Genetics of Pinus radiata, the most widely planted forestry species, in its original and invaded range related to fire

RIPA RR; FRANZESE J; RAFFAELE E; PREMOLI A.

San Carlos de Bariloche

Conferencia; International Conference TOPWOOD + LIA Forestia Adapting forest ecosystems and wood products to biotic and abiotic stress; 2019

Introduced species are exposed to factors that contribute to their genetic differentiation respect to the original populations. The success of some exotic species is due to their ability to rapid change genetically in the face of new selection pressures. This is the case of fire-adapted species, where successive post-fire generations will increase the frequency of individuals highly adapted. P. radiata is an excellent model to study the genetics of fire-adapted invasive species because it's the most widely planted forest species. We analyzed: the role of fire as a selection agent and its effect on the genetic structure and diversity of P. radiata plantations and post-fire invasion in Patagonia Argentina; and the genetic differentiation between its native and two exotic ranges: Australia and Patagonia. Analyzes were carried out on isozyme electrophoresis on starch gels. We tested for divergence among successive post-fire generations and the plantations, as well increase inbreeding after fire due to reductions in population size. The genetic differentiation between cohorts in Patagonia was significant even in comparison with the observed in the native range. The genetic structuring from the exotic range populations could be reflecting high inbreeding due to the effect of genetic drift after introduction. The highest levels of inbreeding in Patagonia compared to Australia can be due to differences in the size of the propagule pressure between introduction events.