Abstract: In order to understand the relationship between soybean seed color and seed vigor, the germination index, seed viability and conductivity of leaching solution of soybean seeds with different colors were compared under standard, low temperature and drought stress, and the soybean seeds were comprehensively evaluated by fuzzy membership function method. The results showed that the germination rate and germination index of mixed color soybean seeds were significantly higher than those of yellow green and yellow soybean seeds; There was no significant difference in viability among the three colors of soybean seeds; Under low temperature and drought stress, the germination potential of mixed color soybean seeds was not significantly different from that of yellow green soybean seeds and yellow soybean seeds; Under standard germination conditions, the germination potential of mixed color soybean seeds was significantly different from that of yellow soybean seeds; It shows that the effect of color on soybean seed germination potential is not as great as that of low temperature and drought stress. The conductivity of the extract of mixed color soybean seeds was significantly lower than that of the other two colors; The D value of mixed color seeds is the largest and the D value of yellow seeds is the smallest, which indicates the following relationship: mixed color seed vigor > yellow green seed vigor > yellow seed vigor. Soybean seed color is significantly correlated with seed vigor. This paper provides a theoretical basis for soybean seed selection, cleaning and processing.

Key words: soybean color, fuzzy membership function, germination index, seed vigor, correlation analysis