Abstract
Studies were made on genetically related chlorosis resistant and susceptible grain sorghum grown in soils known to produce chlorotic and non-chlorotic sorghum plants. Determinations were made on the differences in the distribution pattern of Fe⁵⁹, nutrient balances and Fe⁵⁹ metabolites in chlorotic and non-chlorotic sorghum plants. A visual rating of chlorosis provided a means to classify the sorghum varieties into "chlorotic varieties," "intermediate chlorotic varieties," and "non-chlorotic varieties." No complete Mendelian dominance in the expression of chlorosis was demonstrated and no definite hereditary control in plant nutrition that results in chlorosis was found. A variation in potassium, sodium and phosphorus content in a chlorotic plant was detected, that is, visibly an after effect while close association in calcium and iron nutrition in the production of chlorosis was demonstrated. Soil grown plants indicated no gross variation in the distribution pattern of iron-59 due to differences in varieties, chlorosis production or soils. However, a higher Fe⁵⁹ uptake from a non-chlorotic soil and a higher Fe⁵⁹ uptake by susceptible varieties was demonstrated. Plants grown in nutrient culture showed differences in distribution patters indicating a higher iron precipitation in chlorosis susceptible varieties. There was always more deposition of iron-59 precipitates in tissue of a growing chlorosis susceptible variety, which later showed a similar redistribution patter of the Fe⁵⁹, migrating possible in vascular tissues. Actual chlorosis, however, showed no effect on the distribution patters of phosphpus-32 and calcium-45. A chromatographic analysis for different iron-59 as one metabolite which gradually changes to a secondary metabolite in about 144 hours. This secondary metabolite is presumably an active form of iron that favors rapid green pigmentation in sorghum. An application of δ-aminolevulinic acid to the medium enhances the formation of this secondary metabolite.
Muhsi, Abu Ahmed Abdul ([196). Studies on the uptake and metabolism of Fe⁵⁹ in chlorosis susceptible and resistant grain sorghum : a dissertation. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -776342.