Construction Of Genetic Linkage Maps Of Silver Birch Based On Aflp Markers

White birch was a wood species of high quality,fast-growing and strong adaptability, and has been wide used in the world wide. In order to meet the need of forestry production, the molecular breeding and construction of genetics and mapping were the most fundamental work on white birch. Through the comparing among several molecular techniques, we found that AFLP technique has the following merits such as high polymorphism, high stability, good repeatability, fair resolution, low quantity of needed DNA and simple operation, suggest that the technique is thought to be proper for the research.Female parent, Betula platyphylla Suk from China, and male parent, Betula pendula Roth from Finland were selected. Analysis of random amplified polymorphism DNA (RAPDs) showed two parents held high genetic polymorphism. Parent selection and artificial pollination were performed, and 78 out of 400 plants were randomly selected in the present study. Based on the inheritance and segregation of amplified fragment length polymorphism (AFLP) markers, the linkage map for silver birch was constructed by using a pseudo-testcross mapping strategy. A set of 64 primer combinations were screened, and 45 pair primer combinations were selected to generate AFLP markers within a sample of 78 F1 progenies. A total of 343 segregating sites were identified. Among the identified sites,311 segregating sites belonged to 1:1 segregating site including 143 sites for B. pendula and 168 sites for B. platyphylla. The resulting linkage maps were consisted of 168 marker sites in 9 groups,11 triples,14 pairs, which covered the map distance about 1909.2 cM (Kosambi units). The average map distance between adjacent markers was 16.9 cM.143 linked marker-sites of B. pendula were mapped onto 12 groups,4 triples,9 pairs, which covered the map distance about 1857.3 cM. The average map distance between adjacent markers was 15.2 cM. This map may be used for QTL analysis and molecular assistant selection in birch breeding in the further studies.