Question

Which one is the correct matching?
A. Potato- Late blight- Fusarium udum
B. Citrus- Canker- Pseudomonas rubrilineans
C. Brinjal- Root knot- Meloidogyne incognita
D. Pigeon pea- Seed Gall- Phytophthora infestans

Answer 1

Many parasitic infections affect a hundred hectares of crops. A detailed study about the parasites and diseases caused by them allows for finding solutions and preventions. The southern root nematode is known to cause diseases in both monocotyledons and dicotyledons.

Complete answer:
There are various plant diseases caused by pathogenic organisms. Pathogens form an advantageous relationship for themselves with their host. They take up the nutrients of their host for their use and may cause the death of the host. Sometimes they use their host for reproduction also.
Let us discuss each of the given diseases in brief.
-Potato is a popular root vegetable and it gets infected by a devastating disease-causing pathogenic microbe named Phytophthora infestans. It causes late blight of potato which is characterized by large dark brown blotches on leaf veins of potato. The blotches are bordered by green-grey edges. Diseases result in the formation of large sections of dry brown foliage.
-Citrus fruits like lemons, oranges, etc. get infected by a bacterium called Xanthomonas axonopodis. This pathogenic bacterium causes the citrus canker. The disease causes premature dropping of leaves and fruits.
-Brinjal is a purple spongy absorbent vegetable that is typically used in cooking. The Meloidogyne incognita and Rotylenchulus reniformis are the two nematode species that are major pests causing damage to brinjal. Disease caused by Meloidogyne sp. causes root-knot of brinjal. It causes water and nutrient stress in the plant. Yellowing and wilting of leaves are seen. Plant death may also occur in case of high infections. This root nematode causes root rot.
-Seed gal of pigeon pea causes stunted growth of the plant. Anguina tritici is the causative agent. Endoparasite affects inflorescence and seed development.
Therefore, from the above discussion, we can conclude that option C is the correct answer.

Note: The Meloidogyne incognita belongs to the family Heteroderidae. It is a roundworm and one of the four common species of plant-parasites. These worms are specialized to search for chemical cues that guide them towards specific host roots. Chemical and biological control agents are used for the management of diseases caused by these worms.