Effect of temperature and water on seed germination of Leymus secalinus

This study used a polyethylene glycol reagent and indoor simulation of different levels of drought stress (0, -0.10, -0.20, -0.40, -0.80, and -1.60 MPa) and temperatures (10, 15, 20, 25, and 30 ℃) to study the seed germination characteristics of Leymus secalinus from Baingoin County of Xizang. The results showed that L. secalinus seeds can germinate in constant or variable (alternating) temperatures in the range of 10~30 ℃. A constant temperature of 15 ℃ and alternating temperatures of 20/30 ℃ had significant effects on seed germination, while constant temperatures 10 ℃ and 30 ℃ had extremely significant effects on germination percentage; seed germination was best at 25 ℃. With increasing PEG osmotic potential, the germination rate, germination index, vigor index, and plumule length showed different downward trends, while the radicle length first increased and then decreased. The germination rate of wild L. secalinus was the best (84%) under culture conditions involving 25 ℃ temperature and distilled water, among all the different temperatures and PEG osmotic potentials. At 25 ℃ and -0.10 to 0 MPa osmotic potential, the radicle growth of L. secalinus was better than that of the plumule.