TY - JOUR AU - Awad, Lina K. AU - Fayyadh, Mohammed A. PY - 2018/12/29 Y2 - 2024/03/28 TI - The activity of some Actinomycetes isolates in control of cucumber damping off disease caused by Rhizoctiona solani and Pythium sp. JF - Basrah Journal of Agricultural Sciences JA - Basrah J. Agric. Sci. VL - 31 IS - 2 SE - ORIGINAL ARTICLE(S) DO - 10.37077/25200860.2018.95 UR - https://www.bjas.bajas.edu.iq/index.php/bjas/article/view/44 SP - 11-23 AB - <p style="text-align: justify;">A 28 Actinomycetes isolates which collected from different environmental sources in Basra province were described as Gram positive and are characterized by producing branching hyphae. Two isolates were identified by molecular analysis of 16 S r RNA gene. Molecular identification confirmed that two isolates of Actinomycetes from soil had a similarity of 99% with&nbsp;<em>Streptomyces griseus</em>. The sequence has been deposited at NCBI with Gen bank accession number (NBRC 14886, AB 184627. 1). While the isolates of date palm roots was analogous to&nbsp;<em>Brevibacterium celere&nbsp;</em>and the sequence of this strain deposited at NCBI with Gen bank accession number (DQ164,K414744601). The dual culture technique showed that Actinomyces isolates 44 had high antagonistic activity against&nbsp;<em>Rhizoctonia solani&nbsp;</em>as inhibition zone reached 1.7 cm, in contrast to Actinomyces 24 and&nbsp;<em>S. griseus&nbsp;</em>which revealed a high antagonistic activity against&nbsp;<em>Pythium&nbsp;</em>sp. with inhibition zone reached 1.2 cm for both isolates. Pots experiment showed all Actinomyces isolates were significantly reduced cucumber seedling damping off caused by&nbsp;<em>R. solani&nbsp;</em>and&nbsp;<em>Pythium&nbsp;</em>sp. the disease incidence for&nbsp;<em>R. solani&nbsp;</em>damping off were reduced to 1.0% in actinomycetes 44, Actinomycetes 24 and&nbsp;<em>B</em><em>. celere&nbsp;</em>treatment compared to 11.37 % in control treatment. Disease incidence at&nbsp;<em>Pythium&nbsp;</em>sp. damping off was reduced to 1.0% in Actinomycetes isolates compared with that in control treatment (4.33%). According to this study there is possibility for isolating Actinomycetes isolates which isolated from different environments sources have the ability for reducing cucumber damping off disease caused by&nbsp;<em>R. solani&nbsp;</em>and&nbsp;<em>Pythium&nbsp;</em>sp.</p> ER -