Abstract
Iron-deficiency tolerance of Gramineae plants is well correlated with the amount of mugineic acids secreted. However, not only the degree but also the pattern of iron-deficiency chlorosis is different between rice and barley. This phenomenon cannot be explained by only mugineic acid secretion. We suggested that barley retranslocated iron more efficiently from old leaves to the young leaves as compared with rice. In this work, we compared iron availability among rice, barley, sorghum under various iron-limiting condition. Under iron-limiting condition, growth of barley was relatively higher than that of rice and sorghum. However iron content of barley were lower than that of rice and sorghum. In addition, iron content of barley was almost constant regardless of the iron supply. These results suggest that iron availability is different among gramineae plant species. Correlation between available iron and chlorophyll index will be discussed.
