Authors:M. R Chakraborty, S. Dutta, S. Ojha, and N. C. Chatterjee
Biological control of die-back of bottle brush (Callistemon citrinus) caused by Botryodiplodia theobrome was made with the application of antagonistic agents like Trichoderma viride, T. lignorum, T. harzianum, Aspergillus niger and Penicillium citrinum. The effect of volatile and non-volatile antibiotics of Trichoderma origin on growth inhibition of the die-back pathogen was studied. T. harzianum showed maximum growth inhibition (75.33%) of the pathogen through mycoparasitism and the non-volatiles produced by the same agent exhibited its excellent antagonism to the growth of the pathogen (91.11%) under in vitro condition and that the effect was also proved to be durable.
Authors:L. Kredics, Zsuzsanna Antal, A. Szekeres, L. Hatvani, L. Manczinger, Cs. Vágvölgyi, and Erzsébet Nagy
transcriptional activation of the mycoparasitism related gene prb 1 in Trichoderma atroviride. Mol Gen Genom 267 , 703-712 (2002).
Multiple environmental signals determine the transcriptional activation of the mycoparasitism related
The purpose of this study was to
survey the growth inhibition with volatile antibiosis and killing of Pythium
irregulare by Trichoderma species of various origin under heavy metal stress.
Fourteen strains of T. harzianum, 10 strains of T. virens, and 14 strains of T.
viride were tested in dual culture with the pathogen on heavy metal poisoned
media. Minimum inhibitory concentrations (MIC) for mycelial growth, antibiosis
and Pythium-killing were determined. Although the decreasing order of toxicity
(Cd≯Ni≯Zn) was the same for the growth of Pythium and the antagonists,
the pathogen tolerated 2-4 times higher doses of toxic metals
than Trichoderma strains did. The antagonistic activities proved to be more
sensitive, they were blocked by 0.16-0.67
mM Cd, 0.16-1.25 Ni or Zn. Pythium-killing was observed at higher doses
of Ni than that of Cd or Zn, which were similar toxic to the both investigated
activities. The history of long-term heavy metal exposure of some investigated
Trichoderma strains did not increase the tolerance of mycelial growth, but the
antagonistic activities were more sensitive in those strains that had
originated from not polluted arable soils.
Losses due to plant diseases may be as high as 10-20% of the total worldwide food production every year, resulting in economic losses amounting to many billions of dollars and diminished food supplies. Chemical control involves the use of chemical pesticides to eradicate or reduce the populations of pathogens or to protect the plants from infection by pathogens. For some diseases chemical control is very effective, but it is often non-specific in its effects, killing beneficial organisms as well as pathogens, and it may have undesirable health, safety, and environmental risks. Biological control involves the use of one or more biological organisms to control the pathogens or diseases. Biological control is more specialized and uses specific microorganisms that attack or interfere with the pathogens. The members of the genus Trichoderma are very promising against soil-born plant parasitic fungi. These filamentous fungi are very widespread in nature, with high population densities in soils and plant litters . They are saprophytic, quickly growing and easy to culture and they can produce large amounts of conidia with long lifetime.
Authors:K. Karimi, A. Narmani, I. Pertot, and M. Arzanlou
Proteases constitute a significant part of cell wall-degrading enzymes (CWDEs)
produced by fungal biocontrol agents and particularly crucial in mycoparasitism
of fungal phytopathogens. Plate-based screening methods are routinely used for
screening protease-producing microorganisms including fungi. Skim milk agar
(SMA) is one of the most popular media for the detection of protease producing
bacteria. However, SMA is not efficient to test fast growing fungi, because it
does not give an estimation of the actual amount of secreted protease produced
by fungal inocula. In the current study, the efficacy of two modified
plate-screening methods, including split-SMA (SSMA) and minimal medium
supplemented with skim milk (MSMW) was assessed for detection of protease
production by three representative fungal strains including Trichoderma
longibrachiatum strain N, Beauveria bassiana
strain B and Purpureocillium lilacinum strain PL. Protease
production was revealed on the three tested media by the three strains. However,
the halo diameter of the fungal strains (a proxy for protease production) was
the smallest on SMA. Furthermore, protease production could not be detected for
T. longibrachiatum strain N on SMA due to its fast growth;
while it showed the highest protease activity on both modified media compared
with the other strains. According to the result of this study, the SSMA medium
is an easy and more accurate method compared with the two other different
methods as it displays the actual amount of protease produced by fungal strains
and therefore this method is recommended for quantitative and qualitative
detection of protease production by slow and fast growing fungi.
Authors:Klára Ács, Zs. Kasza, Gyöngyi Lukács, H. Schwab, and Cs. Vágvölgyi
harzianum is repressed during conidiation and mycoparasitism. Microbiol 143 , 3157-3164 (1997).
Glyceraldehyde-3-phosphate dehydrogenase expression in Trichoderma harzianum is repressed during conidiation and mycoparasitism
Authors:W. Dendouga, H. Boureghda, and M. Belhamra
): Hypocrea/Trichoderma: species with conidiophore elongations and green conidia . Mycologia 95 , 1100 – 1140 .
Chet , I. , Benhamou , N. and Haran , S. ( 1998 ): Mycoparasitism and lytic enzymes . In: G. E. Harman and C. P. Kubicek (eds