POTATO GENETIC-RESOURCES - SOURCES OF RESISTANCE AND SYSTEMATICS

The major potato of commerce, Solanum tuberosum L., is the fourth most important food crop in the world after rice, wheat and corn. Fortunat ely, the potato has many primitive cultivars and wild species relative s useful to reduce our reliance on chemical controls. These include re sistances against diseases, pests, and traits for useful agronomic cha racters such as yield, specific gravity, chipping qualities, and suppr ession of enzymatic browning. This paper summarizes some of these qual ities, and provides an overview of germplasm availability and taxonomy of the wild species. The major potato of commerce, Solanum tuberosum L., is the fourth most important food crop in the world after rice, wh eat and maize. It is grown in more countries than any other crop but m aize, and forms the staple crop of many societies. Over 280 million me tric tons were grown worldwide in 1989, with Eastern Europe growing 46 %, Asia 22%, Western Europe 17%, North America 7%, Latin America 5%, a nd Africa 3% (2). It is the leading vegetable crop in acreage and farm value in the United States, with 1.2 million acres planted in 1991, w ith a value of sales almost two and one-half billion dollars (53). Sol anum tuberosum is one species of a group of seven cultivated and 216 a dditional tuber-bearing, and nine non-tuber-bearing wild relatives, al l classified by Hawkes (41) in the genus Solanum, section Petota Dumor t The purposes of this paper are threefold: 1) to provide examples of the proven and potential utility of wild and cultivated landrace membe rs of sect. Petota for reducing our reliance on chemical controls for many pests and diseases that affect commercial cultivars, 2) to provid e an overview of the status of germplasm availability of these species , and 3) to highlight the benefits for continuing germplasm collection s and systematic studies of the group.