Dry Matter Of Seedlings Research Articles

Research Article Physiological Traits and Their Relationships in Black Oat Populations

The objective of this work was to verify physiological quality of black oat populations, in order to know and point out the relationships among physiological characters for selection of progenies. The experiment was carried out at the Laboratory of Plant Breeding and Production, Federal University of Santa Maria, Campus of Frederico Westphalen - RS. Seed samples were collected from 14 black oat populations from small producers in the region, and cultivars BRS Madrugada and BRS Centauro (populations 15 and 16, respectively). A randomized block design with four replications was used. It was evaluated seed length, seed width, thousand seed weight, percentage of germination, non-germinated seeds, abnormal seedlings, hypocotyl length, root length, dry matter of seedlings. Populations revealed a difference in the physiological quality of seeds, and populations 1, 8, 9, 11, 12, 13, with germination within the required standard, have a greater potential to compose progenies. Seed width, thousand seed weight, dry matter of seedlings and hypocotyl length revealed association with germination. It is worth highlighting that seed width and thousand seed weight are characters of easy and immediate measurement that can guarantee greater efficiency of selection.

English

The aim of this work was to evaluate commercially available substrates and levels of potassium on the development of passion fruit seedlings in protected conditions. The experiment was conducted at the city of Presidente Prudente, Sao Paulo within the period from April to September of 2010. The treatments were made with three different substrates (Bioplant®, Coconut fiber and Vivatto®) and four levels of potassium (0, 150, 300 and 600 mg-1 of K dm-³), arranged in a 3 × 4 factorial design with five repetitions. The following parameters were analyzed 120 days after seedlings transplanting: Plant height, number of leaves, length of root, dry matter of shoot, root, total matter and chlorophyll content. The dose of 600 mg dm-3 of K provided the highest seedling height, 85.83 cm independent of the substrate. The commercial substrates Bioplant® and Coconut fiber with a dose of 150 mg dm-3 of K influenced the maximum accumulation of total dry matter of seedlings. However, Vivatto® substrate provided the highest accumulation of total dry matter with application dose of 600 mg dm-3 of K. Mineral potassium fertilization in the substrate Bioplant® and Coconut fiber with a dose of 150 mg dm-3 reduced the length of passion fruit’s roots. Key words: Passiflora edulis Sims., mineral nutrition, protected cultivation.

QUALIDADE FISIOLÓGICA DE SEMENTES DE <i>Tabernaemontana fuchsiaefolia</i> A. DC EM FUNÇÃO DO TESTE DE ENVELHECIMENTO ACELERADO¹

http://dx.doi.org/10.5902/1980509821114Tabernaemontana fuchsiaefolia A. DC é uma espécie da família Apocynaceae, nativa do Brasil, com característica invasora, possuindo potencial para uso em recuperação de áreas degradadas. O trabalho teve o objetivo de avaliar a influência dos métodos de envelhecimento acelerado sobre a qualidade fisiológica e germinação de sementes, utilizando-se o método tradicional e em solução de NaCl, empregando-se a metodologia de gerbox, formando minicâmaras de envelhecimento, em três temperaturas (41, 43 e 45°C) e cinco tempos de envelhecimento (0, 24, 48, 72 e 96 horas). As sementes, após o envelhecimento, foram colocadas para germinar em rolos de papel germitest, em quatro repetições de 25 sementes, em câmaras BOD a temperatura de 30°C, com fotoperíodo de 8 horas. O efeito da temperatura foi comparado pelo teste de Tukey em nível de 5% de probabilidade e o efeito do tempo de envelhecimento, pela análise de regressão. Após 35 dias, foram avaliados percentual, índice de velocidade, tempo médio e frequência da germinação, bem como comprimento de raiz e parte aérea, massa seca de plântulas e percentual de plântulas normais. Observou-se que o método alternativo de envelhecimento com solução de NaCl teve pouca influência na qualidade das sementes, não sendo indicado para testes de vigor para a espécie. O método tradicional, na temperatura de 45°C em período de envelhecimento de 96 horas, promoveu queda na germinação e pode ser utilizado para testar o vigor de sementes de leiteira.

