Effect of biocontrol agents on damping-off and root-rot diseases of quinoa (chenopodium quinoa willd)‎ seedling

الملخص EN

Quinoa, recently introduced to Egypt and is considered as an important crop as it can grow and give considerable yield in new reclaimed salt-affected soils.

Isolation trials from rotted quinoa seedlings collected in Egypt (Fayoum governorate) yielded Fusarium solani, Alternaria sp.,Acremoniumsp.

and F.

oxysporum.

All the isolated fungi were pathogenic and caused damping-off and root-rot diseases.

The efficiency of Streptomycesstrains as a biocontrol agent against the pathogenic fungi was investigated under laboratory and greenhouse conditions.

Streptomyces toxytricinishowed the highest inhibition zone of the three strongest pathogenic fungi.

S.

toxytriciniproduced indole acetic acid (IAA) and exhibited optimum phosphate solubilization.

Streptomycesstrains mixtures reduced damping-off incidence, root-rot incidence and severity as well as significantly increased the number of viable seedlings under greenhouse conditions.

Increase of phenolic content as well as activity of peroxidase and chitinase enzymes in Streptomyces-treated plants proved the biocontrol-induced systemic resistance in quinoa seedlings against a mixture of three pathogenic fungi;F.

solani,Acremonium sp.

and F.

oxysporum.