Identification And Evaluation Of Salt Tolerance For Germplasm Materials Of Elytrigia Desv. At Seedling Stage

Elytrigia Desv., the perennial grasses of Gramineae, are the ideal plant materials of establishing artificial grasslands, improving natural pastures, protecting slopes, conserving water and soils and improving aline-alkalized soil, as well, are indispensable wild gene bank of improve wheat. Therefore, identification and evaluation of salt tolerance of Elytrigia germplasm materials at seedling stage, merit selection of salt-tolerant germplasm materials has the significant scientific theory role in the effective development and utilization of Elytrigia germplasm resources.Effects of salinity treatments on salt indexes, such as the ratio of change of relative growth, salinity tolerance rating, salt-tolerant coefficient, livability, the time of salinity injure to death, the relative water content, cell membrance permeability, content of free proline and MDA, K+/Na+ of 34 germplasm materials of 8 species of Elytrigia Desv. seedlings from 21 different countries were investigated and analyzed using the simulating salinity stress in green house, and the salt tolerance of germplasm materials of Elytrigia Desv. were comprehensivly evalucated at seedling stage. Meanwhile, effects of salinity and days treatments on physiological characteristics, such as the relative water content, cell membrance permeability, content of free proline and MDA of thirteen germplasm materials of Elytrigia intermedia seedlings from 12 different countries were investigated. The results showed that:1. With NaCl concentration increased, the ratio of change of relative growth, salt-tolerant coefficient and livability were decreased; the time of salinity injure to death was shorter, salinity tolerance rating was larger.2. The relative water content of leaves and K+/Na+ were decreased, but the cell membrance permeability, free proline accumulation and content of MDA were increased as the stress of salinity and days were intensified.3. According to the results of principal components analysis and cluster analysis of change rate of RWC, EC, Pro, K+/Na+, the ratio of change of relative growth, salt-tolerant coefficient, livability, the time of salinity injure to death, 34 germplasm materials of Elytrigia Desv. were divided into three grades of the salt tolerance, e.g. the stronger salt tolerance germplasm including ER030, ER035, ER041, EE011, EE014, EE017, EE023, EE026, EE047, EH001, EH002, EPU02; the medium salt tolerance germplasm including ER008, ER014, ER027, ER032, ER037, ER038, ER044, ER045, EE007, EE027, EJ001, EPO02, EPO03, EPO04; and the weaker salt tolerance germplasm including ER028, ER033, ER036, ER039, EE022, EI022, EJ003, EL001.4. According to the results of the correlation and cluster analysis of RWC, EC, Pro, MDA, 13 germplasm materials of E. intermedia were divided into three grades of the salt tolerance, e.g. the stronger salt tolerance germplasm including EI037, EI038, EI043; the medium salt tolerance germplasm including EI017, EI031, EI044, EI046, EI049; and the weaker salt tolerance germplasm including EI020, EI030, EI041, EI042, EI045.5. 0.9% of NaCl concentration was regarded as the salinity threshold of E. intermedia germplasm in accordance with the physiological indexes, the salinity tolerance grade and livability at NaCl stress.