Translocation Of Desirable Glutenin Subunits From Aegilops Longissima To Wheat Genome And Bread-making Quality Analysis

Wheat is one of the world's three most important food crops.It is the staple food of about one third of the world's population.Its dough unique stickiness and elasticity make it possible to make bread,noodles,bread,biscuits,cakes and other foods.High molecular weight glutenin subunit?HMW-GS?is one of the important components of wheat grain storage proteins,which affects dough's elasticity and processing quality.Aegilops longissima,as a diploid species of the Aegilops genus,is an important specie that is closely related genomic of wheat.The most important is that Aegilops longissima contains a large number of excellent genes,and these genes can be used for genetic trait improvement in common wheat and improve wheat processing quality and its ability adapting to biotic stress and abiotic stress environments.This study was designed to induce the whole-arm translocation line between chromosome 1B of wheat and chromosome 1S^l of Aegilops longissima through the technique of somatic variation population and to develop long and short arm-specific molecular markers to Aegilops longissima chromosomes.Then,the arm specific molecular markers to 1S^l chromosome were.used to screen the progenies of the somatic variation populations for producing wheat-Aegilops longissima1S^lL·1BS homozygous translocation lines(20II^W+1II^1SL+1BS)and 1S^lS·1BL homozygous translocation lines(20II^W+1II^1SS+1BL).At the same time,preliminary quality trait analysis of the two types of homozygous translocation lines was conducted in this study.The main findings of this investigation are as follows:1.The F₁ hybrid immature embryos for 15 days post pollination after the crossing between wheat-Aegilops longissima 1S^l?1B?substitution line CB-SLB(2n=42,20II^W+1II^1S)as male parent and Australian wheat variety Westonia as female parent were cultured on callus induction medium.The produced calluses were subcultured twice to induce whole-arm translocation between the 1B chromosome of wheat and the 1S chromosome of Aegilops longissima.Then the calluses were cultured on differentiation medium.A total of 755 regenerated plants were obtained,and somatic variation population was created.The plant regeneration rate was 181%.2.RNA was extracted from Aegilops longissima leaves and a cDNA library of Aegilops longissima was established,followed by Illumina HiSeq sequencing.Finally,54299378 Raw Reads and Clean Reads and 8.14G Clean bases were obtained.After splicing the above Clean Reads,102395 unigenes were obtained.The unigenes'N50 and N90 were 649bp and 236bp,respectively.3.By using the transcriptome sequence of Aegilops longissima and a set of wheat-Aegilops longissima addition lines of DA1S^l#3,DA2S^l#3,DA3S^l#2,DA4S^l#3,DA5S^l#3,DA6S^l#3 and DA7S^l#3,a series of specific molecular markers to each arm of Aegilops longissima chromosomes 1S^l-7S^l were developed,in which a common wheat line Chinese Spring?CS?and a Aegilops longissima line PI542196 were used as controls.Finally,a total of 134 specific molecular markers to each chromosome arms of Aegilops longissima were developed.The molecular markers for the chromosome arm of 1S^lL,1S^lS,2S^lL,2S^lS,3S^lL,3S^lS,4S^lL,4S^lS,5S^lL,5S^lS,6S^lL,6S^lS,7S^lL and 7S^lS are 11,10,17,5,4,8,8,7,29,8,11,4,7,and 5,respectively.4.Using the developed molecular markers specific to 1S^lL,1S^lS,1BL,and 1BS and in situ hybridization the somatic variation population between CB-SLB and Westona was screened.Three wheat-Aegilops longissima 1S^lS?1BL homozygous translocation line(20II^W+1II^1SS+1BL)were obtained from 986 TC₂ populations.Among 831 TC₃ population plantss,one wheat-Aegilops longissima1S^lL?1BS homozygous translocation line(20II^W+1II^1SL+1BS)was obtained.One wheat-Aegilops longissima 1S^lL?1BS homozygous translocation line(20II^W+1II^1SL+1BS)was obtained in 1140 TC₄population plants.The efficiencies for obtaining the target translocation lines in the three populations are 0.3%,0.12%,and 0.088%,respectively.5.The 1Sx2.3 and 1Sy16 genes were identified to be successfully expressed in the 1S^lL?1BS homozygous translocation lines by SDS-PAGE.By preliminary quality analysis of the two kinds of translocation lines,it was found that the dough strength and gluten strength of the 1S^lL?1BS translocation lines were weaker than those in their similar control material.But the dough strength and gluten strength in the 1S^lS?1BL translocation lines were stronger than those in their corresponding control material.In addition,it was found that the total protein content in the translocation lines grown in Beijing is generally higher than the same materials grown in Yunnan.