Management, phenotypic patterns and domestication of Polaskia chichipe (Cactaceae) in the Tehuacan Valley, Central Mexico

Polaskia chichipe, a cactus endemic to Central Mexico, is valued for its edible fruits and branches used as fuel wood. This plant occurs in the wild in thorn-scrub forests, in disturbed areas and in home gardens. Our study documented that this plant species was manipulated through management in situ of wild populations in disturbed areas, where the better phenotypes with larger and sweeter fruits were spared and enhanced by vegetative propagation and transplanting of young plants. Manipulation was also conducted by cultivation in home gardens where the better phenotypes were propagated by branches or seeds or by transplanting complete young plants. Morphological variation was compared among wild, managed in situ and cultivated populations to examine how human manipulation might have influenced modifications in phenotypic patterns. Fruits, seeds and some flower parts of managed populations were, on average, larger than in wild populations, and even larger in cultivated populations. The results suggest that the better phenotypes, from a human perspective, were more abundant in managed in Situ and Cultivated populations due to artificial selection, and that domestication resulted from both types of management. (C) 2004 Elsevier Ltd. All rights reserved.