Effects of salt and temperature on Tagetes erecta seed germination

The two-factor interaction design was employed to explore the effects of different salt concentrations and temperatures on Tagetes erecta seed germination. The results showed that T.erecta seed germinated well at saltless and low salt concentration (2 g·L-1) salinity environment which adapt to a wide temperature range. However, T.erecta seed germination was significantly (P0.05) inhibited at high salt concentrations. There was significant interaction (P0.05) between salt stress and temperature. The salt concentration affected the impacts of temperature on the germination and seedling growth. There was no significant difference between the germination of three temperature treatments at saltless and low salt concentration environment. The germination percentages, seedling height and root length of high temperature treatment were significantly lower (P0.05) than those of the other two temperature treatments when the salt concentration were 4 and 6 g·L-1. The temperature also affected the impacts of salt concentration on the germination and seedling growth. At 15/25 ℃ and 20/30 ℃ treatments, the germination percentage significantly decreased (P0.05) when the salt concentration was greater than or equal to 6 g·L-1. While at 25/35 ℃ treatment, it was significantly decreased (P0.05) when the salt concentration was greater than or equal to 4 g·L-1. The germination index was more sensitive to salinity stress than the germination percentage.