Investigation of genetic and physiological responses of some citrus rootstocks to iron chlorosis

In this work, 16 different citrus rootstock species, genera and cultivars were assessed for their tolerance to iron chlorosis.Different parameters were used to determine the level of iron chlorosis tolerance and to select individuals for breeding studies. Additionally, 16 genotypes (under controlled conditions) and 15 genotypes (under natural conditions) were evaluated for the environmental factors affecting iron stress.In the screening experiments, under controlled conditions Tuzcu 891 sour orange, Gou Tou sour orange, Antalya Kleopatra mandarin and Duncan grapefruit were found to be very tolerant to iron chlorosis, and under natural conditions Tuzcu 31-31 sour orange, Gou Tou sour orange, Sunki mandarin and Antalya Kleopatra mandarin were very tolerant.In addition, the physiological and molecular responses of sensitive and tolerant genotypes to iron chlorosis were studied. Leaf color (SPAD), color ratings, photosynthetic activity, active and total iron concentrations were affected by iron chlorosis. By microarray analysis, genes that are affected by iron chlorosis were identified. Based on these, results FRO4, FRO5, IRT1, Fe-S and Aconitase iron uptake genes are active in citrus.