In Vitro Storage and Cryopreservation of ‘Ōhelo Seed and Tissue Cultures

‘Ōhelo (Vaccinium reticulatum Smith) is a native shrub of Hawaii and Maui commonly found in disturbed, open sites at 640 to 3700 meter elevation. Three cultivars: Kilauea, Red Button, and Nene were selected for ornamental use due to their compact form and bright red and waxy new growth. This study tested in vitro cold storage and cryopreservation of shoot tips of these cultivars and cryopreservation of seed for germplasm preservation. Shoot cultures in tissue-culture bags were maintained in good condition in 4 ºC cold storage for 16 months before requiring repropagation. Shoot tips were moderately desiccation sensitive, but could be cryopreserved by any of three protocols. Regrowth following controlled rate cooling was 42% to 50%; encapsulation dehydration 60% to 75%; and PVS2 vitrification 45% to 70%. Wild collected seed was tested for germination after 3 month at room temperature or -20°C storage and after cryopreservation. Room-temperature stored seed displayed dormancy that was broken by cryopreservation. High levels of germination were noted for the -20°C stored seed and the cryopreserved seed. These studies show that ‘Ōhelo germplasm can be successfully cold stored as tissue cultures or cryopreserved as shoot tips or seeds.