A Study On Seed Dormancy And Germination Character Under Different Temperature In Several Grass Species

Optixnium temperature and light condition have been found out by examinating germination performance (germinative power ,germination percentage and germinative index)of five grass seeds.Results were shown as follows:Optimium temperature is 20/30 0C and 15/25 0C alternative for Agropyron cristatum , 15/25 0C alternative for Bromus inermis and Elymus dauricus, 20/300(12 alternative for Bromus ircutensis and Elymus sibiricus. Light is essential for these five seeds. These five grass seeds which were subjected to pre-sowingsee treatment(hydration and dehydration for 2,3,4 times)have been tested about their torlerance on temperature and on drought.The result demonstrated that seeds showed great germenation performance under 5/25 and 5/30 0C .But germination performance were poor with temperature increasing. Germination percentage reduced to zero when temperature is up to or above 45 0C .But after hydration and dehydration ,gennination were improved and dead rate were reduced greatly .So premium sowing season and pre sowing are essential for grass seeds ,that is to say, these five seeds should be grown in spiring or early summer. Under temperature and drougt stress,seeds may be pre-sowed to impruve their germination and reduce dead rate.