ارزيابي روش فنان ترولين در تعيين غلظت Fe2+ در برگ مركبات

Evaluation of Phenanthroline Method to Determine Fe^2 + Concentration in Citrus Leave

Iron (Fe) is one of the essential elements for plant growth. Plant analysis for total Fe concentration is frequently used for chlorosis diagnosis because of Fe deficiency. But between total Fe concentration in the plant and chlorosis occurrence there good relation, because chlorotic plants usually contain similar or higher amount of total Fe than the healthy green plants. The objectives of this study were to (1) present a suitable method to determine Fe2 +, the fraction of iron involved in the synthesis of chlorophyll processes, and (2) correlation between chlorophyll and Fe2 + in citrus leave. The choice of 1-10 0phenanthroline (o-ph) as an extractor for Fe2 + was based on its remarkably higher stability constant for Fe2 + than Fe3 +. In this study, after sampling and preparing, four concentrations of Phenanthroline solution (1,1.5,2 and 2.5 percentage) on different pH (2,3,4 and 5) with different ratios of plant samples to extractent solution (1:5,1: 10,1:15 and 1:20) were tested inthe completely randomized design (with three replication). On the basis of the acquired results Phenanthroline solution (2%), with pH==3, ratio of plant sample to extractor 1:10, time of reading 12 hours and reading with Spectrophotometer at 510nm wave length were suggested to determine Fe2+. Chlorophyll and Fe2 + content of both chlorotic and green leaves showed straight and significant correlation.