Distinction of Araucaria angustifolia seeds from different locations in Brazil by a specific DNA sequence

Abstract

Brazil pine (Araucaria angustifolia [Bert.] O. Ktze.) used to be a forest-dominating tree in areas above 500 m between 18° and 30° of southern latitude in Brazil. Due to severe clear cutting in the nineteenth and twentieth century, only small local remnants of this landscape-forming conifer are left. Larger attempts at reforestation of grassland areas with this tree in the original region of occurrence have failed so far. Of the possible reasons, use of less suitable provenances (ecotypes) could be involved. It was thus the aim of this investigation to screen for DNA sequences that could possibly be used to identify such ecotypes. For this purpose, seeds from all relevant remaining natural Brazil pine locations in Brazil were collected. Using repetitive oligonucleotide primers, we were able to identify a DNA fragment of 2 kbp length. Interestingly, the frequency of this fragment occurs in parallel with the number, duration and strength of frost periods. Although not a typical microsatellite sequence, this fragment could be used as a marker to screen for ecotypes of Brazil pine. Up to now, we have not been able to find homologies for this fragment on the basis of the nucleotide and the amino acid sequences in the respective libraries.