Effects of triadimefon on seed germination and stress resistance related factors of shoots when coated on winter wheat seeds

In order to evaluate the security of triadimefon coated on winter wheat seeds, different doses of triadimefon were coated on wheat seeds and its effects on the germination of wheat seeds, as well as the stress resistance related biochemical factors of wheat shoots were studied, comparing with that of difenoconazole. The results indicated that the germination index, seed vigor index and germination rate of Zhoumai 22 and Mingxian 169 were all negatively correlated with the dose of triadimefon, and the relationship satisfied with function Y=A+B×e(-x/k); however, the variations of Mingxian 169 was more sensitive to the dose of triadimefon. The triadimefon treatment could lead to lower gibberellins (GAs) contents and higher abscisic acid (ABA) contents in shoots when compared to the blank control, and the variations of GAs and ABA contents showed increased trends with the increase of triadimefon doses, which theoretically explained the dose dependent suppression of triadimefon on wheat seed germination. But the biochemical analysis revealed that triadimefon could increase the chlorophyll content, respiratory rate, soluble protein content and α -amylase activity in wheat shoots, and decrease the electrolyte leakage of shoot cells, which suggested that coated triadimefon would be helpful to some extent to improve the potential stress resistance of wheat shoots. Comparatively, difenoconazole showed less suppression on wheat seed germination and was more helpful to improve the potential stress resistance of wheat shoots when compared to triadimefon.