Non-stored Seeds Research Articles

Corn seeds of different sizes under drying methods and storage periods

The seed is the main input in the production process of the corn crop, and the drying process is crucial for maintaining the physiological quality and longevity of the seeds. Thus, the present study aimed to evaluate the physiological potential of hybrid corn seeds retained in different sieves under drying methods and storage periods. The experiment was conducted with corn seeds of the hybrid Balu 280 PRO, in a completely randomized design, with eight replications of 50 seeds, in a 5 × 2 × 2 factorial scheme, with retention sieves (24 M, 22 M, 20 M, 18 M, and 20 R), drying methods (traditional drying and gas drying) and storage periods (0 and 365 days). The variables analyzed were viability and vigor, based on germination and cold tests, respectively. Data were submitted for variance analysis using the F test (p<0.05) and means were compared using the Tukey test (p<0.05). For non-stored seeds, traditional and gas drying methods are independent for maintaining the viability and vigor of corn seeds. For seeds under 1 year of storage, the traditional drying method is better than gas drying to maintain the physiological quality of corn seeds, but the commercial standard is maintained in both methods. In both traditional and gas drying methods, seed storage favors the reduction of germination and vigor of corn seeds. Seeds retained on 22 M, 20 M, and 20 R sieves have greater vigor when compared to seeds retained on 18 M sieves.

Reproductive capacity and seed germination after various storage of the invasive alien plant Amorpha fruticosa L. - a case study from Bratislava

Amorpha fruticosa L. (Fabaceae) shows two reproductive modes, generative via seeds and vegetative via root-shoots. We studied the reproductive ability on a mixed sample collected from 6 localities in the city of Bratislava: compound fruiting per bush (12.55 ± 8.55), fruiting per bush (70.33 ± 48.04) and fruits per bush (16127.33 ± 24212.25). No significant difference was found between germination values from unpeeled fruits (achenes) and peeled fruits (seeds). Both seeds and fruits germinated very well both immediately after harvest and after storage under different temperature conditions. Peeled achenes germinated earlier. We stored seeds and fruits under different conditions, and found that the highest seed germination values were achieved by seeds stored in the dark at 22°C (60.00%) and by non-stored seeds (57.50%). The longest seedlings grew from seeds (8.48 mm) and from fruits (9.08 mm) stored at 22°C.

Lignin and Activity Enzymatic in Susceptibility to Weathering Damage on Soybean Seeds

The aim of this study was to evaluate the isoenzyme activity in soybean seeds with different lignin contents subjected to harvest delay with artificial incidence of rainfall before and after storage. The experiment was conducted in a randomized block design with three replicates and a 5 × 3 × 2 factorial design, being five soybean cultivars, three harvest seasons (R8, R8 + one pre-harvest rainfall simulation, and R8 + two pre-harvest rainfall simulations), and two storage seasons (0 and 180 days). The pre-harvest rainfall simulations were performed through irrigation at the intensity of 30 mm of water until the pods were soaked and then collected after reached 18% water content. Seeds were evaluated regarding chemical composition (lignin content), physiological quality (germination, accelerated aging), and enzymatic activity (catalase, esterase, alcohol dehydrogenase, malate dehydrogenase, and isocitratelyase). The cultivar AS 7307 RR showed higher lignin content in the integument and higher physiological quality. The harvest delay and the artificial incidence of rainfallpromotesvariation in the electrophoretic pattern of the enzymes catalase, esterase, alcohol dehydrogenase; malate dehydrogenase, and isocitratelyase for stored and non-stored seeds.

