65 core germplasms were identified and evaluated under 15℃（26℃，CK）at the stage of germination. The results showed that the range of relative germination percentage, relative germination power, relative germination index, relative radicle length, relative fresh weight and relative dry weight were 1.00%-123.00%, 0.00%-112.00%, 0.00%-70%, 13.00%-109.00%, 0.00%-100.00%, 0.00%-101.00% respectively, showing that the seeds vigor and growth ability of most materials were influenced by low temperature and just some of them expressed no obvious difference comparing with CK. 7 accessions with extremely high tolerance were screened out.