ROUSSEAUX Maria Cecilia
congresos y reuniones científicas
RESPONSE OF PHOTOSYNTHETIC GAS EXCHANGE AND LEAF CHARACTERISTICS TO ELEVATED TEMPERATURE IN YOUNG OLIVE TREES
MISERERE, ANDREA; ROUSSEAUX, M. CECILIA; PLOSCHUK, E.; BRIZUELA, M. M.; CURCIO, MATIAS; ZABALETA, ROMINA; SEARLES, PETER S.
Congreso; Olivebioteq. 6th International Conference on olive tree and olive products; 2018
Leaf photosynthetic rate and water loss are both regulated by temperature via stomatal opening, and global warmingcould affect these coupled processes in olive trees. Additionally, leaf characteristics including stomatal density canvary according to the environment in which they developed. Thus, our objectives were to: i) evaluate the response ofleaf photosynthetic gas exchange and tree sap flow to elevated temperature in two olive cultivars; and ii) determinethe density of stomata and trichomes in leaves acclimated to two temperature regimes. Two temperature levelswere applied in the summer and fall of two consecutive growing seasons in open top chambers: a control (T0) nearair temperature and a treatment 4°C above the control (T+). Two to three year-old olive trees (cvs. ´Arbequina´ and´Coratina´) were grown in pots and well-watered throughout the experiment. The leaf photosynthetic gas exchangewas measured monthly, and tree sap flow was measured twice during the second growing season. Stomatal andtricome density were determined for leaves developed during the experiment. Photosynthetic rate showed nosignificant response to elevated temperature, but increases in leaf transpiration, stomatal conductance, and sap flowwere consistently observed in both cultivars under elevated temperature. Thus, water use efficiency was significantlyreduced in the heated trees. Leaves of T+ showed some minor changes in stomatal density and tricome density.However, the differences were not consistent between growing seasons. The results suggest that elevatedtemperature with global warming may increase crop water consumption in well-irrigated orchards.