Identification of an antifungal compound in unripe avocado fruits and its possible involvement in the quiescent infections of Colletotrichum gloeosporioides.
Prusky, D.; Kobiler, I.; Fishman, Y.; Sims, J. J.; Midland, S. L.; Keen, N. T.;
Journal of Phytopathology Year: 1991 Vol: 132 Issue: 4 Pages: 319-327 Ref: 18 ref.
1991
บทคัดย่อ
A new antifungal compound was isolated from peel and flesh of unripe avocado fruits and identified as 1-acetoxy-2,4-dihydroxy-n-heptadeca-16-ene. The max. concn of the antifungal monoene in unripe fruits was about 800 micro g/g fresh weight. During ripening the monoene decreased to 40 micro g/g, concomitant with the appearance of disease symptoms. The concn of the antifungal diene, 1-acetoxy-2-hydroxy-4-oxo-heneicosa-12,15-diene, in avocado peel was 1600 micro g/g in unripe fruits, and decreased during ripening to 120 micro g/g. At 750 micro g/ml the inhibition of germ tube elongation of germinated conidia by the monoene and the diene, was 15% and 44%, respectively. A 1:1 mixture of both antifungal compounds in concn ranging from 50 to 750 micro g/ml showed synergistic activity and increased the percentage of inhibited germ tubes of germinated conidia by up to 15% over the sum of activities of the separate compounds. The results are discussed in relation to the hypothesis that these compounds are involved in the quiescence of the germinated appressoria of C. gloeosporioides [Glomerella cingulata] in unripe avocado fruits.