Objective It has important guiding significance for perfecting rice seed quality inspection to carry out TTC staining experiment, select the best combination and explore the changes in the main physiological indexes of rice seeds.

Method Single factor analysis and orthogonal experimental design were used to compare the influence of seed imbibition time, TTC concentration, staining temperature and staining time, on the staining effect, and to screen the best TCC staining combination. Spectrophotometry was used to determine the amylase activity and soluble sugar content in rice embryos under different germination conditions.

Result Rice embryos stained by TTC are divided into five situations: The entire embryo was stained darkly; The entire embryo was stained lightly; The coleorhiza was stained; The coleoptile was stained; The scutellum was stained. The influence of the four factors on the viability of riceseeds is as follows: staining time > staining temperature > TTC concentration > imbibition time; The best condition for TTC staining of rice seeds is as follows: staining time 2 h, staining temperature 30℃, TTC concentration 1%, imbibition time 3 h. Under different germination conditions, the changes of α-amylase, β-amylase activity and soluble sugars in rice seeds were consistent with the changes in seed germination rate.

Conclusion Under the best combination of TTC staining, the staining rate of rice seeds could accurately reflect the viability and germination ability of the seeds. Amylase activity and soluble sugar content may be used as important physiological indicators for predicting and evaluating rice seed vigor.