Applied Cell Biology

Genetic diversity among some isolates of Fusarium oxysporum f. sp. lycopersici from tomato plants in Egypt

Reda H.Sammour, Salah M.Abdel-Momen, Eman A.Elagamey

¹BotanyDepartment,Faculty of Science,TantaUniversity,Tanta, (EGYPT)
²AgricultureResearchCenter, Plant Pathology Institute,TheCentralLaboratory forBiotechnology,Giza, (EGYPT)

Abstract

A combined study of pathogenicity, mycelial compatibility, chemotaxonomic and molecular analyses was conducted to reveal the genetic variability in isolates of Fusarium oxysporium f. sp. lycopersici collected from tomato plants (stems and roots) in Egypt. The results derived from these techniques were corroborative and suggested a considerable genetic diversity among isolates. The extent of diversity, however, differed between analysis methods. The disease severity caused by the studied isolates showed awide range of variation ranged from42.2%to 73.3%on shoot systemand from 31.1%to 62.2 on root system. The cluster analysis of mycelial compatibility data indicated no relationship between mycelial compatibility groups and virulence. The high percentage of polymorphism at both chemotaxonomic and molecular levels suggested a complex evolution pattern and confirmed the polyphyletic origin of Fusariumoxysporium f. sp. lycopersici. In addition, the partial association between the loci generated by one of the used primers and mycelial compatibility groups suggested that some of the latter were clonally derived. Intraspecific hybridization phenomenon was also discussed.

Keywords:

F. oxysporium f. sp.Lycopersici; Tomato plants; Pathogenicity; Mycelial compatibility groups (MCGs); Whole cell proteins; RAPD analysis.