عنوان مقاله [English]
In this research, possibility of utilizing Fusarium (Fusarium spp.) species of rhizosphere was studied as biological control agent of some important weeds of wheat fields .Wild barely (Hordeum spontaneum), wild oat (Avena ludoviciana), rye (Secale cereale) Wild mustard (Sinapis arvensis), and turnipweed (Rapistrum rugosum) were planted on soils sampled from wheat fileds of East Azerbayejan, Alborz, Tehran, North Khorasan, Razavi Khorasan, Khouzestan, Fars, Qazvin, Mazandaran, Kermanshah, and Golestan provinces in greenhouse situation. Fusarium species of plants root were isolated. Effect of Fusarium isolates on seedling radicle length was considered as the criteria for successful control (inhibition of radicle length≥ 70%) in bioassay experiments. In the first step of bioassay experiments, lettuce (Lactuca sativa) seedling was used as a test plant and the next step was carried out on mentioned weed species. Finally, wheat seedling, cultivar Sivand, was used to evaluate host specifity of selected isolates from pervious stages. Isolates with efficient inhibitory effect on weeds with least inhibitory (seedling radicle reduction≥ 10%) effect on wheat, were determined as successful selective biological control agents and identified with morphological and molecular methods. Results showed that one isolate of F. oxysporum on wild mustard and turnipweed, one isolate of F. brachygibbosum on wild barely and one isolate of F. equiseti on wild barely and wild oat, controlled the species very effectively. Knowledge about microbial agenets of biological control of weed species can aid in diversifying current management methods and maintenance of efficacy of available chemical herbicides.