MORPHOLOGICAL TRAITS ASSOCIATED WITH A TOMATO IDEOTYPE FOR A NONRESTRICTIVE ENVIRONMENT

Abstract

An experiment was conducted under glasshouse conditions using 17 tomato (Lycopersicum esculentum Mill.) cultivars which were grown hydroponically at two population densities (12 and 25 pl/m2). The plants were pruned two leaves above the first inflorescence to leave only one cluster per plant. The objective was to evaluate the association of morphological characters (such as stem diameter, stem length, plant width, plant leaf area, flower number and percentage of plants with branched inflorescence) with yield and its components (fruit number, mean fruit weight and percentage of fruit set). A split plot design in random blocks with three replications was used; main plots corresponded to cultivars and the subplots to plant densities. The measurements of morphological variables were done 65 days after planting (dap), with the exception of plant leaf area which was measured 80 dap. Positive and significant correlations at 25 pl/m2 were found between yield and stem diameter, stem length, plant width and plant leaf area (r=0.47**, 0.48**, 0.47** and 0.42**, respectively). The yield of plants with branched inflorescences was almost twice that obtained from plants with a simple one, but in spite of differences among cultivars, this character showed low frequency (4 % in average) in every cultivar. It is proposed to incorporate of thick stem, ligh area and branched inflorescence traits into a single-truss tomato ideotype responsive to high density (25 plants/m2) in nonrestrictive environments.