Exp 14 N(D, sub 0 ) exp 15 N Nuclear Reaction Method for Nitrogen Depth Distribution Measurements in Wheat and Barley

摘要

The exp 14 N(d,p sub 0 ) exp 15 N reaction has been used to measure nitrogen depth distributions in single grains of wheat and barley. With the beam energy used (6 MeV) a depth of 225 mu m was reached. In order to test the applicability of the method for plant breeding purposes we have studied 1000 grains of wheat and grains of barley, which are part of a larger material of about 50 000 grains grown and harvested under controlled biological conditions. The measured nitrogen distributions in wheat show striking correlations with parameters describing the nitrogen level of fertilizer, the time of harvesting, the grain position in a head and the analyzed variety of wheat. Contributions to the spectra from silicon in the hull of barley are demonstrated. Contributions from interfering elements in the aleuron layer in wheat placed a limit of 120 mu m to the depth region analyzed. The importance of effects like pileup, heating of the grains by the beam and grain asymmetries were studied in detail. The possibility to use the technique for selection purposes in plant breeding will be discussed. (Atomindex citation 12:583847)