Trichoderma and sulphoethyl glucan reduce maize root rot infestation and fusaric acid content

Abstract

Roots of maize seedlings (cv. Pavla) infested by Fusarium verticillioides (10 5 /ml) were cultivated on Murashige-Skoog medium (MSM, Sigma, USA) containing CaCl 2 , IAA and kinetin. Simultaneously, a strain of the antagonistic fungus Trichoderma sp. and a sulphoethyl glucan (SEG) isolated from the cell walls of Saccharomyces cerevisiae, were added. Two evaluations (on 7 and 14 days) were done. Productivity parameters of leaves and roots (fwt, dwt, and length), disease severity index (DSI) and fusaric acid (FA) concentration were evaluated. Both Trichoderma sp. and SEG increased productivity parameters of plants in infested variants and maintained it on the level of control plants during 14 days of experiment. Trichoderma reduced the DSI, while SEG increased it. DSI correlated with FA concentration. A�er seven days of cultivation concentration of FA was lower in all infected variants cultivated concomitantly with agents, compared with the one without them. A�er 14 days of cultivation both agents reduced the concentration of FA up to 50% to the non-measurable concentration in variant with Trichoderma. In variant with positive control, where FA was added to SEG, its concentration decreased up to 30%. 1. growth medium, control 2. F. verticillioides 10 5 /ml spore concentration 3. F. verticillioides 10 5 /ml spore concentration with Trichoderma sp.10 6 /ml 4. F. verticillioides 10 5 /ml spore concentration with 0.025% SEG 5. Trichoderma sp. 10 6 /ml 6. 0.025% SEG After 7 days of cultivation as a toxin positive control 7) variant with 0.025% SEG and fusaric acid (FA) in a concentration 8.40 µg/ml was added according to the average level evaluated in situ samples (Nadubinská et al. 2002).In each variant 15 three-days-old seedlings were inserted, in two repetitions. All variants had volume of 200 ml and after 7 days of cultivation a fresh solution of MSM was added to maintain constant volume. We used the strain of F. verticillioides which produced FA in vitro. Plants were cultivated hydroponically in a special room under controlled conditions at temperature of 21/15°C day/night and 16/8 h photoperiod provided by white fluorescent lights, irradiance 180 µmol/m 2 /s, day/night relative humidity 80/60%.Evaluation of experimental results. After 7 and 14 days, the roots were separated from the leaves and evaluated for the degree of infestation, the content of FA, and productivity parameters: fresh weight (fwt), dry weight (dwt), and length. The longest roots and leaves were measured in each plant. To determine the dry weight, leaves and roots were dried separately at 105°C to constant weight. The data were subjected to standard statistical analysis, using SAS program 6. 08 (1990). The means where applicable were tested for significant differences, using the LSD (P < 0.05).Disease severity. The disease severity index (DSI) was rated on the 14 th day using a scale according to Kroon and Elgersma (1993) in plants of each treatment, using a 0 -5 disease index, where 0 indicated a healthy plant; 1 implied penalty of leave...

Biological control of Fusarium basal rot of onion using Trichoderma harzianum and Glomus mosseae

“…The reduction of nitrogen uptake in melon plants inoculated with Trichoderma, with or without mycorrhizae inoculation, is reported by Martinez-Medina et al (2009). However, Trichoderma species are mostly known as biocontrol microorganisms as, in this research, it suppressed 25% of disease incidence in comparison with infected control, which corresponds to those of previous studies (Biswas and Das, 1999;John et al, 2010;Sivan and Chet, 1986;Šrobárová and Eged, 2005). Also, Ros et al (2005) mentioned the ability of Trichoderma species to decrease Fusarium basal rot.…”

Antagonistic interactions between fungal rice pathogenFusarium Verticillioides (Sacc.) Nirenberg andTrichoderma harzianum Rifai

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