Influence of light and temperature on the germination of Passiflora incarnata L. seeds

Abstract

-The study aimed to assess the influence of temperature and light on germination of Passiflora incarnata L seeds. The treatments consisted of five temperature conditions (25, 30, 35, 20-30 and 30-20 °C) and two light conditions (constant light and constant darkness). The experimental design was completely randomized in a 2 x 5 factorial arrangement (light x temperature). The seeds were kept in a germination chamber during the period of 30 days. The germinated seeds were counted daily. At the end of the experiment, the percentage of seed germination (PSG), germination speed index (GSI), the germination rate (GR) and relative frequency of germination (RFG) were calculated. The data obtained were subjected to analysis of variance and means were compared by Tukey test at 5% probability. The relative frequency of germination was represented as graphs. It was observed that light has an inhibitory effect on seed germination. The constant temperature of 35 °C and the alternating temperatures of 30/20 °C promoted a higher germination seed index for Passiflora incarnata.Index terms: passion fruit, medicinal plants, seed propagation.Influência da luz e da temperatura na germinação de sementes de Passiflora incarnata L.RESUMO -O trabalho teve como objetivo avaliar a influência da temperatura e da luz na germinação de sementes de Passiflora incarnata L. Os tratamentos foram constituídos de cinco condições de temperaturas (25, 30, 35, 20-30 e 30-20 ºC) e duas condições de luz (luz constante e escuro constante). O delineamento utilizado foi o inteiramente casualizado, em esquema fatorial 2 x 5 (luz x temperatura). As sementes foram mantidas em câmera de germinação durante o período de 30 dias. A contagem das sementes germinadas foi realizada diariamente. Ao final do experimento foram calculados a porcentagem de germinação, o índice de velocidade de germinação -IVG, a velocidade de germinação -VG e a frequência relativa de germinação. Os dados obtidos foram submetidos à análise de variância e as médias comparadas pelo teste Tukey a 5% de probabilidade de erro. A frequência relativa de germinação foi representada na forma de gráficos. Observou-se que a luz tem efeito inibitório sobre a germinação das sementes. A temperatura constante de 35 °C e a alternada 30/20 °C promoveram maior índice de germinação das sementes de Passiflora incarnata.Termos para indexação: maracujá, plantas medicinais, propagação.

Germination temperatures and treatments to overcome dormancy in Belamcanda chinensis seeds1

“…Values followed by letters between parentheses show the originals means. Dousseau et al 2011, Baskin & Baskin 2014, Zucareli et al 2015, Gomes et al 2016. The presence of light (8 h) in the alternating temperature condition was likely not responsible for the onset of the germination process, since the substrate used (paper roll) is not recommended for light-sensitive seeds (Brasil 2009).…”

Effect of temperature on passion fruit emergence and seedling vigor

“…Exposure to low temperatures over a prolonged period can induce seed dormancy in species of the Passifloraceae family (Osipi and Nakagawa, 2005;Zucareli et al, 2009;Zucareli et al, 2015), reduced by the lower speed of water imbibition (Figure 1), without softening of the seed coat and, consequently, lack of protrusion of the radicle (Marini et al, 2012). In addition, it reduces the activity of enzymes related to the germination process -lipase, amylase, and protease -and increases the activity of enzymes related to stress -superoxide dismutase and catalase (Marcos-Filho, 2005;Flores et al, 2014).…”

“…This lack of uniformity is related to the dormancy process present in various species of Passifloraceae, as reported by Osipi and Nakagawa (2005) in Passiflora alata Dryander, by Zucareli et al (2009) in Passiflora cincinnata Mast., and Zucareli et al (2015) in Passiflora incarnata L.…”

“…It is a critical phase, associated with factors related to the physical, biochemical, and physiological processes of the seed (Marini et al, 2012;Taiz and Zeiger, 2013), which are dependent on environmental conditions such as temperature (Bewley et al, 2014;Zucareli et al, 2015).…”

Tratamentos pré-germinativos em sementes de granadilha (Passiflora ligularis)

“…A temperatura exerce grande influência sobre as reações bioquímicas que regulam o metabolismo necessário para iniciar o processo de germinação, e em consequência, sobre a porcentagem e a velocidade do processo, sendo o comportamento muito diferenciado entre espécies (CARVALHO & NAKAGAWA 2012), principalmente entre espécies frutíferas do gênero Passiflora (ZUCARELI et al 2015).…”