Abstract

Water shortages and population surges pose notable challenges to food security. North China is an important grain base of the country, with limited available water resources. Therefore, it is necessary to research the patterns of photosynthate accumulation, distribution, and transfer in summer maize under water stress. On the basis of existing methods, in this study, we considered the impact of water stress with two methods, namely the distribution coefficient method and the distribution index method. The results showed that the water correction coefficient indices of the stem–leaf ratio spike–stem ratio, and root–shoot ratio were 0.2705, 0.3530, and −0.2097, respectively, which revealed that water stress caused a decrease in the stem–leaf ratio and spike–stem ratio and an increase in the root–shoot ratio. Water stress caused a reduction in the stem distribution index and leaf distribution index and a slight increase in the spike distribution index. The filling stage was the critical period for water stress to affect the distribution coefficient of each organ, while the jointing stage was the critical period for water stress to affect the leaf distribution index. During the middle growth period, water stress exerted the greatest impact on the distribution parameters. Water stress imposed a greater influence on the distribution coefficient than on the distribution index. The two methods effectively simulated the accumulation and distribution process of photosynthates under water stress conditions, and the R², average absolute percentage and root mean square error values were 0.9358–0.9997, 4.15–22.71%, and 2.6–24.37%, respectively. The change trend of the photosynthate transfer rate calculated by the distribution coefficient method under water stress conditions was more consistent with that of the actual values. The distribution coefficient method generally performed better than the distribution index method. This study avoids the problem of solely relying on experimental data to determine crop growth dynamics and provides a way to describe crop photosynthate accumulation continuously and quantitatively.

中文翻译：

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水分胁迫下夏玉米光合分布参数及生物量动态模拟

摘要

水资源短缺和人口激增给粮食安全带来了显着挑战。华北地区是国家重要的粮食基地，水资源有限。因此，有必要研究水分胁迫下夏玉米光合产物积累、分配和转移的规律。在现有方法的基础上，本研究采用分配系数法和分配指数法两种方法考虑水分胁迫的影响。结果表明，茎叶比穗茎比和根冠比的水分修正系数指数分别为0.2705、0.3530和-0.2097，表明水分胁迫导致茎叶比下降。穗茎比和根冠比的增加。水分胁迫导致茎分布指数和叶分布指数降低，穗分布指数略有增加。灌浆期是水分胁迫影响各器官分配系数的关键时期，拔节期是水分胁迫影响叶片分布指数的关键时期。生育中期，水分胁迫对分布参数影响最大。水分胁迫对分配系数的影响大于对分配指数的影响。两种方法有效模拟了水分胁迫条件下光合产物的积累和分配过程，R ²、平均绝对百分比和均方根误差值分别为0.9358~0.9997、4.15~22.71%和2.6~24.37%。水分胁迫条件下分配系数法计算的光合产物转移速率的变化趋势与实际值较为吻合。分配系数法通常比分配指数法表现更好。该研究避免了单纯依靠实验数据确定作物生长动态的问题，提供了一种连续、定量描述作物光合产物积累的方法。