Abstract

Tomato is broadly distributed in tropical and subtropical America, where small farmers cultivate commercial and landraces or heirloom genotypes, which exchange genes within them when are planted in the same plot. In this context, three different genetic groups of tomato were evaluated for agromorphological and yield traits under greenhouse to assess the differences in function of the genotypic homogeneity and heterogeneity. Twenty-four non-conventional hybrids (F1, population-x-advanced lines), seventeen landraces and six advanced lines (F8) were evaluated in a randomized complete block design with three repetitions. Significant differences (p ≤ 0.05) were determined among genetic groups for all variables evaluated, except in days to ripening of fruits at the fifth branch, and within genetic groups, significant differences were also detected. Six hybrids, three landraces and two advanced lines presented remarkable agronomic responses in yield per plant. The hybrids and landraces had high phenotypic variability in plant and fruit traits, with flat-rounded or lightly flattened fruit shapes, qualities demanded in the local markets, and a yield of 2 kg per plant. In Oaxaca, Mexico, small-scale farmers readily accept these heterogeneous genetic groups of tomato. High homogeneity characterized the advanced lines, with a fruit shape convenient for national and international markets. 

Key words: Landraces, non-conventional hybrids, phenotypic divergences, principal component analysis.