玉米光合产物分配与转移模拟方法的研究

Simulation method of distribution and transfer of maize photosynthate

光合产物分配与转移的模拟是作物生长模拟的重要组成部分。以山西省文峪河试验站春玉米3个年度(2018、2019和2020年)灌溉试验(高水处理T1和零水处理T2)资料对光合产物分配方法(分配系数法和分配指数法)进行模拟研究。结果表明:从拟合精度来看,两种方法对茎、叶、穗模拟值与实测值的拟合优度R^(2)均大于0.9,其中穗模拟精度最高(R^(2)>0.95)。水分胁迫会导致茎分配指数减小、叶和穗分配指数增大,且穗分配指数受水分胁迫影响最大;水分胁迫主要是通过影响生长相关性(茎叶比、穗茎比和根冠比)来影响分配系数,其中穗茎比随时间变化过程的模拟效果最好(R^(2)=0.882);茎叶比水分胁迫指数为-0.130,表明水分胁迫会导致茎叶比减小;穗茎比和根冠比的水分胁迫指数分别为0.248和0.143,表明水分胁迫会使穗茎比和根冠比增大;茎、叶、根分配系数在生长前期受水分胁迫影响较小,生长后期水分胁迫导致茎、叶、根分配系数增大以及穗分配系数减小;水分胁迫使光合产物的转移率减小。整体而言,两种方法对光合产物的拟合精度非常接近,但分配系数法对光合产物转移量的模拟结果更接近于实际情况,表明分配系数法具有更好的机理性。

The simulation of photosynthetic product distribution and transfer is an important part of crop growth simulation.Based on the irrigation experiment data(high water treatment T1 and zero water treatment T2)of spring maize of three years(2018,2019 and 2020)at Wenyuhe Experimental Station in Shanxi Province,the distribution methods of photosynthetic products(distribution coefficient method and distribution index method)were adopted for the simulation study.The results showed that the simulated and measured R^(2)values of stem,leaf and spike of the two methods were all above 0.9 in terms of fitting accuracy,and the simulated precision of spike was the highest(R^(2)was above 0.95).Water stress could decrease the stem distribution index,increase the leaf and spike distribution index,and it had the greatest influence on the spike distribution index.Water stress mainly influences the distribution coefficient by affecting the growth correlation indices(stem-leaf ratio,spike-stem ratio and root-shoot ratio).It was found that the simulation effect of spike-stem ratio was the best(the simulated value and the measured value of R^(2)were 0.882),the water stress index of stem-leaf ratio was-0.130,which indicated that the water stress would lead to the decrease of stem-leaf ratio.The water stress indexes of spike-stem ratio and root-shoot ratio were 0.248 and 0.143,indicating that water stress could increase spike-stem ratio and root-shoot ratio.Water stress had little effect on the distribution coefficient of stem,leaf and root at early stage,but at later stage,water stress increased the distribution coefficient of stem,leaf and root,and decreased the distribution coefficient of spike.Water stress reduced the transfer rate of vegetative organs.On the whole,the fitting accuracy of the two methods are very close to each other,but the distribution coefficient simulation method is more close to the actual situation,which shows that the mechanism of the distribution coefficient method is more plausible.