ABSTRACT
Storage of orthodox seeds is the most widely practiced method of ex situ conservation of plant genetic resources as 90% of the 7.4 million accessions stored in genebanks are maintained as seed. In contrast to orthodox seeds, a considerable number of species produce nonorthodox seeds, which are unable to withstand much desiccation and are often sensitive to chilling. Cryopreservation (liquid nitrogen, –196°C) is the only safe and cost-effective option for long-term conservation of genetic resources of these species. However, cryopreservation research is still at a preliminary stage for nonorthodox species. Research priorities for orthodox seed species include improving the longevity of seeds under standard genebank storage conditions, determining critical seed moisture content, developing low-input storage techniques, and improving and monitoring viability. In case of nonorthodox seed species, research should focus on understanding seed recalcitrance and developing improved conservation techniques. Improved germplasm management procedures should also be established.
