Virus (CMV): Affects cucumbers, beans, and other plants, leading to yellowing and mosaic patterns on leaves.
• Tomato Spotted Wilt Virus (TSWV): Results in necrotic streaks and spots on leaves, along with general stunting of the plant.
• Barley Yellow Dwarf Virus (BYDV): Causes yellowing and stunting in barley, oats, and other grasses.

Bacterial Diseases

Bacterial pathogens can lead to various symptoms such as wilting, necrosis, and galls. Common bacterial diseases include:

• Bacterial Wilt: Caused by Ralstonia solanacearum, affecting crops like tomatoes and potatoes, leading to wilting and death.
• Crown Gall: Caused by Agrobacterium tumefaciens, resulting in tumor-like growths on stems and roots of many plants.
• Soft Rot: Caused by Erwinia carotovora, leading to mushy decay in fleshy tissues such as carrots and cabbage.
• Black Rot: Affects cruciferous vegetables like broccoli and cabbage, causing V-shaped lesions on leaves .

Fungal Diseases

Fungi represent the largest group of plant pathogens and are responsible for a wide array of diseases characterized by symptoms like leaf spots, blights, and rots. Common fungal diseases include:

• Powdery Mildew: Affects many plants with white powdery growth on leaves; caused by various fungal species.
• Anthracnose: Leads to dark spots on leaves and fruit; caused by fungi such as Colletotrichum spp.
• Fusarium Wilt: Caused by Fusarium spp., leading to yellowing and wilting in affected plants.
• Sclerotinia (White Mold): Affects a variety of crops, causing rot in stems and fruits