Average Germination Time Research Articles

Ecophysiology germination of Senna uniflora seeds: species for recovery degraded areas

Abstract: Studies on seeds ecophysiology are important to understanding of adaptation mechanisms and of species´ tolerance limits to natural conditions, because determine the potential of use in recovery plans of degraded areas. The aim of this study was to characterize and assess the effect of different temperatures, methods of dormancy overcoming and water and salt stresses on the germination of Senna uniflora. Imbibition curve and germination assay were conducted to assess the effect of temperature regimes (20 °C, 25 °C, 30 °C, 35 °C, 40 °C and 20-30 °C), of methods of overcoming dormancy (without scarification, mechanical scarification, chemical scarification and thermal scarification) and of water and salt stresses at the osmotic potentials (0.0; -0.2; -0.4 and -0.8 MPa) . The assessed variables were germination, germination speed index and average germination time. Methods of mechanical and chemical scarification for 5, 15 and 30 min were efficient to overcome physical dormancy, especially on constant temperature regimes of 25 °C and 30 °C and alternated 20-30 °C. Submitted to conditions of water and salt stresses, seeds germination was reduced with the increase of the osmotic potential, being -0.8 MPa the germination minimum limit, in addition, seeds were more sensitive to water stress than to salt stress.

Seed characteristics of Amygdalus arabica in Adıyaman region of Turkey

Mountain almond (Amygdalus arabica) is a shrub with naturally distributing in Turkey, Iran, Iraq, Syria, Jordan and Saudi Arabia. A. arabica also known as bitter almond and can reach up to 2.5 m. The natural distribution of mountain almond is generally in the Southeast Region of Turkey. The present study carried out to determine the morphological and physiological characteristics of the seed of mountain almond. The seeds were collected from three different populations of A. arabica in Adıyaman. For different each populations seed weight, height, width, thickness, and 1000-seed weight were measured in the laboratory. Morphological characteristics of A. arabica seeds varied according to their populations. Seed germination tests were conducted at 20 °C, after prechilling for 0, 3, 6, and 9 weeks at 4 °C. Prechilling treatments of 3 weeks were insufficient, but 6 and 9 weeks of prechilling were found to eliminate seed dormancy and led to the highest germination percentage. The average germination percentage after 0, 3, 6, and 9 weeks of prechilling were 3.1%, 49.6%, 80.4%, and 81.1%, respectively. The average mean germination time was approximately between 8 and 10 days.

Tuz (NaCl) Stresinin Adi Fiğ (Vicia sativa L.) Tohumlarının Çimlenme ve Fide Büyüme Üzerindeki Engelleyici Etkisinin Hafifletilmesinde GA3 (Gibberellik Asit) ve Kinetin Bitki Büyüme Maddelerinin Uygulanması

Bu çalışmada, tuz (NaCl) stresinin Adi fiğ (Vicia sativa L.) tohumlarının çimlenme ve fide büyümesi üzerindeki engelleyici etkisinin hafifletilmesinde GA3 ve Kinetin bitki büyüme maddelerinin farklı dozlarının etkileri araştırılmıştır. Çalışma tesadüf blokları deneme desenine göre petri ve saksıda olmak üzere iki paralel olarak yürütülmüştür. Denemede değişik dozlarda NaCl (0,5, 1,0, 1,5 ve 2,0 dS/m dozlarında hazırlanan NaCl çözeltisi) uygulanan adi fiğ (Vicia sativa L.) tohumlarına farklı dozlarda Kinetin ve Gibberelik asit dozları (Kontrol-saf su, 300 ppm Gibberellik asit, 50 ppm Kinetin,300ppm Gibberellik asit × 50 ppm Kinetin) uygulanarak tohumlar petri ve saksıda çimlendirilmiştir. Saksı ve petride çimlendirilen adi fiğ tohumlarında çimlenme yüzdesi, ortalama çimlenme süresi, çimlenme değeri, kök ve sap uzunluğu, kök yaş ve kuru ağırlığı, sap yaş ve kuru ağırlığı üzerine GA3 ve Kinetin uygulamalarının etkileri gözlemlenmiştir. Araştırma sonunda GA3 ve Kinetin uygulamaları adi fiğde çimlenme yüzdesine herhangi bir etkide bulunmamış, çimlenme süresini kısaltmış, çimlenme değerini artırmış, GA3 uygulaması kök ve sap uzamasını artırmış Kinetin uygulamasının olumlu bir etkisi olmamış, en fazla kök yaş ve kuru ağırlığı GA3 ve kontrol ünitelerinden elde edilmiştir. Adi fiğ tohumları üzerinde yapılan çalışmada incelenen özellikler üzerinde genel olarak GA3 ve Kinetin uygulamalarının etkileri çok farklı olmuştur. GA3 uygulamalarının kök ve sap uzunluğunu artırdığı, kinetin uygulamasının ise olumsuz yönde etkilediği belirlenmiştir.

