Effect of Cercospora piaropi Tharp and Myrothecium roridum Tode Fries Formulated as Corn Oil Emulsion on Water Hyacinth Shoot Growth under Greenhouse Conditions

A study was done to find out the comparative effect of Cercospora piaropi Tharp and Myrothecium roridum Tode Fries formulated as corn oil emulsion on water hyacinth shoot growth and biomass under greenhouse conditions. The study site was located in Kibos at latitude 0037’S and longitude 37020’E with average temperature of 25 to 300C and 22 to 270C during the day and night respectively, and 60 to 69% relative humidity. Healthy water hyacinth plants were inoculated with the pathogens formulated in corn oil at 1x109, 1x108, 1x107, 1x106 and 1x105spores/ml. The control plants were not inoculated. The experiment was set up in completely randomized design (CRD) with each treatment replicated three times. At weeks 2, 4, and 6 after inoculation, the average shoot length and biomass for the treated basins were separately compared to the average shoot length and biomass of the control plants. Increase in spore density for both pathogens significantly increased relative shoot length and relative biomass. Relative shoot length was 55.07 and 51.93 for C. piaropi and M. roridum respectively at 1x109 spores/ml while relative biomass was 73.53 for C. piaropi and 37.60 at 1x109 spores/ml. Inoculation suppressed shoot elongation and biomass with 1x109 spores/ml being most effective. Cercospora piaropi formulated in corn oil lowered shoot length and biomass of water hyacinth more than M. roridum did.

Antiproliferative Activity of epi-Cercosporin in Human Solid Tumor Cell Lines

From cultures of Cercospora piaropi, a phytopathogenic fungus isolated from symptomatic leaves of water hyacinth was obtained a red compound, which, according to the spectroscopic data, was epi-cercosporin. It showed in vitro antiproliferative activity against the panel of human solid tumor cells HBL-100, HeLa, SW1573 and WiDr. Cell cycle studies revealed that epi-cercosporin induces accumulation of cells in G2/M phase.

Crescimento, esporulação e virulência do inóculo de Cercospora piaropi, agente de biocontrole do aguapé

O presente ensaio foi realizado com o objetivo de avaliar a produção de biomassa micelial bem como a esporulação de Cercospora piaropi, nos meios líquidos V8, ETD (Extrato de Tomate Diluído) e BD (Batata - Dextrose), em períodos de cultivo de 96, 120, 144 e 168 h, sob agitação constante. Adicionalmente foi avaliado o efeito de períodos de desidratação da biomassa micelial (24, 48, 72, 96 e 120 h) sobre a esporulação. Os inóculos obtidos foram avaliados quanto à severidade da doença em plantas de aguapé (Eichhornia crassipes). De acordo com os resultados, o meio ETD proporcionou maior crescimento micelial em relação aos meios BD e V8, destacando-se o período de 144 h de agitação. Entretanto, o meio V8 induziu esporulação superior do patógeno, quando cultivado por 120 h. Os inóculos obtidos nos meios V8 e ETD causaram maiores valores de severidade da doença. O período de desidratação da biomassa micelial a partir de 72 h favoreceu maior produção de conídios. Não houve efeito do período de desidratação sobre a severidade da doença.