Fungal root diseases update March 2016
At the Forest Research Institute (IBL) in Poland we have tested several strains of biological control agents against pathogens causing damping-off. We tested the BCAs on seedlings of Scots pine, common beech and pedunculate oak under controlled conditions in the greenhouse experiments. Strains of Serratia plymuthica, Paenibacillus polymyxa and Trichoderma harzianum were used. Since there was a very large variation in the results obtained in 2014 experiments were repeated in 2015.
Trichoderma harzianum strain DSM25764
The effect of the potential biological control agent (BCA) Trichoderma harzianum has been investigated in cooperation with University of Padova by checking for the presence of the Trichoderma harzianum strain DSM25764 in soil and roots. Soil samples were analyzed (by qRT-PCR) with species-specific primer pairs at different time intervals from soil inoculated with T. harzianum strain DSM25764. A significant increase in the BCA concentration (ng DNA DSM25764/100 ng total DNA) over time emerged in each experiment in treated soil samples, while almost no DNA of DSM25764 was detected in untreated soil samples.
Also treated root samples of all three forest plant species (pine, oak, and beech) showed high DSM25764 colonization levels. The T. harzianum strain DSM25764 was successfuly reisolated from infested soil and root tissues on artificial media.
The T. harzianum strain DSM25764 gave the best results in protecting the seedlings of Scots pine, common beech and pedunculate oak against damping-off pathogens measured as a percentage of emerged seeds. T. harzianum protected almost 100% of oak seedlings while the protection of beech and pine seedlings reached 80%. This biological control agent promoted also growth of the seedlings in all tested variants.
The role of Serratia plymuthica and Paenibacillus polymyxa as a BCAs against damping-off in forest nurseries is still being investigated. Positive results on root development and length of above-ground parts of seedlings were observed in the greenhouse trials.
Plans for 2016
Two forest nurseries located in central Poland were selected for tests in 2016 and 2017. A severe damping-off was noted on these nurseries in past years. We have made all the arrangements with Forest Districts’ authorities to enable us to start the experiments in early May. We are closely cooperating with UNIPD and BIOGARD regarding T. harzianum strain DSM25764 as well as with ENEMA regarding the bacterial BCAs.
See our earlier update on the fungal root diseases research:
Read more about our activities on Fungal root diseases
Picture: IBL, Poland.