狗牙根新品系种子萌发期及苗期耐盐性评价OA

To evaluate the differences in salt tolerance among new lines of bermudagrass(Cynodon dactylon),identify key indicators for salt tolerance assessment,and thereby facilitate the breeding of new salt-tolerant cultivars,this study used 'Xinnong No.1' bermudagrass as the control.Three new lines(C138,C22,C63)were subjected to NaCl stress at concentrations of 0.5%,1.0%,1.5%,2.0%,and 2.5%dur-ing both seed germination and seedling stages.Germination,growth,and physiological parameters were measured.A comprehensive evaluation of salt tolerance was conducted by integrating the entropy-weighted TOPSIS method,membership function analysis,and the Comprehensive Salt Tolerance Index(CSI).The results indicated that salt stress significantly inhibited seed germination and seedling growth of bermudag-rass,with clear differential tolerance observed among the lines.C138 demonstrated the best performance across both stages,maintaining relatively high levels of germination rate,vigor index,aboveground bio-mass,and leaf relative water content under salt stress.C63 performed well under low to moderate salinity(≤1.0%).The entropy-weighted TOPSIS analysis revealed that germination potential and vigor index were major contributing factors during the germination stage,whereas aboveground and belowground bio-mass were key during the seedling stage.Based on the combined analysis of the membership function and CSI,the salt tolerance of the four bermudagrass materials was consistently ranked(from strongest to weak-est)as follows:C138,C63,'Xinnong No.1' bermudagrass,and C22.In summary,C138 exhibits strong compre-hensive salt tolerance and shows promise as an excellent material for saline-alkali land improvement,while C63 is suitable for mildly saline environments.These findings provide a basis for the breeding and promotion of salt-tolerant bermudagrass varieties.