To investigate the salt tolerance of wild Annual bluegrass （Poa annua L.） germplasm resources in Northwest China， ten wild populations collected from Lanzhou （LZ）， Jiuquan （JQ）， Maiji （MJ）， Zhangye （ZY）， Huangzhong （HZ）， Wuwei （WW）， Baiyin （BY）， Jinchang （JC）， Xihe （XH）， and Zhouqu （ZQ） were used as experimental materials. A pot experiment was conducted to investigate the effects of different soil salinity levels （0.2%， 0.5%， 0.8%， and 1.1%） on plant growth， cell membrane system， and osmotic adjustment system of P. annua， and to comprehensively evaluate their salt tolerance. The results showed that with increasing salt stress， plant height， leaf length， leaf width， and potassium and calcium ion contents of the ten germplasms decreased gradually， whereas relative electrical conductivity， malondialdehyde content， free proline content， soluble sugar content， and sodium ion content increased. The overall salt tolerance of the germplasms was ranked as LZ>JQ>BY>JC>ZY>WW>HZ>ZQ>XH>MJ. At a soil salinity level of 0.8%， theLZ and JQ exhibited lower salt injury than the others， indicating stronger salt tolerance， and suggesting their potential for cultivation in saline soils of Northwest China.

Poa annua L.  /  Salt stress  /  Growth traits  /  Osmotic adjustment  /  Na⁺ and K⁺ concentrations  /  Salt tolerance