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Genetic variation of ecophysiological traits in red alder (Alnus rubra Bong.)
- Dang, Q.L., Xie, C.Y., Ying, C., Guy, R.D.
- Canadian journal of forest research = 1994 v.24 no.11 pp. 2150-2156
- Alnus rubra, provenance, genetic variation, photosynthesis, leaf conductance, stomata, xylem water potential, mesophyll, drought tolerance, adaptation, water vapor, British Columbia
- We examined the genetic variation of ecophysiological traits within and among 40 red alder (Alnus rubra Bong.) provenances (two families per provenance) in a common-garden experiment in the summer of 1993. The provenances were representative of the entire species range in British Columbia, Canada. We found significant genetic variation among provenances (P < 0.001) in photosynthetic rate (A), mesophyll conductance (g(m)), transpiration rate (E), stomatal conductance (g(sw)), stomatal sensitivity to water vapour pressure deficit (SENS(VPD)), intercellular to ambient CO2 concentration ratio (Ci/Ca), and midday xylem water potential. Photosynthetic water-use efficiency, however, did not differ significantly among provenances. There were no significant differences between families within provenance for any of these variables. A weak but significant geographic trend was detected in ecophysiological traits: midday xylem water potential, A, g(m), and E increased, and SENS(VPD) decreased, from southeast to northwest. Photosynthetic rate, E, g(m), g(sw) and midday xylem water potential were positively related to each other, but negatively correlated with SENS(VPD). Ci/Ca was negatively correlated with g(sw). These correlations indicate that red alder might have undergone genetic differentiation in drought resistance.