Antagonistic Effect of Hard Palate Isolates on Selected Fungal Plant Pathogens

Abstract

The search for antifungal agents with possible novel application in battling plant diseases cannot be overemphasized. Hence, a study was carried out to investigate the antagonistic ability of some hard palate isolates; Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus sp., Micrococcus sp. and Aspergillus flavus against four test phytopathogenic fungi - Colletotrichum lindemuthianum, Colletotrichum capsici, Sclerotium rolfsii and Fusarium oxysporum, monitored over a period of five days incubation.  All isolates were subjected to screening against the plant pathogens and most of the isolate showed antagonistic activity. Bacillus sp. and Micrococcus sp. (57.0±0.0 and 51.1±0.1: P=.05) showed the highest antagonistic activity after day 5 and 4 respectively against Colletotrichum lindemuthianum. A steady inhibition of Colletotrichum capsici by Aspergillus flavus (51.2±0.2 to 52.0±0.0) was observed from day 3 to 5. Antibiotic sensitivity was carried out on the isolated bacteria. Most of the bacterial isolates were susceptible to gentamycin (15-19±0.0: P=.05), while none of the organism showed susceptibility to pefloxacin and streptomycin (0.0±0.0). Bacillus sp. showed susceptibility to chloramphenicol and gentamycin; and Micrococcus sp. to cotrimoxazole and erythromycin. Pseudomonas aeruginosa (0.0±0.0) was resistant to all the antibiotics. This research paper further discussed the use of hard palate microflora as possible source(s) of biocontrol agents in the control of plant diseases, especially those caused by the selected test fungal pathogens.