Evaluation The Quality Of A Disomic 1U/1B Triticum Aestivum-Aegilops Umbellulata Substitution Line

Aegilops umbellulata(2n = 2x = 14,UU)is an important diploid species of Aegilops Linn.,which contains several valuable genes for genetic improvement of wheat.The 1U chromosomes of Ae.umbellulata contain high molecular weight glutenin subunits(HMW-GS)with abnormal molecular sizes than those of wheat,which maybe used to improve the processing quality of common wheat.To evaluate the quality effect of 1U chromosome of Ae.umbellulata,we obtained a disomic1U/1B Triticum aestivum-Ae.umbellulata substitution lines in previous investigations.In this study,we further verified this substitution line by molecular cytological analysis,sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE),and reverse phase-high performance liquid chromatography(RP-HPLC)techniques.Further,the disomic 1U/1B T.aestivum-Ae.umbellulata substitution line 1266 and its three hexaploid wheat parents were planted in two loactions(Wenjiang and Chongzhou)in the two planting seasons of two consective years.The main agronomic and seed-size related traits,processing quality,and the contents gluten proteins[HMW-GS,low-molecular-weight glutenin subunits(LMW-GS),and gliadins] and gluten polymers [including extractable-(EPP)and unextractable-protein ploymers(UPP)] and the ratios among ingridents,starch gelatinization parameters,gluten microstructure,and quality parameters of steamed bread and bread products were tested and compared.The main results are as follows:1.Fluorescence in situ hybridization(FISH)confirmed that wheat line 1266 was a disomic 1U/1B T.aestivum-Ae.umbellulata substitution line.SDS-PAGE detected the Ux and Uy subunits originated from Ae.umbellulata PI 226500,and no HMW-GS were found at the Glu-B1 of the disomic 1U/1B T.aestivum-Ae.umbellulata substitution line.The metaphase pairing of pollen mother cells of 1266 was normal.RP-HPLC results showed that the absorption peaks in the glutenin and gliadin regions of 1266 were similar to those in Ae.umbellulata PI 226500,suggesting that these proteins may be derived from the 1U chromosomes.2.Major agronomical and seed-size related traits were tested and compared for the disomic 1U/1B T.aestivum-Ae.umbellulata substitution line 1266 and its three common wheat parents CSph1 b,Shumai 126,and Mianmai 37.The results showed that the disomic 1U/1B T.aestivum-Ae.umbellulata had better agronomical and seedsize traits than the parent CSph1 b,including shorter plant height,longer spike length,and larger 1000-grains weight.Compared with the parents Shumai 126,and Mianmai37,the disomic 1U/1B T.aestivum-Ae.umbellulata substitution line 1266 had shorter plant height than Shumai 126,and its agronomical and seed-size related traits were very similar to Shumai 126 and Mianmai 37 except for 1266 had decreased 1000-grain weight than Shumai 126.3.Processing quality test showed that the disomic 1U/1B T.aestivum-Ae.umbellulata had better processing quality parameters than the three common wheat parents CSph1 b,Shumai 126,and Mianmai 37,such as higher protein content and wet gluten content and longer dough stability time.4.The contents of amylose and amylopectin in the disomic 1U/1B T.aestivumAe.umbellulata substitution lines 1266 were similar to those of the three common wheat parents except for 1266 had higher peak viscosity than that of all the three common wheat parents.5.Microstructure image analysis showed that the disomic 1U/1B T.aestivum-Ae.umbellulata substitution line 1266 had higher protein junctions,junction density,and branching rate than those of the three common wheat parents,suggesting that transferring the 1U chromosomes of Ae.umbellulata may result in more protein connections and more cross-links in the gluten networks,and this result was further verified by scanning electron microscopy of wheat dough.6.The quality of finished steamed bread showed that the hardness and chewability of the disomic 1U/1B T.aestivum-Ae.umbellulata substitution line 1266 were higher than those of the Shumai 126,and Mianmai 37,but lower than that of the CSph1 b.The disomic 1U/1B T.aestivum-Ae.umbellulata substitution line 1266 had larger bread volume than all the three common wheat parents.Further,the disomic1U/1B T.aestivum-Ae.umbellulata substitution line 1266 had lower ratios of large stomata to small stomata than all three common wheat parents,suggesting that bread slices of 1266 had a closer arrangement of stomata and improved bread strength than that of the three common wheat parents.Thus,the disomic 1U/1B T.aestivum-Ae.umbellulata substitution line 1266 had potential to value in improving steam bread and bread in comparision with all three common wheat parents.