Evaluation of the Bioactivity of Botryosphaeria Species Isolated from Acacia Species

Introduction Current research emphasizes the endophytic fungi that produce secondary metabolites for biotechnological relevance. Botryosphaeriaceae species can produce significant bioactive compounds, and the Botryosphaeria genus is gaining attention in this regard. Aims This study aims to evaluate the bioactivity of Botryosphaeria species from Acacia species. Methods Botryosphaeriaceae species were isolated from Acacia karroo . Morphological and molecular identification was conducted using ITS and BOT primers. The dual method was utilised to determine the antifungal properties of the endophytic fungi. The PCR amplicons were sent for sequencing. Results The overall colonization rate reached 74%, with 18% attributed to the target species. Most isolates exhibited rapid growth, except for isolate 68. Nine isolates were identified as members of the Botryosphaeriaceae family via amplification with BOT primers. Isolate 13 showed strong antifungal effects against two test pathogens, while isolate 78 displayed moderate activity. BOT primer amplification yielded a 372 bp product. BLAST analysis identified isolate 13 as Botryosphaeria dothidea (MT197291.1; 92.76% identity) and isolate 78 as B. dothidea (AF027746.1; 98.41% identity). Endophytic fungi inhabit plant tissues asymptomatically, often engaging in mutualistic associations. Discussions This study confirms the high colonization of endophytic fungi and identifies Botryosphaeria dothidea with notable antifungal potential. Isolate 13 showed strong inhibition against test pathogens, suggesting possible biocontrol applications. Molecular and morphological tools effectively confirmed species identity. Limitations include the use of a single primer and limited pathogen screening. Conclusion The endophytic fungi isolated from Acacia karroo have the potential to be used as fungicides in the agricultural sector. These bioactive compounds have enormous prospects in the biotechnological sphere.