<b>Germination and emergence of passion fruit (<i>Passiflora edulis</i>) seeds obtained by self- and open-pollination

Seed dormancy is an important adaptive mechanism in many species and is generally lost during plant domestication because of selection that occurs through the collection and planting of seeds. We compared germination and seedling emergence in selfed and open-pollinated progenies obtained from eight passion fruit vines (genotypes). Self-pollination was performed at the button stage to overcome self-incompatibility. The experiment was a randomized block design in a factorial scheme (2 x 8; type of progeny x genotypes) with four replicates and 50 seeds per experimental unit. At 14, 21 and 28 days after sowing, the germination percentage and the emergence speed index were analyzed. The total length of seedlings (cm), shoot length (cm), radicle length (cm) and total dry matter of seedlings (g) were evaluated 28 days after sowing. The mass of 100 seeds (g) was determined before sowing. Differences were noted between genotypes and progeny types with respect to germination and emergence speed. In general, seeds obtained by selfing exhibited earlier germination and a higher emergence speed. It was concluded that seed dormancy is associated with the genotype of the embryo and is most likely conditioned by a dominant genetic effect.

Dynamics of reserves of soybean seeds during the development of seedlings of different commercial cultivars

Physiological quality and vigor of the seeds comprise properties that determine a high level of activity and performance during germination and seedling emergence, having a direct relation with the establishment of the stand of a crop. In this context, the assessment of seedling development, including the analysis of the seed reserves mobilization are a reliable method to investigate the physiological potential of seed lots. In this preliminary study, the aim was to investigate the dynamics of seed reserves mobilization of a sample of soybean commercial cultivars. By means of the seedling length bioassay and weight of dry matter of seeds, cotyledons, hypocotyls and radicles, information on the reserves mobilization during the germination process was obtained. Data were subjected to analysis of variance and Scott and Knott test, and afterwards, phenotypic correlations between traits were obtained. The results have shown that the dry matter of seeds, reserves reduction of seeds and dry matter of seedlings are positively correlated, and thus, seeds containing more reserves may be more effective during the early development of seedlings. In contrast, reserve reduction of seeds and conversion efficiency of the seeds reserves in the dry matter of seedlings are negatively correlated.

Effect of harvesting stages on seedling characters of groundnut (Arachis hypogaea L.)

The studies revealed that in seedling characters of groundnut after each harvesting stage tested by carried out germination test in laboratory observed root length (cm), shoot length (cm), dry matter of seedlings (g) were increased after PM in all six varieties of groundnut.

Armazenamento de sementes de Parkia pendula (Willd.) Benth. ex Walp. (FABACEAE) em diferentes embalagens e ambientes

Parkia pendula (angelim-saia) é uma árvore natural na Amazônia brasileira. Com o objetivo de avaliar o comportamento germinativo e a qualidade fisiológica, suas sementes foram acondicionadas em embalagens de diferentes permeabilidades: sacos de alumínio, plástico e papel, e armazenadas por um período de seis meses, nos ambientes câmara refrigerada e ambiente natural. Foram avaliados: teor de água; porcentagem de germinação; tempos médios de emissão de raiz e plântulas; comprimento e massa seca de plântulas ao segundo, quarto e sexto mês, e a produção de mudas no início e no término do armazenamento. As sementes mantêm-se viáveis e com qualidade por seis meses de armazenamento. Em câmara refrigerada, as embalagens recomendadas são sacos de plástico e de papel. No ambiente natural, é possível usar os três tipos de embalagens. Sementes armazenadas na câmara refrigerada por seis meses produziram mudas de melhor qualidade para a característica relação altura/diâmetro de colo, para sementes armazenadas em saco plástico e saco de alumínio.

