A difference in source-sink structure and chalky grain in early indica rice cultivars with different sink-potentials | 不同库容类型杂交早籼稻品种源库结构对垩白的影响

Chinese. 目的揭示不同库容量类型早籼稻品种齐穗期源库结构对稻米垩白的影响。方法以18个杂交早籼稻品种为材料，采用聚类分析法将供试品种按库容量分为大、中、小3种类型，研究不同类型品种源库结构、灌浆特性和垩白的差异，分析源库结构对籽粒灌浆和垩白的影响。结果齐穗期LAI、灌浆期净同化率等大库容类型＞中库容类型＞小库容类型，而单位库容的叶面积、茎鞘重和净同化率等则相反；籽粒灌浆速率大库容类型＜中库容类型＜小库容类型，而灌浆历期则相反；稻米垩白粒率和垩白度则表现为大库容类型＞小库容类型＞中库容类型。结论大、中库容类型品种，灌浆物质不足，灌浆速率低，垩白粒率和垩白度高，宜采取扩源措施降低稻米的垩白粒率和垩白度；小库容类型品种灌浆物质充足，灌浆速率快，垩白粒率和垩白度也高，宜采取扩库措施降低稻米的垩白粒率和垩白度。

English. Objective The aim of this study is to reveal the effect of source-sink structure at full heading stage to chalky grain of early indica rice cultivars with different sink potentials. Method Eighteen hybrid early rice cultivars were cultured in 2008 and 2009, respectively. The tested rice cultivars were classified into 3 types with large, middle and small sink potential respectively by using cluster analysis method. Then source and sink structure, grain filling characteristics and chalky grain of each sink potential types were compared, based on which the effects of source-sink structure on grain filling and chalky grain were analyzed. Result The results showed that LAI and net assimilation rate during grain filling were in the order of large sink potential type＞middle sink potential type＞small sink potential type. But comparisons of leaf area, stem and sheath weight and net assimilation rate per unit sink potential showed an opposite order. Grain filling rate was in the order of large sink potential type＜middle type＜small type, while grain filling duration showed an opposite order. Chalky grain rate and chalkiness were in the order of large type＞small type＞middle type. Conclusion As large and middle sink potential type cultivars had inadequate grain filling material, low grain filling rate, high chalky grain rate and chalkiness, strategies for enlarging source size should be used to lower chalky grain; And as small sink potential type cultivars had sufficient grain filling material, high grain filling rate, high chalky grain rate and chalkiness, strategies for enlarging sink size should be used to lower chalky grain.