摘要 : Aerobic rice is a water-saving technology whereby improved varieties are cultivated under non-flooded conditions. However, continuous cultivation leads to proliferation of soil-borne pathogens such as Pythium spp. This study was c... 展开 Aerobic rice is a water-saving technology whereby improved varieties are cultivated under non-flooded conditions. However, continuous cultivation leads to proliferation of soil-borne pathogens such as Pythium spp. This study was conducted to screen for growth-promoting activity of three local isolates of Trichoderma sp. and assess the potential biocontrol activity of the best growth-promoting isolate against the virulent Pythium arrhenomanes 60 (Pa60) and P. arrhenomanes 76 (Pa76) previously isolatedfrom diseased aerobic rice roots. Identity of Trichoderma spp. was determined through sequencing of the internal transcribed spacer (ITS) region of the rRNA gene cluster. Trichoderma isolates were screened for growth promotion of the aerobic rice variety Apo. Among the three isolates, Trichoderma ghanense CDO (TgCDO) exhibited consistent growth-promoting ability. Potential biocontrol activity of TgCDO was determined through plate assays, microscopic observations and pathogenicity tests. TgCDO exhibitedantibiosis, inhibitory metabolite production and antagonistic activity against Pa60 and Pa76. TgCDO reduced the growth of Pa60 and Pa76 by 39-56% (P<0.05) through antibiosis while inhibitory metabolites reduced growth by 76-100% (P<0.001). Microscopic observations demonstrated the parasitism of Pythium by TgCDO. Pot tests verified the biocontrol efficacy as observed in 21% (P<0.001) reduction of stunting in seedlings and complete alleviation (P<0.01) of root length reduction. 收起