Biocontrol potential of endophytic fungi in medicinal plants from Wuhan Botanical Garden in China
Abstract Many medicinal plants possess antimicrobial activities, and have antagonistic endophytic fungi that help them protect from pathogen attack. The aim of this study was to examine endophytic fungi in traditional Chinese medicinal plants, and understand if these organisms have antimicrobial activities and they can be potentially used for biological control of plant diseases. A total of 208 endophytic fungal isolates were collected from stems (83) leaves (121) and flowers (4) of 26 medicinal plant species. The majority of the isolates belonged to Alternaria, Phomopsis, Colletotrichum, Phoma and Acremonium as well as several species allocated to Mycelia sterilia. A detached leaf assay was conducted by testing these isolates on wheat powdery mildew (Blumeria graminis f. sp. tritici, or Bgt) Fifteen isolates of endophytic fungi inhibited Bgt, exhibiting control efficacies ranging from 65.4% to 100% Of these isolates, LPS 1, SCS 6 and 16 6, exhibited significant inhibition of Bgt proliferation >90% Isolate LPS 1 isolated from the stem of Ilex cornuta Lindl. ex Paxt. had the highest efficacy, resulting in 100% inhibition of Bgt growth on detached leaf segments. Based on morphological characteristics and phylogenetic analyses of the ITS rDNA sequences and translation elongation factor 1 alpha (TEF 1a) gene regions, LPS 1 was identified as Lasiodiplodia pseudotheobromae. A range of culture conditions for LPS 1 were examined and the results indicated that optimal antifungal activity resulted from static cultures in PDB (pH 7.0) inoculated with three mycelial plugs and incubated at 30 degC for 6 days. With further study, LPS 1 can be a candidate for biological control.