1. Plant germplasm conservation research Patricia Berjak Berjak, P. (2005) Science 307, 47-49 Berjak, P. (2006) Journal of Horticultural Science & Biotechnology 81, 781-782

2. Plant germplasm conservation research The opening of the ‘Doomsday Vault’ a few days ago, and The fact that the AU/NEPAD Plan of Action (2005) prioritises establishment of an African Network of Gene Banks –Spotlights the importance of plant germplasm conservation.

3. Plant germplasm conservation research While plant genetic resources conservation is most conventiently and easily achieved by dry seed storage, There are many species that produce unstorable, desiccation-sensitive, recalcitrant seeds The genetic resources of such species are essentially unstorable.

4. a dearth of data..... but plant germplasm conservation research recalcitrant seeds are all  desiccation-sensitive  metabolically active, but variably so, from species to species short- to medium-term storage period only weeks to months. Problems:  seed-associated micro- organisms;  germination in storage our focus is on recalcitrant (desiccation-sensitive), essentially unstorable seeds significant contribution to 'partner-screening' an ongoing sceening programme

5. all recalcitrant seeds are  desiccation-sensitive &  metabolically active, but variably so, from species to species  still unresolved questions hampering complete understanding this variabiity plant germplasm conservation research a dearth of data..... but short- to medium-term storage period only weeks to months. Problems:  seed-associated micro- organisms;  germination in storage our focus is on recalcitrant (desiccation-sensitive), essentially unstorable seeds

6. plant germplasm conservation research dearth of data..... but a dearth of data..... but recalcitrant seeds are all  desiccation-sensitive  metabolically active, but variably so, from species to species short- to medium-term storage period, as cool as possible, but only weeks to months. Problems:  seed-associated micro- organisms;  germination in storage;  ultimate loss of vigour & viability our focus is on recalcitrant (desiccation-sensitive), essentially unstorable seeds

7. plant germplasm conservation research cryostorage of the germplasm of recalcitrant-seeded species: information and vital issues liquid nitrogen @ -196 o C developmental stage of embryonic axes critical elimination of all microfloral inoculum developing optimal in vitro protocols for excised axes optimising dehydration rate explaining & solving the problem of shoot apex necrosis developing & optimising cryoprotectant treatments determining the best cooling (freezing) rate optimising thawing & rehydration procedure seedling formation - the real indicator of success why less success with tropical vs temperate material? embryonic axes, alternative explants & synthetic seeds

8. plant germplasm conservation research cryostorage of the germplasm of recalcitrant-seeded species: information and vital issues liquid nitrogen @ -196 o C developmental stage of embryonic axes critical elimination of all microfloral inoculum developing optimal in vitro protocols for excised axes optimising dehydration rate explaining & solving the problem of shoot apex necrosis developing & optimising cryoprotectant treatments determining the best cooling (freezing) rate optimising thawing & rehydration procedure seedling formation - the real indicator of success why less success with tropical vs temperate material? embryonic axes, alternative explants & synthetic seeds

9. plant germplasm conservation research cryostorage of the germplasm of recalcitrant-seeded species: information and vital issues liquid nitrogen @ -196 o C developmental stage of embryonic axes critical elimination of all microfloral inoculum developing optimal in vitro protocols for excised axes optimising dehydration rate explaining & solving the problem of shoot apex necrosis developing & optimising cryoprotectant treatments determining the best cooling (freezing) rate optimising thawing & rehydration procedure seedling formation - the real indicator of success why less success with tropical vs temperate material? embryonic axes, alternative explants & synthetic seeds

10. plant germplasm conservation research cryostorage of the germplasm of recalcitrant-seeded species: information and vital issues liquid nitrogen @ -196 o C developmental stage of embryonic axes critical elimination of all microfloral inoculum developing optimal in vitro protocols for excised axes optimising dehydration rate explaining & solving the problem of shoot apex necrosis developing & optimising cryoprotectant treatments determining the best cooling (freezing) rate optimising thawing & rehydration procedure seedling formation - the real indicator of success why less success with tropical vs temperate material? embryonic axes, alternative explants & synthetic seeds

11. plant germplasm conservation research cryostorage of the germplasm of recalcitrant-seeded species: information and vital issues liquid nitrogen @ -196 o C developmental stage of embryonic axes critical elimination of all microfloral inoculum developing optimal in vitro protocols for excised axes optimising dehydration rate explaining & solving the problem of shoot apex necrosis developing & optimising cryoprotectant treatments determining the best cooling (freezing) rate optimising thawing & rehydration procedure seedling formation - the real indicator of success why less success with tropical vs temperate material? embryonic axes, alternative explants & synthetic seeds AS RAPIDLY AS POSSIBLE, BY OUR TECHNIQUE OF FLASH DRYING

