Split Application of Potassium Reduces Rice Chalkiness by Regulating Starch Accumulation Process Under High Temperatures
Chalkiness in rice is adversely affected by high temperatures during the flowering and grain-filling stages. Potassium (K) is essential for improving grain quality and heat resilience. The effects of split application K fertilizer on rice chalkiness under high temperatures during the flowering and g...
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MDPI AG
2025-01-01
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| Series: | Agronomy |
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| author | Xinyue Zhang Youfa Li Junjie Dong Yuanze Sun Haowei Fu |
| author_facet | Xinyue Zhang Youfa Li Junjie Dong Yuanze Sun Haowei Fu |
| author_sort | Xinyue Zhang |
| collection | DOAJ |
| description | Chalkiness in rice is adversely affected by high temperatures during the flowering and grain-filling stages. Potassium (K) is essential for improving grain quality and heat resilience. The effects of split application K fertilizer on rice chalkiness under high temperatures during the flowering and grain-filling stages were investigated in this study. Four treatments, including ambient temperatures with basal K fertilizer (AT-K1), high temperatures with basal K fertilizer (HT-K1), high temperatures with 70% K pre-transplanting and 30% K at the heading stage (HT-K2), and high temperatures with 30% K pre-transplanting and 70% K at the heading stage (HT-K3), were conducted. The results revealed that the chalky grain rate and chalkiness degree were reduced by 9.2–13.72% and 12.16–19.91%, respectively, by the split application of K fertilizer through effectively modulating the sucrose-to-starch conversion process in the rice grains, relative to the single basal application of K fertilizer under high temperatures. Specifically, the split application of K fertilizer reduced the enzymatic activities of SuSy, ADPGase, and SBE by 3.17–34.20% at 5–10 DAA, and GBSS and SSS by 6.48–13.50% at 5 DAA, but enhanced them by 5.50–54.90% from 15 DAA and 2.07–97.10% from 10 DAA. Similarly, the gene expression levels of enzymes involved in this process were decreased by 3.52–24.12% at 5 DAA but increased by 8.61–30.00% at 20 DAA by the split application of K fertilizer. This modulation led to a retardation in the excessive accumulation of starch during the early grain-filling stage but a higher starch accumulation rate during the middle and later stages, combined with a longer duration of starch accumulation, ultimately resulting in higher starch accumulation and reduced rice chalkiness. These results suggest that the application of K fertilizer during the heading stage is effective in compensating the deterioration of rice chalkiness by high temperatures. |
| format | Article |
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| institution | Kabale University |
| issn | 2073-4395 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | MDPI AG |
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| series | Agronomy |
| spelling | doaj-art-8daf9324b5214a0184d5f276f8132aa42025-01-24T13:16:47ZengMDPI AGAgronomy2073-43952025-01-0115111610.3390/agronomy15010116Split Application of Potassium Reduces Rice Chalkiness by Regulating Starch Accumulation Process Under High TemperaturesXinyue Zhang0Youfa Li1Junjie Dong2Yuanze Sun3Haowei Fu4Jiaxing Academy of Agricultural Sciences, Jiaxing 314016, ChinaJiaxing Academy of Agricultural Sciences, Jiaxing 314016, ChinaJiaxing Academy of Agricultural Sciences, Jiaxing 314016, ChinaLiaoyuan Academy of Agricultural Sciences, Liaoyuan 136299, ChinaJiaxing Academy of Agricultural Sciences, Jiaxing 314016, ChinaChalkiness in rice is adversely affected by high temperatures during the flowering and grain-filling stages. Potassium (K) is essential for improving grain quality and heat resilience. The effects of split application K fertilizer on rice chalkiness under high temperatures during the flowering and grain-filling stages were investigated in this study. Four treatments, including ambient temperatures with basal K fertilizer (AT-K1), high temperatures with basal K fertilizer (HT-K1), high temperatures with 70% K pre-transplanting and 30% K at the heading stage (HT-K2), and high temperatures with 30% K pre-transplanting and 70% K at the heading stage (HT-K3), were conducted. The results revealed that the chalky grain rate and chalkiness degree were reduced by 9.2–13.72% and 12.16–19.91%, respectively, by the split application of K fertilizer through effectively modulating the sucrose-to-starch conversion process in the rice grains, relative to the single basal application of K fertilizer under high temperatures. Specifically, the split application of K fertilizer reduced the enzymatic activities of SuSy, ADPGase, and SBE by 3.17–34.20% at 5–10 DAA, and GBSS and SSS by 6.48–13.50% at 5 DAA, but enhanced them by 5.50–54.90% from 15 DAA and 2.07–97.10% from 10 DAA. Similarly, the gene expression levels of enzymes involved in this process were decreased by 3.52–24.12% at 5 DAA but increased by 8.61–30.00% at 20 DAA by the split application of K fertilizer. This modulation led to a retardation in the excessive accumulation of starch during the early grain-filling stage but a higher starch accumulation rate during the middle and later stages, combined with a longer duration of starch accumulation, ultimately resulting in higher starch accumulation and reduced rice chalkiness. These results suggest that the application of K fertilizer during the heading stage is effective in compensating the deterioration of rice chalkiness by high temperatures.https://www.mdpi.com/2073-4395/15/1/116rice (<i>Oryza sativa</i> L.)high temperaturespotassium management strategiesrice chalkinessstarch accumulation |
| spellingShingle | Xinyue Zhang Youfa Li Junjie Dong Yuanze Sun Haowei Fu Split Application of Potassium Reduces Rice Chalkiness by Regulating Starch Accumulation Process Under High Temperatures Agronomy rice (<i>Oryza sativa</i> L.) high temperatures potassium management strategies rice chalkiness starch accumulation |
| title | Split Application of Potassium Reduces Rice Chalkiness by Regulating Starch Accumulation Process Under High Temperatures |
| title_full | Split Application of Potassium Reduces Rice Chalkiness by Regulating Starch Accumulation Process Under High Temperatures |
| title_fullStr | Split Application of Potassium Reduces Rice Chalkiness by Regulating Starch Accumulation Process Under High Temperatures |
| title_full_unstemmed | Split Application of Potassium Reduces Rice Chalkiness by Regulating Starch Accumulation Process Under High Temperatures |
| title_short | Split Application of Potassium Reduces Rice Chalkiness by Regulating Starch Accumulation Process Under High Temperatures |
| title_sort | split application of potassium reduces rice chalkiness by regulating starch accumulation process under high temperatures |
| topic | rice (<i>Oryza sativa</i> L.) high temperatures potassium management strategies rice chalkiness starch accumulation |
| url | https://www.mdpi.com/2073-4395/15/1/116 |
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