Molecular And Cytogenetics Identification Of The Wheat-Aegilops Variabilis Introgression Lines

Aegilops variabilis（2n=4x=28,UUS^vS^v）carries a variety of wheat biotic and abiotic resistance genes,and is an important gene source for wheat genetic improvement.Moreover,the chromosome pairing level of hybrid F₁ between wheat Ph gene mutants（ph1b mutants and Kaixianluohanmai containing ph-KL gene）and Ae.variabilis is high,indicating that its excellent genes may be relatively easy to be transfered into wheat through homoeologous recombination.In this study,we used common wheat Chinese Spring to cross with Ae.variabilis accession AS24 and backcross.BC₂F₁s with alien chromosome introgression were selected.The resulted introgression lines were then crossed with common wheat Kaixianluohanmai to create introgression lines carrying ph-KL and single alien chromosome,which laid the material foundation for creating translocation lines in further.The main results obtained are as follows:1.By cytological screening,additional lines WH1-1-4 carrying 1S^v,3S^vand 5S^v and WH1-4-2 carrying 3U and 7U were selected.2.Crossing WH1-1-4 with KL and followed with backcrossing or selfing,seven 1S^vmonosomic addition lines,and nine 5S^v monosomic addition lines were successfully obtained by molecular and cytological markers screening,but there was no 3S^vmonosomic addition line.Preliminary analysis showed the ability of 3S^v chromosomes transmission through gametes was weaker than chromosomes 1S^v and 5S^v.3.Seven 3U monosomic additional lines and five 7U monosomic addition lines were selected in WH1-4-2/KL F₁s by molecular and cytological marker screening.The resulted lines were continually backcrossed with KL to increase the proportion of KL genomic.Molecular markers and cytological identification showed that 7 out of 10BC₁F₁s of 3U monosomic additional with KL carried chromosome 3U;Five of the 10BC₁F₁ of 7U monosomic addition lines with KL carried chromosome 7U.It indicated that both 3U and 7U chromosomes have relative high transmission frequencies in the wheat background.4.Molecular markers analysis showed some of the obtained introgression lines may carry ph-KL gene,laying a foundation for the creation of translocation in further.5.No HMW-GSs band corresponding to Glu-S¹x and Glu-S¹y was observed in SDS-PAGE analysis of the 1S^v monomic addition line.Further analysis using p Ta-713 and（CTT）₁₀repeat sequence probes showed that the long arm of the 1S^v may have partly deleted or recombined with other alien chromosomes.