Question

Late blight of potato is caused by :

• A. Ustilago
• B. Pseudomonas
• C. Phytophchora infestans
• D. Colletotricum falcatum

Answer 1

The Correct Option is C

Phytophthora infestans, a pathogen of class Phycomycetes attacks a number of members of family Solanaceae, the important being potato and tomato. It causes blight over leaflets, tubers and the disease is known as late blight of potato since, it's destruction is seen in the later stages (under cool and moist conditions) of the plant, not only destroying the whole field but the infection continues to advance inside the tubers under storage conditions. Ustilago (class Basidiomycetes) is a parasite growing on several plants (mostly Graminae family) and causes smut disease (loose or covered smuts) by producting spores termed as teliospores, or chlamydospores. e.g., Ustilago nude var. tritici causes loose smut of wheat. Colletocrichum falcacum is incitant of red rot of sugarcane. Pseudomonas sp. besides dentrification, causes deterioration of materials, spoilage of food and food poisoning. PseudomoncLy tobaci causes wild fire disease of tobacco.