Efeito do condicionamento osmótico na germinação e vigor de sementes de sorgo com diferentes qualidades fisiológicas

Abstract

O objetivo nesta pesquisa foi avaliar o efeito do condicionamento osmótico na germinação e no vigor de sementes de sorgo, cultivar IPA 1011, com diferentes qualidades fisiológicas. O delineamento experimental foi o inteiramente casualizado com quatro repetições, no esquema fatorial 2 x 2, constando de quatro tratamentos: 1. sementes envelhecidas; 2. sementes não envelhecidas; 3. sementes envelhecidas e condicionadas osmoticamente e 4. sementes não envelhecidas e condicionadas osmoticamente. A qualidade das sementes foi avaliada por meio do teor de água (TA), massa de mil sementes (MMS), primeira contagem (PCG), teste de germinação (TG), índice de velocidade (IVG) e tempo médio de germinação (TMG), envelhecimento acelerado (TEA), teste de frio (TF), condutividade elétrica (TCE) e lixiviação de potássio (TLK). Os resultados mostraram que o envelhecimento artificial afeta negativamente o desempenho das sementes de sorgo, podendo tais efeitos serem parcialmente revertidos pelo condicionamento osmótico, sendo que essa técnica não influencia a germinação, mas promove benefícios no vigor das sementes de qualidade fisiológica superior e inferior.

<b>Priming and stress under high humidity and temperature on the physiological quality of <i>Brachiaria brizantha</i> cv. MG-5 seeds

“…Priming is an alternative method to stress processes (Paparella, Araújo, Rossi, Wijayasinghe, Carbonera and Balestrazzi (2015). Seeds are often subjected to priming, as reported by Oliveira and Gomes Filho (2010) for sorghum seeds. These authors reported that priming partially reversed the negative effects of aging.…”

Methods for priming maize seeds

“…Priming or physiological conditioning is based on the controlled hydration of the seeds, so that pregermination metabolic process begins without radicle protrusion (Heydecker et al, 1975). Among the improvements achieved through priming, can be mentioned the increase in germination percentage, germination speed, length and seedling dry mass, as well as the increase in the ability of seeds to withstand stress during germination (Arif et al, 2010;Arif et al, 2014;Dezfuli et al, 2008;Khalil et al, 2001;Masetto et al, 2013;Oliveira and Gomes Filho, 2010;Pereira et al, 2008;Sediyama et al, 2012;Yasari, et al, 2013).…”

Effectivity of X-ray test to evaluate the physiological quality of sesame seeds due to fruits position at the plant

“…This fact is possibly correlated with the maturity of these seeds, since, according to AbdulBaki & Baker (1973), the non-uniform maturation of sesame dehiscent plants results in the production of immature seeds in the apical part that release more leachates because they are in the stage of development and maturation. In addition, the high mean value of the electrical conductivity, 444.53 Μs cm -1 g -1 , found in sesame seeds from capsules of the upper third means that these seeds are much deteriorated and with low vigor (Oliveira & Gomes Filho, 2010). These results agree with those observed by Silva et al (2017) who evaluated the physiological quality of sesame seeds, BRS -Seda cultivar, as a function of organic fertilization and position of the fruits in the plant, and concluded that seeds from the upper third were less vigorous in the electrical conductivity test when compared to seeds from the middle and lower thirds.…”