C-LT C-N Champagne plants under low-temperature treatment Chilling Cold acclimation FD FT Freezing tolerance HRM Journal Article LG LT N PQL Pisum sativum Research Support, Non-U.S. Gov't SSCP SSH Suppression subtractive hybridisation T-LT T-N Terese plants under low-temperature treatment WFD control/unchilled control/unchilled Champagne plants control·unchilled Terese plants freezing tolerance frost damages in controlled conditions high resolution melting curve linkage group