Changes in tocochromanols and glutathione reveal differences in the mechanisms of seed ageing under seedbank conditions and controlled deterioration in barley

“Orthodox” seeds are desiccation tolerant, enabling dry storage for agricultural and conservational purposes. Protocols of “controlled deterioration” (CD) using elevated temperatures and seed water contents (WCs) are frequently used to study mechanisms of seed ageing. However, the relevance of using CD to understand how seeds age at lower water contents and temperatures has been disputed. Here, comparisons in antioxidant changes are drawn between barley seed stored for up to 15 years in a seedbank with seeds aged using CD (45 °C, 75% RH; WC = 13% FW) under normoxia (21%) or elevated (75%) O2. Regardless of ageing method, glutathione (GSH) levels decreased concomitantly with an oxidative shift in the glutathione redox state (EGSSG/2GSH) as viability was lost. An earlier oxidative shift in EGSSG/2GSH and more rapid loss of seed vigour was found in seeds aged by CD under 75% O2, compared to 21% O2, but longevity was not shortened by elevated O2. Seedbank-aged seeds contained more glutathione disulphide (GSSG) levels, leaked more electrolytes upon imbibition and contained less tocochromanols than non-stored seeds. In contrast, in response to CD, levels of GSSG fell, electrolyte leakage did not increase and tocochromanol levels increased (21% O2), or remained stable (75% O2). In a further set of 24 barley genotypes stored for up to 15 years at 20 °C (WC = 11% FW) and 0 °C (WC = 8% FW), tocochromanol levels positively (r = 0.42) correlated with total germination, which ranged between 1-78% (20 °C) and 65-97% (0 °C). Of all tocochromanol species, α-tocopherol correlated most with total germination (r = 0.49) and γ-tocotrienol least (r = 0.08). It is concluded that CD is not a perfect model for understanding mechanisms of ageing that occur under seedbank conditions.

Fusarium verticillioides inoculum potential and its relation with the physiological stored corn seeds quality

The pathogenic fungi may be associated with the seeds during development, harvest and storage, and it can be disseminated through them. This work evaluated the seeds performance of three hybrid corn cultivars, BM 840 PRO, BM 810 and BM 207, submitted to different inoculum potentials of Fusarium verticillioides . Seeds were uniformly distributed over the medium fungal colony developed on PDA (potato dextrose agar) containing mannitol in water potential -2.0 MPa. Seeds remained in this way for different periods of contamination (0, 24, 48, 72 and 96 hours). Before and after seven months of seed storage the evaluations were performed. Seeds treated with fungicide Derosal Plus® (carbendazim + thiram, 250 mL p.c. 100 kg -1 ofseeds) were used as control. The increased of inoculum potential of F. verticillioides fungus on corn seeds caused reduction in physiological quality in the potentials 72 and 96 hours of exposure before and after storage. The highest Fusarium verticillioides incidence is observed in non-stored seeds. Fusarium verticillioides incidence on corn seeds accentuates the deterioration in storage.

Comparative study on wheat grains produced from plants treated by irradiated sodium alginate and stored in refrigerator with newly planted on vitality, quality, and their resistance to lesser grain borer (Rhyzopertha dominica)

Field experiment was conducted to compare between the wheat grains produced from plants sprayed by 1% solution of irradiated Na- alginate )ISA) stored in refrigerator for 30 months with those planted recently on vitality, quality and resistance to injury by Rhyzopertha dominica invasion. It was observed that untreated stored grains T1 decreased germination percentage about 15% comparing by newly planted control (T) and the depress in the stored treated grains were 7, 2 & 3% in 80 (T2), 120 (T3), and 160 (T4) kGy, respectively. While insignificant changes for the aforementioned treatments in concern to germination rate observed. The best growth characters were observed in T4. The highest soluble sugar, total carbohydrates and total amino acids were detected in T3. In entmology experiment it was noticed that all treatments had a range of resistance to R. dominica injury under laboratory conditions. The resistance cannot be attributed to grain size, but attributed to infestation percentage and frass weight. The most resistance found in stored grains (T3 and T2), respectively, in general non-stored seeds was more resistance to R. dominica than those stored in refrigerator. Moreover, (ISA) treatments had an inhibitory effect on insect amylase which varying from 85.6% - 56.1% and invertase which varying from 67.3% - 6.8%. Except pest tested with stored grains (T4) at low temperature showed an increase 13.5% and 20.6% in amylase and invertase activity, respectively. Irradiated sodium alginate preserved grains survival after long storage period especially T3 followed by T4. Also,using ISA before sowing stimulate the growth and yield.

