ARS | Publication request: Use of cryotherapy to eradicate pathogens from horticultural crops

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 23, 2012
Publication Date: July 31, 2012
Citation: Volk, G.M. 2012. Use of cryotherapy to eradicate pathogens from horticultural crops. Meeting Abstract. Available: http://ashs.org/abstracts/m/abstracts12/ abstract_id_12207.html.

Technical Abstract: Cryotherapy is a method by which pathogens are eliminated from infected plant materials through the process of exposing the shoot tips to cryogenic temperatures and then recovering them. It has been successfully implemented in potato, sweet potato, grapevine, raspberry, Prunus, and other fruit crops to eliminate pathogens that have been difficult to clean-up using traditional methods. Candidatus Liberibacter asiaticus (Las), the bacterium associated with huanglongbing (HLB), has been eliminated from Citrus using cryotherapy methods. The success of cryotherapy depends on the selective survival of cells in the meristems. Cells that do not host pathogens survive the exposure to liquid nitrogen, while cells that harbor the pathogens are killed. Most shoot tip grafts use meristems with only one leaf primordium (about 0.1 mm long); however, we have found that larger meristems (about 1mm long and including about three leaf primordia) increases the survival rate and makes the procedures more reproducible. Application of cryotherapy for eradication of other Citrus diseases such as viroids and Citrus tatterleaf capillovirus may provide a better alternative than traditional shoot tip grafting methods.