All tomato FOL and FORL isolates
rendered colonies with conidia and mycelia with morphological
characteristics typical of F. oxysporum [42]. The characteristic
morphological and molecular properties of fungal isolates were
compared with a reference FORL culture obtained from Dr. J. Scott
(University of Florida, USA). The culture characteristics and
micromorphology were investigated by using PDA and carnation
leaf agar[26]. Symptoms include typical one-sided wilting and dark
brown vascular discoloration. Upper stem tissues and wilted
seedlings were disinfested by immersion in a 1.0% aqueous solution
of sodium hypochlorite for 2 min, rinsed in sterile water, and placed
on PDA medium. After 72 h, hyphal growth was recovered and resubcultured on PDA and incubated at 25
C in 12-h light/dark
cycles. Identification was based on colony morphology and conidial