Can fungal endophytes protect American Chestnut (Castanea dentata) from blight (Cryphonectria parasitica)?

Endophytes were isolated from surface-sterilized stem sections of C. dentata following established culture protocol by plating surface sterilized sections onto Difco potato-dextrose agar (PDA) (Schulz et al., 1993). Stem sections were cut into manageable pieces before being serially submerged in 95% ethanol for 30 seconds, a sodium hypochlorite solution (5.25% v/v) for 3 minutes, 75% ethanol for 30 seconds, followed by sterile, distilled water for 30 seconds.  Each section was imprinted on PDA and the aliquots of the rinse water were plated to confirm surface sterilization.  Isolations were only performed from batches of sterilized stems that had no contamination on the imprint and aliquot plates. Transverse and longitudinal sections of stems were plated on potato dextrose agar. Emerging endophytes were isolated in individual axenic cultures, resulting in a library of 109 cultivable endophytes.