Question

Which of the following fungi is a parasite on the mustard plant and causes the disease white rust of crucifers?
(a) Albugo candida
(b) Puccinia graminis Tritici
(c) Saccharomyces cerevisiae
(d) Ustilago hordei

Answer 1

This is an obligate parasite and requires a suitable host to reproduce. They are destructive plant pathogens and can reproduce asexually and sexually both.

Complete answer:
Albugo candida is a fungal parasite that attacks mustard plants and causes the disease called the white rust of crucifers. This is one of the species of oomycete found in the family Albuginaceae. As compared to other oomycetes it has a relatively smaller genome. The oomycetes are commonly known as water molds.
-This pathogen mainly infects the plants of the family Brassicaceae and causes the sickness known as white rust or white rankle rust.
-This pathogen can infect the plants in different stages of growth like the seedling stage, the growing stage, the flowering stage, and the fruiting stage.
-This pathogen has been recorded in almost all the varieties of the mustard groups of plants.
-The infection of white rust or white rankle rust appears on stems, leaves, and inflorescences as a mass of white or cream-colored pustules, each about 2 mm in diameter, packed with sporangia.
-While the new pustules are borne the older ones become larger at the center.
-The symptoms of white rust or white rankle indicate distortion, abnormal growth forms, and sterile inflorescences.
-It is mainly found in many countries where the cruciferous crops are grown such as in countries of Europe, Asia, Africa, Australasia, North, Central, and South America.

So, the correct answer is, 'Albugo candida '.

Note:
-Albugo candida mainly infects the plants of the family Brassicaceae and causes the sickness known as white rust or white rankle rust.
-The symptoms of white rust or white rankle indicate distortion, abnormal growth forms, and sterile inflorescences.
-This pathogen has been recorded in almost all the varieties of the mustard groups of plants.