Abstract: Trehalose-based (TBT-PAR) additive was tested in order to optimize PCR amplification for DNA isolated from recalcitrant plants. Retrotransposon-based inter-primer binding site reactions were significantly improved with TBT-PAR solution using genomic DNA isolated from flax (Linum usitatissimum L., genotypes Kyivskyi, Bethune) grown in radio-contaminated and non-radioactive remediated Chernobyl experimental fields. Additionally, similar improvements were observed using 19 recalcitrant genotypes of maize (Zea mays L.) and three genotypes of yacon (Smallanthus sonchifolius, Poepp. et Endl., genotypes PER05, ECU45, BOL22) grown in standard field conditions.