Effects of temperature on the germination of Diptychandra aurantiaca (Fabaceae) seeds

Diptychandra aurantiaca is a tree belonging to the Fabaceae family. The wood of this tree is moderately heavy and resistant, and it is used to make posts, wooden sleepers and building, among other structures. The aim of this work was to evaluate seed germination and the initial growth of the primary roots in D. aurantiaca at different temperatures using seeds collected in the village of Taboco in Mato Grosso do Sul state, Brazil. The seeds were subjected to constant temperatures of 20, 25, 30 and 35ºC and alternating temperatures of 20-30 and 25-35ºC using four replications of 25 seeds per treatment in a germination chamber. The results showed that most seeds germinated at 25 and 30ºC, with 97 and 87%, respectively, thus indicating that these temperatures are efficient to not only promote germination but also to potentiate the speed (1,1 - 25 and 30ºC) and decrease the average germination time (9.0 - 25ºC and 7.1 - 30ºC), highest allocation of dry biomass (0.0067 g at 25ºC and 0.0055 g at 30ºC) and the greatest primary root size (17.5 mm at 25ºC and 16.5 mm at 30ºC).