Construction Of Wheat Genetic Map Using EST-SSR Molecular Markers

Genetic maps play a significant role in the genetic improvement of crops,acceleration the breeding process,location of functional gene cloning.With the continuous development of modern molecular biology,increasing number of molecular markers have been developed.Molecular marker-assisted breeding has brought new methods and approaches to breeding.In this study,the recombinant inbred lines?RILs?populationwhichobtainedbycrossing Syn-SAU-1 and three pistil mutant?TP?were used as the materials.Two genetic maps of wheat were constructed using EST-SSR markers and combining previous molecular markers.The main results are as follows.1.585 EST-SSR primers were used to amplify theindividuals of RILs and their parents,of Chuanmai 42 and Chuannong 16 and their hybrids.Among them,555 pairs of primers had amplification products,and the effective rate of amplification is 94.87%.69 pairs of primers showed polymorphism in both parents with 11.79%poly morphism rate.2.The genetic linkage map was constructed in Joinmap vision 4.0 with the RILs population of the Chuanmai 42×Chuannong 16.A total of 169 markers were mapped to 14 linkage group,including 73 FSRAP markers,76 SSR markers and 20 EST-SSR markers.The genetic map was 1680.2 c M long,and average distance between two markers was 13.24 cM.The map contains 14 linkage groups,which consist of 169markers and including,cover a genome length of 1680.2 cM with an average distance between markers of 13.24 cM.The EST-SSR markers mainly distributing on the 1B chromosome,with 4 markers,followed by1A and 4A chromosome,2 EST-SSR markers each.While,only one EST-SSR marker located on 3A,5A,6A,7A,2B,3B,4B,5B,3D,6D and 7D,respectively.3.Syn-SAU-1 and three pistil mutant?TP?and their hybrid F₂ populations were amplified by PCR using 230 pairs of SSR primers.A total of 710 alleles sites were detected,and an average of 3 alleles sites were amplified by each pair of primers.The highest polymorphism was found in the D genome group?74.0%?,followed by B genome?60.5%?,A genome is the lowest,only 59.7%.4.317 pairs of EST-SSR primers were used to amplify the Syn-SAU-1 andTP and their F₂ population.Among them,60 pairs of primers showed polymorphism,accounting for18.92%.Using the above SSR markers and EST-SSR markers,the genetic map of wheat was constructed using the F₂ population of TP×Syn-SAU.The map consisted of5 linkage groups consisting of 26 markers,including 9 SSR markers and 17 EST-SSR markers,covering a genome length of 1023.7 cM and an average distance between markers was 39.37 cM.