| Barley(Hordeum vulgare L.)is one of the oldest plants in the world, its advantage in genetic and the importance in economic are regarded as the model crop about Gramineae for research. Recently, with the rapid development of brewing industry, malting barley becomes more and more important. In the development and production of malting barley, barley leaf stripe becomes more and more serious, it has a strong impact on the production and quality of malting barley. For the germplasm resources scarcity of resistant leaf stripe disease, it is important to use molecular marker assisted breeding to cultivate resistant leaf stripe of new variety.In this study, 100 barley parent materials are used to resistance evaluation and an immune material and a high susceptible material were found. The combination was establish and worked at the gene mapping through the BSA. Soon after, 42 new SSR markers were developed and analysis the polymorphism. The new leaf stripe resistance gene in barley was named Rdg3, which is not only the first domestic in China but also the third in the world. The work plays an important role in future breeding new stripe disease resistant varieties, which also has a great significance to reduce pesticide application and environmental pollution. The main conclusions are as follows:1.To understand the resistant in various barley materials, using the barley leaf stripe isolate QWC for 100 barley varieties to know the reaction. The results indicate that one immune variety was identified. There were 10 highly resistant, 22 moderately, 37 susceptible and 30 highly susceptible materials were also demonstrated. Among these materials, the immune variety was Ganpi2 which is no disease plant and the highly susceptible material was Alexis with the incidence rate of 88.24%.2. The combination from immune variety Ganpi2 and the highly susceptible material Alexis, using the resistance evaluation knew the disease percentage in F1 was zero. The F2 segregating population of barley disease with 276 plants on the basis of the combination with two materials was established, through the onset of statistical found that there were 197 disease-resistant plants and 79 disease-susceptible plants. By the chi square dictation, it can inherit in accordance the rate of 3:1 with Mendelian inheritance. It determined that the resistance genes for disease as the dominant, which showed that the stripe disease resistance gene was controlled by a single gene. There were 103 markers had the polymorphism in two parents were detected from 525 markers in 1-7H. Soon after, the SSR marker technology was applied to establish the gene pools and then the resistance gene of Rdg3 was located in the short arm of chromosome 7 by bulked segregant analysis(BSA) and linked with Bmag7, Bmag206 and scssr07970. Besides, 42 pairs of SSR primers were developed from the short arm of chromosome 7H and 6 markers showed the polymorphism in two parents materials. Then, we used the 11 SSR markers and 6 new developed markers to scan F2 population. Finally, the resistance gene Rdg3 was located between markers Bmag206 and Bmag7, and the genetic interval between Rdg3 and Bmag206 or Bmag7 are 1.78 or 2.86 c M, respectively.3. The 48 barley materials by using 42 developed SSR markers to scan polymorphism, there were 29 can be employed. A total of 125 alleles were found from 48 materials by 29 SSR markers, ranged from 2 to 9 with 4.3 loci in average and the markers Bmg24 and Bmg25 had the highest number with 9. The average genetic diversity and polymorphic information content(PIC) values observed were 0.5596 and 0.5132 respectively with a varied from 0.1462 to 0.8234, and each marker obtained with a data heterozygosity of 2.98%. |
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