Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/13/2013
Publication Date: 8/13/2013
Citation: Bonnart, R.M., Shepherd, A., Lee, R.F., Krueger, R., Volk, G.M. 2013. Cryopreservation of citrus in the USDA-ARS national plant germplasm system collection. Meeting Abstract. 2nd International Symposium on Plant Cryopreservation. p.62.
Technical Abstract: Diverse Citrus germplasm from the USDA-ARS National Plant Germplasm System, University of California Riverside, and the California citrus industry is at risk of being lost as a result of disease infestations and unexpected weather disasters. At the National Center for Genetic Resources Preservation we have developed methods to cryopreserve shoot tips excised from diverse Citrus species including Citrus sinensis, C. reticulata, C. unshiu, C. clementina, C. x citroncirus, C. limon, C. meveri, and Fortunella margarita. These methods use screenhouse and greenhouse-grown plants as source materials and rely upon micrografting onto Citrus seedling rootstocks for recovery. A long-term storage experiment was initiated in 2011 to confirm shoot tip survival after extended exposure to liquid nitrogen. There was no decline in viability after one year. Fall processing appears to increase survival of shoot tips compared to those cryopreserved in the winter, spring and summer months. We also found that freezing on foils resulted in higher levels of survival than freezing in vials. For the seven cultivars included in this experiment, the average viability of shoot tips cryopreserved using cryovials was 53% and the viability of shoot tips cryopreserved on foil strips was 83%. These results suggest that clones in Citrus germplasm collections can be successfully cryopreserved within genebanks.