Effect of soaking in Jellyfish on some parameters of wheat and lentil seedlings

The potency of soaking in digested or stock jellyfish on germination of wheat (Triticum aestivium) and lentil (Lens culinaris) seeds was studied. Also, the photosynthetic pigments, ultrastructure of leaves and minerals in the produced seedling were estimated. The results revealed that soaking seeds in digested jellyfish solution recorded the highest germination capacity and germination rate in lentil seeds. Also, improves seedlings height, number of leaves and fresh weight of the produced seedlings than those from soaked in stock jellyfish or in water. Soaking lentil seeds in stock or digested jellyfish mostly increased chlorophyll a, b and carotenoisds, contrarwisewashappened in wheat seedlings as compared to control values. A great variation in microelements and heavy metals in dry matter of seedlings that were produced from seeds soaked either in stock or digested solution of jellyfish. Some elements increased another decreased and some disappeared in both wheat and lentil seedlings. Also, the ultrastructural examination by transmission electron microscopy of seven days old wheat or lentil leaf revealed no abnormalities but some organelles as ribosomes, vesicle rough and smooth endoplasmic reticulum are higher in micrograph.

Germinação e vigor de sementes de gabiroba em função do tamanho do fruto e semente

O conhecimento dos aspectos biométricos de frutos e sementes e a sua influência na germinação são importantes para a produção e características de espécies nativas. Este trabalho objetivou avaliar a influência do tamanho do fruto e da semente na germinação e vigor de sementes de gabiroba (Campomanesia adamantium). Para a caracterização biométrica, foram selecionados, aleatoriamente, 120 frutos, divididos, visualmente, em quatro classes, com predominância de tamanho, nas quais foram avaliados o diâmetro longitudinal e transversal e a massa das sementes. A caracterização da semente foi realizada em 30 frutos de cada classe, por meio da determinação do número de sementes íntegras, vazias e total de cada fruto. O potencial fisiológico das sementes, em função do tamanho dos frutos, foi analisado por meio dos seguintes testes: curva de embebição, grau de umidade, percentagem e índice de velocidade de germinação, comprimento de plântulas, massa fresca e massa seca total de plântulas. O delineamento foi inteiramente casualizado, com quatro tratamentos. Os frutos foram classificados de acordo com o diâmetro longitudinal e transversal, respectivamente, como pequeno (12,71 mm; 12,46 mm), médio pequeno (15,38 mm; 15,01 mm), médio grande (18,84 mm; 18,02 mm) e grande (22,74 mm; 22,36 mm). As classes de frutos pequeno, médio pequeno e médio grande apresentaram sementes com maior percentagem e velocidade de germinação, enquanto frutos classificados como grandes proporcionaram plântulas com maior acúmulo de biomassa.

Exogenous glycinebetaine and humic acid improve growth, nitrogen status, photosynthesis, and antioxidant defense system and confer tolerance to nitrogen stress in maize seedlings

Abiotic stresses, including nitrogen stress (NS), can hamper photosynthesis and cause oxidative damage to plants. Upregulation of the antioxidative defense system and photosynthesis induced by exogenous glycinebetaine (GB) and humic acid (HA) can mitigate the inhibitory effects of NS on plants. In the present investigation, the beneficial effects of exogenously applied GB and HA were examined on growth, leaf N status, photosynthesis, lipid peroxidation, and activities of some key antioxidant enzymes in the seedlings of maize cv. Zhengdan 958 (ZD958) exposed to NS. NS caused a significant reduction in total dry matter of seedlings of ZD958, but both GB and HA proved effective in mitigating this inhibition, hence, the beneficial effects of GB being more pronounced than those of HA. NS led to a considerable decrease in leaf total N and endogenous GB contents, stomatal conductance (gs), net photosynthetic rate (Pn), intercellular CO2 concentration (Ci), and activities of two key C4 photosynthesis enzymes phosphoenolpyruvate carboxylase (PEPCase) and ribulose-1,5-bisphosphate carboxylase (RuBPCase) as well as of superoxide dismutase (SOD) and peroxidase (POD). This treatment caused an increase in lipid peroxidation, but showed no effect on POD activity. Exogenous application of varying doses of GB resulted in a decrease in lipid peroxidation and Ci, and an increase in leaf total N and endogenous glycinebetaine (EGB) content, Pn, and activities of RuBPCase, PEPCase, SOD, and catalase (CAT) under NS. In contrast, application of different doses of HA resulted in a decrease in lipid peroxidation, an increase in Pn, gs, and Ci as well as SOD, CAT, and POD activities without increasing leaf total N and EGB content, and enhanced RuBPCase and PEPCase activities. The present study suggests that exogenous application of GB and HA can induce tolerance in maize plants to NS, but through the regulation of different mechanisms.

