PHENOTHYPIC DIVERSITY IN 15 WILD POPULATIONS OF TOMATO (Solanum lycopersicum L.)

Abstract

ABSTRACT

Objective: Generate information on the morpho-agronomic variability of 15 populations of wild tomato from different areas of Mexico.

Design/methodology/approach: A completely randomized experimental design with 17 treatments (populations) and 10 replicates (individuals) was used. The experimental unit consisted of a single plant (individual), where sixty-four morphological and agronomic descriptors proposed by Bioversity International were evaluated. Analysis of variance was performed with repeated measures and the differences of means were compared by the Tukey (P ≤ 0.05) multiple range test. A principal component and multiple correspondence analysis were performed with the quantitative and qualitative variables, respectively.

Results: Wide variability in morphological and fruit quality attributes, such as consistency and total soluble solids, were found. Principal component analysis and multiple correspondence analysis explained phenotypic variation with 67.41 and 42.06 % in the first three components and dimensions, respectively. The most discriminatory traits were those of fruits and inflorescences, which separated the populations into four groups. The first group was integrated by plants with uniparous inflorescence, with heirloom-type red fruits and small to intermediate size; the second by uniparous and multiparous inflorescences, with cherry and grape-type fruits of yellow, orange and red colors, and very small size; the third by uniparous and forked inflorescences, with ball and cocktail-type fruits of red, orange and yellow colors, and small to intermediate size; and the fourth by uniparous inflorescence, with ball-type fruit of purple color and intermediate size.

Limitations on study/implications: To better understand the variability and phylogenetic relationships of these populations, a molecular characterization must be done.

Findings/conclusions: All wild populations showed high phenotypic variability in the vegetative and reproductive phases, the fruit and inflorescence characteristics contributed the most to their discrimination. The most frequent fruit shapes were slightly flattened and rounded, and the fruit sizes were very small and small. Generally, the indeterminate plants showed higher degrees Brix than the semi-determinate ones. The red fruits had higher Brix​​ than oranges, yellow and purple, but the latter had better flavor. A type of leaf not reported in the descriptors for tomato was discovered, which was called ‘with sprouts’.

Keywords: Solanum lycopersicum L., native populations, mor-pho-agronomic characterization.