Abstract

SAENZ-ROMERO, Cuauhtémoc; BEAULIEU, Jean  and  REHFELDT, Gerald E.. Altitudinal genetic variation among Pinus patula populations from Oaxaca, México, in growth chambers simulating global warming temperatures. Agrociencia [online]. 2011, vol.45, n.3, pp.399-411. ISSN 2521-9766.

Climatic change will decouple the matching between genotypes and environments. Studying the patterning of genetic variation among pine populations along altitudinal gradients under simulated climatic change temperatures, would provide insights about how to realign the present populations to future environments. Fourteen Pinus patula populations from the forests of the Native Indian Community of Ixtlán de Juárez, state of Oaxaca, México, were collected in January-March 2005 and 2006 along an altitudinal gradient (2400 m to 3050 m, one population every 50 m of altitudinal difference). Seedlings were grown in growth chambers at the Laurentides Forestry Center, Quebec city, Canada, under two temperature treatments aiming to simulate: contemporary temperature (average 17 °C) and a future global warming scenario (average 21 °C). Seedlings were evaluated after inducing a second growing season (between 8 and 12 months of age). Populations differed significantly (p≤0.001) for seedling height and aerial dry weight, and exhibited a significant (p≤0.02) although weak altitudinal clinal pattern, with populations from lower altitudes having on average taller and heavier seedlings than populations from higher altitudes (r²=0.064 and r²=0.094).

Keywords : altitudinal gradients; altitudinal seed zoning; assisted migration; climate change; genetic differentiation.