Relationship of Ethylene Production and Aerenchyme Formation on Oxidation Ability and Root Surfaced-Iron (Fe2+) Accumulation under Different Iron Concentrations and Rice Genotypes
Siti Maryam Harahap, Munif Ghulamahdi, Sandra Arifin Aziz, Atang Sutandi, Miftahudin

Abstract
Iron toxicity in rice plant can occur during the vegetative and generative phase. Different rice genotypes show different responses to iron toxicity both morphologically and physiologically. The aim of this study was to evaluate the relationship of root ethylene production and aerenchyme formation on the ability of rice root to oxidize and accumulate iron (Fe2+) on root surface under different iron concentration and rice genotypes. This research was conducted at the greenhouse, Bogor Agricultural University, Indonesia from October to December 2012. experiment that consisted of two factorial was completely randomize designed with three replications. The first factor was four level Fe concentrations, i.e.: 0, 500, 1000, and 1500 ppm and the second factor was IRH108, IR64 and Indragiri rice genotypes. The results showed that there was significant differences on the ethylene production, aerenchyme size, plaque content, and Fe2+ distribution in root tissue among each genotype. It was concluded that Indragiri was a tolerant genotype to iron toxicity as indicated by the highest ethylene production (116.71 nl.g-1fresh weight-1.h-1), the highest root Fe2+ content (21,271 ppm), the largest size of aerenchyme (80,230.11nm), and the highest plaque content (1,864.12).

Full Text: PDF