An average of about 50 endophytic species per plant species was found in surveys done before the year 2000
(Stone et al., 2004). When molecular methods for the identification of fungi began to be applied to endophyte
research (i.e. rDNA sequencing; Arnold et al., 2000; Guo et al., 2000), the number of fungal species identified
per host plant species increased substantially. The reason for this is that an important proportion of fungal isolates may be sterile in laboratory cultures. Genotypic identification methods have allowed to identify, or at least to distinguish, among sterile cultures