12. plant germplasm conservation research cryostorage of the germplasm of recalcitrant-seeded species: information and vital issues liquid nitrogen @ -196 o C developmental stage of embryonic axes critical elimination of all microfloral inoculum developing optimal in vitro protocols for excised axes optimising dehydration rate explaining & solving the problem of shoot apex necrosis developing & optimising cryoprotectant treatments determining the best cooling (freezing) rate optimising thawing & rehydration procedure seedling formation - the real indicator of success why less success with tropical vs temperate material? embryonic axes, alternative explants & synthetic seeds

13. plant germplasm conservation research cryostorage of the germplasm of recalcitrant-seeded species: information and vital issues liquid nitrogen @ -196 o C developmental stage of embryonic axes critical elimination of all microfloral inoculum developing optimal in vitro protocols for excised axes optimising dehydration rate explaining & solving the problem of shoot apex necrosis developing & optimising cryoprotectant treatments determining the best cooling (freezing) rate optimising thawing & rehydration procedure seedling formation - the real indicator of success why less success with tropical vs temperate material? embryonic axes, alternative explants & synthetic seeds GLYCEROL &/or SUCROSE &/or DMSO

14. plant germplasm conservation research cryostorage of the germplasm of recalcitrant-seeded species: information and vital issues liquid nitrogen @ -196 o C developmental stage of embryonic axes critical elimination of all microfloral inoculum developing optimal in vitro protocols for excised axes optimising dehydration rate explaining & solving the problem of shoot apex necrosis developing & optimising cryoprotectant treatments determining the best cooling (freezing) rate optimising thawing & rehydration procedure seedling formation - the real indicator of success why less success with tropical vs temperate material? embryonic axes, alternative explants & synthetic seeds BEST EXTREMELY RAPIDLY IN NITROGEN SLUSH @ -210 o C

15. plant germplasm conservation research cryostorage of the germplasm of recalcitrant-seeded species: information and vital issues liquid nitrogen @ -196 o C developmental stage of embryonic axes critical elimination of all microfloral inoculum developing optimal in vitro protocols for excised axes optimising dehydration rate explaining & solving the problem of shoot apex necrosis developing & optimising cryoprotectant treatments determining the best cooling (freezing) rate optimising thawing & rehydration procedure seedling formation - the real indicator of success why less success with tropical vs temperate material? embryonic axes, alternative explants & synthetic seeds Ca/Mg SOLUTION FOUND TO BE VERY GOOD

16. plant germplasm conservation research cryostorage of the germplasm of recalcitrant-seeded species: information and vital issues liquid nitrogen @ -196 o C developmental stage of embryonic axes critical elimination of all microfloral inoculum developing optimal in vitro protocols for excised axes optimising dehydration rate explaining & solving the problem of shoot apex necrosis developing & optimising cryoprotectant treatments determining the best cooling (freezing) rate optimising thawing & rehydration procedure seedlings & established plants = success why less success with tropical vs temperate material? embryonic axes, alternative explants & synthetic seeds

17. plant germplasm conservation research cryostorage of the germplasm of recalcitrant-seeded species: information and vital issues liquid nitrogen @ -196 o C developmental stage of embryonic axes critical elimination of all microfloral inoculum developing optimal in vitro protocols for excised axes optimising dehydration rate explaining & solving the problem of shoot apex necrosis developing & optimising cryoprotectant treatments determining the best cooling (freezing) rate optimising thawing & rehydration procedure seedling formation - the real indicator of success why less success with tropical vs temperate material? embryonic axes, alternative explants & synthetic seeds INTENSIVE ANALYSES ARE UNDERWAY

18. plant germplasm conservation research cryostorage of the germplasm of recalcitrant-seeded species: information and vital issues liquid nitrogen @ -196 o C developmental stage of embryonic axes critical elimination of all microfloral inoculum developing optimal in vitro protocols for excised axes optimising dehydration rate explaining & solving the problem of shoot apex necrosis developing & optimising cryoprotectant treatments determining the best cooling (freezing) rate optimising thawing & rehydration procedure seedling formation - the real indicator of success why less success with tropical vs temperate material? embryonic axes, alternative explants & synthetic seeds

19. the ultimate objective a cryobanking facility for African biodiversity conservation, particularly for species producing short-lived recalcitrant (or other non-orthodox) types of seeds.......... which is vital in the face of global climate change!