Genetical and physiological effects of ultraviolet radiation on Cylindrocarpon heteronemum [electronic resource].

Includes references.

In this study the effect of ultraviolet (UV) radiation on cellulose production of Cylindrocarpon heteronemum as well as the fungus itself was evaluated associated with some factors such as temperature degrees, pH degrees and incubation periods. Results showed that exposure periods of ½ and 1 hr of UV radiation stimulated the production of carboxymethyl cellulase (Cx), filter paper cellulase (C1), and β-glucosidase (β-G) enzymes at 20°C, pH 5.0 and 7.0, 9 days post incubation, and then the activity was decreased to reach its lowest with increase temperatures, pH, incubation periods and exposure period of radiation. The genetic variation between wild type and the UV treated-mycelium of C. heteronemum was determined by random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). Through the analysis of genomic DNA of C. heteronemum, the wild type was distinguished by presence of 9 unique fragments that disappeared in the DNA extracted from UV-treated mycelia. Some specific fragments were produced only at ½ and 1 hr exposure times which disappeared in the DNA of control. It might responsible for causing induction of growth and enzymatic activity or correlated to them. A number of specific fragments were detected with the lethal period of UV and disappeared with control and others; it could be correlated to the inhibition of growth.

Summary in Arabic.

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