Microorganisms colonizing seed of wheat (Triticum aestivum L.) and oilseed rape (Brassica napus L.) were identified by sequencing analysis of genes encoding rRNA in this thesis. Bacteria were identified according to the sequence of part of gene for 16S rRNA and fungi were identified according to the sequence of part of gene for 28S rRNA. Subsequently, the effect of low-temperature plasma seed treatment on the viability of the detected microorganisms was assessed.