To ensure sufficient seed viability, the germination ability of spinach accessions is monitored according to ISTA procedures at regular intervals (Van Treuren et al., 2013). Threshold values for regeneration are 80% germination for cultivated material and 60% for accessions of wild species. Accessions are also regenerated when germination has decreased with at least 15% during a monitoring interval or when the remaining seed weight has dropped below 29 grams.
As cultivated spinach and it’s wild relatives S. turkestanica and S. tetrandra are dioecious species that are wind-pollinated, accessions are regenerated in isolation under controlled greenhouse conditions or in outdoor regenerations tunnels. In general, at least 80 plants are used for the regeneration of cultivated spinach, 160-300 plants for regenerating accessions of wild species. Regenerations are carried out in close cooperation with 9 breeding companies affiliated to the Dutch association for the plant reproduction material sector (Plantum NL). More detailed information about regeneration procedures can be accessed through the link provided in the right margin of this page.