A significantly enhanced role for plant genetic resource centres in linking in situ and ex situ conservation to aid user germplasm access

Plant genetic resources (PGR) serve as the cornerstone for global varietal enhancement and food security. However, these resources face significant threats, including diversity erosion and extinction, are often inadequately conserved, and frequently remain inaccessible for practical use. Traditionally, PGR have been primarily conserved through population seed samples stored ex situ in genebanks. In contrast, complementary in situ techniques – whether involving crop wild relatives (CWR) in genetic reserves or crop landraces (LR) on-farm – have largely remained experimental. The demand from breeders for a broader diversity is driving a more integrated approach that combines ex situ and in situ methods. This paper posits that such an integrated strategy would be mutually advantageous for PGR, biodiversity, and farmer-based conservation communities. As a foundation for future PGR science, we propose the three ‘Principles of PGR Conservation and Use Congruence’ and outline the practical processes involved in in situ and on-farm conservation. We also review the challenges associated with integrating ex situ and in situ conservation, specifically addressing how collaborative resource management can be established, how potential resource users can access in situ and on-farm conserved PGR, how to promote user access to in situ conserved populations, and the progress made thus far in integrating in situ and ex situ efforts. While it is acknowledged that full integration may be unrealistic without adequate resources for Genetic Resource Centres and the rectification of skill gaps, the potential to significantly enhance the long-term, sustainable conservation of PGR diversity holds profound existential benefits for humanity in the 21st century.