Effects of excessive ear removal on functional leaf assimilate accumulation and transport in wheat | 过度剪穗对小麦功能叶片同化产物积累及转运的影响

chinois. 通过剪穗处理，人为增大源库比率，研究籽粒库对功能叶片同化产物积累及转运的影响，为进一步探究源库互作条件下叶片的衰老机理提供理论依据。以小偃6号和9430小麦为供试材料，在小麦扬花期，从穗顶部向下剪去穗长的3/4，留基部的1/4小穗，以不剪穗为对照，于剪穗后每隔7 d测定小麦顶三叶的叶绿素含量、干物质积累量、可溶性糖和淀粉含量及灌浆后期顶三叶的丙二醛含量。剪穗处理后，小麦顶三叶出现明显的“叶色倒置现象”。剪穗处理21 d后，小偃6号倒二叶和倒三叶的叶绿素含量明显高于旗叶；剪穗后28 d，9430倒二叶的叶绿素含量高于旗叶。剪穗处理增加了干物质、可溶性糖在功能叶片中的积累，增加了淀粉在旗叶、倒二叶中的积累，而使倒三叶中淀粉的积累减少；剪穗处理使旗叶的丙二醛含量增加，倒二叶和倒三叶的丙二醛含量降低。剪3/4穗处理明显加速了旗叶的衰老，而使倒二叶和倒三叶的衰老得以延续。

anglais. Effects of grain sink on functional leaf assimilate accumulation and transport were studied by ear removal treatment artificial increase of source, sink ratio, in order to provide theoretical evidence on leaf senescence mechanism under source-sink interaction. Using the Xiaoyan 6 and 9430 as experiment materials, 3/4 ear was removed from the topmost portion of each ear at the flowering stage, intact ear being control. The chlorophyll content, dry leaf weight, soluble sugar and starch content were determined every 7 d after ear removal, and MDA content was determined at anaphase of grain filling. Leaf-color inversion phenomenon was more obvious at anaphase of grain filling after ear removal. The chlorophyll content of top 2nd leaf and top 3rd leaf of Xiaoyan 6 were obviously higher than that of flag leaf 21 days after ear removing, chlorophyll content of top 2nd leaf 9430 was higher than that of flag leaf 28 days after ear removing. Compared with control, functional dry leaf matter and soluble sugar content increased after ear removal; The starch content in flag leaf and top 2nd leaf increased, and the starch content in top 3rd leaf reduced; The chlorophyll content in flag leaf reduced, and chlorophyll content in top 2nd leaf and top 3rd leaf increased; The MDA content in flag leaf increased, and MDA content in top 2nd leaf and top 3rd leaf reduced. Removing 3/4 ear treatment accelerated flag leaf senescence, and delayed the top 2nd leaf and top 3rd leaf senescence.