Physiological quality of castor bean seeds originating from different racemes in the plant

The harvesting is one of the most critical phases in castor bean seed production system, once physiological quality of the seeds produced in the different types of racemes in the plant can be affected. The aim of this study was assessing physiological quality of castor bean seeds in function of position of the racemes on plant. Castor bean seeds, cv. IAC-226, harvested separately at distinct periods from primary, secondary, and tertiary racemes, or of mixture of seeds originating from the different types of racemes were used. Soon after harvest, the following determinations were performed: moisture content; 1,000 seeds weight; germination; first count of germination; seedling emergence; emergence speed index; and length and dry matter of seedlings. A completely randomized experimental design was used with four repetitions. Data were subjected to ANOVA and means were compared by Tukey test, at 5% probability. The seeds from primary racemes present higher weight and vigor as compared to seeds produced on other types of racemes. Seeds originating from secondary and tertiary racemes present post-harvest dormancy, being this event more evident on seeds originating from tertiary racemes.

Yellow Jacket Seed Coating Improves Establishment of ‘Prosper’ Summer-Dormant Tall Fescue

Establishment of summer-dormant tall fescue [Schedonorus phoenix (Scop.) Holub syn. Festuca arundinacea Schreb.] pastures may be difficult in the Southern Great Plains because of insufficient autumn precipitation. We determined the effects of seeding rates, seed coating with Yellow Jacket, and supplemental irrigation during establishment on seedling dry matter (DM) and aboveground biomass DM of summer-dormant tall fescue cv. Prosper at Vernon, TX, during two growing seasons. Seeding rates affected seedling DM differently in the full and reduced supplemental irrigation systems and had a significant effect on aboveground biomass DM only in the first growing season. Seed coating increased seedling DM regardless of supplemental irrigation amount and it increased aboveground biomass DM only in the reduced supplemental irrigation system during the first growing season. Results indicate that Yellow Jacket seed coating may improve establishment and productivity of summer-dormant tall fescue in the first growing season, especially with limited soil moisture.

Sunflower seedlings dry matter content as affected by chemical treatment and storage length

Chemical treatment of seed is a common crop protection measure. In the case of sunflower seed, fungicides are used regularly and insecticides at an increasing rate. In some cases, sunflower hybrid seed not planted in the first year is planted in the second or even third year after production. Seed vigour decreases gradually over time, which negatively affects seed emergence and subsequent plant growth and development. Seed with high vigour is expected to germinate quickly, producing seedlings that grow fast and uniformly. The objective of this study was to assess the effects of seed chemical treatment and storage length on seedling dry matter content in different sunflower hybrids. The study included several variants with fungicide and pesticide treatments and an untreated control. In the case of the hybrid NS-H-111, highest values of the studied characteristic were recorded in the control and directly after chemical treatment. In the case of the hybrid Sremac, the lowest value was recorded in seed treatment with benomyl+metalaxyl, highest in the treatments directly after chemical treatment and in seed stored for six months. In the case of the hybrid Sumadinac, highest values were recorded in the control and in seed treatment with fludioxonil+metalaxyl, the lowest in seed treatment with fludioxonil+metalaxyl+im idacloprid. Regarding the effect of different seed storage periods, highest values of the studied characteristic were recorded shortly after chemical treatment and in seed stored for six months.

