control of bipolaris oryzae the causal agent of rice brown spot disease via soil streptomyces sp. isolate g

bipolaris oryzae causes rice brown spot disease which reduces rice yield with substantial global impact. streptomycetes isolated from rice fields of guilan province, iran, showed antifungal activity against the tested pathogen. from five active streptomyces spp. isolates, isolate g showed high antagonistic activity. to determine its taxonomical identity, its colonies characterized morphologically by scanning electron microscope. some of the physio-biological properties of antifungal principle (s) also determined. the pcr molecular analysis of active isolate represented its identity partially. in this regard, 16s rdna of isolate g was amplified using universal bacterial primers fd1 and rp2. the pcr products were purified and sequenced. sequence analysis of 16s rdna was then conducted using ncbi blast method. our findings are early steps in characterization of this isolate. we hope to determine its precise physiological criteria including its in-depth biological activity for its future in vivo evaluation under field condition