Abstract: With two-line hybrid rice Yangliangyou 6 and Liangyoupeijiu and three-line hybrid rice Shanyou 63 as materials, the relationships of source, sink and flow with grain filling were studied. The seed-setting rate, grain filling degree and grain yield of Yangliangyou 6 and Shanyou 63 were significantly higher than those of Liangyoupeijiu. The export percentage and transformation percentage of the matter in culms and sheaths of Yangliangyou 6 and Shanyou 63 were significantly higher than those of Liangyoupeijiu. Activities of sucrose synthase, adenosine diphosphoglucose pyrophosphorylase, starch synthase and starch branching enzyme in grains were higher in Yangliangyou 6 and Shanyou 63 than in Liangyoupeijiu, and were very significantly correlated with maximum grain filling rate, mean grain filling rate, grain filling degree and grain weight. The spikelet number, grain yield and total sink load per area of vascular bundle and phloem of Yangliangyou 6 and Shanyou 63 were significantly smaller than those of Liangyoupeijiu, and the greater the load, the lower the seed-setting rate and the poorer the grain filling. The transportation rate per area phloem of Yangliangyou 6 was greater than that of Liangyoupeijiu or Shanyou 63. The results suggested that Yangliangyou 6 possesses strong source, great sink activity and efficient flow, which lay a physiological basis for its high seed-setting rate and good grain filling.

Key words: hybrid rice, source-sink characteristics, grain filling, enzyme activity

摘要： 以两系杂交稻扬两优6号和两优培九及三系杂交稻汕优63为材料，研究了源、库、流特征及其与籽粒充实的关系。 扬两优6号和汕优63的结实率、籽粒充实度和产量明显高于两优培九；扬两优6号和汕优63茎鞘物质输出率和转换率显著高于两优培九；扬两优6号和汕优63籽粒中蔗糖合成酶、腺苷二磷酸葡萄糖焦磷酸化酶、淀粉合成酶和淀粉分支酶的活性显著高于两优培九，且上述各酶的活性与籽粒最大灌浆速率、平均灌浆速率、谷粒充实度和粒重呈极显著的正相关；扬两优6号和汕优63的单位维管束和韧皮部的颖花负荷、现实产量负荷、总库容负荷显著小于两优培九，且负荷越大的组合结实率就越低，充实度也就越差。扬两优6号单位面积韧皮部的物质转运速率显著高于两优培九和汕优63。表明扬两优6号具有源足、库强、流畅的特点，这是它结实率高和籽粒充实度好的生理基础。

关键词: 杂交稻, 源库特征, 籽粒充实