THE VASCULAR ARCHITECTURE OF THE FRUIT RECEPTACLE OF RED RASPBERRY DETERMINED BY 3D NMR MICROSCOPY AND SURFACE-RENDERING TECHNIQUES

The three-dimensional structure of the vascular system in the fruit receptacle of red raspberry was determined using NMR microscopy in combination with computer techniques which highlight the surfaces of specific tissue types. The surface-rendering technique is particularly valuable in situations where there are large differences in image characteristics between the tissue of interest and the rest of the specimen, and thus ideal for the delineation of the vascular tissue in the raspberry receptacle. This was shown to consist of a conical network of bundles with a spiral pattern of gaps; the carpellary traces emerged from the proximal end of each gap. The inner xylem and outer phloem tissues each appeared as a pair of fused columns in the surface-rendered images, and each carpellary trace had a separate supply from the xylem and phloem.