Biochemical and physiological analysis in carrot seeds from different orders of umbels

Abstract

-In carrot seed production, harvesting of the umbels is generally staggered, or sometimes the whole plant is harvested with the umbels at different stages of maturation; in that case, there is a risk of harvesting immature seeds and of losses due to natural dehiscent, or to physiological deterioration as a result of unfavourable environmental factors. The present study aimed to evaluate the physiological and biochemical changes related to the maturation of 'Planalto' carrot seeds from diferent umbels. The samples were collected 120 days after anthesis, with the primary, secondary and tertiary umbels being harvested separately. Seeds were analysed for germination, first count and germination rate, at temperatures of 25 °C (optimum) to 35 °C (adverse), as well as for emergence in the greenhouse and the emergence rate. Analyses were also carried out of the enzymes peroxidase (POX), ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD), and of the total protein. Seeds obtained from the primary and secondary umbels displayed a higher rate of germination than from the tertiary umbels, with the seeds from the primary umbels showing high activity for peroxidase, catalase and superoxide dismutase, and low activity for the enzyme ascorbate peroxidase.Key words: Daucus carota L.. Physiological quality. Enzyme activity.RESUMO -Na produção de sementes de cenoura, a colheita das umbelas é geralmente parcelada ou, em algumas vezes, colhe-se a planta toda com umbelas em diferentes estádios de maturação; nesse caso, corre-se o risco de colheita tanto de sementes imaturas como de ocorrerem perdas devido à debulha natural ou por deterioração fisiológica em consequência de fatores ambientais desfavoráveis. O presente estudo teve como objetivo avaliar as alterações fisiológicas e bioquímicas relacionadas à maturação das sementes de cenoura cv. Planalto provenientes de diferentes umbelas. As colheitas foram realizadas aos 120 dias após a antese, onde foram colhidas umbelas primárias, secundárias e terciárias separadamente. Sementes foram analisadas quanto a: germinação, primeira contagem e índice de velocidade de geminação nas temperaturas de 25 ºC (ótima) e 35 ºC (adversa), além de emergência em casa de vegetação e índice de velocidade de emergência. Foram ainda realizadas análises das enzimas peroxidase (POX), ascorbato peroxidase (APX), catalase (CAT) e superóxido dismutase (SOD), além das proteínas totais. As sementes obtidas das umbelas primárias e secundárias apresentaram germinação superior às sementes das umbelas terciárias, sendo que as sementes das umbelas primárias apresentaram elevada atividade de enzimas peroxidase, catalase e superóxido dismutase e baixa atividade da enzima ascorbato peroxidase. Palavras-chave:Daucus carota L.. Qualidade fisiológica. Atividade enzimática.

Determination of Hydrogen Peroxide Content and Antioxidant Enzyme Activities in Safflower (Carthamus tinctorius L.) Seeds After Accelerated Aging Test

“…Seed deterioration and aging increase peroxide and ROS in seeds and cause cell damage due to oxidative stress [27,28]. Changes in the activity of antioxidant enzymes are crucial biomarkers for observing biochemical changes during seed deterioration [29]. There are important changes in the activities of enzymes such as CAT, SOD and POD during the degradation and aging of seeds [30].…”

Seed Aging, Storage and Deterioration: An Irresistible Physiological Phenomenon

“…The decrease in catalase activity is thus correlated with the decline in the seed viability and also indicates its poor affinity for H 2 O 2 (Gutteridge and Halliwell 1990). Changes in these enzymatic activities are very important biomarkers in monitoring the biochemical changes resulting from deteriorative processes (Silva et al 2016).…”

“…Techniques related to biochemical aspects have also been employed to assess seed quality to determine the activity of enzymes involved in cell respiration (Silva et al 2016) and reserve mobilization. The decline in activity of an enzyme in the seed lowers the respiratory capability, thus leading to a decrease in the energy and assimilate supply of the germinating seeds.…”

Physiological quality of parsley seeds in function of size

“…rate and vigor (Miranda, Dias, Picoli, Silva, & Nascimento, 2017;F. E. C. B. Pereira, Torres, Silva, Granjeiro, & Benedito, 2014;Silva, Sekita, Dias, & Nascimento, 2016).…”