Most plants invest the greater part of their effort in tissues and organs (sinks) that are important for their long-term survival. Fruits and seeds represent such organs and they are considered as permanent, irreversible sinks. In contrast to temporary sinks, the plant cannot retrieve the invested storage materials from fruits and seeds because they abscise from the mother plant. Developing fruits and seeds are usually strong sinks, exhibiting a very high amount of assimilate import. The amount of storage material that the plants invest in seeds is huge. Thus it is not surprising that approximately 70% of all food for human consumption comes from seeds, mostly cereals (“endospermic seeds”) and legumes (“nonendospermic seeds”) (Bewley and Black, 1985). © 1995 by Marcel Dekker. All rights reserved.

Much of the plant material we eat originates from reproductive and storage sinks. Crop yield is the ultimate product of the whole plant’s net photosynthesis and the relative partitioning of dry matter to the organ of agricultural significance. The photosynthetic activity of the sources determines the potential amount of assimilates that can be transported to the sinks. The question is whether assimilate distribution to the sinks is controlled by the source (a feed-forward effect) or by the sink (a feedback effect). Many investigators have suggested that the overall physiological and metabolical processes taking place in the sink tissues are the main factors determining assimilate partitioning (see Krapp et al. 1993). However, a recent discussion of the question of sink strength and the extent of its importance in source-sink relationships (Farrar 1993) emphasized the range of contradictory views. © 1996 by Marcel Dekker, Inc. All Rights Reserved.

Adopting an interdisciplinary approach to the study of photoassimilate partitioning and source-sink relationhips, this work details the major aspects of source-sink physiology and metabolism, the integration of individual components and photoassimilate partitioning, and the whole plant source-sink relationships in 16 agriculturally important crops. The work examines in detail the components of carbon partitioning, such as ecology, photosynthesis, loading, transport and anatomy, and discusses the impact of genetic, environmental and agrotechnical factors on the parts of whole plant source-link physiology. © 1996 by Marcel Dekker, Inc. All Rights Reserved.