The collection composition
The collection of melon is small and was adopted by CGN in 2005. It contains only accessions which could not be found in other collections, 17 originating from the Netherlands. Part of the collection comes from the former IVT and about 30 accessions were collected during an IPGRI collection mission in Pakistan in 1981. This resulted in a total of 83 accessions (March 2012) of which only 59 accessions are presently available because regeneration is needed to meet the CGN standards. They will be added in time. When morphological and molecular markers are available the collection can be rationalised. The available collection comprises of 7 cultivars, 40 landraces mostly from Pakistan and Egypt and 5 accessions of unknown population type. Melon comes in many different types and can be sweet to sour. Because the collection is so small it is not divided in types.
To be incorporated in the collection, accessions need to have a minimum seed viability of 80% for cultivated material and 60% for accessions of wild species. Regeneration is carried out when seed viability is to low or when the remaining seed quantity has dropped below 12.5 g.
Regeneration/multiplication takes place in insect-free glasshouses on a substrate system where the stems are grown along ropes. For melon, which is a cross-pollinator, ten plants are used. When samples are heterogeneous, fourteen plants are used.
The Dutch breeding companies assist in the regeneration of melon. Some accessions which are difficult to regenerate are put in isolation cages with bumble bees for pollination. During the growing season plants are monitored by the Dutch Plant Health Service for seed borne diseases in order to prevent seed contamination.
Regenerations are carried out in close cooperation with breeding companies which are member of the Dutch Association for the Plant Reproduction Material Sector (Plantum NL).
Characterization of fruit vegetables takes place during regeneration. Almost all accessions have been morphologically described. Until 2006 about 30 descriptors were used for each crop. Since 2006 the fruit vegetables are characterized by minimum descriptors developed by the ECPGR Working Groups. The minimum descriptor lists consist of about ten descriptors per crop and can be found at the ECPGR Solanacaeae webpage. All characterization data are made available on-line and in downloadable files.
The collections are well photo-documented, many pictures of (un)ripe fruits, plant and flowers are available. When necessary new pictures will be taken during regeneration and added to the CGN website.