GENETICS, GENETIC RESOURCE EVALUATION, AND GENETIC IMPROVEMENT OF LANDSCAPE TREES AND SHRUBS
Location: Floral and Nursery Plants Research Unit
Title: Interploid hybridizations in ornamental cherries using Prunus maackii
Submitted to: Journal of Environmental Horticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 19, 2012
Publication Date: June 15, 2012
Citation: Pooler, M.R., Ma, H., Kidwell Slak, D.L. 2012. Interploid hybridizations in ornamental cherries using Prunus maackii. Journal of Environmental Horticulture. 30:89-92.
Interpretive Summary: Flowering cherries (Prunus species) are popular plants in landscapes, and also have significant economic impact to the wholesale and retail nursery industries. Over one million plants are sold wholesale each year at a value of more than $22 million. Despite the large number of Prunus species with diverse origins and ornamental traits, the most widely cultivated flowering cherry trees planted in the U.S. represent only a few species. The United States National Arboretum has an ongoing breeding program aimed at broadening this narrow genetic base of flowering cherry by developing new cultivars with disease and pest resistance, tolerance to environmental stresses, and superior ornamental characteristics. As part of this objective, we created interspecific hybrid trees using a cold-tolerant, pest resistant species, Amur cherry. Because this plant is tetraploid (containing four sets of chromosomes), and other ornamental species are diploid (containing two sets of chromosomes), the hybrids are triploid (containing three sets of chromosomes). These hybrids may have ornamental value per se, or may be useful as breeding stock to incorporate traits of interest that aren’t found in the diploid ornamental species. We will continue to evaluate these crosses for ornamental potential, as well as to explore other methods to increase the genetic diversity of ornamental cherry cultivars in the landscape.
The United States National Arboretum has an ongoing flowering cherry (Prunus) breeding program aimed at broadening the genetic base of cultivated ornamental cherries by developing new cultivars with disease and pest resistance, tolerance to environmental stresses, and superior ornamental characteristics. Interploid crosses, specifically 2X × 4X, in ornamental Prunus would be beneficial in breeding because they could allow introgression of traits not available in the diploid germplasm (pest resistance, cold hardiness), and could result in the creation of seedless triploids that would not set nuisance fruit and possibly have extended bloom durations. This report documents successfully hybrids of P. maackii (Manchurian or Amur cherry), a tetraploid species, with P. campanulata, P. ‘Umineko’, and P. maximowiczii, all diploid species. Chromosomes of one of these resulting triploid hybrids were successfully doubled using oryzalin in tissue culture to create a hexaploid plant.