THE EFFICACY OF SOME ENDOPHYTES BACTERIA ISOLATED FROM TOMATO PLANTS TO SUPPRESS FUNGUS Alternaria solani IN LABORATORY CONDITIONS

Abstract

Under laboratory conditions, the study assessed the efficacy of certain endophytic bacteria isolated from healthy tomato plants in suppressing the pathogenic fungus Alternaria solani, which causes early blight in laboratory conditions. The study was carried out in the Fungal Diseases Laboratory, Department of Plant Protection, Ministry of Agriculture for the 2022 season. 20 bacterial isolates were obtained in several fields in Baghdad Governorate. the pathogenicity assay on tomato plants grown in pots revealed that 50% of the endophytic bacterial isolates showed pathological symptoms when tested individually on aplant, such as yellow spots, necrosis, wilting and death of certain plant leaves or the whole plant. In laboratory conditions, the results showed that 40% of the endophyte bacterial non pathogenic isolates caused a significant reduction in the growth rate of the pathogen on Potato Dextrose Agar (PDA). A.solani growth was most significantly inhibited by the isolate B9, which achieved 81.11%. Molecular diagnostics of bacterial isolation (B9) using the Bacterial ribosomal genes (16S rRNA) showed that it is the bacterium Alcaligenes faecalis.