Leaf water relations of Eucalyptus cloeziana and Eucalyptus argophloia in response to water deficit

Abstract

Leaf water relations responses to limited water supply were determined in 7-month-old plants of a dry inland provenance of Eucalyptus argophloia Blakely and in a humid coastal provenance (Gympie) and a dry inland provenance (Hungry Hills) of Eucalyptus cloeziana F. Muell. Each provenance of E. cloeziana exhibited a lower relative water content at the turgor loss point, a lower apoplastic water content, a smaller ratio of dry mass to turgid mass and a lower bulk modulus of elasticity than the single provenance of E. argophloia. Osmotic potential at full turgor and water potential at the turgor loss point were significantly lower in E. argophloia and the inland provenance of E. cloeziana than in the coastal provenance of E. cloeziana. There was limited osmotic adjustment in response to soil drying in E. cloeziana, but not in E. argophloia. Between-species differences in water relations parameters were larger than those between the E. cloeziana provenances. Both E. cloeziana provenances maintained turgor under moderate water stress through a combination of osmotic and elastic adjustments. Eucalyptus argophloia had more rigid cell walls and reached lower water potentials with less reduction in relative water content than either of the E. cloeziana provenances, thereby enabling it to extract water from dryer soils.

Adaptive diversity in Castanea sativa Mill. half-sib progenies in response to drought stress

“…Reduction in TB, one of the first responses to water stress, has also been described in wild progenies of chestnut (Eriksson et al, 2005;Pliura and Eriksson, 2002) as well as in other species (Black-Samuelsson et al, 2003;Ngugi et al, 2003).…”

Drought conditioning improves water status, stomatal conductance and survival ofEucalyptus globulussubsp. bicostataseedlings

“…The other two provenances, adapted to mesic conditions (Tab. I), exhibited mechanisms of drought adaptation that seemed to favor seedling growth rather than survival [27,31]. But, to assess more accurately the relationships among seedlings responses to drought and the dryness of seed origin it would be necessary to study a larger number of provenances of E. globulus subsp.…”

Intercambio gaseoso de dos clones de Paulownia elongata x fortunei al primer año de desarrollo vegetativo en tres sitios del centro-sur de Chile

“…Estas diferencias pueden observarse incluso entre especies del mismo género creciendo en las mismas condiciones edafoclimáticas (Orlovic et al 1998, Ngugi et al 2003. Por ejemplo, Liu et al (2003) detectaron diferencias en los parámetros de intercambio gaseoso en tres especies del género Salix establecidos en un sitio semiárido de China, donde S. matsudana Koidz., especie introducida, presentó a lo largo del día menores tasas de fotosíntesis y conductancia estomática que las especies nativas S. gordejevii Y.L.…”

“…ex Trautv. El efecto del agua en la tasa de fotosíntesis y conductancia estomática fue estudiado por Ngugi et al (2003Ngugi et al ( , 2004, determinando para las especies Eucalyptus argophloia Blakely y E. cloeziana F. Muell. altas tasa de fotosíntesis (13,4 y 7,8 μmol CO₂/ m²/seg) y conductancia estomática (194,3 y 70,5 mmol H 2 O/m²/seg), respectivamente, en presencia de 100% de contenido humedad del suelo.…”

“…altas tasa de fotosíntesis (13,4 y 7,8 μmol CO₂/ m²/seg) y conductancia estomática (194,3 y 70,5 mmol H 2 O/m²/seg), respectivamente, en presencia de 100% de contenido humedad del suelo. La reducción del contenido de humedad al 70 y 50%, redujo la tasa de fotosíntesis y conductancia estomática de ambas especies en un 30 y 50%, respectivamente (Ngugi et al 2003(Ngugi et al , 2004.…”