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.

Germinação de sementes de Aristolochia elegans Mast. em diferentes temperaturas e concentrações de giberelina

“…As observed, the mean germination speed increased with increasing temperature to a maximum of 29°C (Figure 2C). As reported by Paim et al (2018), the mean germination time is a parameter of great importance for the determination of seed vigor, as it assumes that the most vigorous seeds germinate in a shorter time, a fact not demonstrated in this work, since the treatments with the lowest mean germination time do not necessarily present the highest germination percentages, attesting that the mean time alone is not a parameter to determine seed vigor.…”

Calidad de plantas de Myrceugenia myrtoides O. Berg en función de la fertilización con nitrógeno

“…Popularly known as "guamirim", M. myrtoides is characterized as a tree or shrub of up to 4 m high, easily recognized by its grayish trichomes covering the branches, petioles and abaxial leaf surface, which are discolors, lanceolates and with acuminate apex (Landrum, 1981). Similar to other species of the Myrtaceae family, such as Myrcia cuprea (Ferreira et al, 2013), Acca sellowiana (Sazima and Sazima, 2007) and Myrciaria cauliflora (Gobato et al, 2018), M. myrtoides has ornamental potential, because of its size and glauca shade, for use in urban afforestation and in the recovery of degraded environments, since the consumption of fruits by bird fauna facilitates the settlement of areas (Paim et al, 2018). However, although it has multiple uses, few phytotechnical studies related to the species have been conducted, thus limiting its use.…”