Reduction of Grain Yield in Rice Shaded during the Early Grain Filling Period is not the Result of Inhibition of Potential Grain Dry-Matter Increase
Reduction of Grain Yield in Rice Shaded during the Early Grain Filling Period is not the Result of Inhibition of Potential Grain Dry-Matter Increase
复制标题
灌浆前期遮荫水稻产量降低并非抑制籽粒干物质潜在增加的结果
DOI：
10.1626/jcs.69.413
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发表时间：
2000
影响因子：
--
通讯作者：
M. Sugawara
中科院分区：
文献类型：
--
作者：
T. Kobata;M. Sugawara
抽穗后10天(DAY0-10)水稻籽粒碳同化物供应不足被认为是降低籽粒干物质潜在增加量(ΔGP)的原因。然而，当观察到籽粒干物质增量(ΔG)下降时，遮荫期后的同化物供应是否足以支持ΔGP尚不确定。根据我们的模型分析，我们的目标是证明遮荫处理后的ΔG不是通过ΔGP的减少而是通过同化物供应的缺乏而减少的。在我们的模型中，ΔG由同化物供应(当前干物质生产量(ΔW)加上秸秆中保留的同化物(SP)决定，ΔG有一个由ΔGP定义的上限。在这项研究中，ΔGP是在有足够的同化物供应的情况下估计的，这些同化物是通过定期间伐植物提供的。在第0-10天遮荫，ΔG和ΔW即使在遮荫处理结束后也有所降低。将抽穗期观测到的ΔW和SP输入到模型中，计算ΔG和秸秆干物质增加量(ΔS)。计算的粮食和秸秆干重与实际观测数据吻合较好。因此，我们认为在DAY0-10期间遮荫增加的籽粒干物质不是被ΔGP不可避免的减少所抑制，而是由于在活跃的ΔG期间缺乏同化物供应所抑制。
A shortage of carbon assimilate supply to rice grain during the first ten days after heading(DAY0-10)has been considered to reduce the potential grain dry-matter increase(ΔGP). It was, however, uncertain whether assimilate supply after the shading period was sufficient to support ΔGP when the reduction of grain dry-matter increase(ΔG)was observed. Our objective was to demonstrate that ΔG after the shading treatments was reduced not through the decrease in ΔGP but through a lack of assimilate supply, based on our model analysis. In our model, ΔG is determined by assimilate supply(current dry-matter production(ΔW)plus reserved assimilate in straw(SP)and the ΔG has an upper limitation defined by ΔGP. In this study ΔGP was estimated under a sufficient supply of assimilates which were provided by periodical thinning of the plants. By the shading during DAY0-10, ΔG as well as ΔW were reduced even after the end of the shading treament. Observed ΔW and SP at the heading were input to the model to calculate ΔG and straw dry-matter increase(ΔS). The calculated dry weight of the grain and straw coincided closely with the actual observed data. We herewith suggest that the grain dry-matter increase by shading during DAY0-10 was not suppressed by inevitable reduction of ΔGP but rather by a lack of assimilate supply during the active ΔG period.