Studies on respiration in Fusarium-infected beans

Abstract

Bean plants, when inoculated with Fusarium oxysporum developed disease symptoms 7–9 days later and died within the next 3 weeks. The most common visible symptoms of the disease were wilting, yellowing, vein clearing, and necrosis of the leaves. Just before expression of these symptoms, from 5 days onwards, the leaves of the infected plant respired at a higher rate than those of the healthy plant. With the appearance of the foliar symptoms on the 7th or 8th day, however, the respiration rate began to fall steadily until the plant wilted completely. The tracheal sap of the inoculated plant was found to be toxic and increased the rate of respiration of leaf tissues.