Seleção de linhagens F5 de tomateiro em dois sistemas de cultivo sob temperaturas elevadas

Abstract

Adverse environmental conditions, particularly high temperatures in tomato cause lower fertilization of the flowers, reducing fruit set and consequently the productivity. The ideal temperature for a better development and fruiting plant is 25 to 28ºC during the day and 15 to 18ºC overnight, outside these limits, the plant has trouble setting fruit. Thus, the aim of this work was to select F5 lines of tomato high temperature tolerance and genetic stability and adaptability in two culture environments. We evaluated 20 lines F5, and two controls Yoshimatsu and hybrid SE 1055 F1. The maximum mean temperature during the experiment inside the greenhouse and in the field were 37.46ºC and 32.55ºC, respectively, considered out of range to the ideal development of tomato, especially in the greenhouse, where the average maximum temperature was far above the ideal. Lines 08, 12 and 13 showed the highest percentage of fruit in a greenhouse, however in the field, there was no difference between lines. In field experiment, the cultivar Yoshimatsu and lines 06 and 08, showed average mass commercial fruit per plant more than 4.0 kg. Lines 06 and 08 showed high adaptability and stability and productivity for mass marketable fruits per plant, in the two environments, and for purposes of selection, the most suitable.