THE PROMISE OF UNDOMESTICATED POTATOES
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In this report we have not described wild potatoes—of which there are several hundred species in the Andes. But this is not to suggest that the wild species lack utility. Indeed, some of them have unusual genetic qualities. A few, for instance, are virtually immune to the most formidable pests in potato farmers' fields.
British agronomist R.W. Gibson has found two species of Bolivian wild potato whose leaves are veritable minefields to insects. Even a tiny aphid—one of the potato's major enemies—crawling over the surface breaks open minute, four-lobed hairs that cover the leaves. This releases a sticky material that clings so firmly that the aphid's legs become glued to the leaf and it dies. The glue will also catch the Colorado potato beetle, potato leafhoppers, and both tarsonemid and tetranychid mites. These particular wild potatoes are unsuitable as food crops, but already researchers are beginning to breed them with the common potato to give it glandular hairs with which to ensnare its insect enemies.
The photomicrograph reveals an aphid that has become stuck to the leaf of Solanum berthaultii. (Rothamsted Experimental Station)