Exploración y caracterización de poblaciones silvestres de jitomate (solanaceae) en tres regiones de Michoacán, México

Abstract

In order to characterize populations of wild tomato (“tinguaraque”) in the Mexican State of Michoacan, fi eld observations were made from January to September of 2007. Three regions were selected: “Valle de Apatzingan”, “Valle de Los Reyes” and “Cienega de Chapala”. Through interviews to farmers and previous studies, more particular samplings were made in each region. The characterization included: environmental, morphological, physiological and entomological aspects. In 45% of the visited sites, populations of the wild tomato were recorded. They were located in altitudes from 314 to 1 550 m; precipitation of 751 to 1 014 mm per year, maximum and minimum temperatures of 35.2 and 11.7ºC, and varied levels of soil fertility. Registered populations correspond to the species Solanum lycopersicum L. (var. cerasiforme), of which two groups could be distinguished: big fruits (2.12 to 2.23 x 2.41 to 2.55 cm) and small fruits (1.05 to 1.22 x 1.10 to 1.25 cm). The germination speed, expressed as the time that germinates 50% of seed was variable; ranged from 2.7 (2.5-3.0) days until 10.6 (8.6-15.6) days. With exception of a morphospecies (Col: Chrysomelidae: Chrysomelinae), associated phytophagous insects corresponded to pest species of tomato; the principals were: whitefl y (Hem: Aleyrodidae) and aphids complex (Hem: Aphididae), Lyriomiza sativae Blanchard and L. trifoli Burgués, Epitrix sp. and Manduca sp. The psilid of the solanaceae Bactericera cockerelli Sulc. Was only registered in the Cienega region, while the bug Cyrtopeltis notata Distant, was the most insidious in tinguaraque. The diversity of environmental conditions in those that the wild populations of S. lycopersicum develop in Michoacan indicates a wide diversity (ecotypes) of this species.