Amirreza Amirmijani

Mesquite trees are widely acknowledged as an immensely significant arboreal species within the southern region of Kerman province, thereby rendering them ecologically and economically indispensable. Root rot disease, emanating from the Fusarium oxysporum pathogen, constitutes one of the prevailing afflictions that adversely affect mesquite trees. The present investigation scrutinized the potential biocontrol ramifications of mesquite root bacteria in combating F. oxysporum. Over the course of the various seasons of 2022, samples were systematically collected from the roots of mesquite trees. Following the process of isolation and purification, a total of 35 bacterial isolates were successfully acquired. In order to gauge the biocontrol effects of these bacteria against F. oxysporum, dual-culture tests as well as the examination of volatile compounds were conducted. Among the aforementioned bacterial isolates, namely UJBCC37, UJBCC38, UJBCC39, and UJBCC40, inhibitory capacities against the growth of F. oxysporum were discerned during the dual-culture tests. Notably, none of these four isolates exhibited the ability to generate volatile compounds. Furthermore, to further delve into the fundamental aspects of biological control exhibited by antagonistic bacteria, protease, amylase, and hydrogen cyanide production tests were carried out. The results obtained from the study unveiled that all four isolates were able to effectively produce protease, whereas UJBCC38 and UJBCC39 showcased the capacity to generate amylase. However, none of the isolates demonstrated the production of hydrogen cyanide. Given the indigenous nature of these isolates to mesquite trees, they harbor the potential for effective utilization in the management of mesquite root rot.