© 2005 Heron Publishing—Victoria, Canada
Scion–rootstock interaction affects the physiology and fruit quality of sweet cherry
Berta Gonçalves (1, 2), José Moutinho-Pereira (1), Alberto Santos (3), Ana Paula Silva (3), Eunice Bacelar (1), Carlos Correia (1) and Eduardo Rosa (3)
1. CETAV - Centre for Technological, Environmental and Life Studies, Department of Biological and Environmental Engineering,
University of Trás-os-Montes e Alto Douro, Apartado 1013, 5000 Vila Real, Portugal / 2. Corresponding author (bertag@utad.pt) / 3. CECEA - Research Centre for Agricultural Sciences and Engineering, Department of Plant Science and Agricultural Engineering,
University of Trás-os-Montes e Alto Douro, Apartado 1013, 5000 Vila Real, Portugal / Received February 4, 2005; accepted April 2, 2005; published online October 3, 2005
Summary
Water relations, leaf gas exchange, chlorophyll a fluorescence, light canopy transmittance, leaf photosynthetic pigments and
metabolites and fruit quality indices of cherry cultivars ‘Burlat’, ‘Summit’ and ‘Van’ growing on five rootstocks with differing
size-controlling potentials that decrease in the order: Prunus avium L. > CAB 11E > Maxma 14 > Gisela 5 > Edabriz, were studied during 2002 and 2003. Rootstock genotype affected all physiological
parameters. Cherry cultivars grafted on invigorating rootstocks had higher values of midday stem water potential (ΨMD), net CO2 assimilation rate (A), stomatal conductance (gs), intercellular CO2 concentration (Ci) and maximum photochemical efficiency of photosystem II (PSII) (Fv/Fm) than cultivars grafted on dwarfing rootstocks. The ΨMD was positively correlated with A, gs and Ci. Moreover, A was positively correlated with gs, and the slopes of the linear regression increased from invigorating to dwarfing rootstocks, indicating a stronger regulation
of photosynthesis by stomatal aperture in trees on dwarfing Edabriz and Gisela 5. The effect of rootstock genotype was also
statistically significant for leaf photosynthetic pigments, whereas metabolite concentrations and fruit physicochemical characteristics
were more dependent on cultivar genotype. Among cultivars, ‘Burlat’ leaves had the lowest concentrations of photosynthetic
pigments, but were richest in total soluble sugars, starch and total phenols. Compared with the other cultivars, ‘Summit’
had heavier fruits, independent of the rootstock. ‘Burlat’ cherries were less firm and had lower concentrations of soluble
sugars and a lower titratable acidity than ‘Van’ cherries. Nevertheless, ‘Van’ cherries had lower lightness, chroma and hue
angle, representing redder and darker cherries, compared with ‘Summit’ fruits. In general, ΨMD was positively correlated with fruit mass and A was negatively correlated with lightness and chroma. These results demonstrate that: (1) water relations and photosynthesis
of sweet cherry tree are mainly influenced by the rootstock genotype; (2) different physicochemical characteristics observed
in cherries of the three cultivars suggest that regulation of fruit quality was mainly dependent on the cultivar genotype,
although the different size-controlling rootstocks also had a significant effect.
Keywords:
canopy light transmittance, chlorophyll a fluorescence, fruit physicochemical characteristics, gas exchange, leaf metabolites,
photosynthetic pigments, Prunus avium, size-controlling rootstocks, water relations.
