植物病理学および微生物学ジャーナル

概要

Root Zone Microflora is Responsible for Suppressiveness of the White Root Rot Disease in Akwete Rubber Plantations

Ikediugwu FEO and Ubogu Monday

The rhizosphere microorganisms of rubber plants (Hevea brasiliensis) were determined using the soil dilution plate method, while the rhizoplane was determined by serial washing of root lengths and plating on PDA plates. Fungi belonging to the genera Aspergillus, Trichoderma, Penicillium, Botryodiplodia and Mucor were isolated from both the rhizoplane and rhizosphere of rubber, at both Iyanomo and Akwete rubber plantations. Staphylococcus sp., Bacillus sp. were the only bacteria isolated from the rhizoplane and rhizosphere, together with Bacillus cereus var mycoides, which occurred only on the rhizoplane. A. niger, together with species of Trichoderma, constituted by far the dominant mycoflora in the rhizoplane, at both Iyanomo and Akwete, while A. niger, Penicillium spp. together with Trichoderma spp. dominated at the rhizosphere. In vitro interactions showed that the occurrence of antagonists of R. lignosus: Trichoderma spp., Penicillium spp., and Botryodiplodia theobromae, isolated from the root zone of rubber plants were significantly higher at Akwete, than at Iyanomo plantations (P=0.05).