两系组合两优培九与三系组合Ⅱ优58后期光合生产特性比较研究

以本地表现最好的三系杂交稻Ⅱ优58和两系杂交稻两优培九为材料，比较研究了两组合后期叶片叶绿素含量与功能随时间发生的变化、剑叶在后期不同阶段光合速率的变化及后期干物质的转运与分配。结果表明：两系杂交稻后期虽具有叶绿素功能期较长和光合速率较稳定等优势，但在中肥条件下，仍表现库大源小，干物质转运欠畅，源库流关系欠协调，因而结实率较低，谷粒充实度较低，限制了其增产潜力的发挥。两系杂交稻的超高产栽培，必须以高产土壤为基础。

Comparison of Photosynthetic Characteristics between Two-line Hybrid Rice Liangyou Peijiu and Three-line Hybrid Rice Ⅱ You 58 after Heading Stage

The difference of photosynthetic characteristics between two-line hybrid rice Liangyou Peijiu and three-line hybrid rice Ⅱ You 58 was compared after heading stage. The results showed that compared with Ⅱ You 58, Liangyou Peijiu had a longer functional period of photosynthesis and the photosynthetic rate decreased more slowly in flag leaf. Even so, under middle fertility conditions, its source-sink relation could not be well coordinated for its relatively smaller source but larger sink, and its dry matter could not be transferred to spikelets normally, which results in a lower seed setting rate and a poorer grain filling in Liangyou Peijiu than in Ⅱ You 58, thus limiting the high-yielding potential of Liangyou Peijiu. To achieve a super high yield of two-line hybrid rice Liangyou Peijiu, fertile soil is a must in its cultivation.