Detekcja fitopatogenów z rodzaju Phytophthora w glebach leśnych za pomocą analiz DNA

Pathogenic oomycetes from the genus Phytophthora attack the base trunks and root systems of trees causing their illness and dying. Under favorable conditions, they may cause damage to even 90% of fine roots. For this reason, they are a particular threat to seedlings in nurseries of forest trees and ornamental plants. Early detection and identification of Phytophthora species is a key issue in forest protection. The aim of this study was to compare the two methods of identification of pathogenic Phytophthora in soil samples collected around 50 selected oaks in Krotoszyn and Karczma Borowa forest districts. Each of the soil samples were analyzed in parallel: 1) direct isolation of genomic DNA from soil and 2) isolation of genomic DNA from soil, preceded by its three day pre−incubation in a selective medium for Phytophthora. Species identification was performed by PCR amplification with primers specific for the species of Phytophthora. The results indicate that the use of pre−incubation phase of soil in a medium−PARP PeaBroth before isolation of DNA, increases the sensitivity of detection of these phytopathogens using PCR. With pre−incubation, the method revealed 54% of positive findings, while simultaneously conducted the same analysis of soil samples by using only direct DNA isolation from soil and PCR amplification provided only 30% of positive findings.