Paternal inheritance of chloroplast and mitochondrial DNA in huon pine (Lagarostrobos franklinii).

In conifers, plastid DNA is passed on through the male line (pollen grain). Transfer of mitochondrial DNA is maternal in the well-researched Pinaceae family (conifers I) and is considered mostly paternal in other conifer families (conifers II). However, few studies in confers II have definitely established the mode of transfer using molecular markers within species. This is the first molecular genetic study on organelle transfer in the Podocarpaceae family. Two intraspecific crosses of a rare Tasmanian podocarp, Lagarostrobos franklinii , were established with the same iconic father, which is a vegetative clone of a 11,000 year-old tree. Polymorphic positions in the parents’ genomes of one cross were identified using genome skimming and bioinformatics. Illumina data were compared with a published plastome and newly assembled mitochondrial DNA contigs representing about half of the father’s genome. Derived PCR-based markers were used to genotype parents and offspring of both crosses. Plastid DNA and mitochondrial DNA were both paternally inherited. We discuss other molecular genetic studies on mitochondral DNA transfer in conifers II, which all suggest paternal transfer. This could mean that this trait evolved only once, between 280 and 320 MYA, in the ancestor of this group.