The influence of polyacetylenes on the susceptibility of carrots to storage diseases

The amounts of the polyacetylenes falcarindiol (heptadeca-1,9(Z)-dien-4,6-diyn-3,8-diol) and falcarinol (heptadeca-1,9(Z)-dien-4,6-diyn-3-ol) were determined in the roots of a number of commercial carrot cultivars in order to study their influence on resistance to storage rots caused by three different fungi. The content of the diol was much higher in periderm/pericyclic parenchyma than in phloem parenchyma and the outer tissues were less susceptible to Mycocentrospora acerina than the inner tissues. A strong and significant negative relationship was found between falcarindiol contents in the periderm/pericyclic parenchyma and susceptibility to Mycocentrospora acerina for 14 of the 16 cultivars tested. The relationship was less noticable for Sclerotinia sclerotiorum and not significant for Rhizoctonia carotae.