L-Triptofan ve Melatonin’in Düşük ve Yüksek Sıcaklık Koşullarında Turp ve Ispanağın Tohum Çimlenme Performansına Etkileri

Bu çalışmanın amacı L-Triptofan ve Melatonin uygulamalarının farklı sıcaklık koşullarında turp ve ıspanak tohumlarının çimlenme özellikleri üzerindeki etkilerini araştırmaktır. Farklı konsantrasyonlarda L-Triptofan (125, 250, 375 ppm) ve Melatonin (5, 10, 25 µM) ile muamele edilmiş tohumlar, optimum (21 ˚C), üşüme stresi (7˚C) ve yüksek sıcaklık (35 ˚C) koşullarında çimlenme testlerine tabi tutulmuştur. Distile su ile muamele edilmiş tohumlar kontrol olarak kabul edilmiştir. Denenen hormonlar, düşük sıcaklıkta (7 ˚C) turp tohumlarının ortalama çimlenme süresi, %50 çimlenme oranına ulaşma süresi ve taze ağırlık sonuçları üzerine önemli etkiler oluşturmuştur. Bu sıcaklık derecesinde, 10 µM melatonin uygulaması, ortalama çimlenme süresini ve tohumların %50 çimlenme oranına ulaşma süresini, hormon uygulanmamış tohumlara göre uzatmıştır. 125 ppm ve 250 ppm L-Triptofan uygulaması yaş ağırlık değerlerini artırmıştır. Ispanak tohumlarında düşük sıcaklık koşulunda (7 ˚C) hormon uygulamalarının en büyük etkisi %50 çimlenmeye ulaşmak için gerekli süre özelliğinde gözlenmiştir. L-Triptofan' ın 375 ppm dozu bu süreyi kontrole göre kısaltırken, 25 µM melatonin uygulaması ise uzatmıştır.

Effect of natural zeolites and zeolites added with microorganisms for the growth of cabbage (Brassica oleracea var. capitata L.)

In this study the effect of natural zeolites and zeolites added with micro-organisms for the growth of cabbage (Brassica oleracea var. capitata L.) was evaluated, in order to highlight whether the microbiological component is the basis of the functionality of zeolites. The 3 experimental groups in cultivation were: 1) group without zeolites (CTRL) (peat 100%), irrigated with water and substrate previously fertilized; group with natural chabazite (CN) and fertilised substrate; group with chabazite enriched with micro-organisms (CM) and fertilised substrate. (Patented formula rif.28106IT/MB/BF). The test showed a significant increase in the agronomic parameters analyzed in plants treated with natural zeolites and zeolites with the addition of micro-organisms compared to the control. Also with regard to the physiological analysis of plants there was a significant increase in the parameters analysed, in the thesis treated with zeolites with the addition of micro-organisms and natural zeolites compared to the control. Finally, it should be noted that in the thesis treated with zeolites enriched with micro-organisms and in that with natural zeolites, the experiment also showed an increase in the percentage of germination of seeds and a significant reduction in the average time of germination compared to the untreated control (CTRL). The use of zeolites, as demonstrated by this test, can guarantee the grower a qualitative improvement of the plants in cultivation, ensuring better management of the use of fertilizers and water for irrigation. The zeolites are able to interact actively with the organic components present in the soil or brought with the fertilization, and have the ability to make more available the mineral and nutritional components present within their crystal lattice, based on the needs of the plant.

