TAXONOMICAL AND MORPHOLOGICAL ASSESSMENTS OF INFRA-SPECIFIC DIVERSITY IN CULTIVATED FLAX (LINUM USITATISSIMUM L.)

Agrobiodiversity research and efficient genebank management need tools for qualitative and quantitative assessments of crop diversity at the infra-specific level. For 2,748 accessions of flax (Linum usitatissimum L.) from the collection at Plant Gene Resources of Canada (PGRC) a grouping at the infra-specific level into four convarieties and 26 botanical varieties was conducted. Alternatively, for 2,545 accessions, genetically distinct morphological groups were defined using seven highly heritable morphological characters with 19 distinct character states. Both methods showed concentration towards a few phenotypic groups within the flax collection. Both methods also indicated a reduction of phenotypic diversity over time within 61 North American flax cultivars released during the 20(th) century. The results of the infra-specific classification showed that the same phenotypic groups dominated the flax accessions held in the German (Leibniz Institut fur Pflanzengenetik und Kulturpflanzenforschung, IPK) and the Canadian (PGRC) national seed genebanks. The assessment of functional diversity within large genebank collections remains an urgent task. The methods applied here can be used to survey large germplasm collections or subsets of the flax gene-pool.