EFFECTS OF IN VITRO CULTURE METHODS DURING THE ROOTING STAGE AND LIGHT QUALITY DURING THE SEEDLING STAGE ON THE GROWTH OF HYDROPONIC EVERBEARING STRAWBERRY

To achieve the mass production of pharmaceutical proteins in genetically modified (GM) strawberry (Fragaria x ananassa Duch. cv. 'HS138'), a continuous supply of a large number of uniform seedlings is required. We modified the micropropagation method which is suitable for subsequent hydroponic cultivation in a closed plant production system with artificial lighting. In this study, we conducted 6 treatments comprising 2 in vitro culture methods (PM: photomixotrophic culture or PA: photoautotrophic culture) during the rooting stage for 3 weeks and 3 light qualities (white, red and blue) for 4 weeks after transplanting to the ex vitro hydroponic system. The PM plantlets without roots were cultured on agar during the rooting stage, and their roots were washed to remove the agar before transplanting them to the hydroponic system. In contrast, the PA plantlets were cultured on a fibre rod as the supporting medium, which was the same medium as that used in the hydroponic stage. At the end of the rooting stage, the number of leaves, leaf area and dry matter were significantly higher in the PA plantlets than in the PM plantlets. During the hydroponic cultivation stage, the dry matter of seedlings was significantly higher under white and red light conditions than under blue light condition, irrespective of the culture method during the rooting stage. These results suggest that a combination of the PA culture methods during the rooting stage and white or red light condition after the transplanting can improve the efficiency of the propagation method used for GM strawberry production.

Response of date palm (Phoenix dactylifera) seedlings to organic manure, N and K fertilizers in polybag nursery

A trial was conducted at NIFOR’s sub-station, Dutse, Jigawa State, Nigeria to investigate the influence of soil fertility amendment using inorganic fertilizers and organic manure on date palm seedlings in polybag nursery. Experimental design was a 3 ◊ 4 ◊ 4 factorial with organic manure (dried poultry droppings) at 0, 50 and 100 g per seedling, ammonium sulphate at 0, 2, 4 and 8 g per seedling and muriate of potash at 0, 2, 4 and 8 g per seedling. Seedling dry matter significantly increased with increasing rates of organic manure applied. Application of ammonium sulphate or muriate of potash beyond 2 g per seedling significantly reduced seedling dry matter. Manure ◊ N interaction effect on dry matter was significant. However, manure ◊ muriate of potash or manure ◊ N ◊ muriate of potash or muriate of potash ◊ N interaction were not significant. Leaf nutrient contents were not significantly enhanced by the application of the soil amendment treatments. Supplementation of poultry manure with ammonium sulphate enhanced date palm seedling dry matter. Thus while poultry manure could serve as alternative soil fertility treatment to inorganic N or K, its supplementation with inorganic sources of N may be needed to enhance seedling dry matter.

Crop responses to sulfonylurea residues in soils of the subtropical grain region of Australia

Crop response following applications of sulfonylurea herbicides can vary considerably across the grain region of subtropical Australia. The aim of the study was to develop recommendations for safe re-cropping following chlorsulfuron, triasulfuron, and metsulfuron-methyl specific for the different soils and climates of this region. Seedling dry matter (SDM) and grain yield were measured at 17 sites over 4 seasons. Soils were ferrosols (pH 5.5–6.8), sodosols (pH 6.6–7.1), and vertosols (pH 7.8–9.0). Sorghum and sunflower were sown at plant-backs between 2 and 20 months, and chickpea at 10–13 months, after applications of sulfonylurea herbicides. Seedling response of the summer crops to these herbicides was substantially different for the 3 soils. Crop response in theferrosols was largely unaffected by plant-back, soil, or climatic factors after a minimum of 2–3 months. In contrast, response of summer crops in the vertosols and sodosols was strongly affected by plant-backs for up to 10 months, and SDM was more affected in sodosols than in vertosols. Predictive relationships between SDM and plant-back, cumulative temperature, and measured chlorsulfuron residues were developed for sowing summer crops in these soils. In ferrosols and vertosols, chickpea was unaffected by any treatment following plant-back of 10–12 months. These findings indicate that shorter re-cropping is possible in this region than currently recommended. However, the decision should be based not only on plant-back, but on soil type, cumulative temperature, and possibly even residue level in soil. These more specific recommendations will improve the safety and flexibility of re-cropping following applications of sulfonylurea herbicides in this region.

