STUDIES ON CERTAIN FUSARIUM .ROTS OF ONION

Abstract

Fusarium rot diseases caused by species of Fusarium are one of the important diseases that attacks onion plant for seed and bulb production. Therefore, the present investigation was planned to study the role . of onion seeds in fungus transmition, the association of Fusarium oxysporum f. sp. cepae and F. moniliforme with diseased onion parts, the variation of pathogenic capability of Fusarium o:xysporum f. sp. cepae and Fusarium moniliforme on omon cv. Giza 6 seed and bulb onion, the variation within fungal species and isolates using molecular biological approaches e.g. protein profile isozyme analysis and PCR., Pathogensis related Proteins chemical analysis of onion for seed production and for bulb production and the constitute of root exudates for amino acids and sugars and their role in pathogensis process and the effect of some bioagents againt Fusarium oxysporum and Fusarium moniliforme.

Results of this work can be summarized as follows:

1 - Eighteen onion seed samples were collected from different parts of Assiut, New Vally, EI-Mina and Beni Sweef Governorates.

2- Ten isolates of Fusarium moniliforme and 8 isolates of F. oxysporum f sp. cepae were obtained either from onion seeds, onion diseased parts or from onion rhizosphere.

3 - All the tested isolates proved to be pathogenic on seed and bulb onion with different degrees of virulence.