Investigating the Mendelian inheritance, genetic linkage, and genotypic disequilibrium for ten microsatellite loci of Araucaria angustifolia

Abstract

Araucaria angustifolia is a dioecious and wind pollinated conifer that typically occurs in higher attitudes of Southern Brazil. After a significant reduction of its population during the twentieth century, public policies have enabled natural populations to recover. As new studies focus on the genetics of the species it is important to investigate Mendelian inheritance, genetic linkage, and genotypic disequilibrium for the microsatellite loci developed for the species. Here we analyze ten microsatellite loci developed for A. angustifolia by genotyping 295 adult trees and 13 open pollinated progenies from a forest fragment in Santa Catarina, Brazil. The likelihood G-test shows a perfect 1:1 Mendelian segregation for all ten loci, indicating that these molecular markers are genetic markers. Significant genetic linkage between pairwise loci was detected in only 3% of the tests, suggesting that these loci are not located in the same linkage groups within the chromosomes. However, genotypic disequilibrium was detected in 51% of pairwise loci for adult trees, probably due to the strong spatial genetic structure of the population. Our results indicate that the ten loci analyzed can be used in studies on genetic diversity and structure, mating system, and gene flow of the species.