effect of bio-fertilizers on greenhouse cucumber resistant to damping-off disease caused by pythium aphanidermatum and increase of yield component

damping-off disease of cucumber caused by soil-born fungi pythium aphanidermatum is one of the most destructive diseases of cucumber. in this research, the effect of three bio-fertilizers including; nitroxin, mycorrhiza and vermicompost in single and combined form on induced resistance and yield components in greenhouse cucumber (es-2862) infected with damping-off disease was investigated. these experiments were performed in a completely randomized design with four repetitions in greenhouse condition. the measurment of disease severity showed that v+n+m (37%) and vermicompost + nitroxin (73%) treatment have the highest and the lowest effects on disease severity reduction, respectively. the mixed treatment of three bio-fertilizers has the best effect on increase of yield components when compared to control. the application of mycorriza alone showed the lowest effect on majority of traits. gene expression analysis of cupi4 and chitinase genes by qrt-pcr showed that expression level of two genes has been affected by bio-fertilizers treatment. for cupi4 gene (23.65), combination of three bio-fertilizers and for chitinase gene (2.45), mycorrhizal treatment showed the highest effect of expression pattern. regarding the results, it can be concluded that these bio-fertilizers could be use as bio-control agents to plant improving against pathogenic fungal agents.