The United States now has a central “library” for mulberry trees and their genetic relatives. Trees of 19 mulberry accessions have been planted at the Agricultural Research Service’s Clonal Repository at Davis, Calif., and other accessions are being considered for inclusion. Cuttings from the trees--suitable for rooting or grafting--will be available next year to plant breeders and researchers.

The national collection of trees ensures that future generations will have a variety of genetic material for breeding better mulberry trees. Consumers value the trees for their sweet, berry-like fruits as well as the shade they provide. Until now, mulberry collections were maintained only by hobbyists and private nurseries.

Interest in the mulberry is on the increase. For example, Fruit Gardener magazine has named it the 1997 “Fruit of the Year” as part of an effort to recognize valuable but unusual crops.

The new mulberry collection includes five identified Morus species, two mulberry hybrids and three Morus accessions for which the species names are unknown.

The repository’s curator is asking researchers, hobbyists and the fruit industry for help in describing the major characteristics of each accession. He also seeks information about other mulberry plants being considered for the collection. Important factors include the tree’s origin, fruit characteristics, productivity, climate adaptability and other horticultural traits.

Of particular interest is an accession that goes by the common name “Pakistan.” It produces an abundance of long, slender fruits. They can grow to about 3-1/2 inches long in Virginia and 4-1/2 inches in California. Most mulberry varieties bear fruit only about 1 to 2 inches long.

The Davis repository is also home to the nation’s collection of almonds, apricots, cherries, figs, warm-season grapes, kiwifruit, nectarines, olives, peaches, persimmons, pistachios, plumcots, plums, pomegranates and walnuts. ARS stores germplasm for preservation and research at 25 other U.S. locations.

Scientific contact: George A. White, USDA-ARS National Clonal Germplasm Repository, Davis, Calif., phone (916) 752-7009, fax (916) 752-5974, e-mail davgw@ars-grin.gov