Salt Tolerance Identification At Seedling Stage And Molecular Marker Evaluation Of Wheat Germplasms

At present,the area of salinized soil is expanding,and the growth and development of crops are under different degrees of salt stress,facing the risk of reduced yield and quality.It is one of the most direct and effective measures to excavate the salt-tolerant germplasm resources.In this study,the wheat salt-tolerant variety"Shanrong 3"was used as a control to identify 362 wheat germplasm stored in thelaboratory,and the salt-tolerant germplasm was selected according to the salt damage index,and the salt-tolerant sites were evaluated by molecular markers.This study provides a reference for the breeding of salt-tolerant wheat varieties.The main study results are presented as follows:1.Identification and screening of salt tolerance phenotype at seedling stage: According to the results of the pre-test,the concentration(250 mmol·L^-1)at the maximum difference between the salt phenotype between"Shanrong 3"and"Chinese spring"was used as the germplasm identification concentration.362 wheat germplasm（including 163local species and 199 breed species）were identified in the laboratory,including 32,150,15,125,54,respectively,with the ratios of 8.84%,41.43%,34.53%,14.92%and0.28%of the total materials.One high-resistant material identified was Paozi wheat （SI=16.00%）;54 salt-tolerant germplasm were selected,including Xiaoyan 6（SI=30.00%）,"Yunhang"series（Yunhang 22-33,SI=25.92%;Yunhang 137,SI=27.23%;Yunhang 805,SI=27.43%）and"Linkang"series（Linkang 16,SI=36.46%;Linkang 17,SI=36.77%）.The proportion of 163 local species and 199 breed species with salt tolerance grade was basically the same.Among them,the proportion of local species was 48%,breed species was 51%.Among these salt-tolerant germplasm,19 materials had higher salt tolerance than the control varieties Shanrong 3,namely Paozimai,Yunhan 22-33,Laolaixia, Linkang 5047,Baimaizi,Huangguaxian,Jintai 102,Dabaipi,Lougumai,Yunhang 137,Yunhang 805,Baituzitou,Jinmai 57,Linkang 5027,Banjiemang,Fen 2365,Yunhan 115,Taixue 7 and Hongxumai.2.Identification and analysis of molecular markers:362 wheat germplasm were amplified using 25 salt-related molecular markers previously synthesized by the laboratory PCR amplification products by electrophoresis using an N-PAGE 8%non-denaturing polyacrylamide gel,statistical belt type.The results showed that:WSSR4,WSSR13,WSSR39,WSSR75,WSSR14,WSSR130,WSSR85,Xgwm148,Xwmc11,Xwmc169,Xgwm455,Xbarc144,Xgwm304 show two marker types;Xgwm312,WSSR44,Xcfd49,WSSR126,Xgwm335,Xgwm174,Xcfd 9,Xgwm350,and Xwmc503 showed three marker types;Xgwm314,Xwmc170,and Xwmc44 showed four marker types.The analysis of variance showed that the marked difference between WSSR39（linkaged with salt-resistant genes Bl-85）,WSSR130（linkaged with salt-resistant genes Ta Clp B5）and wheat germplasm indicate significant correlation（P<0.05）,Xwmc170（linkaged with salt-resistant genes Nax1）and wheat germplasm indicate extremely significant correlation（P<0.01）.UPGMA was used to construct cluster maps,and 362 wheat accessions were divided into six groups.