| dc.description.abstract | A screening of 18 different varieties of graminaceous plants (rye, oats, and upland rice) was done based on their susceptibility to iron deficiency-induced chlorosis. Graminaceous plants reduce or prevent chlorosis using Strategy II, which is based on phytosiderophore release that can reduce inaccessible soil iron to iron accessible for plants in the form of Fe-phytosiderophore complexes. The plants were grown in a greenhouse in a quartz sand soil. A separate experiment was performed that examined the susceptibility of soybean (Glycine max) to iron deficiency-induced chlorosis. Soybean is a non-graminaceous plant that does not use Strategy II. Soybean was grown in growth chambers under low and high light regimes. In both experiments, the following parameters were studied: weekly water use of the plants, dry weight of above and belowground biomass, and leaf chlorophyll content measured using a SPAD meter. Additionally, different parameters of the revised Fe-binding assay protocol by Reichman and Parker (2007) were tested to examine whether their results could be reproduced and whether, subsequently, the method could be used to measure the fourth parameter—the concentration of phytosiderophores released by the plants. However, consistently reproducible results could not be obtained with the above assay protocol, and the fourth parameter was not used in the study. On the basis of the results obtained, the 18 screened varieties were ranked from the most susceptible to least susceptible to chlorosis. Rice varieties were found to be the most susceptible, followed by oat varieties. Rye varieties were the least susceptible, and most varieties did not show any susceptibility to chlorosis. Additionally, soybean plants showed extreme susceptibility to chlorosis in comparison with the 18 grass varieties, which indicated that plants using Strategy II are better able to withstand iron limitation. Light intensity did not significantly affect the susceptibility to chlorosis in soybean. | |