Endosperm prevents toxic amounts of Zn from accumulating in the seed embryo - an adaptation to metalliferous sites in metal-tolerant Biscutella laevigata.

Seed germination represents the first crucial stage in the life cycle of a plant, and the seed must contain all necessary transition elements for the development and successful establishment of the seedling. Problematically, seed development and germination are often hampered by elevated metal(loid) concentrations in industrially polluted soils, making their revegetation a challenging task. Biscutella laevigata L. (Brassicaceae) is a rare perennial pseudometallophyte that can tolerate high concentrations of trace metal elements. Yet, the strategies of this and other plant species to ensure reproductive success at metalliferous sites are poorly understood. Here we characterized several parameters of germination and used synchrotron X-ray fluorescence microscopy to investigate the spatial distribution and concentration of elements within B. laevigata seeds from two metallicolous and two non-metallicolous populations. We find that average germination time was shorter and the seed weight was lower in the metallicolous compared to the non-metallicolous populations. By allowing for at least two generations within one growth season, relatively fast germination at metalliferous sites accelerates microevolutionary processes and likely enhances the potential of metallicolous accessions to adapt to environmental stress. We also identified different strategies of elemental accumulation within seed tissues between populations. Particularly interesting patterns were observed for zinc, which was found in 6-fold higher concentrations in the endosperm of metallicolous compared to non-metallicolous populations. This indicates that the endosperm protects the seed embryo from accumulating toxic concentrations of metal(loid)s, which likely improves reproductive success. Hence, we conclude that elemental uptake regulation by the seed endosperm is associated with enhanced metal tolerance and adaptation to metalliferous environments in B. laevigata.

Effective microorganisms for germination and root growth in Kalanchoe daigremontiana

The aim of the experiment was to evaluate the use of effective micro-organisms (EM) as promoters of root development and germination of K. daigremontiana plants. The 3 experimental groups in cultivation were: 1) group without micro-organisms (CTRL), irrigated with water and previously fertilised substrate; 2) group with sugar cane molasses (ML) and fertilised substrate; 3) group with effective micro-organisms (EM) and fertilised substrate. The test showed a significant increase in the agronomic parameters analysed in plants treated with effective micro-organisms. In fact, all plants treated with (EM) showed a significant increase in plant height, number of leaves, vegetative and radical weight, number and weight of new shoots, leaf area. Also regarding the physiological analysis of plants there is a significant increase in the parameters analyzed in the thesis with effective micro-organisms. In particular, there was a significant increase in the chlorophyll content, in leaf net photosynthesis rate (Pn) and water use efficiency (WUE) and an equally significant reduction in transpiration (TR) and stomatological conductance (Gs). In the thesis treated with EM, the experiment also showed an increase in the percentage of seed germination and a significant reduction in the average germination time. Effective micro-organisms can be a valuable tool for grafting before planting new plants, for spraying and irrigation of crops, for reducing or eliminating completely the use of plant protection products against pathogens and diseases, during the storage of plant raw materials and to increase the biological activity of the soil.

Fibers of the seagrass Posidonia oceanica as substrate for germination of lentil seeds

Concern regarding the environment is increasing day by day. Industrialized countries are aware of the problem that waste creates and are focusing efforts toward solving it by recycling and reusing different kinds of waste. Posidonia oceanica is a seagrass species endemic to the Mediterranean Sea, which creates tons of fiber waste that accumulates along the shoreline. This work demonstrates the feasibility of obtaining substrates for plants from P. oceanica fibers. We analyze the fiber structure by scanning electron microscopy, and observe the germination rate and the average germination time for lentils seeded on Posidonia substrates in comparison to those seeded on cotton. Two different lengths of Posidonia fiber are studied, as well as the influence of desizing and bleaching. The values for gemination rate and germination time showed comparable or even better results than cotton, allowing us to conclude that Posidonia substrates can be used for agricultural purposes. These results offer a new application for the valorization of waste from the Mediterranean coast by reusing the Posidonia fibers. Moreover, when the fibers are bound together by means of a biopolymer, chitosan, the results show that the germination rate is higher than without chitosan treatment, and the average germination time is reduced by approximately 1 day. Thus, we can conclude that the germination process is faster and more effective.

