IN VITRO STUDY OF BIOCONTROL POTENTIAL OF RHIZOSPHERIC MICROORGANISMS AGAINST FUSARIUM OXYSPORUM F.SP. ALBEDINIS

Abstract

The present work investigated the ability of antagonistic microorganisms to inhibit the growth of pathogenic strains responsible for the vascular fusarium wilt of date palm or Bayoud's disease. The objective was to evaluate the antagonistic effect of native strains of Trichoderma longibarchiatum, Penicillium sp., Fusarium sp. and one isolate of Bacillus sp. against four isolates of Fusarium oxysporum f.sp. albedinis (Foa) under in vitro conditions. The isolates Bacillus sp. and Fusarium sp. were isolated from soil samples of the rhizosphere of date palm of Tamanrasset region in Algeria, these strains were morphologically identified, and a dual culture confrontation was carried out, placing the Foa in the center of the Petri dish and Bacillus sp. in the two cardinal points. For T. longibarchiatum, Penicillium sp. and Fusarium sp. they were confronted against Foa with a dual confrontation, the inhibition rates were determined, and a percentage of inhibition obtained varied from 64.29 to 65.75%; 57.14 to 64.29% and 36.36 to 52.05% for T. longibarchiatum, Penicillium sp and Fusarium sp. respectively. While Bacillus sp. exhibits the lowest percentage of inhibition in this study, and they were less than 16.67%. Comparison of mean value for each pair between T. longibrachiatum, Penicillium sp., Fusarium sp. on one hand and Bacillus sp. on the other hand concluded that there is a highly significant difference between these three fungal isolates and Bacillus sp. concerning inhibition rates with P-value (P <0.0001). Contrary, no significant difference was observed between T. longibrachiatum and Penicillium sp. with P = 0.1895 and the two antagonists show the same letter A in the letter connection ratio, which means no difference in the level of inhibition.