Photosynthetic contribution of the ear to grain filling in wheat: a comparison of different methodologies for evaluation.
Photosynthetic contribution of the ear to grain filling in wheat: a comparison of different methodologies for evaluation.
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DOI：
10.1093/jxb/erw116
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发表时间：
2016-04
影响因子：
6.9
通讯作者：
Araus JL
中科院分区：
文献类型：
--
作者：
Sanchez-Bragado R;Molero G;Reynolds MP;Araus JL
这项研究证明了在良好的农艺条件下，穗作为籽粒灌浆的同化物来源的关键作用，并比较了不同的表型分析方法。秆（特别是旗叶）和穗被认为在为小麦籽粒灌浆提供同化物方面起主要作用。然而，过去取得的结果因所采用的方法而异。三种不同的方法进行了比较，旨在评估秆（光合器官低于穗）和穗籽粒灌浆的相对贡献。前两个包括应用光合作用抑制处理，包括使用除草剂DCMU和器官遮光。第三种是非侵入性方法，将成熟籽粒的碳同位素组成（δ 13 C）与花序梗、芒和颖片的水溶性组分的δ 13 C进行比较。在良好的农艺条件下，对几个CIMMYT先进品系进行了试验。δ ~（13）C法认为穗的光合作用贡献大于秆。然而，在应用δ 13 C方法时，应考虑到一些方法上的考虑，特别是所使用的取样方法，以防止收获后呼吸作用。阴影的方法分配了一个类似的贡献，穗秆。DCMU的方法分配了更大的作用，秆，但除草剂应用到秆影响穗，从而偏最终粒重。此外，DCMU和遮光方法可能会引起补偿效应，高估了未受影响器官的贡献。这项研究可能有助于开发精确的表型分析工具，以确定可能有助于提高粮食产量的生理性状，如穗光合作用。
This study proves the key role of the ear as a source of assimilates for grain filling under good agronomical conditions and compares different methodologies of phenotyping. The culm (particularly the flag leaf) and the ear are believed to play a major role in providing assimilates for grain filling in wheat. However, the results obtained in the past varied depending on the methodology applied. Three different methodologies were compared that aimed to assess the relative contribution of the culm (photosynthetic organs below the ear) and the ear to grain filling. The first two consisted of applications of photosynthesis inhibition treatments, including the use of the herbicide DCMU and organ shading. The third was a non-intrusive method that compared the carbon isotope composition (δ13C) of mature kernels with the δ13C of the water-soluble fraction of the peduncle, awns and glumes. Several advanced CIMMYT lines were tested under good agronomic conditions. The δ13C approach assigned a higher photosynthetic contribution to the ear than to the culm. However, some methodological considerations should be taken into account when applying the δ13C approach, particularly the sampling method used, in order to prevent post-harvest respiration. The shading approach assigned a similar contribution to the ear as to the culm. The DCMU approach assigned a greater role to the culm but herbicide application to the culm affected the ear, thus biasing the final grain weight. Moreover DCMU and shading approaches may cause compensatory effects which overestimated the contribution of unaffected organs. This study may help to develop precise phenotyping tools to identify physiological traits such as ear photosynthesis that could contribute towards increasing grain yield.