In nature, it is still not possible to discern between pathogenic and non-pathogenic Fusarium isolates, because some of the species although are not pathogenic but they are obviously associated with unhealthy plants and appear as saprophytes or endophytes (Nelson et al. 1983). This phenomenon also deals with an etiology of bakanae disease that is still under discussion. Most of the studies implicated that F. fujikuroi or other species in the section Liseola and their allied species are also involved in causing the disease. Initially, the pathogen responsible for the bakanae disease of rice was identified as F. moniliforme Sheldon (Snyder and Hansen 1945; Booth 1971; Nirenberg 1976) and later re-identified as F. fujikuroi Nirenberg (Nirenberg 1976), the anamorph of Gibberella fujikuroi Sawada. Some earlier phytopathologists, who only used morphological characters to distinguish the species, believed that F. moniliforme was the only species involved (Snyder and Hansen 1945; Nirenberg 1976; Nelson et al. 1983). Recent findings revealed conflicting results and suggested that other species of Fusarium in the section Liseola may be involved in infection of bakanae disease (Amoah et al. 1995, 1996; Desjardins et al. 1997, 2000).