Schriften zu Genetischen Ressourcen - Genres

A. DIEDERICHSEN, D. KESSLER, P. KUSTERS, J.P. RANEY and K.W. RICHARDS
Genetic diversity and infraspecific classification in flax (Linum
usitatissimum L.)
A. DIEDERICHSEN, D. KESSLER, P. KUSTERS, J. P. RANEY and K.W. RICHARDS 1
Introduction
The distinction between fibre flax and linseed is based on agrobotanical differences and
is of great practical value for efficient communication in agronomy and trade. Characterisation
and evaluation data of the flax world collection at Plant Gene Resources of
Canada (PGRC) as presented here are discussed in terms of infraspecific 2 groupings.
Infraspecific taxa in flax can be used as units to quantify biodiversity and as tool to manage
genebank collections or to discuss biodiversity related issues (DIEDERICHSEN and
RICHARDS 2001). Based on the biological species concept, cultivated flax, Linum usitatissimum
L. subsp. usitatissimum, and its wild progenitor, pale flax, Linum usitatissimum
L. subsp. angustifolium (Huds.) Thell., are combined into one botanical species
(HAMMER 2001). LINNAEUS (1753) distinguished in his “Species Plantarum” four botanical
varieties of cultivated flax based on morphological differences. Early botanists proposed
separate species names for oil-seed flax (Linum humile Mill.) and flax with
spontaneously opening capsules (Linum crepitans Boenningh.). ALEFELD (1866) described
eleven varieties of cultivated flax, HOWARD (1924) grouped Indian flax into 26
botanical varieties, and ELLADI (1940) described 119 botanical varieties. Later agrobotanists
recognised that too much taxonomic splitting caused confusion. DILLMAN
(1953) distinguished ten infraspecific groups with several varieties in a mixed formal
and informal classification. KULPA and DANERT (1962) reduced the number of botanical
varieties to 28 belonging to four convarieties and the most recent formal infraspecific
classification by CERNOMORSKAJA and STANKEVIC (1987) distinguished five subspecies
of cultivated flax.
1 Plant Gene Resources of Canada
Agriculture and Agri-Food Canada
Saskatoon Research Centre, 107
Science Place, Saskatoon, SK
S7N 0X2, Canada
2 The terms infraspecific and intraspecific can be considered as synonyms. The word infraspecific
(= below the species level) is used here. The taxonomic system is considered to represent a hierarchical
structure, and the word intraspecific (= within the species) does not indicate this as clearly.
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