Rice Science ›› 2023, Vol. 30 ›› Issue (6): 598-612.DOI: 10.1016/j.rsci.2023.06.003

• Research Papers • Previous Articles     Next Articles

Translocation and Distribution of Carbon-Nitrogen in Relation to Rice Yield and Grain Quality as Affected by High Temperature at Early Panicle Initiation Stage

Ji Dongling1, Xiao Wenhui1, Sun Zhiwei1, Liu Lijun1, Gu Junfei1, Zhang Hao1, Matthew Tom Harrison3, Liu Ke3, Wang Zhiqin1, Wang Weilu1,2()   

  1. 1Jiangsu Key Laboratory of Crop Genetics and Physiology / Jiangsu Key Laboratory of Crop Cultivation and Physiology, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China
    2Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Institutes of Agricultural Science and Technology Development, Yangzhou University, Yangzhou 225009, China
    3Tasmanian Institute of Agriculture, University of Tasmania, Newnham Drive, Launceston, Tasmania 7248, Australia
  • Received:2023-03-08 Accepted:2023-06-30 Online:2023-11-28 Published:2023-08-10
  • Contact: WANG Weilu (weiluwang868@yzu.edu.cn)


Due to climate change, extreme heat stress events have become more frequent, adversely affecting rice yield and grain quality. The accumulation and translocation of dry matter and nitrogen substances are essential for rice yield and grain quality. To assess the impact of high temperature stress (HTS) at the early panicle initiation (EPI) stage on the accumulation, transportation, and distribution of dry matter and nitrogen substances in various organs of rice, as well as the resulting effects on rice yield and grain quality, pot experiments were conducted using an indica rice cultivar Yangdao 6 (YD6) and a japonica rice cultivar Jinxiangyu 1 (JXY1) under both normal temperature (32 ºC / 26 ºC) and high temperature (38 ºC / 29 ºC) conditions. The results indicated that exposure to HTS at the EPI stage significantly decreased rice yield by reducing spikelet number per panicle, grain-filling rate, and grain weight. However, it improved the nutritional quality of rice grains by increasing protein and amylose contents. The reduction in nitrogen and dry matter accumulation accounted for the changes in spikelet number per panicle, grain-filling rate, and grain size. Under HTS, the decrease in nitrogen accumulation accompanied by the reduction in dry matter may be due to the down-regulation of leaf net photosynthesis and senescence, as evidenced by the decrease in nitrogen content. Furthermore, the decrease in sink size limited the translocation of dry matter and nitrogen substances to grains, which was closely related to the reduction in grain weight and the deterioration of grain quality. These findings significantly contribute to our understanding of the mechanisms of HTS on grain yield and quality formation from the perspective of dry matter and nitrogen accumulation and translocation. Further efforts are needed to improve the adaptability of rice varieties to climate change in the near future.

Key words: rice, early panicle initiation stage, high temperature stress, carbon-nitrogen translocation, grain yield, grain quality