Yao Sumei et al. from Henan University of Science and Technology and College of Life Science and Technology published an article entitled "Dynamic simulation and Characteristic Analysis of ALA effect on grain filling of winter wheat at different grain locations". The effects of 5-ALA (ALA) on grain filling of winter wheat at grain position were studied. The results showed that different concentrations of exogenous 5-ALA had significant effects on weak grains, and 30mg/ LALA had the most obvious effect on grain weight gain.

　　1. Analysis of filling characteristics of winter wheat in the whole filling stage under different concentrations of 5-ALA

　　As can be seen from the table, during the whole filling period, 10~50mg/L ALA treatment made the grain filling start early, the time to reach the maximum filling rate earlier, the maximum filling rate and the average filling rate higher, and the active filling growth period longer, thus increasing the grain weight. ALA treatment of 10~50mg/L had the greatest influence on the characteristic parameters of grain Ⅲ position grouting.

　　2. Analysis of filling characteristics of winter wheat at different concentrations of 5-ALA in filling stage

　　It can be seen from the table that 5-ALA has different effects on the grain of the same grain potential at different filling stages of winter wheat, and has different action modes and degrees on the grain of different grain positions. In the early and middle stages of filling, ALA treatment can promote the filling of three grain sites, shorten the duration of the early stage of filling, and start the filling in advance by increasing the filling rate, which is conducive to the filling of the three grain sites and increase the grain weight. In the later stage of grout filling, ALA treatment can weaken the advantage of strong grain over weak grain, promote the filling of weak grain, and prolong the duration of strong grain filling. This effect alleviates the competitive advantage of strong grain over weak grain in the acquisition of grout material, and enables the weak grain to obtain more sources of nutrients in the later stage of grout filling, which is beneficial to the later stage grout filling of weak grain. Thereby increasing the grain weight.

　　In this experiment, the results showed that different concentrations of exogenous 5-ALA had significant effects on the weight gain of weak grains in winter wheat during filling stage, and 30mg/L ALA had the most obvious effect on the grain weight gain.