Source-Sink Relationships in Crop Plants

摘要

In crop plants, the physiological basis of dry matter production is dependent on the source-sink concept, where the source is the potential capacity for photosynthesis and the sink is the potential capacity to utilize the photosynthetic products. A developing leaf is a sink, but when fully grown it becomes a potential source. Instances of a single organ playing the roles of both source and sink are discussed, as well as the nature of additional sinks and metabolic sinks. Sink size is the potential capacity for maximum production of a crop. The intensity and capacity of sink dynamics, the mechanics of source and sink, and the factors influencing them are reviewed with examples. In tropical and subtropical climates the source appears to be the major limitation to higher yields in rice. In temperate climates, the sink is the limiting factor, as nearly all spikelets become grains. Examples of crop plants are reviewed, focusing on the limitations of their sources and sinks.