Effect of Geographical Location, Year, and Cultivar on Survival of Malus sp. Dormant Buds Stored in Vapors of Liquid Nitrogen

Abstract

Clonal woody crop germplasm collections often originate and are grown in distinct geographical locations. Because the degree of cold-hardiness is known to be a factor in the successful use of dormant bud cryopreservation for Malus, it was suggested that material from relatively warmer climates would not respond to cryopreservation as well as material from colder environments. To test this hypothesis, the effect of growing provenance on cryosurvival of dormant buds from three Malus (apple) cultivars grown in three locations (Geneva, NY; Davis, CA; and Corvallis, OR) was tested in 3 consecutive years. Dormant winter buds were harvested at the three locations, cryopreserved, and bud viability was tested by grafting. The collective 3-year mean viability for cryopreserved dormant apple buds for the three locations ranged from 63% to 81% of the buds surviving with the highest survival from the Corvallis site; however, the Geneva twigs were exposed to the lowest preharvest temperature. These results suggest that the temperature at the growing location may not hinder application of the dormant bud cryopreservation method with Malus to the extent previously speculated.