Temperature and light in seed germination of Myrceugenia myrtoides O. Berg

Abstract

Myrceugenia myrtoides (Myrtaceae) is a species of tree size, occurring restricted to the state of Rio Grande do Sul state in Brazil, and Uruguay, presenting ornamental potential. The interest in native species for diverse uses is increasing, but their insertion is limited due to the lack of information on its propagation and cultivation. Thus, the objective of this study was to evaluate the effects of temperature and light on the germination of M. myrtoides seeds, in order to generate information that could aid in the propagation of the species and the exploration of its potential. The effects of constant temperatures of 20, 25 and 30 °C under a 16-hour photoperiod were evaluated. To evaluate the effect of light, the germination was tested in continuous darkness and under photoperiod of 16 hours, at a temperature of 25 °C and light intensity of 27 and 33.75 μmol m-2s-1 under white light quality and diffuse green light. The results showed a lower average germination time at temperatures of 25 and 30 ºC and a higher accumulation of dry mass under 30 ºC. There was superiority in the variables of seedling formation, shoot and root length and seedling formation under the number of seeds germinated at 25 ºC. However, the different light conditions tested did not affect the percentage of ermination. It is concluded that the temperature of 25 °C was the most adequate for seed germination and development of M.myrtoides seedlings and their seeds are classified as neutral photoblasts.