水稻群体成穗率与干物质积累动态关系的模拟研究

Relationship Between Productive Tiller Percentage and Biomass Accumulation in Rice (Oryza sativa L.): A Simulation Approach

应用两个水稻茎数动态模型 (TIL和 RGR模型 ) ,分析了成穗率与群体干物质积累动态的关系。结果表明 :(1)成穗率与最高茎数呈极显著负相关 ,支持了“降低苗峰是提高成穗率的关键”的结论 ;(2 )最高茎数与穗分化始期干重呈极显著正相关 ,前期干物质积累过快是苗峰过高的原因之一 ;(3)成穗率与群体干物质积累动态密切相关。同样的干物质积累量 ,干物质积累动态不同 ,其茎数动态相差很大。在抽穗期干物质积累量相近的情况下 ,穗分化以前干物质积累所占的比例越大 ,成穗率越低。采用一组独立的实测资料进行分析 ,也得到了相似的结果。由此可见 ,优化干物质积累动态是提高成穗率 。

The relationship between productive tiller percentage (PTP) and biomass accumulation was studied using a simulation approach. The TIL and RGR models were used in the analyses. Results showed that: (1) PTP was significantly (P<0 01) and negatively correlated with maximum tiller number per unit area (n max ), supporting the conclusion drawn from experiments that reducing n max is a key to increase PTP; (2) The n max was positively correlated with biomass at panicle initiation, suggesting that a high crop growth rate before panicle initiation results in high n max ; (3) PTP was affected by the trajectory of biomass accumulation. With a given amount of biomass at flowering, the more the biomass at panicle initiation, the lower the PTP. Analysis of an independent data set measured in the field experiment conducted during 1998 dry season at the International Rice Research Institute gave similar results. It seems that an optimized trajectory of biomass accumulation is essential for a rice population to achieve an optimized tiller production and high PTP and grain yield.