Detection of Seed – Borne Fungal Pathogens Associated with Barley (Hordeum vulgare) Seeds and Their Bio-Control Under Laboratory Conditions

Abstract

Abstract A total of 185 fungal isolates were acquired and identified, with these isolates originating from two distinct varieties of barley seeds, there were 67 isolates obtained from seeds of the initial Aswad Mosul cultivar and 118 isolates from seeds of the white Nur cultivar harvested during the 2022-2023 season., the fungus Rhizopus spp. was the most frequently in barley seeds with rate (37.8%) followed by Aspergillus terrus and Aspergillus niger at rate (18.3%), (13,5%) frequently while Rhizoctonia spp. and Alternaria sp. reached (9.1%), (8.6%) Consecutively, Phoma, Helminthosporium and Fusarium graminearum get (1.6%), Penicillium spp. (3.7%), Drechslera spp., Stemphylium spp., Pleosporaceae sp. get (1.08%) and A. flavus achieved the lowest rate (0.5%). In the initial assessment of pathogenicity using radish seeds, it was observed that only two isolates exhibited a high level of pathogenicity. The germination rate in their treatments ranged from 50-70%, whereas the control treatments displayed a significantly higher germination rate of 97%., the isolate of Fusarium graminearum gave the highest rate of decrease in seed germination (50%) followed by Rhizctonia spp. reached 40% in laboratory. The antagonistic activity assessed in vitro using the dual culture technique, Trichoderma. viride showed statistically significant inhibition which reach scale 1. The morphological identification confirmed by using polymerase chain reaction assay of ITS1, 5.8S, and ITS2 are parts of the internal transcribed spacer of the rDNA, the results of the nitrogenous base sequence within the BLAST (Basic Local Alignment Research Tool) platform for the amplification products of ITS1-ITS4 showed the classification of tested fungal isolate isolate represented the fungus. F. graminearum.