USE OF NMR-SPECTROSCOPY AND MAGNETIC-RESONANCE-IMAGING FOR DISCRIMINATING JUGLANS-NIGRA L SEEDS

Black walnut (Juglans nigra L.) seeds are large and require stratifica tion for germination. However, many seeds fail to germinate following stratification. Radiography can be used to select empty seeds, but can not determine which full seeds will germinate. The objective of this s tudy was to determine if any discrimination could be achieved through use of nuclear magnetic resonance (NMR) spectroscopy or magnetic reson ance imaging (MRI) of seeds. Both NMR spectroscopy and MRI were as eff ective as radiography for detecting empty seeds. NMR spectroscopy befo re stratification showed that most full seeds gave proton spectral pea ks for both water and lipids; some full seeds, however, showed no majo r lipid peak and consistently failed to germinate following stratifica tion. NMR spectra of seeds following stratification were similar to th ose obtained before stratification. Results of MRI experiments mirrore d those of spectroscopy experiments: seeds lacking large amounts of li pid produced images with very low intensity relative to those containi ng abundant lipid. Images of all embryos were more intense following s tratification. Among seeds containing large amounts of lipid, germinab le seeds were indistinguishable from non-germinable ones by either met hod.