Isolation and identification of fungi causing root rot and wilt of sour orange seedling and testing the pathogenicity of some isolates of Fusarium sp.

Abstract

This study was conducted with the aim of isolating the fungi causing root rot and wilt of citrus seedling in some nurseries that produce citrus seedling in Lattakia, sex pathogenic fungal genera were isolated and purified from the root  and crown area of seedling samples that had symptoms of infection with the disease, These fungi are:

 Fusarium, Pythium.Rhizoctonia,Phoma,Nigrospora,Phytophthora. Fusarium was the most frequent compared to other fungi 70.37% followed by Rhizoctonia 19.14, then Phoma 4.47%,then Pythium 2.47%, then Phytophthora and Nigrospora 1.85%.

The pathogenicity of fifteen isolates of Fusarium sp. Was tested on 45-days-old sour orange seedlings, the infection rate ranged between 0 and 100% and the severity of infection between o and 84%, the percentage of F.solani isolates was 46.66%, F. oxysporum 33.33% and 20% of the other Fusarium species.