First record of the fungus Rhizoctonia solani as a cause of root rot disease and damping off in Celosia argenta in the Province of Karbala and Babylon / Iraq

Abstract

This study was conducted with the aim of isolating and diagnosing the fungus that causes root rot and damping off Celosia argenta in some nurseries in the Province of Karbala and Babylon and testing its pathogenicity in the laboratory and under greenhouse conditions. The results showed that 20 isolates of the fungus Rhizoctonia solani were phenotypically diagnosed. Isolation Rh16 significantly compared to the other isolates in its reduction of the percentage of germination of red radish seeds on water agar media, as the percentage of germination in it was 0.00% and the percentage of inhibition was 100% Compared to the comparison treatment, in which the percentage of seed germination was 100%. The results of the plastic pots experiment in the greenhouse also showed that the results matched the laboratory experiment, as the isolate Rh16 was significantly superior in reducing the germination rate, reaching 0.00% and 100% inhibition when treating the seeds of rooster mane with the isolated fungi compared to the control treatment, the percentage of germination in it was 100%. The results of the molecular diagnosis showed that the most pathogenic isolate of Rh16 belongs to the fungus Rhizoctonia solani and it was deposited in the American Gene Bank under the entry number ON383979.1., Celosia argentea,