Interaction Effects of Rootstock and Genotype on Tolerance to Iron Deficiency Chlorosis in some Quince (Cydonia oblonga Mill.) Genotypes from Central Regions of Iran

Quince (Cydonia oblonga Mill.) is categorized as a susceptible species of fruit trees to the chlorosis of iron deficiency. The use of resistant sources to iron deficiency could be the most economic and advantageous method for resolving the problem. Therefore in this study the susceptibility of thirteen quince genotypes from Esfahan was evaluated, using the leaf chlorophyll content as the index of iron deficiency intensity. The quinces were propagated on crataegus, pear and quince seedling rootstocks and evaluated both in the greenhouse and nursery conditions for two consecutive years. Among various scion/rootstock combinations, the quinces on the pear rootstocks demonstrated high incompatibility in the first year of transplanting. Other combinations did not show the incompatibility. A positive effect of nursery condition on the mean chlorophyll contents of the apical and basal leaves in all quince genotypes was also observed. Genotypes NB3, NB4 and SHA1 were less susceptible than others to the iron chlorosis on most rootstocks. Genotypes PH2 and KVD2 were moderately or highly susceptible. The quince rootstock increased, susceptibility of KVD1 to chlorosis, while crataegus and pear rootstocks decreased it. For KM1 crataegus rootstock, and for ET1 crataegus and pear rootstocks increased susceptibility of the genotypes. Other genotypes demonstrated variable behavior depending on the rootstock kind and environmental conditions