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 re ceptacle of red raspberry was determined using NMR microscopy in combi nation with computer techniques which highlight the surfaces of specif ic tissue types. The surface-rendering technique is particularly valua ble in situations where there are large differences in image character istics between the tissue of interest and the rest of the specimen, an d thus ideal for the delineation of the vascular tissue in the raspber ry receptacle. This was shown to consist of a conical network of bundl es with a spiral pattern of gaps; the carpellary traces emerged from t he proximal end of each gap. The inner xylem and outer phloem tissues each appeared as a pair of fused columns in the surface-rendered image s, and each carpellary trace had a separate supply from the xylem and phloem.