Establishment Of Turf-type Ryegrass Efficient Genetic Transformation System And The Genetic Engineering Of Stress Tolerance

This research was intent to establish a transgenic system of turf grass 'rye grass' with high efficiency and endow it with stress tolerance ability.First,we improved the regeneration ability of cultivar 'Impulse' by adjusting hormone components and proportions,increasing osmosis in the medium,supplying with some organic substances and changing culture methods to increase the biomass of the embryo-gcnic callus.The results showed that the medium,which were constituted with MS added by3 mg/L2,4-D,0.1 mg/LBAP,0.5 g/Linositol,0.5 g/L casein,2 g/L gclritc and 30 g/L cane sugar,was the most suitable condition for informing cmbryogcnic callus from the mature seeds.After subculture in the solid medium with 2.5g/L proline,we harvested more cmbryogcnic callus as the initial materials for transgcnic rcscarch. Compared with the liquid culture,the former was more convcnicnt for transgenic procedures and less albinos.In order to crcate new rye grass with better stress tolerance,wc inscrtcd a gcne by particle bombardmcnt as well as Agrobacterium tumefancies LBA4404.The genc, HS1,was a member of HS polygcnc family in Arabidopsis thaliana.Identification transgenic rye grass by PCR and herbicide spraying,there wcrc six transgcnic lines, and one of them(TS) was significantly different from control plants.T5 was with strong sprouts and long roots.Treated transgcnic plants by drought,T2 and T3 had better drought tolerance,and the former was better than the latcr,and another linc T1 had no significant diffcrcncc with control plants.Trcatcd parts of transgcnic plants with 200mMNacl for tcn days,those had better pcrformancc undcr salt stress especially TS.Under stress wc mcasurcd the proline contcnts,thc MDA accumulation, and the activities of SOD and CAT.The rcsults showed that most transgcnic plants had thc low prolinc and MDA contcnts and the high activitics of SOD and CAT. Morcovcr,in thc tcndcncy of cnzymc activities,thc vitality of transgcnic lincs could keep for a long time under stress,and control plants wcrc opposite with thcm.This meant that transgcnic lincs had a better pcrformancc in eliminating frcc radicals and stabilizing the membrane and the macro-molecular.So wc concluded that HS1 had the same strcss tolcrancc ability in thc rye grass,which was suitablc for hcrcdity improvcmcnt.