Identification and Biocontrol of Fusarium oxysporum Affecting Lucky Bamboo (Dracaena sanderiana Hort. ex. Mast.).

Abstract

Lucky bamboo is an economically crucial ornamental plant worldwide due to its durability, rapid growth capacity, and versatile uses. However, diseases caused by various fungal pathogens negatively affect bamboo production, resulting in yield losses. In the present study, fungal agents causing disease in Dracaena sanderiana were isolated and evaluated for their pathogenicity. The MF-1 and MF-2 isolates that showed pathogenicity were characterized morphologically and molecularly. Chitinase enzymes were partially purified from four different bacteria and biochemically characterized, and the antifungal activities of these bacteria and chitinases were evaluated. As a result of the diagnosis, both isolates were identified as Fusarium oxysporum with ~99% similarity. It was determined that the partially purified chitinases from Pseudomonas chlororaphis C-37A and Agrobacterium radiobacter A-16 had the highest activity with values of 9.44 and 1.02 EU/mL, respectively. Additionally, the pH and temperature values at which C-37A's chitinase exhibited optimal activity were determined to be 8 and 30 °C, while those for A-16's chitinase were found to be pH 4 and 40 °C. After 120 min, C-37A's chitinase retained 50% of its activity at 90 °C, while A-16's chitinase retained 80% of its activity at 40 °C. C-37A inhibited the growth of MF-1 and MF-2 by 83% and 75%, respectively. Additionally, the inhibition rates of A-16, Bacillus megaterium M-3, and KBA-10 ranged from 68% to 29%. In chitinase applications, the highest inhibition rates of 28% (MF-1) and 23% (MF-2) were obtained from C-37A chitinase. In conclusion, it was observed that bioagent bacteria provide sustainable biological effects against F. oxysporium in D. Sanderiana, and that the chitinase enzyme purified from these isolates can be used as a biocontrol agent in agriculture, as well as potentially evaluated in various industrial applications.