Adequação do teste de envelhecimento acelerado para avaliação do vigor de sementes de leucena

Abstract

RESUMOLeucaena leucocephala (Lam.) de Wit. (Fabaceae) é uma leguminosa arbórea indicada para a composição de sistemas agroflorestais e alimentação de animais em regiões de clima semiárido. Dada sua importância, objetivou-se com este estudo adequar a metodologia do teste de envelhecimento acelerado para avaliação do vigor das sementes. Para tanto, procederamse a execução de testes de envelhecimento acelerado à temperatura de 41 °C durante 0, 48, 72 e 96 h em lotes de sementes, com avaliação da porcentagem de germinação pós-envelhecimento e correlação simples com as variáveis germinação, primeira contagem, velocidade de germinação, condutividade elétrica e emergência de plântulas. Após 48 h de envelhecimento não foi constatada diferença na porcentagem de germinação das sementes dos lotes, e apenas o período de exposição de 96 h apresentou correlação significativa com o teste de emergência de plântulas. O teste de envelhecimento acelerado conduzido a 41 °C durante 96 h é eficiente para diferenciar lotes de sementes de L. leucocephala em níveis de vigor. Palavras-chave: Leucaena leucocephala; qualidade fisiológica; sementes florestais; semiárido Adequacy of the accelerated aging test to evaluate the vigor in leucena seeds ABSTRACTLeucaena leucocephala (Lam.) de Wit. (Fabaceae) is an arboreal species suitable for the composition of agroforestry systems and animal feeding in semiarid climates. Given its importance, the aim of this study was to adapt the methodology of the accelerated aging test to evaluate the vigor of L. leucocephala seeds. To this end, they proceeded to implementation of accelerated aging at 41 °C for 0, 48, 72 and 96 h in seed lots, with evaluation of the percentage of post aging germination and simple correlation with the variables germination, first count, speed of germination, electrical conductivity and seedling emergence. After 48 h of aging was no difference found on the percentage of germination of the lots, and only the 96 h exposure period showed a significant correlation with the seedling emergence test. The accelerated aging test conducted at 41 °C for 96 h is effective to differentiate lots of L. leucocephala seeds in vigor levels.

Accelerated aging test in the determination of safflower seeds vigor

“…With the increase of the temperature and longer time spent in aging conditions, the germination tends to be negatively affected (Flavio and Paula 2010). However, this information cannot be generalized, since in the present study, as found by Araújo et al (2017) in leucene seeds, some lots increased the germination percentage with the expansion of the period of exposure to accelerated aging. This fact is explained due to the greater stress tolerance of these lots, thus giving them greater physiological potential.…”

“…It can be observed that there was a significant increase in the moisture content of the seeds after the traditional accelerated aging test (Table 3), as observed by Araújo et al (2017) in leucene seeds. Marcos Filho (2016) states that the moisture content corresponds to the equilibrium point, which increases with the elevation of the relative humidity of the air and vice-versa.…”

Improving the method for determining the physiological and sanitary potential of Gherkin seeds

“…It was also verified that seed deterioration increases with the increment of the exposition period to the accelerated aging test, once the reduction of germination was verified within each temperature tested (Araújo et al 2017). Frandoloso et al (2017) sustain that temperature increment promotes more drastic effects in germination than the extension of the exposition period to accelerated aging, as we verified at a temperature of 45 o C. Peng et al (2011) found in aging that high temperatures and high relative humidity caused lower selectivity of plasma membranes, in addition to reactive oxygen species triggering lipid peroxidation.…”

Piptadenia moniliformis Benth. seeds subjected to accelerated aging

“…seeds, at different temperatures and aging times, found a (A) (B) S11 = 85,9382 -0,5671x R 2 = 0,96 S12 = 75,9640 + 0,9697x -0,0268x 2 + 0,00011x 3 R 2 = 0,93 S13 = 64,9543 + 1,7911x -0,0469x 2 + 0,0002x 3 R 2 = 0,99 S14 = 87,39885/(1 + e 0,08692(x -54,71915) ) R 2 = 0,99 S15 = 78,58186/(1 + e 0,05619(x -69,81257) ) R 2 = 0,96 S11 = 75,0338 -0,0873x -0,0033x 2 R 2 = 0,90 S12 = 81,1968 -0,0169x -0,0045x 2 R 2 = 0,96 S13 = 76,4203 -0,0025x -0,0036x 2 R 2 = 0,92 S14 = 74,8360 + 1,1674x -0,0287x 2 + 0,0001x 3 R 2 = 0,91 S15 = 73,9777 + 0,9725x -0,0289x 2 + 0,0001x 3 R 2 = 0,95 significant reduction in germination. In Leucaena leucocephala seeds, germination declined in the different lots, increasing the accelerated aging time (Araújo et al, 2017). Considering three P. moniliformis seed lots, Aquino et al (2018) concluded that aging for 24 h at 41°C was the most appropriate condition to separate seed lots into different vigor levels since it produced results similar to those obtained when classifying the initial quality of the lots.…”