Molecular Cytological Identification Of Aegiops Comosa Derivative Line,Agronomic And Quality Traits Analyzation Of 1M/1D Substitution Line

The Aegilops genus is one of valuable genetic resources for genetic improvement of wheat.Aegilops comosa?2n=2x=14,MM?is a diploid species that harbors genes or loci associated with various diseases resistance and quality improvement of wheat.Ae.comosa and Ae.uniaristata are two species sharing similar phenotype in Comopyrum section.PI 554419,formerly classified as Ae.uniaristata,however,the leaf color,length and width of this accession in seedling stage showed significant difference with other Ae.uniaristata and Ae.comosa accessions and behaved as an intermediate type.The spike characteristic of PI 554419 was similiar to Ae.comosa but different to Ae.uniariststs.In this study,we reclassified PI 554419 as Ae.comosa by comparing the fluorescence in situ hybridization?FISH?signals,and the patterns of PCR-based landmark unique gene?PLUG?markers and conserved orthologous set?COS?markers of PI 554419with other Ae.uniaristata and Ae.comosa accessions.Some derivatives with alien M chromosomes from PI 554419 were identified from distantly hybridization crosses between common wheat and T.turgidum-Ae.comosa amphidiploid PI 94668/PI 554419 by molecular cytological method.Finally,a substitution line NB4-8-5-9 was obtained.Further,the agronomic and grain traits,and flour processing quality properties of NB4-8-5-9 in two different places in 2018 were compared with its common wheat parents.The main results are as follows:1.The FISH signals of pSc119.2 and pTa713 of PI 554419 showed higher similar to four Ae.comosa than five Ae.uniaristata accessions.Similarly,the patterns of three PLUG from Ae.uniaristata and two COS markers from Ae.comosa of PI 554419 were similar to Ae.comosa accessions but dissimilar to Ae.uniaristata accessions.Thus,PI 554419 should be reclassified to Ae.comosa.2.Alien M chromosomes were identified from some PI 554419 derivatives.In F₂generation of PI 94668/PI 554419//CSph2b crosses,we obtained eight different derivative types with one to four M chromosomes combinations from 1M,2M,3M,and7M,respectively.Further,a substitution line,NB4-8-5-9,was identified from the BC₂F₃generation of multiple crosses of PI 94668/PI 554419//CSph1b///CM 39////13P2-6.3.FISH and Sodium dodecyl sulfate polyacrylamide gel electrophoresis?SDS-PAGE?results suggested that the NB4-8-5-9 was a 1M/1D substitution line.This substitution line contains four high molecular weight glutenin subunits,of which the subunits 17+18originated from the Glu-B1 of CM39 and the Mx+My subunits derived from the Glu-M1of PI 554419.In year 2018,the 1M/1D line NB4-8-5-9 and its parents were planted in Wenjiang and Chongzhou.The agronomic,grain traits and the processing quality properties of NB4-8-5-9 and its common wheat parents were evaluated.Results showed that NB4-8-5-9 were significantly higher than three parents in terms of spike length,grain length and grain length/width.NB4-8-5-9 was significantly higher than CSph1b in terms of thousand grain weight,grain width,projected area,grain hardness index,gluten index and dry gluten in two places as well as wet gluten and dough stability time in Wenjiang,and it also showed no significant difference with CSph1b in terms of plant height,dough develop time and valorimeter value in two places as well as number of spikelets,Zeleny sedimentation value,wet gluten and dough stability time in Chongzhou.NB4-8-5-9 was significantly higher than 13P2-6 in terms of plant height,number of tillers,wet and dry gluten in two places as well as dough develop time in Chongzhou and dough stability time in Wenjiang;NB4-8-5-9 performed no significant difference with 13P2-6 in terms of number of spikelets,thousand grain weight,projected area,grain hardness index,protein content,weakening degree and valorimeter value in two places and dough develop time in Wenjiang as well as gluten index,grain width,water absorption and dough stability time in Chongzhou.NB4-8-5-9 were significantly higher than CM39 in terms of number of tillers and weakening degree in two places,projected area in Wenjiang and plant height in Chongzhou;NB4-8-5-9 showed no significant difference with CM39 in terms of number of spikelets and thousand grain weight in two places and plant height in Wenjiang as well as projected area and gluten index in Chongzhou.