Effect of Planting Date on Germination Indices of Erflor cultivar of Sunflower Seeds

An experiment was performed to test the sensitivity of seed production and climatic conditions effect on mother plant. The seeds from different planting dates in field experiment were studied randomly in 2013 during four replications at the laboratory of Agriculture Faculty of Islamic Azad University, Khoy Branch. The results showed that the effect of sowing date on shoot length and dry weight, root germination, mean germination time, germination average, germination and mean germination were significant. Based on the results of the experiment, seeds from the first to third sowing dates had the best germination time and the average germination time for the best seedlings due to the highest length and stem and rootstock weight. In general, it became clear that the delay in planting the mother plant decreases seed quality. MGT indices showed a significant negative correlation with GR. Also, MDE increased the length and weight of the stem.

DORMANCY OVERCOMING IN Bowdichia virgilioides Kunth SEEDS

Bowdichia virgilioides Kunth is a tree species of the family Fabaceae. The species is well adapted to dry and poor lands, being indicated for reforesting activities, being widely used on wood structures for civil construction, and also as a species with high medicinal potential. This study aimed to evaluate methods for overcoming dormancy of B. virgilioides seeds through different types of scarification and water submersion. To do so, four treatments and control were used: T1 - seeds with no treatment, T2 – mechanical scarification with # 120 sandpaper; T3 – chemical scarification with concentrated sulfuric acid (98%) for 10 minutes; T4 – submersion in hot water (80°C) for 5 minutes; T5 – submersion in water at room temperature (approximately 30°C) for 48h. The experiment was conducted in a Completely Randomized Design (CRD) and the analyzed variables were: germination percentage (%G), average germination speed (VMG) and average germination time (TMG). Data was analyzed using the “GerminaQuant” software and results compared using Tukey’s test at 5% probability. Germination percentage was higher for treatments 3 and 4, with the decreasing sequence: T3 – 82%, T4 – 64%, T2 – 9%, T1 – 4% and T5 – 2%. Regarding average germination time, only T2 and T1 were statistically different from each other, T2 had the shortest time (10.33) and T1 the longest time (30.33). For VMG, T2 and T3 presented the best results, being statistically different from the other treatments, with 0.093 and 0.085 as respective results of T2 and T3. It could be concluded that treatments with immersion in sulfuric acid for 10 minutes (T3) and immersion in water at temperature of 80°C for five minutes (T4) are more efficient for improving germination percentage of B.virgilioides seeds, being the recommended methods for overcoming seed dormancy.

Germination of spores of Amazonian ferns Polypodium aureum in different culture media

Abstract The greatest diversity of ferns occurs in the tropics, where approximately three in four of the species are found. In the Brazilian flora, the ferns have megadiversity, being an important plant group. The objective was to evaluate the spores germination of ferns Polypodium aureum in different types of culture medium. The sporangia were removed from fertile fronds and sterilized with sodium hypochlorite 0.57% during 30 minutes. After sterilization, the sporangia were seeded in culture media agar, MS, SH, White and B5. The experimental design was completely randomized being composed of 5 treatments (agar media, B5, SH, White and MS) and 10 replications. The ratings occurred every 3 days over a period of 45 days, counting the number of spores germinated. After this period, the germination percentage, germination time on medium, germination speed index and timing of germination were calculated. The germination percentage and the index of synchronization have not changed in function of different culture media. The medium White presented the highest average for the germination speed index whereas the agar media, MS, SH and B5 had the same germination speeds. The percentage of mortality was higher in MS medium, the White medium presented the lowest percentage of mortality, and the media composed by agar, SH and B5 showed intermediate values. The lowest average germination time occurred at the media SH and B5, since the environment composed by agar showed higher average germination time. The media MS and White showed similar results to the agar, SH and B5. Based on the obtained results, it can be concluded that the White medium is the most effective on the germination of spores of Polypodium aureum.

