Plum Crazy: Rediscovering Our Lost Prunus Resources

Abstract

Received for publication 22 May 2000. Accepted for publication 13 June 2000. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact. E-mail address: dokie@saa.ars.usda.gov Recent utilization of genetic resources of peach [Prunus persica (L.) Batsch] and Japanese plum (P. salicina Lindl. and hybrids) has been limited in the United States compared with that of many crops. Difficulties in collection, importation, and quarantine throughput have limited the germplasm available. Prunus is more difficult to preserve because more space is needed than for small fruit crops, and the shorter life of trees relative to other tree crops because of disease and insect problems. Lack of suitable rootstocks has also reduced tree life. The trend toward fewer breeding programs, most of which emphasize “short-term” (long-term compared to most crops) commercial cultivar development to meet immediate industry needs, has also contributed to reduced use of exotic material. Probably all modern commercial peaches grown in the United States are related to ‘Chinese Cling’, a peach imported from China over 100 years ago (Myers et al., 1989). More recently imported germplasm has not significantly impacted modern production. The relatively few available accessions of wild peach relatives have been useful primarily in development of peach rootstocks. In contrast, a large shipping plum industry in California has been developed based on plum cultivars imported 100 years ago from Japan and on hybrids of those plums with native species. Native American germplasm has unrealized potential to help solve current plum problems and stone fruit rootstock problems. However, few resources are devoted to this effort. This germplasm will be discussed in more detail in relation to the U.S. Dept. of Agriculture (USDA)–Agricultural Research Service (ARS) breeding program at Byron, Ga.