EVALUATION OF SOME FUNGI AND BACTERIA AS BIOLOGICAL AGENTS TO FUSARIUM WILT  OF BANANA

Ziedan, E. H.; Farrag, Eman S.; Saad, Moataza M.

doi:10.21608/jpp.2007.208127

EVALUATION OF SOME FUNGI AND BACTERIA AS BIOLOGICAL AGENTS TO FUSARIUM WILT OF BANANA

Document Type : Original Article

Authors

¹ Plant Pathology Dept. National Res. Center, Cairo, Egypt.

² Agric. Botany Dept. Fac. of Agric. South Valley Univ. Quina, Egypt.

³ Microbial chem. Dept. National Res. Center Cairo, Egypt.

10.21608/jpp.2007.208127

Abstract

Fusarium oxysporum Schlechtend : Fr f.sp . cubense (FOC) (E F. Smith). Snyder & Hansen were the most causal organism causing wilt disease of banana plant at Beheira , Gharbea and Assuit Governorates, Egypt. Fusarium wilt disease of banana showed to be similar to those of other plants. Discoloration brown to dark of pseudostem and rhizomes was the most indicator of Fusarium wilt of banana plants.
In vitro four microbial isolates from the banana root and rhizosphere showed highly antagonistic activity to F.oxysporum f. sp. cubense. These isolates were identified as Bacillus subtilis (Ehrenberg) Cohn (No.1), Pseudomonas fluorescens Migula(No.3), Trichoderma harzainum Rifai (No.6) and Laetisaria arvalis Burds (4). Bacillus subtilis (Ehrenberg) Cohn (No.1); Pseudomonas fluorescens Migula (No.3) and T. harzianum isolates were the most antagonistic isolates inhibiting mycelial growth of F. oxysporum f.sp. cubense.These antagonistic strains were excreted antifungal lytic enzymes on liquid medium containing dead mycelium of F. oxysporum f. sp. cubense i.e. chitinase, β1-3,β1-4 glucanases and protease. Chitinase and protease enzymes were the most lytic produced by all antagonistic strains.while β1-3and β1-4 glucanases were produced at a moderate rate.
Bacillus subtilis (Ehrenberg) Cohn (No.1) was the most antagonistic strain producing chitinase and protease followed by L. arvalis and T. harzianum. On the other hand, Bacillus subtilis and L. arvalis were the most antagonistic producing difusible and volatile antibiotics followed by P. fluorescens. while, T. harzianum was the least antagonistic phase of antibiotics. Pot trails conducted during a summer season, revealed that dipping banana roots transplanting root in the suspension of B.subtilis, P.fluorescens Migula, T.harzianum Rifai and Laetisaria arvalis Burds 3x10⁸ (CFU/ ml ) for one and two hours or soil drench with 100 and 200 ml / pot were effectively reduced wilt disease incidence of banana plants, respectively. Under field naturally infestation with F.oxysporum f.sp. cubense soil dranch of banana around rhizome region by suspension of B.subtilis, P.fluorescens Migula, T.harzianum Rifai, and fungicide (Topsin) reduced the wilt incidence than control . Soil drenched with 300 ml of B. subtilis significantly reduced the wilt incidence by 50% compared with control. Whereas the P. fluorescens Migula failed to control Fusarium wilt. B. subtilis was the most promising biocontrol agent against wilt disease of banana.

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