What organisms are infected by downy mildews ?
Albugo candida is a common downy mildew. It grows as a parasite on many plants of the mustard family, e.g. mustard, radish, cabbage, turnip, etc., and cause a disease called ‘white rust’. White blisters appear on the stem and the leaf. Gradually the disease spreads to the flowers and the ovaries.
The mycelia ramify through the intercellular spaces of the host plant and branch profusely. The hyphae are unseptate and multinucleate. Here and there they send globular or button like haustoria into the living cells of the host to absorb food from them.