Influence of light, temperature and humidity on substrate and osmoconditioning during the germination of Mimosa bimucronata (DC) O. Kuntze.

Abstract

The maricá (Mimosa bimucronata (DC) O. Kuntze) is a forest species, belonging to the family Fabaceae, considered endemic to the Atlantic Forest biome. The present work aimed to study the germinative behavior of M. bimucronata seeds under different temperatures and light qualities, as well as to evaluate the effect of the amount of water (humidity) in the substrate and the osmoconditioning during germination. Thus, the experiment was performed using a completely randomized design. The treatments were distributed in a 4 × 4 factorial scheme (temperatures and light qualities), with 4 replicates of 25 seeds each. The means were compared by Tukey's test at 5% probability. The volume of water and osmoconditioning of substrate was evaluated and data were subjected to regression analysis. The following variables were analyzed: first count of germinated seeds, germination, germination speed index, and electrical conductivity. The results revealed that seeds are neutral photoblasts, needing a constant temperature of 30 °C along with a white light for appropriate germination and vigor. Seeding on two sheets of paper towel moistened with water volume (mL) from 2.62 to 2.70 times was more suitable for conducting the germination test. The osmotic conditioning was inefficient in maintaining germination of these seeds.

Temperatures and light regimes in the germination of Areca vestiaria and Areca triandra seeds

“…(Costa et al, 2018) and Mauritia flexuosa L. f. (Almeida et al, 2018). In many species, the presence of light favors the germination of the seeds, while in others, the germinative behavior of the seeds is favored in the absence than in the presence of light (Melo et al, 2018). Thus, it can be inferred that both species of this research are classified as neutral photoblastics, since there was germination regardless of the presence or absence of light, being in accordance with what was proposed by Bewley et al (2013) and Marcos Filho (2015).…”

INFLUÊNCIA DA QUANTIDADE DE ÁGUA NO SUBSTRATO SOBRE A GERMINAÇÃO DE SEMENTES DE PAU-PRETO (Cenostigma tocantinum DUCKE)

“…Para espécies como Hylocereus undatus (OLIVEIRA JUNIOR et al, 2015), Cucumis melo (AMARO et al, 2014) e Mimosa bimucronata (MELO et al, 2018) as sementes apresentaram maior IVG nos tratamentos com maiores volumes de água, diferindo dos resultados obtidos no presente estudo na qual a disponibilidade de 3,5 vezes o peso do substrato não foi favorável para a germinação, IVG e TMG de paupreto. O excesso de umidade no substrato pode impedir a penetração de oxigênio e afetar negativamente a germinação, além de propiciar maior incidência de fitopatógenos, levando à redução no vigor (MELO et al, 2005).…”

Diaspores biometry, temperatures and light regime on seed germination of Ptychosperma macarthurii (Arecaceae)

“…This is because a large number of species have a favorable germinal reaction to changes in temperature, due to the similarity of what happens in the environment where they develop, in which daytime temperatures are higher than nighttime temperatures (Carvalho & Nakagawa, 2012). Melo et al (2018) report that germination speed is a good index to measure the occupation of a species in a given environment, since rapid germination is characteristic of species whose strategy is to establish themselves in the environment as quickly as possible because it takes advantage of favorable conditions.…”