Determination of Fe Deficiency Tolerance in Sunflower Genotypes

Abstract

Iron deficiency (Fe) is an important nutritional disorder of plants and humans worldwide including Turkey. Sunflower is known as a Fe sensitive crop and its deficiency leads to severe yield and quality losses. In this study, the sensitivity of different sunflower genotypes to Fe deficiency was determined. For this purpose, sunflower genotypes TR-6149-SA, TR-3080 and 6480 were grown either without Fe (0 µmol) or with Fe (100 µmol) hydroponically. At the end of experiment symptom grade, SPAD value, chlorophyll concentration, shoot dry matter yield, Fe-reductase activity, shoot Fe concentration and pH value of growth medium were measured. It was found out that Fe uptake and Fe reductase activity were the most important factors determining the Fe-deficiency tolerance of a genotype. In the deficiency of Fe conditions, the activity of Fe reductase enzyme in the roots was found higher in the genotype of TR-3080 compared to the other genotypes. The results revealed that the genotypic responses to the different Fe concentrations applied are significantly different and Fe reductase enzyme activity may play an important role in amelioration of iron deficiency.