Impact of herbivory on leaf hydraulic traits and stomatal conductance in sweet cherry (Prunus avium).

PESCHIUTTA, MARÍA L.; BUCCI, SANDRA J.; SCHOLZ, FABIÁN G.; ARIAS, NADIA; PEREYRA, DANIEL; GOLDSTEIN, GUILLERMO

Buzios

Congreso; XIII Congresso Brasileiro de Fisiologia Vegetal, XIV Reunião Latino-Americana de Fisiologia Vegetal; 2011

Herbivory results in resource reduction through a loss of nutrients and/ or photosynthetic area, often leading to a reduction in plant fitness.  Prunus avium is frequently affected by Caliroa cerasi (Hymenoptera: Tenthredinidae) by skeletonizing the leaf surfaces however there are no studies evaluating the consequences on functioning of sweet cherry. We evaluated the impact of herbivory by C. cerasi on stomatal conduct-ance (gs), transpiration (E) and leaf hydraulic conductance (Kleaf) in P. avium. Fifteen damaged and undamaged adult trees of three varieties of P. avium  (‘Van’, ‘Lapins’ and ‘Bing’) were selected in an orchard in South Patagonia, Argentina (46° 32’S; 71° 37’ W; 220slm). Leaf area index (LAI), leaf size (LA), percentage of removed leaf area and number of leaves affected per plant, stomatal conductance, transpiration rate and  leaf  hydraulic  conductance  were  measured  during  the  period  of maximum attack of C. cerasi. ‘Lapins’ was the variety more affected by herbivory, 62 % of its leaves exhibited signals of herbivory by C. cerasi, which produced a decrease of 41% in total leaf area per plant. Leaf size of attacked leaves was 18 to 26% lower than leaf size of intact plants depending of the variety. Stomatal conductance and transpiration rate of remaining leaf area were not modified in damaged plants. Leaf hydraulic  conductance  measured  in  leaves  recently  damaged  did  not change significantly respect to control plants (7.1 *10-5, 1.0 *10-4 and 1.3 *10-4 kg MPa-1 s-1 m-2 for ‘Bing’, ‘Lapins’ and ‘Van’ respectively). However several days after herbivory attack vein leaf exhibited a full rupture  which  decreased  leaf  water  transport  capacity.  These  results suggest  that  herbivory  affects  the  water  balance  of  whole  plant  and could consequently impact on gas exchange and growth.