Germination characteristics of Cynodon dactylon seed in Xinjiang under PEG stress

In order to understand drought resistance of 6 Bermuda grass germplasm at germinating stage and select suitable PEG concentrations for drought resistance selection, the seed germination rate, germination energy, germination index, radicle length, plumule length, ration of radicle to plumule and seedling weight were measured under 0%, 7.5%, 15.0%, 22.5%, 30.0% PEG (polyethylene glycol) stress and the drought resistance ability of these germplasm was determined using subordinate function method. The results showed that the seed germination percentage, germination energy, germination index of Bermuda grass significantly decreased (P<0.05) with the increase of drought stress, and the significant reduction of different indices did not appear in the same PEG concentration. Higher PEG concentration stress reduced seed radicle length, plumule length, ration of radicle to plumule and seedling weight. The optimal concentration to evaluate drought tolerance of Bermuda grass was 15% PEG. According to subordinate function analysis, the drought resistance of 6 Bermuda grass from strong to weak was Cd016, Cd043, Cd047, Cd002, Cd034, Cd013.