Seedling indices of four tree species in nursery and their correlations with field growth in Tamil Nadu, India.

Selection of quality seedlings in nursery is important for raising fast-growing trees for production of fuelwood and other products. In order to identify the morphophysiological variables that can be used in nursery for selection purpose, a study on growth, drymatter production, and rate of photosynthesis was undertaken with seedlings of four tree species, viz, Acacia nilotica, Albizzia lebbeck, Dalbergia sissoo and Eucalyptus camaldulensis. The species varied significantly in growth, drymatter production and photosynthetic rate in nursery. E. camaldulensis was the fastest in growth and A. nilotica had maximum number of leaves. Total drymatter production was maximum in D. sissoo followed by A. lebbeck. The rate of photosynthesis was maximum in D. sissoo followed by A. nilotica and lowest in A. lebbeck. Among the various seedling attributes, height, number of leaves per plant, rootweight and photosynthetic rate exhibited significant correlations with seedling drymatter. Seedling diameter showed weak positive correlations with drymatter of both seedlings as well as two-year old field trees. However, number of leaves per plant, rootweight, shootweight and leafweight showed significant correlations with two-year field tree drymatter, the strongest correlation (r = 0.96, P = 0.001) was found between number of leaves per plant and field tree drymatter. Although plant height and leaf photosynthetic rate showed a positive correlation with two-year field growth, the relationship was statistically non-significant. The study reveals that maximum value for leaf number and dryweight of seedling components such as root, shoot and leaf can be used as criteria for selecting nursery stocks for field planting in semiarid conditions.

Effect of high temperature treatment on disinfestation and quality characteristics of sorghum

SummarySorghum grain (two varieties) was modified to different water contents (12% to 16% wet weight basis) and heated to 60°C, 70°C and 80°C for periods of 4, 8 and 12 min. Germination, seedling vigour, seedling dry matter, free fatty acid (FFA) content, fungal contamination and infestation with the insect pest Rhyzopertha dominica (F.) were all markedly affected by heat treatment. The effectiveness of the heat treatment was also influenced by the size of the sample used. Heat treatment at 60°C and 70°C resulted in germination being unaffected or stimulated while at 80°C and the higher water contents significantly reduced, when compared to untreated controls. The dry matter of seedlings, and seedling vigour was positively correlated with germination and heat treatment. Heat treatment had no effect on FFA. All stages of the insect pest, R. dominica, were destroyed at 70°C and an 8 min exposure time. However, the water content of the sorghum was critical in determining the efficacy against this pest. The percentage fungal contamination of grain was reduced from 90% to about 25% by heat treatment. However, some grain fungi, particularly Eurotium spp., Aspergillus niger and Penicillium spp. could still be isolated from sorghum grain treated at 80°C for up to 12 minutes.

Nodulation and nitrogen accretion response of Cercocarpus betuloides seedlings to phosphorus supplementation and water availability

Greenhouse experiments were conducted to assess the effect of phosphorus (P) supplementation and water availability on incidence of nodulation and nitrogen (N) fixation by Cercocarpus betuloides seedlings. Phosphorus supplementation resulted in a two-fold increase in shoot and total dry matter of seedlings grown in a P-deficient soil. Seedlings grown in P-supplemented soil supported a larger number (4.8 vs. 0.3) and fresh mass (0.179 vs. 0.009 g) of nodules than did controls. Nitrogenase activity (acetylene reduction), N concentration and N accretion were greater for seedlings grown in P-amended soil than for controls.