Isolation and characterization of polymorphic microsatellite markers from flax (Linum usitatissimum L.)
Flax (Linum usitatissimum L.) is the third largest natural fiber crop and one of the five major oil crops in the world. Flax can be used as model plant for the bast fiber plants because of its small size and self pollination characters. Development of highly polymorphic co-dominant markers will be important for the molecular and genomic research in flax. Two microsatellite-enriched flax genomic libraries were constructed for trinucleotide TTC and ATC motifs. A total of 206 new microsatellite-containing sequences were identified and classified. Thirty eight polymorphic microsatellite markers were characterized and evaluated in eight cultivars from different countries and regions. These loci produced 2 to 12 alleles per locus with an average of 3.395. The observed and expected heterozygosities ranged from 0.000 to 1.000 (mean 0.257) and from 0.125 to 0.950 (mean 0.516), respectively. The mean polymorphic information content (PIC) value over 38 loci was 0.429, with 13 loci
having PIC greater than 0.5. These novel polymorphic microsatellite loci will be useful in genetic linkage map construction, germplasm classification and identification, gene identification and QTL mapping, and marker-assisted selection in breeding of L. usitatissimum.
Key words: Flax, Linum usitatissimum, microsatellite, polymorphism.