Appraisal Of Drought And Salt Resistance Of Triticum-leymus Substitution Alien At Germination And Seedling Stages

In order to study the effect of drought and salt stress on physiological parameters and identify the resistance of triticum-leymus substitution line, experiments were conducted at the greenhouse of Northwest A&F University in 2014, April to August. In drought resistance experiment, Experimental materials are 2 triticum-leymus substitution lines 2Ns,6Ns,3 parents M842,4286,7182 and 2 native cultivars Jinmai47, Chinese-spring, drought stress is divided into two gradients: contrast(CK), simulated drought(PEG 100g/L), treatment at germination and seedling stages, then tested various physiological indexs 14 days later. In salt tolerance experiment,the same 7 materials were divided into three gradients of salt stress: contrast(CK), moderate salt(150 mmol/L)and severe salt(250 mmol/L), then the salt-related indexes of germination and seedling stage were measured.Under simulated drought stress, the average bud length and average root length of 2 triticum-leymus substitution lines were significantly reduced; Germination rate and rooting rate slightly decreased. Leaf relative conductivity and proline content of 2 triticum-leymus substitution lines were increased significantly; MDA content, the soluble sugar content, the activities of SOD, POD and CAT increased to some degree; The soluble protein content increased slightly; Intercellular CO2 concentration of trace has increased, while root vigor, net photosynthesis rate, transpiration rate and stomatal conductance decreased to a certain degree.Under moderate salt stress, the average bud length and average root length of 2 triticum-leymus substitution lines were significantly reduced; Germination rate and rooting rate slightly decreased, while under severe salt stress, the front two indexes decline reduced, the later two indexes decline increased. Proline content, leaf relative conductivity, the content of soluble sugar and SOD activity increased significantly with the increasing intensity of salt stress; Under moderate salt stress, the activities of POD and CAT increased to some degree, while under severe salt stress, the increase in the former, the latter increase down; The soluble protein content increased first and then decreasedwiththeincreasingintensityofsaltstress,butstillhigherthanthecontrol;intercellularco2concentrationoftracehasincreasedwiththeincreasingintensityofsaltstress,whilerootvigor,netphotosynthesisrate,transpirationrateandstomatalconductancedecreasedtoacertaindegreeunderdifferentsaltstress.thecomprehensiveresultsshow,theresistanceof2 ns,6nswereweakerthanjinmai47,strongerthanother4 materials.inthefuture,couldimprovethebreedingmethod,takethistwomaterialsasparentsforthebreedingofnewvarieties,optimizegermplasmresources.