Zhang Xuepeng, Huang Chao, Meng Ye, Liu Xuchen, Gao Yang, Liu Zhandong, Ma Shoutian
Key Laboratory of Crop Water Use and Regulation, Ministry of Agriculture and Rural Affairs, Institute of Farmland Irrigation Research, Chinese Academy of Agricultural Sciences (CAAS), Xinxiang 453002, China.
Crop Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, China.
Plants (Basel). 2023 Aug 23;12(17):3034. doi: 10.3390/plants12173034.
In the main agricultural area for waxy maize production in China, waterlogging occurs frequently during the waxy maize jointing stage, and this causes significant yield reduction. It is very important to understand the physiological mechanism of waterlogging stress in waxy maize during the jointing stage to develop strategies against waterlogging stress. Therefore, this study set waterlogging treatments in the field for 0, 2, 4, 6, 8, and 10 days during the waxy maize jointing stage, and were labelled CK, WS2, WS4, WS6, WS8 and WS10, respectively. By analyzing the effect of waterlogging on the source, sink, and transport of photoassimilates, the physiological mechanism of waterlogging stress in the jointing stage was clarified. The results show that PEPC and POD activities and Pro content decreased significantly under WS2 compared to CK. Except for these three indicators, the Pn, GS, leaf area, kernel number, yield, and puncture strength of stems were significantly decreased under the WS4. Under the WS6, the content of MDA began to increase significantly, while almost all other physiological indices decreased significantly. Moreover, the structure of stem epidermal cells and the vascular bundle were deformed after 6 days of waterlogging. Therefore, the threshold value of waterlogging stress occured at 4 to 6 days in the jointing stage of waxy maize. Moreover, waterlogging stress at the jointing stage mainly reduces the yield by reducing the number of kernels; specifically, the kernel number decreased by 6.7-15.5% in 4-10 days of waterlogging, resulting in a decrease of 9.9-20.2% in the final yield. Thus, we have shown that waterlogging stress at the jointing stage results in the decrease of potential waxy maize kernel numbers and yield when the synthesis of sources was limited and the transport of photoassimilates was restricted.
在中国糯玉米主产区，糯玉米拔节期经常发生涝害，导致产量大幅下降。了解糯玉米拔节期涝渍胁迫的生理机制对于制定抗涝渍胁迫策略非常重要。因此，本研究在糯玉米拔节期设置了0、2、4、6、8和10天的田间涝渍处理，分别标记为CK、WS2、WS4、WS6、WS8和WS10。通过分析涝渍对光合产物源、库及运输的影响，阐明了拔节期涝渍胁迫的生理机制。结果表明，与CK相比，WS2处理下PEPC和POD活性以及Pro含量显著降低。除这三个指标外，WS4处理下Pn、GS、叶面积、穗粒数、产量和茎穿刺强度均显著降低。WS6处理下，MDA含量开始显著增加，而几乎所有其他生理指标均显著下降。此外，涝渍6天后茎表皮细胞和维管束结构发生变形。因此，糯玉米拔节期涝渍胁迫的阈值出现在4至6天。此外，拔节期涝渍胁迫主要通过减少穗粒数降低产量；具体而言，涝渍4 - 10天穗粒数减少6.7 - 15.5%，最终产量降低9.9 - 20.2%。因此，我们表明，当源的合成受限且光合产物运输受阻时，拔节期涝渍胁迫会导致糯玉米潜在穗粒数和产量下降。
