Molecular Evaluation and Increasement of Cyst Nematode Resistance Gene Frequency During Several Generations of Self Pollination in Sugar Beet

In order to increase beet cyst nematode resistance gene frequency, one population named 261*(20314*W-1009) that contains Hs1pro-1 was used in present research. In first year, the population was planted in selection plotes in field. Single plants were labeled and leaf samples were prepared. Then DNA extraction from leaves was done and molecular analysis of plants containing resistance gene accomplished using STS marker and specific PCR test. In second year, gall signs onto resistant vernalized roots were noted and the roots were planted under cages in isolated plots to produce S1 seeds.The S1 seeds were sowed in greenhouse for molecular analysis and in the steckling field to produce the roots. The roots were vernalized in the field in winter season. The molecular results of the S1 plants by Hs1pro-1 marker showed that presence of the resistant gene among the S1 lines is varied 25 to 63 percent. In third year, the vernalized roots were planted under cages in isolated plots to produce new S1 seeds. The new S1 seeds were grown in greenhouse for molecular analysis. The molecular results of the new S1 plants by Hs1pro-1 marker showed enhancement of the resistant gene among the S1 lines that varied 39 to 80 percent. The results showed that resistance gene frequency can be increased by increasing in selfing number and genotypic selection by molecular marker.