| Wheat is an important crop.A part of wheat is difficult to satisfy human needs,due to prone to lodging and have weak resistance to diseases and pests,which limits the grain yield.Dwarf wheat has the advantages of high grain yield,lodging resistance,disease and pest resistance,drought resistance,salt and alkali resistance,which has good breeding potential.During the"green revolution",the research on dwarfing wheat and dwarfing genes has made progress.A total of 25 dwarf Rht genes（Rht1～Rht25）were found,but only Rht1,Rht2 and Rht8 were used in genetic breeding.In general,dwarf wheat resources are still insufficient,and the research degree of dwarf gene is not enough,especially tetraploid dwarf wheat with high nutritional value in grains,which is seldom used in actual breeding.It is necessary to explore new dwarf sources,identify new dwarf genes,strengthen research of the existing dwarf resources and dwarf genes.Durum wheat ANW16G carries the dwarf gene Rht18,which is an important tetraploid dwarf resource.But there are few studies on ANW16G.In order to strengthen the research and application of tetraploid dwarf wheat,develop dwarf genes with breeding value and analyze the genetic law of controlling plant height genes.In this study,210 F2 populations were obtained by the cross of dwarf wheat ANW16G and tall wheat LD222.The main gene+polygene quantitative genetic analysis was carried out on the plant height and internode length of F2 population.The genetic map was constructed by FSRAP and SSR markers with QTL mapping.The following results were obtained:1.The plant height and its correlation traits of F2 population showed continuous skewed distribution,which accorded with the genetic characteristics of quantitative traits.The plant height and the internode length of each stem showed significant positive correlation,and the correlation between the plant height and the last internode length was the highest.Plant height is an additive dominant epistatic genetic model controlled by two major genes,and the internode length of each stem is an additive dominant genetic model controlled by one major gene.2.1936 pairs of FSRAP primers were screened by parents,170 pairs of primers with obvious polymorphism and high stability were screened out.A total of 245polymorphic loci were detected.The number of polymorphic loci detected by each pair of primers is between 1 and 6,and a few primers can detect about 10 polymorphic loci.397 pairs of SSR primers were screened by parents,among which 87 pairs were significantly different from each other,and each pair of primers detected 1-3polymorphic loci.3.A tetraploid dwarf wheat genetic map was drawn,overall length of 1860.2cM,including 14 linkage groups（group1-group14）,7 of these groups（group1-group7）were distributed on chromosomes 1A,2A,3A,4A,5B,6A and 6B,but the other 7 groups（group8-group14）failed to locate chromosomes.A total of 146 markers were anchored in the genetic map,including 138 FSRAP markers and 8 SSR markers.The average genetic distance between the markers was 12.7cM,and the group 6 linkage had the largest number of superscripts,with 28 markers.The total genetic distance was 203.8cM,and the average genetic distance between the markers was 7.2cM,which was located on the 6A chromosome.The group 4 linkage has the longest total genetic distance,285.8cM,including 14 markers.The average genetic distance between markers is20.4cM,which is located on 4A chromosome.4.A total of 30 QTLs of plant height and internode length were detected,which were distributed on chromosomes 1A,3A,4A,6A and 6B,among of 4 were major QTLs.There are 9 QTLs control plant height,including 1 major QTL.The LOD value ranges from 3.01 to 5.55,which are distributed on chromosomes 1A,3A,4A and 6A.There are also 9 QTLs control the length of the 1th internode,which are distributed on chromosomes 1A,3A,6A and 6B.The LOD value ranges from 3.03 to 6.45,and 2 of them are major QTLs.One QTL controls the length of the 2th internode and was located on chromosome 1A,the LOD value was 4.03.There are 5 QTLs controlling the length of the 3th internode,one of these is the main QTL,and the LOD value is between 3.17and 5.03,distributed on 1A,3A and 4A chromosomes.There are four QTLs control the length of the 4th internodes,the LOD value is between 3.39 and 3.55,and they are also distributed on 1A 3A and 4A chromosomes.There are two QTLs control the length of the 5th internode,the LOD value is 3.22-3.65,which are distributed on the 3A chromosome.All the QTLs showed additive effect,and most of them showed negative effect,indicating that these QTLs were mainly from the dwarf parent ANW16G,control the height of the plant reduce,and there were QTLs enrichment on chromosome 1A and3A. |
