Abstract: In order to study the variation pattern of wax powder content in different types of Sorghum,the colorimeter method based on the principle of chromatic aberration in physics was used for the first time to measure the wax powder content.The results showed that there were significant differences among different types of Sorghum varieties,and even if different genotypes in the same type of Sorghum germplasm.The top,middle and bottom stems of Forage Sorghum contain high,low and high content of wax powder,respectively.And the content of wax powder in the middle stem was most closed to the average value of mixed wax powder and could be used as representative content of the whole plant.The starting time and duration of the different types of Sorghum varieties transfering into each growth stage varied significantly,and the accumulated amount of wax powder in the same growth stage was also different.The tendency of wax powder contents in terms of different growth stages among different types of Sorghum varieties were slightly different:in Forage Sorghum,heading stage > flowering stage > filling stage > wax ripeness stage > complete ripeness stage,while in Sweet Sorghum,filling stage > heading stage > flowering stage > wax ripeness stage > complete ripeness stage.And the wax powder content in the flowering stage represented the average value of the whole growth period.The diurnal changes of wax powder content followed a monopeak curve,and wax powder content reached the peak value around 13:00.Some wax powder contents were negatively correlated with the stem brix in Sorghum.The study showed that there were significant differences in different types of Sorghum wax powder and the content changed regularly.The results above provided a scientific reference for breeding high wax Sorghum varieties to improve resistance.

Key words: Sorghum, Wax powder, Change rule, Chromatic aberration method

CLC Number: 

• S514.01