Condições de armazenamento e conservação do potencial fisiológico de sementes de diferentes cultivares de amendoim

Abstract

Seed storability of different peanut cultivars The conservation of the physiological potential of peanut seeds during storage is considered of great importance by seed companies, since the chemical composition of the seeds which are rich in lipids, combined with inadequate storage conditions can directly interfere in the seed longevity. Thus, the objective of this research was to evaluate the conservation of the physiological potential of peanut seeds stored in different environments, seeking to identify possible physiological changes during this period. Two peanut cultivars (IAC OL3 and RUNNER IAC 886) were used, each represented by three seed batches produced in different regions and stored for 9 months in the following conditions: Cold and dry chamber (11oC / 24% relative humidity RH), dry chamber (19oC / 40% RH), and natural environment (24oC / 66% RH), preceded or not by the threshing. Seed performance was evaluated in quarterly seasons through germination and vigor tests (traditional accelerated aging and saturated NaCl solution, electric conductivity, emergence of field seedlings, computerized analysis of seedlings images SVIS) and test of sanity. The activity of the enzymes superoxide dismutase, catalase, malate dehydrogenase and esterase was also determined by the electrophoresis technique. The data were submitted, separately for each cultivar, to the analysis of variance, in a completely randomized design (laboratory tests) and in randomized blocks (field tests); the means were compared by the Tukey s test (α ≤ 0.05). It was found that the physiological potential of seeds of IAC OL3 and RUNNER IAC 886 is preserved when stored in a cold and dry chamber, being the water content safe to reduce the deterioration rate of the seeds both inside the pods and threshed, during storage, both cultivars, is 4.4%. The storage sub-optimal conditions of temperature and relative humidity as the natural environment, promotes greater negative interference in the speed of deterioration of the seeds of the threshing system. Changes in enzyme systems of superoxide dismutase and catalase identifying the progress of deterioration of peanut seeds at different storage conditions preceded or not the threshing operation.