An efficient in vitro shoot propagation of cranberry (Vaccinium macrocarpon Ait.) by axillary bud proliferation

摘要

Cultures of two cranberry (Vaccinium macrocarpon Ait.) cultivars, 'Ben Lear' and 'Pilgrim', and three cranberry clones from natural stands in Newfoundland were established in a nutrient medium containing N~6[2-isopentenyl]adenine (2iP) from nodal and/or shoot-tip explants obtained under aseptic conditions. The cultivars differed in shoot regeneration in terms of shoot number per explanl with various concentrations of 2iP over two culture periods. Best total shoot production was obtained when nodalsegments were cultured in the medium supplemented with 2.5-5.0 mg 2iP l~(-1) (12.3-24.6 #mu#M). With higher 2iP levels, shoots did not expand and had a high mortality rate. Nodal explants of the three clones cultured in the same nutrient medium supplemented with 2.5 mg 2iP l~(-1) (12.3 #mu#M) produced three to five healthy axillary shoots per explant. In another experiment, nodal explants were more productive than shoot tips. In all experiments with subculture, there was an increase in shoot multiplication rate for all genotypes. Shoots were rooted in vitro in the same media used for shoot proliferation, but without any growth regulators. After their transfer to potting medium, almost all of the rooted plants survived. Cranberry genotypes can be efficiently propagated and maintained through nodal culture in a nutrient medium without auxin that contains 2.5-5 mg2iP l~(-1) (12-25 #mu#M).