| Wheat（Triticum aestivum L.）is one of the three most important food crops in the world.With the continuous development of modern breeding practices,the genetic diversity of wheat varieties has become narrow,which not only becomes the focus of wheat variety improvement,but also poses a serious threat to national food security production.As a wild relative of wheat,Thinopyrum species are rich in resistances to various kinds of biotic and abiotic stresses.It is an important topic in wheat distant hybridization and chromosome engineering breeding to explore and utilize their alien genes to develop the wheat-Thinopyrum species translocation lines.In this study,molecular cytogenetic analysis were carried out on 86 newly created translocation lines,and disease resistance assessment 31wheat-Thinopyrum species translocation lines with excellent disease resistance were screened out to provide new germplasm resources for wheat disease resistance breeding,which laid a foundation for the theory study and breeding practices of the wheat-Thinopyrum translocation lines.The specific results are as follows:1.GISH was used to analyze the number and type of translation chromosomes in the 86 wheat-Thinopyrum species translocations lines.The results showed that the chromosome number of 40 and 35wheat-Th.ponticum translocation lines were 42 and 44,respectively.The translocation types were diverse,including 31 small fragment translocation lines,22 large fragment translocation lines,19 whole arm translocation lines,4 insertion translocation lines and 3 reciprocal translocation lines and 7 complex translocation lines.The wheat translocated chromosome fragments were involved in 18 wheat chromosomes except 1D,4B and 7B by using FISH analysis.Statistics analysis showed each wheat chromosome,genome and homologous group participating in the simple and reciprocal interspecies translocations.A total of 19 wheat A-genome chromosomes were the most involved in translocation;followed by 18 D-genome chromosomes and 16 B-genome chromosomes.group-2 chromosomes were mostly involved in the translocations with a number of 11,and group-7chromosomes were leastly involved in the translocations with a number of 2.Translocations to wheat chromosome 4D were mostly abserved with a number of 6.2.The stripe rust race CYR34 was used to assess 76wheat-Thinopyrum translocation lines for resistance to stripe rust at the seedling stage,and 3 lines with stripe rust resistance were screened out.The leaf rust race THTT was used to evaluate 176 wheat-Thinpyrum translocation lines for resistance to leaf rust at the seedling stage,and 28 lines against leaf rust were screened out. |
