Development And Analysis Of Introgression Lines On Chromosome 4H-7H In Barley (Hordeum Valgare L.)

Bariey (Hordeum vulgare L.) is the fourth largest crop in China, which is used as the main raw material for beer industry, and it plays an important role in the development of national economy. Nowadays breeders are faced with a plight of the narrow genetic base of parents. In order to achieve breakthroughs in breeding, it's essential to strengthen the introduction of genetic resources and the understanding and control of the genetic basis of agronomic traits. Wild germplasm resources are rich in genetic variations, which by fully exploiting the favorable genes and using for breeding have important theoretical and practical value. It is important to construct a reasonable mapping population and position QTL precisely for exploiting the favorable genes of wild resources.In this research, one set of introgression lines (ILs) was selected with molecular marker-assisted selection from BC1F2 population, which was constructed by backcrossing candidate introgression lines with Scarlett and letting F1 plants self. This set of introgression lines covered chromosome 4H-7H genome of wild barley ISR42-8, the introgressions per line of which were fewer than candidate introgression lines, having shorter target introgression segments, to detect the favourable genes in introgressions and expand barley germplasm resources. The main results are as follows:1. The genetic linkage map of barley, using 96 markers'information, was mapped out. The inferred marker linkage map covered 1,089 cM with an average marker density of 11.3 cM.96 markers distributed in seven different chromosomes genome of barley in this linkage map, which contained 18 and 17 markers, respectively, in chromosome 4H and 7H. Nine markers were at chromosome 6H, which were the fewest.2. One set of 37 introgression lines (ILs) was selected from BC1F2 population. The ILs contained, on average,1.8 introgressed segments and 3.5%(38.5 cM) of exotic germplasm and the average length of the target introgressions was 26.2 cM, with a general coverage of wild barley ISR42-8 in the chromosome 4H-7H genome but lack of introgression fragments of some markers.3. The trait performances of 45 ILs were different from the characters of Korff's research, as planted in different environment, mainly for the difference of the early flowering between the specific lines and the difference of flowering date in advance.