Comparison of genetic diversity of flax (Linum usitatissimum L.) between Canadian cultivars and a world collection

This study reports results of phenotypic measurements of genetic diversity in the world collection of flax maintained by Plant Gene Resources of Canada (PGRC) and compares the range of diversity in the world collection with the diversity observed in 19 Canadian registered flax cultivars. Morphological and seed-oil characters were used to describe the phenotypic diversity in 2331 flax accessions. The plants were grown by PGRC at Saskatoon, Saskatchewan, Canada, in 1998 and 1999. The comparison between the Canadian cultivars and the world collection was based on single characters, as. well as on character complexes by application of an existing intraspecific classification for the species. Considering single quantitative or qualitative character expressions, the Canadian cultivars represented a wide range in diversity for the species. The variation of characters Canadian plant breeders have selected for (e.g. plant height. seed weight, seed colour, petal colour, oil content) was reduced further than those characters not focused on by plant breeders (e.g. dotting of the sepals. style colour, ciliation of capsule septa, oil quality characters). A comparison of diversity based on the intraspecific classification proposed for flax by Kulpa and Danert, who described 28 botanical varieties, showed that all Canadian cultivars belong to two botanical varieties. This study demonstrates the usefulness of agrobotanical characterization of genebank collections for plant breeding and illustrates the application of the traditional method of intraspecific classification for comparison of gene pools.