Microcutting Production from Sequential Reculturing of Hardy Deciduous Azalea Shoot Tips

Abstract

Abstract Differences were observed in microcutting harvests from 5 shoot tip explant sequential recultures of the hardy deciduous azalea ( Rhododendron spp.) accessions 800374, 620014, and 800057. In general microcutting production increased and then declined over reculture times in a nearly bell-shaped curve for all 3 clones tested. Maximum numbers of usable microcuttings were harvested in the 3rd and 4th recultures. Productivity varied among the 3 clones, with accession 800374 the most prolific and accession 800057 the least. The microcutting height was the same for all 5 recultures of accessions 800374 and 620014, whereas, in accession 800057 the height declined from the 1st through the 5th reculture. The microcutting quality rating was similar throughout all recultures of accessions 800374 and 620014, but accession 800057 produced higher quality microcuttings in the 3rd reculture than in the 5th reculture. Rooting of microcuttings in soilless medium increased from the 1st to the 5th reculture for all 3 clones, reaching more than 97% for the last 2 harvests.