Protective function of an ultraviolet-absorbing compound associated with conidia of Glomerella cingulata

Abstract

Conidia of Glomerella cingulata (Stoneman) Spaulding et Schrenk from agar culture were exposed, dry, to middle-wavelength u. v. radiation. Conidia taken from cultures grown in light that included middle-wavelength u. v. survived irradiation for longer than conidia grown in darkness. A compound with maximum absorbance near λ310 nm was associated with the conidia grown in light; but was absent from the conidia grown in darkness. Addition of the purified “compound 310” to dark-grown conidia prolonged their survival under irradiation. It is postulated that in nature this compound aids the survival of G. cingulata conidia, which are produced on the surface of infected apple fruits in orchards, exposed to direct insolation.

Keywords:

• Glomerella cingulata
• conidia
• compound 310 nm
• ultraviolet radiation
• mycology
• physiology