The use of active strains of Triehoderma and Streptomyces in biological monitoring of coniferous seedlings

摘要

At present, around 30% of all forest seedlings in Siberia are destroyed by plant pathogens. Pesticides and organic compounds are widely used to control plant pathogens in many countries. However, the degradation of such compounds is very difficult andthe concentration and/or accumulation of them are leading to higher toxicity levels. Triehoderma species have been investigated for over 80 years. These fungi are well studied and have shown efficience on biocontrol of different phytopathogens, including some (such as Fusarium and Alternarid) from the phyloplane. They have been used recently as biocontrol agents, and their isolates have recently become available commercially. Nowadays, biofungicides formulated with Triehoderma, are used to control several soil-borne pathogens which cause damping-off and root rot diseases. This development is largely the result of a change in public attitude towards the use of chemical pesticides (including fumigates, such as methyl bromide, which had been widely usedin forest nurseries to control soil-borne pathogens) (Prochzkova et al,. 1997). The other prospective organisms recommended for biologocal control are actinomycetes. However, these are few in world reforestation practice (Dumroese et al., 1998). This paper highlights factors that have influenced the acceptance and use of biological control of forest seedling production systems used in reforestation in Siberia.