CGN fennel collection

Composition

The fennel collection is one of the newest crop collections at CGN. It includes material from breeding companies, seed producers, other gene banks, and research institutes. Wild fennel material was collected in Albania (2022–2023) and North Macedonia (2024). In the coming years, the collection will continue to expand in terms of accession numbers, origins, and fennel types.

Regeneration

Fennel is a biennial crop that is typically sown around September for seed production. Flowering requires a period of cold (vernalization) during the early growth stages of the plant. If germination is poor, a cold treatment of one week in a refrigerator can enhance germination.

After 3–4 weeks, seedlings are transplanted into larger pots. Following vernalization but before flowering, plants are transferred to insect-proof isolation cages in an unheated greenhouse to prevent cross-contamination between accessions. Fennel is a strong cross-pollinator and protandrous, making proper isolation crucial to ensure genetic integrity.

For regeneration, approximately 80 plants per accession are used for wild material, with a minimum of 40 plants. For cultivated material, a slightly smaller population size of around 60 plants per accession is considered sufficient, with a minimum of 40 plants.

Pollination is facilitated by flies or bumblebees, which may need to be introduced multiple times to ensure adequate pollination of late-flowering plants. Flowering and seed ripening may extend over several weeks. After seed maturation, seeds are harvested, dried, cleaned using sieves and air blowing, and tested for germination to assess quality.

Characterisation & evaluation

The CGN fennel collection has not yet been extensively characterized or evaluated. In the future, characterization fields will be used to comprehensively assess the collection.