Mating system and genetic diversity in natural populations of European larch (Larix decidua) and stone pine (Pinus cembra) located at higher elevations

Mating system and genetic diversity were investigated in natural populations of European larch (Larix decidua MILL.) and stone pine (Pinus cembra L.) located at the upper Limits of the species ranges in the Italian Alps. Multilocus estimates of outcrossed progeny (t(m)) were relatively low in both populations (t(m) = 0.675 for larch and 0.808 for stone pine), indicating that self-fertilization is an important component of their mating system. Mean single-locus estimates of t differed only slightly from t(m) suggesting that there was a little inbreeding other than selfing, despite expected clustering of family members in those stands. The genetic structure of adult trees was consistent with the high levels of genetic diversity typically observed within populations of conifer species.