INVESTIGADORES
PASTORINO Mario Juan
artículos
Título:
Genetic variation in seedling-water-use-efficiency of Patagonian Cypress populations from contrasting precipitation regimes assessed through carbon isotope discrimination.
Autor/es:
PASTORINO, MARIO JUAN; APARICIO, ALEJANDRO; MARCHELLI, PAULA; GALLO, LEONARDO ARIEL
Revista:
Forest Systems
Editorial:
Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)
Referencias:
Lugar: Madrid; Año: 2012 vol. 21 p. 189 - 198
ISSN:
2171-5068
Resumen:
Water-use efficiency (WUE) is a physiological parameter that plays a significant role in the evolutionary dynamics of
many forest tree species. It can be estimated indirectly through carbon isotope discrimination (Δ). In general, plants of more
arid origins have lower values of Δ. In order to study the degree of genetic control of this parameter and the genetic variation
in Δ of Patagonian Cypress seedlings, three Argentinean natural populations chosen to represent two contrasting precipitation
regimes were sampled in a common garden trial. The dry situation was represented by two neighboring marginal forest
patches from the steppe, while the humid condition was represented by a population with 1,200 mm higher mean annual
precipitation. Height (H) and Δ were measured in 246 five-year-old seedlings from 41 open-pollinated families. The factor
family had a significant effect on both variables; however heritability for Δ was found not to be significant in two out of
the three populations. This could be explained by low sample size in one of them and by a real evolutionary effect in the
other. An inverse association between H and Δ was verified, which is interpreted as evidence of an adaptation process at
the intra-population level. The studied populations were not shown to discriminate carbon isotopes differently; hence
evidence of adaptation to current environmental conditions could not be obtained. On the other hand, the arid populations
proved to be quite different in terms of genetic variation, which seems to be the consequence of genetic drift and isolation.