engleski

Biological control of Sclerotinia sclerotiorum by Trichoderma atroviride in lettuce

The fungus Sclerotinia sclerotiorum (Helotiales) is the causal of white rot, economically important disease of various crops in temperate climates. Sclerotium is the most important S. sclerotiorum resting body in nature because it remains viable and dormant for many years in the soil. Control measures such as solarization and fallow land are partially successful, but they are not feasible in many breeding conditions. The soil application of fungicides is environmentally unacceptable and limited to foliar application in vegetation. Therefore, the development of biological control is of great importance. Species of fungal genus Trichoderma are among the most commonly studied biocontrol microbes and are presently marketed as bio-control agents or active ingredients of biopesticides, biofertilizers, plant growth enhancers, and stimulants of natural resistance. The most represented species are T. harzianum and T. viride, and they are combined in 55% of commercial biofungicides on the international market. We tested antagonism of Croatian indigenous isolate T. atroviride against S. sclerotiorum, under laboratory and protected environments. In vitro assays showed excellent antagonisms to S. sclerotiorum evidencing hyperparasitic activity. The sclerotia were completely degraded after 2 months. In the greenhouse, the disease caused by S. sclerotiorum in lettuce was reduced by treating seedlings with a T.atroviride spore suspension. The lettuce infected with S. sclerotiorum and treated with T. atroviride were healthy and in better condition than untreated infected lettuce and also, than control, untreated uninfected lettuce.

antagonism ; beneficial fungi ; fungi–fungi interaction ; hyperparasitism

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