Mineral Nutrition, Yield and Source-Sink Relationships
Mineral Nutrition, Yield and Source-Sink Relationships
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DOI：
10.1016/b978-0-12-384905-2.00005-4
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发表时间：
2012-01-01
期刊：
影响因子：
--
通讯作者：
White, Philip
中科院分区：
文献类型：
--
作者：
Engels, Christof;Kirkby, Ernest;White, Philip
本章描述了养分在调节植物产量形成过程中的作用。作物的产量受生物量生产及其对收获植物器官的分配所控制。生物量生产取决于叶片的光合活性，即源活性和叶面积，即源大小。营养物质是叶片生长所直接需要的，也是光合作用器官的组成部分。营养供应通过光氧化、水力和激素信号以及糖信号间接控制光合作用和叶片衰老。作为呼吸电子链的组成部分，营养物质也通过影响呼吸ATP合成的效率来影响呼吸。本章进一步描述了光合作用分配到收获的植物器官是如何被这些器官利用同化物进行生长和储存的能力所控制的，即它们的汇强度，以及这是如何受到营养供应的影响的。营养物质在调节汇的形成中起着重要作用，例如通过它们对开花、授粉和块茎形成的影响，以及控制汇器官的储存过程。营养供应也会改变植物激素的内源性浓度，从而调节汇源关系。在高等植物中，源器官和汇器官在物理上彼此分离。因此，韧皮部中光合产物和营养物质从源头到汇的远距离运输对植物的生长和产量至关重要。本文还描述了源地同化物的韧皮部装载、汇地的韧皮部运输和韧皮部卸载的原理。
This chapter describes the role of nutrients in regulating plant processes underlying yield formation. The yield of crop plants is controlled by biomass production and its partitioning to harvested plant organs. Biomass production is dependent on photo-synthetic activity of leaves, i.e. source activity, and leaf area, i.e. source size. Nutrients are directly required for leaf growth and as integral constituents of the photosynthetic apparatus. Nutrient supply indirectly controls photosynthesis and leaf senescence via photooxidation, hydraulic and hormonal signals as well as by sugar signalling. Nutrients also affect respiration as constituents of the respiratory electron chain and by their influence on the efficiency of respiratory ATP synthesis. The chapter further describes how photosynthate partitioning to harvested plant organs is controlled by the ability of these organs to utilize assimilates for growth and storage, i.e. their sink strength and how this is influenced by nutrient supply. Nutrients play an important role in regulating sink formation, for example by their effects on flowering, pollination, and tuber initiation, as well as in controlling storage processes in the sink organs. Nutrient supply also modifies endogenous concentrations of phytohormones, which, in turn, regulate sink-source relationships. In higher plants source and sink organs are physically separated from one another. Therefore, long-distance transport of photosynthates and nutrients in the phloem from source to sink is essential for growth and plant yield. The principles of phloem loading of assimilates at source sites, phloem transport and phloem unloading at the sink sites are also described.