CIRAD, UMR AGAP, Montpellier, France.
AGAP, Univ Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France.
Plant Cell Environ. 2020 Mar;43(3):579-593. doi: 10.1111/pce.13693. Epub 2020 Jan 21.
This study aimed to understand the response of photosynthesis and growth to e-CO conditions (800 vs. 400 μmol mol ) of rice genotypes differing in source-sink relationships. A proxy trait called local C source-sink ratio was defined as the ratio of flag leaf area to the number of spikelets on the corresponding panicle, and five genotypes differing in this ratio were grown in a controlled greenhouse. Differential CO resources were applied either during the 2 weeks following heading (EXP1) or during the whole growth cycle (EXP2). Under e-CO , low source-sink ratio cultivars (LSS) had greater gains in photosynthesis, and they accumulated less nonstructural carbohydrate in the flag leaf than high source-sink ratio cultivars (HSS). In EXP2, grain yield and biomass gain was also greater in LSS probably caused by their strong sink. Photosynthetic capacity response to e-CO was negatively correlated across genotypes with local C source-sink ratio, a trait highly conserved across environments. HSS were sink-limited under e-CO , probably associated with low triose phosphate utilization (TPU) capacity. We suggest that the local C source-sink ratio is a potential target for selecting more CO -responsive cultivars, pending validation for a broader genotypic spectrum and for field conditions.
本研究旨在了解光合和生长对不同源库关系水稻基因型的 e-CO 条件（800 与 400 μmol mol ）的响应。定义了一个称为局部 C 源库比的代理性状，即旗叶面积与相应穗上小穗数的比值，在受控温室中种植了五个具有这种比值差异的基因型。在抽穗后 2 周（EXP1）或整个生长周期（EXP2）期间施加不同的 CO 资源。在 e-CO 下，低源库比品种（LSS）的光合作用增益更大，并且它们在旗叶中积累的非结构性碳水化合物比高源库比品种（HSS）少。在 EXP2 中，LSS 的籽粒产量和生物量增益也更大，可能是由于其强大的库。不同基因型之间的光合能力对 e-CO 的响应与局部 C 源库比呈负相关，这一性状在不同环境下高度保守。在 e-CO 下，HSS 受到库的限制，可能与低三磷酸甘油醛利用（TPU）能力有关。我们建议，局部 C 源库比是选择对 CO 更敏感的品种的一个潜在目标，有待更广泛的基因型谱和田间条件的验证。
