Abstract: Flax (linum usitatissimum) is one of the major fibre and oil yielding crops. AFLP is very useful molecular marker for a number of plant species. To reveal the genetic diversity and find ways to broaden the genetic background of Chinese fibre flax varieties, we analyzed 18 Chinese fibre flax cultivars and other 67 accessions (including linseed, landrace and wild species) from different countries in the world by using AFLP marker. In total, 168 polymorphic alleles were detected with seven pairs of AFLP primer. For each pair of primer, 24 alleles on the average was detected in all accessions. Unweighted pair-group method with arithmetical averages (UPGMA) cluster analysis was used to estimate the genetic distances and to construct a dendrogram by NTSYS 2.1. The results showed that all 85 accessions were classified into four groups at 0.53 of similarity coefficient, which distinguish the varieties of flax (Linum usitatissimum) from three wild flax species. All varieties of flax were classified into five sub-groups (all fibre flax accessions were in one sub-group and the most of linseed accessions divided into other four sub-groups) at 0.67, indicating linseed possessed genetic basis broader than the fibre flax. In Chinese fibre flax varieties, Heiya cultivars had high genetic similarity, and its genetic basis was narrower than that of Shuangya variety. The results also showed that there were close relationship between Linum bienne and Linum usitatissinum, and sustained the hypothesis that fibre flax has evolved from linseed.

Key words: Flax germplasm, Genetic diversity, Relationship, AFLP marker