Use of NMR spectroscopy and magnetic resonance imaging for di~riminating Juglans nigra L. seeds

Black walnut (Jug/am nigra L.) seeds are large and require stratification for germination. However, many seeds fail to germinate following stratification. Radiography can be used to select empty seeds, but cannot determine which full seeds will germinate. The objective of this study was to determine if any discrimination could bc achieved through use of nuclear magnetic resonance (NMR) spectroscopy or magnetic resonance imaging (MRI).of seeds. Both NMR spectroscopy and MRI were as effective as radiography for detecting empty seeds. NMR spectroscopy before stratification showed that most full seeds gave proton spectral peaks for both water and lipids; some full seeds, however, showed no major lipid peak and consistently failed to germinate following stratification. NMR spectra of seeds following stratification were similar to those obtained before stratification. Results of MRJ experiments mirrored those of spectroscopy experiments: seeds lacking large amounts of lipid produced images with very low intensity relative to those containing abundant lipid. Images of all embryos were more intense following stratification. Among seeds containing large amounts of lipid, germinable seeds were indistinguishable from non-germinable ones by either method.