Identification of wheat varieties（lines） for salt tolerance and screening of germplasm in Ningxia spring wheat region

【Objective】The salt tolerance of wheat varieties（lines） was identified in Ningxia spring wheat region,salttolerant germplasms were screened,in order to provide excellent germplasm resources for salt-tolerant genetic improvement of spring wheat in Ningxia. 【Method】Using 230 wheat varieties（lines） from home and abroad adapted to Ningxia spring wheat region as experimental materials. The salt tolerance at the bud stage and seedling stage and molecular marker analysis were identified respectively,and correlation analysis was also conducted on the phenotypic traits of salt-tolerant varieties（lines） with salt injury grade（SIG）≤3 under salt stress. Moreover,a comprehensive evaluation was made by calculating the subordinative function value of salt-tolerant germplasms at both bud stage and seedling stage. 【Result】1.0% NaCl was the appropriate concentration for wheat salt tolerance identification. The numbers of varieties（lines） with SIG grades of 1（high tolerance）, 2（salt tolerance）, and 3（medium tolerance） at the bud stage were 15, 25 and 49 respectively, accounting for 6.52%, 10.87% and 21.30% respectively. The numbers of varieties（lines） with SIG grades of 1, 2 and 3 at the seedling stage were 0, 5 and 48 respectively, accounting for 0, 2.17% and 20.87% respectively. The SIG at both the bud stage and the seedling stage were mainly grade 3. The average distribution frequency of 22 molecular markers for salt tolerance in wheat reached 72.85% among 230 varieties（lines）. Among them, a total of 10 molecular markers, namely Xgwm335, Xgwm558, WSSR4, WSSR39, WSSR85, WSSR126, Xbarc144, Xbarc324, Xcfd6 and Xwmc110, were distributed in 89 samples at the bud stage and 53 samples at the seedling stage of salt-tolerant varieties（lines）（SIG≤grade 3）. they could be used for the assisted selection of salt tolerance at the bud stage and seedling stage of wheat. WSSR44 was only detected in Jiangxizao among salt-tolerant varieties（lines）. The distribution of other 11 markers in 230 varieties（lines） was 2.17%-70.00%,and was lower than the average value（72.85%）. For salt-tolerant varieties（lines） with SIG≤3 at both the bud stage and the seedling stage,their relative salt injury rates（RSIR） and salt injury indexes（SII） were not correlated with the phenotypic traits（P＞0.05）. The subordinative function values of yield,important quality traits,RSIR and SII of 22 salt-tolerant varieties（lines） with SIG≤3 at both the bud stage and the seedling stage under normal growth conditions were calculated. The subordinative function values of 11 varieties（lines） were higher than the average,which not only showed better salt tolerance,but also were better in yield and important quality traits. 【Conclusion】1.0% NaCl is the appropriate concentration for the salt tolerance identification of wheat. The salt-tolerant varieties（lines） with SIG≤3 identified at both the bud stage and the seedling stage are mainly MT. Ten molecular markers can be used as assisted selection markers for salt tolerance. The RSIR and SII of salt-tolerant varieties（lines） are not correlated with phenotypic traits. The 11 varieties（lines） show salt tolerance while also having better yield and important quality traits.