Analysis Of SSR Related Loci For Stem Strength In Wheat

The lodging is an important factor resulting in decease of wheat yield.The stem strength of wheat has been used as an index of lodging resistance.In this paper,stem strength value of 174 wheat cultivars and lines grown in two environments were assayed.It was analysis of correlation between stem strength and 26 SSR markers locus on chromosome 2D.Primers was designed in the coding region of T2DG3 gene,we try to develop molecular markers which was associated with stem strength.The results can provide valuable information for MAS.The main results are summarized as following.1.The phenotypic values of stem strength were determined for two years.Analysis of variance showed that there was no significant difference between repeats,and the difference was extremely significant in wheat varieties.The correlation analysis indicated that there was a significant positive correlation in stem strength between 2013 and 2014.(r=0.441,P<0.01).2.A total of 4 markers with polymorphism were selected on the wheat chromosome 2D,and SSR markers gwm539 and barc11 were positively correlated with the stalk strength for two years(P<0.05).The physical distance was 40 cM between gwm539 and barc11,and there was a T2DG3 gene associated with lignin biosynthesis in the two marker intervals.3.A new molecular marker was developed in the coding region of T2DG3 gene.The Chinese Spring nulli-tetrasomic lines were used to test the chromosomal specificity of the primer sets,molecular markers were located on wheat 2D chromosomes.We used 174 wheat varieties for valid verification.There were 8 types of amplified fragment,namely T2DG3-1~T2DG3-8,were divided into four types as A,B,C and D.Type A contains three amplified fragments types(T2DG3-1 r=-0.15,P<0.05;T2DG3-2 r=-0.15,P<0.05;T2DG3-6 0.229,P<0.01)which playing a negative regulation on T2DG3,so stem strength with type A was lower than mean.Type C contains three amplified fragments types(T2DG3-3,r=0.265,P<0.01;T2DG3-4,R-0.15,P<0.05;T2DG3-7r=0.265,P<0.01)which playing a positive regulation T2DG3,so stem strength with type C was obviously higher than mean.Type B contains one amplified fragment type(T2DG3-4)which playing a positive regulation on T2DG3,and also contains the types(T2DG3-5+ T2DG3-8)playing negative regulation,so stem strength with type B was close to the mean.Type D contains one amplified fragment type(T2DG3-4)which playing a positive regulation on T2DG3,but contains more types(T2DG3-5+ T2DG3-8?T2DG3-6)which negative regulation on T2DG3,so stem strength with type D wasobviously lower than mean.To a certain extent,It was shown that primer T2DG3-8FR can identify the stem strength in wheat varieties.