Intra-specific variations of embolism resistance and water loss regulation in response to drought: A Case study on the Cordilleran cypress (Austrocedrus chilensis)

SERGENT AS; MARTIN-ST PAUL NK; FERNÁNDEZ M.E.; DALLA SALDA G; VARELA S.; GYENGE JE; PASTORINO M; DIEZ JP; ROZENBERG P; MARTÍNEZ MEIER A

Bordeaux

Workshop; III Xylem International Meeting; 2017

INRA

Embolism resistance and water loss regulation (through stomata closure and minimum transpiration) determine species drought resistance. Whereas the former trait allows to resist increasing tensions that develop during drought, the latter dampens water potential drops during a drought episode. It is currently not known how these two traits vary among different populations of the same species in respect to aridity level they experienced. We measured embolism resistance (air-injection method) and estimated water-regulation traits (pressure volume curves or stomatal conductance response to water potential) in different populations of Austrocedrus chilensis that experienced different water deficit levels. Water regulation traits were measured on population growing in a 15 years old common garden. Trees from the corresponding in-situ populations were sampled (top branches) and measured for both embolism resistance and water regulation traits. Preliminary results indicate that intraspecific variability in embolism resistance is large for this species and but do not differ among in-situ populations. Preliminary findings, also suggests that populations experiencing higher level of water deficit seem to exert a tighter regulation of water loss during drought, both in natural conditions and in the common garden.