Germinação, qualidade sanitária e armazenamento de sementes de canafístula (Peltophorum dubium)

Neste trabalho, objetivou-se avaliar o efeito de métodos de superação de dormência e do ambiente de armazenamento sobre a qualidade fisiológica e fitopatológica das sementes de canafístula (Peltophorum dubium). As sementes foram submetidas aos seguintes tratamentos de superação de dormência: escarificação com lixa (200); imersão em água na temperatura ambiente, durante 24 e 72 h; imersão em ácido sulfúrico por 2, 6, 10, 15, 20 e 30 min; imersão em água quente (70, 80 e 90 C); e umedecimento do substrato com solução de KNO3 (0,2%). As sementes foram armazenadas na temperatura ambiente e a 10 C por 210 dias. Os efeitos dos tratamentos e do armazenamento foram avaliados por meio do teor de água, teste de germinação (cinco repetições de 30 sementes), de comprimento de plântulas e sanidade (400 sementes), com incubação por oito dias (22-25 C). Na análise estatística dos dados, utilizou-se o delineamento experimental inteiramente casualizado em esquema fatorial 2 x 14 (condições de armazenamento x tratamentos para a superação da dormência). As médias foram comparadas pelo teste de Tukey (P>0,5). Com relação às sementes não armazenadas, os melhores tratamentos para superar a dormência e promover a germinação foram escarificação com lixa ou ácido sulfúrico por 15 a 30 min; quanto às sementes armazenadas, houve a imersão em água quente (70 a 80 ºC). Os fungos detectados nas sementes foram Pestalotia sp., Alternaria sp., Rhizopus sp., Nigrospora sp., Curvularia sp., Fusarium sp., Rhizoctonia sp., Aspergillus sp., Cladosporium sp. e Fusarium semitectum.

Changes in the ascorbate-glutathione system during storage of recalcitrant seeds of Acer saccharinum L.

Two seed lots of <em>Acer saccharinum</em> (recalcitrant), with an initial moisture content of 50% and 55%, were stored at +3<sup>o</sup>C for 6 months. After this time, their viability (measured as germinability) reached 100% and 30%, respectively. In embryo axes and cotyledons extracted from seeds, two major low molecular antioxidants were assayed: ascorbate (ASA and DHA) and glutathione (GSH and GSSG); and activities of enzymes of the ascorbate-glutathione cycle were measured: ascorbate peroxidase (APO) (E.C. 1.11.1.11), monodehydroascorbate reductase (MR) (E.C. 1.6.5.4), dehydroascorbate reductase (DHAR) (E.C. 1.8.5.1), and glutathione reductase (GR) (E.C. 1.6.4.2.). GSH and GSSG contents of embryo axes of stored seeds decreased, as compared to the control (fresh, non-stored seeds), but a larger decrease was observed in seeds with 30% viability. In cotyledons, a particularly high increase in the GSH content in relation to the control was observed in seeds with 100% viability, while the GSSG content was significantly lower in both stored seed lots than in the control. The ASA level was twice as high in seeds with 30% viability as in the control, both in embryo axes and in cotyledons. The activity of enzymes of the ascorbate-glutathione cycle was higher in embryo axes than in cotyledons. In embryo axes of seeds with 100% viability, enzyme activities were slightly lower than in the control, while in those of seeds with 30% viability, their activities were higher than in the control. The observed changes in activities of enzymes of the ascorbate-glutathione cycle and in ascorbate and glutathione levels suggest that the stored seeds of <em>A. saccharinum</em> have an active antioxidant system, which plays an important role in maintaining their viability during storage.

