Exploring and conserving genetic resources of corn salad: distribution and collecting of wild Valerianella spp. species in Poland

Wild plant species represent a rich source of genetic variation and are therefore indispensable as a source of novel traits for crop improvement. Despite their importance crop wild relatives (CWR) are generally underrepresented in genetic resources collections. Here we performed an inventory of the CWR of corn salad ( Valerianella locusta ), a leafy vegetable that has increased in interest as food crop, and investigated their representation in genetic resources collections. In addition, we reported on the diversity collected for corn salad CWR during an expedition in Poland in 2024. Exploring the plant database Plants of the World Online, our inventory resulted in 79 CWR of which only 22 were represented in the genetic resources data repository Genesys. Focusing on the European distribution area resulted in 32 CWR of which only seven were included in Genesys with a total of 51 accessions. V. locusta occurs in the wild throughout Europe but only 15 accessions originating from only four European origin countries were encountered in Genesys. The collecting expedition covered most of Poland and resulted in 59 new accessions, including 54 of V. locusta , four of V. dentata and one of V. carinata . The expedition materials originated from a wide variety of habitat types and plant associations, while a large diversity in thousand-seed weight was observed among the accessions. It was concluded that CWR are poorly represented in current genetic resources collections of corn salad. The expedition was the first systematic collecting effort for corn salad CWR in a country and the collected materials greatly extend the genetic resources of corn salad available to the user community of gene bank collections.