International Journal of Agriculture, Environment and Food Sciences, cilt.4, sa.3, ss.236-243, 2020 (Hakemli Dergi)
‘Clemenules’ (Nules, Clementina de Nules) has been a very popular variety in fresh mandarin markets especially in
the Mediterranean region countries. It is commercially grown on sour orange rootstocks in the calcareous soils of Turkey.
However, production of ‘Clemenules’ needs a substituted rootstock in addition to sour orange due to hypersensitive
of sour orange to the “Citrus Tristeza Virus”. ‘Clemenules’ mandarin grafted onto ten rootstocks was evaluated
in order to determine the influences of rootstocks on fruit yield, quality and photosynthetic variables of the scion as
well as their relationship. Rootstocks significantly affected (p<0.05) fruit yield and using Volkameriana significantly
increased fruit yield of ‘Clemenules’ (44.71 kg tree-1). Similarly, sour orange and Volkameriana rootstocks positively
affected fruit weight and height (p<0.05). Total acids (%) and ripening index varied within rootstocks and FA-517
resulted the highest total acids in fruits juice samples of ‘Clemenules’ whereas the lowest ripening index was determined
in fruits grafted on Flhorag1. Leaf chlorophyll concentration (Chl) and leaf chlorophyll fluorescence in the
light adapted stage (Fv’/Fm’) of the scion differed based on rootstocks. In addition to fruit yield and characteristics,
rootstocks also significantly affected variables related to photosynthesis. Cleopatra mandarin, sour orange and Volkameriana
increased the photosynthetic rate (PN), while transpiration rate (E), and stomatal conductance (gS) of the
scion were higher on Volkameriana rootstocks. FA-5 maintained the highest water use efficiency (WUE) in comparison
to other rootstocks evaluated. The present research has clearly shown that rootstocks were able to influence the
quality of fruits and the physiological activity. Regarding fruit yield and photosynthetic performance of ‘Clemenules’
mandarin variety, Volkameriana and sour orange performed well. However, considering the calcareous soils of the
Mediterranean Region, FA-5 citrandarin proved to be potential rootstock for enhanced photosynthetic rate and WUE.