Abstract: Cynanchi auricuti is widely distributed in the Kashi region, and it is a plant that can better adapt to the saline soil in southern Xinjiang. At present, there are few reports on the mechanism of the adaptation of Cynanchi auricuti to saline soil. Based on this, we studied the effects of daily germination rate, germination rate, germination potential, germination index, radicle length and growth rates of Cynanchi auricuti under typical neutral salt NaCl and alkaline salt Na2CO3 stresses in Kashi City. Relative salt-harmed rate and salt-tolerance were evaluated. The results showed that NaCl and Na2CO3 had significant effects on the daily germination rate, germination rate, germination potential, germination index, radicle length and growth rates. The stress of Na2CO3 was stronger than that of NaCl. Relative salt-harmed rate of Na2CO3 was higher than that of NaCl, and the high concentration of Na2CO3 directly inhibited the seed germination of Cynanchi auricuti. The salt-tolerant salt concentration, salt-tolerant semi-lethal concentration and salt-tolerant limit concentration of NaCl were higher than that of Na2CO3 at the germination stage. This experiment provides information for further research on the mechanism of Cynanchi auricuti adaptation to saline-alkali soil, and also lays a foundation for the improvement of saline soil in southern Xinjiang.

Key words: cynanchi auricuti, seed germination, NaCl stress, Na2CO3 stress