Germination test of Eucalyptus phaeotricha seeds

Abstract

The rules for seed analysis do not have recommendations for conducting the germination test of Eucalyptus phaeotricha seeds. Thus, the aim of this study was to determine the best substrate, temperature, conduction time, and substrate moistening level for the germination test of E. phaeotricha seeds. First count of germination, germination, germination speed index and mean time of germination were evaluated. The first experiment was carried out in a completely randomized design, in a factorial scheme (6 x 2), corresponding to six temperature regimes (15, 20, 25, 30, 35 °C and 20-30 °C) and two substrates (paper and sand) with four replicates, and the means were compared by Tukey test at 0.05 probability level. In the second experiment, the germination test was installed with the most favorable substrate and temperature identified in the previous step, evaluating substrate moistening levels equivalent to 1.0, 1.5, 2.0, 2.5 and 3.0 times the dry weight of the substrate; due to the quantitative nature of the treatments, the data were subjected to regression analysis and curve fitting. The germination test of E. phaeotricha seeds should be conducted at 30 °C on paper, moistened with a water volume of 2.2 times the dry weight of the paper, with initial and final counts at 6 and 14 days after sowing, respectively.

Effect of Size Classification on Physical and Physiological Quality Aimed at Pelletizing Seeds of Eucalyptus Species

“…Marketed eucalyptus seed lots are a mixture of pure seeds with inert material, such as unfertilized eggs and crop remains (Affonso et al, 2018;Brasil, 2013). Due to the small size and similar physical characteristics of these materials, it is difficult to obtain seed lots with high purity by processing only (Santos, 2016).…”

Determinação da metodologia para o teste de germinação de sementes de Eucalyptus urophylla S. T. Blake (Myrtaceae)

“…Foram realizadas contagens diárias do número de plântulas normais até a data de estabilização da germinação, verificada quando o número de plântulas normais se manteve estável por três dias de contagem sucessiva (AFFONSO et al, 2018;TOMAZ et al, 2015;2016). Considerou-se plântula normal aquela que possuía parte aérea, raízes primárias íntegras e bem desenvolvidas e comprimento total de plântulas maior que 3 mm; os resultados foram expressos em porcentagem (BRASIL, 2009;AFFONSO et al, 2018).…”

“…A primeira contagem de germinação foi determinada quando a germinação atingiu aproximadamente 50% daquela obtida ao final do teste (AFFONSO et al, 2018;TOMAZ et al, 2015;2016). Índice de velocidade de germinação: realizado em conjunto com o teste de germinação e calculado com base na contagem diária das plântulas normais até a data final do teste de germinação de 26 dias e aplicando-se fórmula estabelecida por Maguire (1962).…”

“…Após a finalização do segundo experimento, foram identificadas duas temperaturas ideais, associadas ao substrato, para ambos os lotes para elaborar as curvas de germinação, visando à data da primeira contagem (50% daquela obtida ao final do teste) e da contagem final do teste de germinação, utilizando os dois lotes (TOMAZ et al, 2015;2016;AFFONSO et al, 2018).…”

Micromorphological Observation of Eucalyptus Seeds, Multivariate Statistical Analyses and Modeling of Their Germination Under Salt Stress and Osmotic Constraint

“…The number of germinated seed was counted every day for 30 days. The standard germination test ended at 30 days because from this date on, no normal seedlings emerged in any treatment for three successive counts (Affonso et al, 2018) The parameters of the germination rate (GR), the mean time of germination (MTG) and the coeffient of velocity (CV) of Kotowski (1962), were calculated as follows, Here, n is the total number of germinated seeds and N is the total number of tested seeds. Where D is the number of days counted from the date of sowing and N is the number of seeds germinated on day D. Coeffient of velocity: equation 1, where, ni is the number of seeds newly germinating on day i and Di is the number of days from sowing…”