CGN coriander collection

History

The collection was originally assembled by the former institute CPRO (Centre for Plant Breeding and Reproduction Research) in Wageningen. In the late 1990s, it was transferred to CGN. At CGN, the collection remained inactive (‘dormant’) in storage for more than 30 years. Part of the collection was transferred to USDA-ARS in the United States, where the accessions are also maintained. In 2025, the coriander collection at CGN was reactivated. Despite the long storage period, the seeds were found to be in good condition and are now available for distribution.

Composition

The CGN coriander collection consists of a modest number of accessions, including breeding material, landraces, and wild types. In the coming years, the collection will be further expanded in terms of size, geographical origin, and genetic diversity.

Regeneration

Coriander is typically grown as an annual crop, although some genotypes may exhibit a biennial growth cycle under certain conditions. Flowering is influenced by day length and temperature and can be promoted in some accessions through vernalisation.

Seeds are sown in trays in September. If germination is poor, a cold treatment of one week in the refrigerator can enhance germination capacity. After 3–4 weeks, the seedlings are transplanted into larger pots. Before flowering, the plants are transferred to an insect-proof isolation cage in an unheated greenhouse to prevent cross-pollination between accessions.

Coriander has hermaphroditic flowers and is predominantly self-pollinating, though cross-pollination may occur—especially in genetically diverse populations or when different accessions flower simultaneously. Insects such as bees and flies contribute to pollination and enhance seed set. For regeneration, a minimum of 40 plants per accession is used, with a preferred number of 60 plants, to maintain sufficient genetic diversity.

Pollination can be supported by repeatedly introducing pollinating insects, particularly to ensure coverage of late-flowering plants. After seed maturation, seeds are harvested, dried, and cleaned using sieves and air flow. Germination capacity is then tested to assess seed quality.

Characterisation & evaluation

The CGN coriander collection was recently reactivated and has not yet been extensively characterised or evaluated. In the future, the material will be systematically assessed, including through characterisation field trials.