| In this study,genetic diversity was analyzed by SSR markers for wild oats(Avena sterilis & A.barbata)collected from the southern,northern,and north of the middle in Israel,and cultivated oats from Italy and China.Salt-tolerants of wild oats genotypes were screened using different concentrations of NaCl solutions.The results showed that:1.A total of 105 microsatellite(SSR)markers were used to screen wild and cultivated oats for polymorphism.Thereinto,total 22 SSR markers indicated high polymorphism,repeatability,and stability.The 22 SSR markers evenly scattered along the different chromosomes and regions.The genetic diversity and structure of 118 wild oat genotypes and 95 cultivated oats were analyzed using the selected 22 SSR markers.For wild oat,total 87 allelic variations were detected by 19 SSR markers,with an average of 4.57 allelic variations per marker,and ranged from 3 to 8.The average polymorphism information content(PIC)was 0.7704,which varied from0.5230 to 0.9456.Among them,AM7 marker had the most allele loci,and AM4 marker had the largest PIC value.For the cultivated oats,total 22 allelic variations were detected by 7 SSR markers,with an average of 3.14 allelic variations per marker,and varied from 2 to 4.The average PIC was 0.6107,with a range of 0.4358-0.7287.Among them,the AM7 and AM49 markers had the most allele loci,and the AM3 markers had the highest PIC value.2.The cluster analysis based on the SSR polymorphisms of wild oat genotypes using UPGAM method showed that it was divided into five groups on the GS value of0.7195.There were 46,58,4,2 and 3 genotypes from I to V group,respectively.The classification limits were not obvious,and the northern-central populations cross-categorize with the northern and southern populations.3.The population structure of 118 wild oat genotypes was analyzed using the structure 2.3.4 software.The results showed that 11 wild oat populations were divided into three groups,which were following the ecogeographic distribution of the wild oatpopulations.The relationship between wild oat genotypes in north region and those in south region was far.The results of population genetic structure analysis and cluster analysis were generally consistent.4.Salt resistance experiment for wild oat seed germonation showed that the growth of wild oat seedling under NaCl stress was inhibited.Treatment with different NaCl concentrations had different effects on the root length and shoot length of seedlings of different oat genotypes.The overall trend was gradually decreasing with increasing salt concentration.The 250 mMol/L NaCl solution led to some seedlings of oat genotypes death.There were significant differences among different populations under the treatment of 100 mMol/L NaCl.Salt stress had little effect on the Nah and Tg populations.5.In the GLM model,the association analysis between the SSR marker and10 salt tolerance score for wild oat seedlings growing in different NaCl concentrations showed that the eight out of the 19 SSR markers were significantly associated with 10traits(P<0.05).The maximum interpretation rate of phenotypic variation was 47.74 %,while the minimum value was 16.37 %.The association analysis between SSR marker and four agronomic traits of wild oats,e.g.plant height,biomass yield,1000-seed weight,and whole growth period.indicated that the five out of the 19 SSR markers were significantly associated with four traits(P < 0.05).The maximum interpretation rate of phenotypic variation was 18.82 %,while the minimum value was 7.36 %.In addition,it has been found that the number of markers associated with different agronomic traits is different;the same marker locus can also be associated with multiple traits.Accordingly,it provides a good reference and basis for further study on the development and genetic laws of oats,as well as to improve salt tolerant cultivated cereals varieties using wild oat resources. |
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