Pathogenicity test of contaminated fungi isolates of tissue culture on date palm seedlings (Phoenix dactylifera L.)‎ in the greenhouse

الملخص EN

This study was carried out in the laboratories and greenhouse of the date palm research center at the University of Basrah.

The aim of this study is to evaluate the pathogenicity of fungi and their filtrates that cause tissue culture contamination on seedling of date palm under greenhouse condition.

The results of the isolation fungi from date palm tissue cultures showed that there were many fungal contaminations, which included Alternaria alternata, Fusarium sp., and Rhizopus stolinfer.

Also the results showed that the most frequent fungus was Alternaria alternata with 33%, followed by Fusarium sp.,with 26%, and while the least frequent fungus was Rhizopus stolinfer with 1%.

The pathogenicity assay of these isolated fungi on date palm seedlings showed that all of these tested fungi were nonpathogenic against these plantlets, except the isolates of A.

alternata, which recorded a 28%, followed by Fusarium sp., with a 16%, while the other isolates were not recorded.

The efficiency of fungal surpeninat on date palm seedlings showed the superiority of the fungal surpeninat of A.

alternata and Fusarium sp.

Other fungi recorded discoloration symptoms on the roots of date palm seedlings by about 12 and 8%, respectively.

The study's findings indicate that these polluting fungi have pathological effects on tissue culture growth, but the greatest effect of fungal contamination is concentrated on their secretion of toxins and other metabolic products, which also compete for nutrients in the tissue culture medium, resulting in weak growth and deterioration of tissue growth