| Triticum Petropavlovskyi Udacz.et Migusch.(2n=6x=42,AABBDD)is usually called Xinjiang rice wheat,which is distributed in Xinjiang autonomous region of China.Xinjiang rice wheat shows distinct characters compared with common wheat by its long spike,long glume,long grain and high grain weight.It belongs to the primary gene pool of the cultivated wheat and useful genes can be introduced into common wheat by normal hybridization and genetic recombination.In this study,a(T.petropavlovskyi akesu ×Chinese spring)RIL population was used to construct a high-density molecular linkage map using SSR and SNP markers.A(T.petropavlovskyi luopu × Yangmai158)CSSL population was constructed.Using the above two populations,QTLs for spike length(SL),glume length(GL),kernel length(KL),kernel width(KW)and thousand-grain weight(TGW)were mapped.The main results obtained were as follows:1.Polymorphism analysis between T.petropavlovskyi akesu and Chinese spring using SSR and SNP markersA total of 1,908 SSR markers evenly distributed on 21 wheat chromosomes were used for polymorphism analysis between T.petropavlovskyi akesu and Chinese spring.A total of493 polymorphic loci was identified,and the polymorphism rate was 25.84%.The numbers(rate)of polymorphic loci in genome A,B and D were 177(36.20%),184(24.05%)and132(20.18%),respectively.Axiom(?)Wheat 660 K Genotyping Array containing 630,517 SNPs was used to genotyping T.petropavlovskyi akesu and Chinese spring.A total of84,541 polymorphic SNPs were identified,and the polymorphism rate was 20.54%.The numbers of polymorphic SNPs in genome A,B and D were 32,865(21.05%),45,157(24.12%)and 6,519(9.55%),respectively.2.Construction of high-density molecular genetic map using(T.petropavlovskyi akesu×Chinese spring)RIL populationA genetic map consisted of 493 SSRs and 84,541 SNPs was constructed by linkage analysis.The map had 2,551 loci distributed on 21 chromosomes,spanned a total length of1,627.067 c M,with an average marker density of 0.638 c M.The A genome had 1,081 loci,with total and average genetic distances of 555.29 c M and 0.514 c M,respectively.The B genome had 989 loci,with total and average genetic distances of 579.594 c M and 0.586 c M,respectively.The D genome had 481 loci,with total and average genetic distances 492.184 c M and 1.023 c M,respectively.For each chromosome,the length of genetic distance ranged from 51.862 c M(1D)to 93.153 c M(6B);the number of loci ranged from 39(4D)to187(4A),and the average genetic distance ranged from 0.403 c M(3A)to 2.181 c M(4D).3.Mapping of QTLs for spike and grain-related traits using(T.petropavlovskyi akesu×Chinese spring)RIL populationUsing the phenotyping data of the RIL population in four environments,QTL were identified for different traits.Twenty two QTLs for SL were mapped.They distributed on14 chromosomes and explained the phenotypic variation ranged from 1.05%(3B)to57.54%(7A);Twenty three QTLs for GL were mapped.They distributed on 13 chromosomes and explained the phenotypic variation ranged from 1.03%(6B)to 65.28%(7A);Nine QTLs for TGW were mapped.They distributed on 7 chromosomes and explained the phenotypic variation ranged from 1.51%(6B)to 55.39%(7A);Sixteen QTLs for KL were mapped.They distributed on 12 chromosomes and explained the phenotypic variation ranged from 4.24%(1D)to 56.53%(7A);Nine QTLs for KW were mapped.They distributed on 9 chromosomes and explained the phenotypic variation ranged from 11.07%(4D)to 51.48%(7A).4.Mapping of QTLs for spike and grain-related traits using(T.petropavlovskyi luopu×158)CSSL populationExtreme pools for four traits(long and short spike,long and short glume,long and short kernel,high and low thousand-grain weight)were constructed using CSSL lines and use for genotyping by Axiom(?)Wheat 660 K Genotyping Arrays.A total of 1,704 SNPs for SL were predominantly distributed on chromosomes 2DL(600,035,480-609,778,224)and7AL(510,551,798-514,716,981).A total of 643 SNPs for GL were predominantly distributed on chromosome 7AS(126,174,703-138,960,124).A total of 4,090 SNPs for KL were predominantly distributed on chromosome 1DS(13,059,013-15,876,340),3BS(335,867-7,605,846),7AS(126,174,703-138,960,124;146,466,732-154,870,704)and 7AL(484,081,129-497,735,199;510,551,798-514,716,981;533,145,418-538,849,795).A total of 1,026 SNPs for TGW were predominantly distributed on chromosome 1DS(13,059,013-15,876,340)and 7AS(126,174,703-138,960,124).We predict the above chromosomal regions contain QTLs contributing to corresponding traits.5.Prediction of genome regions contributing to investigated traits combining the results from the two populationsQTLs on chromosomes 1DS,3BS,7AS and 7AL could be detected in the two populations across different environments.Major QTLs controlling KL were located on chromosome 1DS and 3BS.A major QTL controlling SL and GL was located on chromosome 7AS.A major QTL controlling SL and KL was located on chromosome 7AL.We propose these regions may contain important gene clusters,either have pleitrophic effects or have different genes controlling more than one trait. |
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