ORANGE VARIETIES AS INTERSTOCK IN 'VERNA' LEMON TREES INCREASE THE SALT TOLERANCE BUT NOT THE DROUGHT OR FLOODING TOLERANCE
A research on the ability of interstocks to increase the abiotic stress tolerance in lemon trees was conducted with three independent experiments. A comparison of 2-year-old Verna lemon trees [Citrus limon (L.) Burm.; VL] grafted on Sour Orange (C. aurantium L.; SO) rootstock either without an interstock (VL/SO), or interstocked with Valencia orange (C. sinensis Osbeck; VL/V/SO), or with Castellano orange (C. sinensis Osbeck; VL/C/SO) in salinity, drought and flood conditions was carried out. In the salinity experiment, trees were supplied with nutrient solutions containing 0, 30, or 60 mM NaCl for two months. In the drought experiment, half the trees were reduced by 25% watering every 5 days for 20 days. In flood experiment, half the trees were flooded for 9 days. The experiments were conducted under greenhouse conditions. Leaf water relations, leaf gas exchange and mineral nutrition were measured. Interstocked Citrus trees are more salt-tolerant than non-interstocked trees. Leaf concentrations of Cl- and Na+ were higher in VL/SO trees than in VL/C/SO or VL/V/SO trees. The mechanism involved in the reduction of leaf Cl ions by an interstock could be linked to its low Eleaf values during the day and/or to their high S:R DW ratios. Valencia variety reported greater salt-tolerance to VL trees than Castellano, even though leaf Cl and Na+ levels were similar in the two interstocked trees. Verna lemon trees interstocked with orange varieties did not improve the flooding and drought tolerance. When Valencia orange was used as the interstock, the flooding and drought tolerance was drastically reduced.
Vicente Gimeno, , Inma Simón, , Vicente Martínez, , Manuel Nieves, , Rashad M. Balal, and Francisco García-Sánchez, (2015). ORANGE VARIETIES AS INTERSTOCK IN 'VERNA' LEMON TREES INCREASE THE SALT TOLERANCE BUT NOT THE DROUGHT OR FLOODING TOLERANCE. Acta Hortic. 1065, 1335-1342
abiotic stress, citrus, leaf water relations