Characterization and identification of the causal organism of gummosis
A total of two Ceratocystis isolates (UGM AD 1 and UGM AD 2) were obtained from diseased A. decurrens at MVNP. Mature ascomata were produced in culture during a 2-week incubation on PDA. The ascomata had black, globose to sub globose bases (Fig. 3a) and long necks with ostiolar divergent hyphae (Fig 3b) exuding hat-shaped ascospores from their tips (Fig. 3c). Ascomata varied in size, the neck and base were 0.2-1.3 and 0.2-0.6 mm long, respectively. Chlamydospores and both barrel-shaped and cylindrical conidia were produced in culture. (Fig. 3d, e). Based on ITS sequence BLAST on the GenBank database (https://blast.ncbi.nlm.nih.gov), isolates (AD 1 and AD 7) fromA. decurens showed the closest similarity to Certocystis fimbriata (Fig. 4).
Molecular analysis involved 15 nucleotide sequences withCeratocystis fimbriatomima (MH863157) as an out group. There were a total of 172 positions in the final dataset Evolutionary analyses were conducted in MEGA7.