Xiao Xiaolu, Duan Bo, Huang Fangyuan, Zhi Ximin, Jiang Zhan, Ma Ni
Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Oil Crops Research Institute, Chinese Academy of Agricultural Science, Wuhan, 430062, China.
Sci Rep. 2024 Dec 28;14(1):31243. doi: 10.1038/s41598-024-82602-5.
The photosynthetic mechanism responsible for the differences in yield between different rapeseed varieties remains unclear, and there have been no consensus and definite conclusions about the relationship between photosynthesis and yield. Representation of the whole plant by measuring the photosynthetic performance at a single site may lead to biased results. In this study, we comprehensively analyzed the main photosynthetic organs of four high-yielding rapeseed varieties at the seedling, bud, flowering, and podding stages. The canopy photosynthetic parameters were derived by measuring the photosynthetic area, net photosynthetic rate, and chlorophyll content, and canopy photosynthetic capacity was used to evaluate the light utilization efficiency of different rapeseed varieties to establish the relationship between canopy photosynthetic traits and yield. The results showed that there were significant differences in photosynthetic traits among different parts of rapeseed plants. The photosynthetic trait parameters of the whole plant differed significantly when represented by leaves at different positions among different varieties, and different rapeseed varieties exhibited significantly different sensitivity to light intensity. The whole-plant study showed that the canopy photosynthetic capacity was the highest and second highest at the seedling and bud stage, respectively, both of which were closely and positively correlated with rapeseed yield, and ZY501 had higher canopy photosynthetic capacity than other varieties at these two stages due to its larger canopy photosynthetic area. Canopy chlorophyll content was also positively correlated with canopy photosynthetic capacity. These results indicated that investigation of photosynthetic characteristics at single sites in rapeseed might lead to biased results of photosynthetic capacity in different varieties, and provided a new evaluation index for studying the light utilization efficiency of rapeseed. Our results also clarified that canopy photosynthetic area has significantly greater contribution to canopy photosynthetic capacity than canopy photosynthetic efficiency, and provided a theoretical basis for investigating the photosynthesis mechanism underlying high crop yield.
不同油菜品种间产量差异所涉及的光合机制尚不清楚，关于光合作用与产量之间的关系也未达成共识并得出明确结论。通过在单一部位测量光合性能来表征整株植物可能会导致结果有偏差。在本研究中，我们全面分析了四个高产油菜品种在苗期、蕾期、花期和结荚期的主要光合器官。通过测量光合面积、净光合速率和叶绿素含量得出冠层光合参数，并利用冠层光合能力来评估不同油菜品种的光利用效率，以建立冠层光合特性与产量之间的关系。结果表明，油菜植株不同部位的光合特性存在显著差异。不同品种间以不同位置叶片表征整株植物时，光合特性参数差异显著，且不同油菜品种对光强的敏感性差异显著。整株研究表明，冠层光合能力在苗期和蕾期分别最高和次高，这两个时期均与油菜产量密切正相关，且在这两个时期，ZY501因冠层光合面积较大而具有比其他品种更高的冠层光合能力。冠层叶绿素含量也与冠层光合能力呈正相关。这些结果表明，在油菜单一部位研究光合特性可能会导致不同品种光合能力结果有偏差，并为研究油菜光利用效率提供了新的评价指标。我们的结果还阐明，冠层光合面积对冠层光合能力的贡献显著大于冠层光合效率，并为研究作物高产的光合机制提供了理论依据。
