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

RIPA R R; FRANCESE J; RAFFAELE E.; PREMOLI AC

Congreso; 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 tothe original populations. The success of some exotic species is due to their ability to rapid changegenetically in the face of new selection pressures. This is the case of fire-adapted species, wheresuccessive post-fire generations will increase the frequency of individuals highly adapted. P. radiatais an excellent model to study the genetics of fire-adapted invasive species because it´s the mostwidely planted forest species. We analyzed: the role of fire as a selection agent and its effect on thegenetic structure and diversity of P. radiata plantations and post-fire invasion in PatagoniaArgentina; and the genetic differentiation between its native and two exotic ranges: Australia andPatagonia. Analyzes were carried out on isozyme electrophoresis on starch gels. We tested fordivergence among successive post-fire generations and the plantations, as well increase inbreedingafter fire due to reductions in population size. The genetic differentiation between cohorts inPatagonia was significant even in comparison with the observed in the native range. The geneticstructuring from the exotic range populations could be reflecting high inbreeding due to the effectof genetic drift after introduction. The highest levels of inbreeding in Patagonia compared toAustralia can be due to differences in the size of the propagule pressure between introductionevents.