Qualidade fisiológica de sementes de palmiteiro-vermelho em função da desidratação e do armazenamento

Para algumas espécies com sementes recalcitrantes, como o palmito-vermelho (Euterpe espiritosantensis Fernandes), a secagem parcial favorece a manutenção da viabilidade durante o armazenamento. O objetivo deste trabalho foi verificar o efeito da desidratação e do armazenamento na germinação e vigor das sementes de palmito-vermelho. Dois lotes de sementes (L1 e L2) foram colocados para secar por 0; 20 e 40 horas (três sublotes) em câmara seca e armazenados a 15ºC em sacos plásticos fechados. Foi realizado um ensaio em delineamento inteiramente casualizado para cada lote de semente, com os tratamentos dispostos em fatorial 3 x 6 (L1) e 3 x 10 (L2), correspondendo a três tempos de secagem e seis ou dez semanas de armazenamento. A qualidade das sementes foi avaliada a cada seis semanas, durante 30 e 54 semanas para respectivamente L1 e L2, por meio do teor de água (U), porcentagem de germinação (G) e vigor (primeira contagem e índice de velocidade de germinação). O teor de água das sementes de ambos os lotes foi em média de aproximadamente de 46; 40 e 36%, respectivamente, para 0; 20 e 40 horas de secagem, sem alterações importantes em função do período de armazenamento. Para sementes não-armazenadas, a secagem reduziu de modo significativo o vigor, mas não comprometeu a germinação. O lote L1 apresentou sementes viáveis em todos os sublotes até o final do armazenamento (G = 71; 61 e 45% para 0; 20 e 40 horas, respectivamente). As sementes do lote L2 apresentaram perda total da viabilidade por volta da 30a.semana apenas no sublote onde foram secas por 40 horas (U = 36%). Nos demais sublotes, as sementes se mantiveram viáveis até 54 semanas de armazenamento (G = 46%). A secagem parcial reduziu o vigor e diminuiu a longevidade das sementes. Com base nos resultados obtidos pode-se concluir que sementes de E. espiritosantensis devem ser armazenadas sem secagem, com 45-46% de teor de água.

Moist storage of Brazil nut seeds for improved germination and nursery management

Seed storage of species from the humid tropics is often problematic because of seed sensitivity to desiccation and low temperatures, conditions traditionally considered necessary for long-term seed storage. In this study, Brazil nut seeds from 10 families were stored for five-and-a-half months under moist conditions at warm ambient temperatures. A randomized complete block design was employed for analysis of seed moisture content and germination, with storage and family as the main treatment factors. Moist storage of Brazil nut seeds clearly improved germination and can greatly facilitate nursery management. Seeds that were stored and then had testas removed germinated more quickly (Day 14 versus Day 60), exhibited greater percentage germination (74.8 versus 53.5%), and a reduction in seed deterioration (25.2 versus 46.5%). Storage also improved germination rate, and no seeds germinated prematurely while in storage. Moist storage improved germination of some families more than others such that stored seeds exhibited more uniform germination across all families. The delayed and prolonged germination of nonstored seeds may be due to endogenous seed dormancy that appears to be favorable for increasing the effective storage period of Brazil nut. During storage, embryo maturation may have taken place and/or a chemical inhibitor may have been leached from the embryos, resulting in improved Brazil nut germination.

Changes in protein synthesis in embryonic axes after long-term storage of maize seeds

AbstractThe aim of this work was to analyse the capacity for protein synthesis in embryonic axes from long-term-stored maize seeds, including the role of proline. Embryonic axes from seeds stored for 13 years (S) and non-stored seeds (NS) were incubated in nutrient media after application of [14C]proline. Transformation of [14C]proline into other amino acids was analysed by thin-layer chromatography. After 6 h of incubation, no other labelled amino acids were found. Incorporation of14C into total soluble and cell-wall (proline-rich) proteins was assessed during this period. Incorporation of [14C]proline into specific cell-wall proteins was lower in S than in NS axes.Studies using [35S]methionine showed that protein synthesis was slower in axes of S than in NS seeds. Analyses of these proteins by gel electrophoresis and fluorography revealed qualitative differences between the [35S]methionine proteins synthesized by both types of axes. The NS: S ratios for the [35S]proteins were larger than those from the [14C]proline assays. These data may be interpreted as an indication of differential deterioration of transcription or translation in the axes during long-term seed storage.