Nuclear Magnetic Resonance Microimaging of Strawberry Flower Buds and Fruit

Abstract

Nuclear magnetic resonance (NMR) can be used to examine tissue structure and developmental changes during growth and maturation of plant organs nondestructively. Spin-lattice, relaxation time (T1)-weighted, inversion recovery, spin-echo images of strawberry (Fragaria×ananassa Duch.) flower buds were acquired at 3 and 1 day before anthesis and receptacles at 4, 10, 15, and 25 days after anthesis (DAA). The central pith and ovules of flower buds imaged intensely with inversion echo times between 0.1 and 0.5 seconds. Achenes and the vascular cylinder, composed of vascular bundles surrounding the pith, were prominent in receptacles at 4 and 10 DAA. Vascular bundles leading to achene positions, cortex and pith tissues, and the vascular cylinder were evident in receptacles at all developmental stages. A general trend to homogeneity of structure was observed in images of receptacles nearing full maturity (25 DAA). Inversion recovery, spin-echo NMR microimaging may be useful for studying internal physicochemical changes in flower buds and fruit of strawberry and of other fruit crops.