Isolation and identification of beneficial orchid mycorrhizal fungi in <i>Bletilla striata</i> (Thunb.) Rchb.f.(Orchidaceae)

Orchid mycorrhizal fungi (OMF) are essential for orchids growth. <i>Bletilla striata</i> (Thunb.) Rchb.f.(Orchidaceae) has high ornamental and medicinal value. Beneficial OMF isolation is crucial to improve the survival rate of <i>B. striata</i> tissue culture and transplanting. In this study, we isolated and identified the beneficial OMF in <i>B. striata</i> from the roots of sterilized wild <i>B. striata</i> seedlings by culturing in four different mediums. The germination states of <i>B. striata</i> seeds inoculated with diverse OMF were classified and calculated. Fresh and dry weight increments of <i>B. striata</i> seedlings inoculated with diverse OMF were recorded after 90 d of culturing on 1/2 MS medium. ITS sequences of beneficial fungi were amplified by PCR and taxonomically identified using BLAST against the GenBank nucleotide database. Ten kinds of OMF strains were isolated from <i>B. striata</i> and named R1 to R10. R6 significantly promoted <i>B. striata</i> seeds germination (<i>p</i> B. striata seedlings (<i>p</i> Serendipita. R3 was identified as <i>Schizothecium fimbriatum</i> by 100% ITS identity. R6 and R3 were beneficial OMF in <i>B. striata.</i>