Production of Oxalic Acid by Sclerotium Cepivorum During Infection of Onion

ABSTRACT

Sclerotium cepivorum, causal agent of white rot of onion, produced oxalic acid in culture and in infected onion tissue. The concentration of oxalic acid in infected onion sets was 3.3 mg per gram initial dry weight of onion tissue by 12 da after inoculation, at which time maceration of the onion sets was essentially complete. It is suggested that maceration of onions by S. cepivorum may be by synergistic action of oxalic acid and endopolygalacturonase, as has been shown in diseases caused by Sclerotium rolfsii and Sclerotinia sclerotiorum.

Key Words:

• maceration
• oxalic acid
• white rot of onions