Caracterização do tomateiro submetido ao déficit hídrico

Abstract

The experiment was conducted to evaluate the morphological/physiological characteristics of tomato plants when submitted to different levels of water deficit and, based on these results, indicate the best characters for the selection ofplants with more tolerance to water deficit. The experimental delineation was in randomized complete block design, with four replications, arranged in splitplot, in which the main treatments (plots) were composed by two strains (TOM-684 and M-82) and the subplots, by four levels of soil moisture (100 %, 75 %, 50 % and 25 % of the field capacity). The following parameters were evaluated: fruit production, leaf, stem and root system fresh and dry mass, , stem diameter, plant height, number of leaves, photosynthesis, transpiration, foliar temperature, intracellular moisture, intracellular carbon dioxide, stomatal conductance, conductance of intracellular CO2and total conductance. With the reduction of soil moisture occurred reduction in the number of leaves, plant height and leaf, stem and root system fresh and dry mass, transpiration, photosynthetic rate, fruit production and increase of foliar temperature The stomatal conductance differed between both strains, with higher values for the TOM-684 strain, which reduced stomatal conductance from 0,70 to 0,25 mol m-2s-1between levels of 100 and 25 % of field capacity. Plant height and the number of leaves may be used in breeding programs as a tool for the selection of plants with higher resistance to water deficit.