Effect of pre-germinal treatment and temperature on the germination of achenes of Baccharis dracunculifolia DC

The species Baccharis dracunculifolia, known as alecrim-do-campo is very rough, of great economic importance, recommended for recovery of degraded areas, but is little explored by propagation through seeds. In order to understand aspects of reproductive biology of B. dracunculifolia of achenes, this study aims to verify the influence of pre-germination treatment and the influence of different germination temperatures in the performance of seed germination. The seeds were placed in translucent germination boxes, with four replicates of 30 seeds for each treatment. Germination was carried out with pre-germination treatment stratification (5°C) for 0, 1, 2, 3, 4 and 5 days, with a photoperiod of 14 h with light and 10 h in dark, in a germination chamber B.O.D. The 15°C treatment was carried out with 0, 1, 2, 3, 4 and 5 days with pre-germination treatment stratification (5°C) and successively for all treatments. After this period, the same photoperiod of 15, 20, 25, 30 and 35°C remained. The germination was evaluated for 30 days, considering the number of germinated seeds; those showing radicle protrusion of less than 2 mm, the speed index, the average time and average speed of germination. The temperature of 20°C without pre-germinative treatment provided 17.8% of germination. The highest speed of germination was obtained at 30°C with pre-germination treatment stratification (5°C) for 4 days. The temperature of 35°C inhibited germination and there was no significant effect on mean germination time. The pre-germinating treatment for three days, combined with the temperature of 20°C, provided a higher average speed of germination. Thus, it appears that the pre-germination treatment stimulated germination of achenes, suggesting that longer periods of chill accumulation increased seed germination subjected to high temperatures.

Phytochemical screening and toxicity of Crambe abyssinica Hochst extracts on Solanum lycopersicum L., Euphorbia heterophylla L., Bidens pilosa L. and Glycine max (L.) Merril

This study aimed to identify the main groups of secondary compounds from Crambe abyssinica and evaluate the bioactivity of the hexane, ethyl acetate and methanol extracts on the seed germination and seedling development of tomato, wild poinsettia, hairy beggartick and soybean. The phytochemical screening considered the presence or absence of total saponins, triterpenoids, flavonoids, coumarins, tannins, phenols and alkaloids. In the seeds it was evaluated: germination percentage, germination velocity index, average germination time, index of allelopathic effects, shoot and root length and seedlings dry matter. In the phytochemical screening it was observed that each solvent extracted different compounds. Flavonoids were found only in the ethyl acetate extract and saponin only in the methanol extract. A high allelopathic effect of hexane, ethyl acetate and methanolic extracts of crambe on the bio-indicator species tomato was observed. The hexane and ethyl acetate extracts also showed inhibitory effect on the weed hairy beggartick and did not present negative effects on soybean. There is the possibility of isolating the bio-active compounds of crambe and use them as a bio-herbicide to the alternative control of the weed hairy beggartick.

Average time of dispersal and germination of Fabaceae seeds retrieved from goat feces

This study aimed to evaluate the viability of seeds of butterfly pea, stylosanthes cv. Campo Grande, tropical kudzu and archer after passage through the gastrointestinal tract (GIT) of goats; and to evaluate these animals as dispersing agents. Fifty grams of seeds of each plant were mixed with the concentrate and given to 20 goats, whose feces were collected up to 102 hours after ingestion for seed retrieval and subsequent germination test. This was a completely randomized design in a factorial arrangement: 4 Fabaceae plants x 17 sampling times with five replicates. The percentage of seed retrieval ranged from 16.9 to 70.9%; butterfly pea and archer, respectively. The passage through the GIT positively affected the germination of kudzu seeds; which presented the highest germination average (45%), and negatively the seeds of stylosanthes and butterfly pea, which presented respectively, 15 and 13%. The period of highest seed dispersal was 24 - 42 hours, peaking in 36 hours. Under these conditions, goats may be considered as legitimate seed dispersers.

Seed position and influences on Caesalpinia pulcherrima germination and reserve proteins

Caesalpinia pulcherrima has diverse uses in the world, including ornamental and landscape characteristics, but there is a great disparity of germination during the time of seedlings production, being this factor attributed to the position of the seeds in fruits. This study aimed to evaluate some germinative aspects and concentration of reserve proteins in C. pulcherrima seeds in the function of its position in fruits. The work was carried out in greenhouse, in a completely random experimental design, with five seed position in the pod, based on the distance from seed to the peduncle (P1 - distal, P2 - distal/median, P3 - median, P4 -proximal/ median, P5 - proximal). Eight replicates with eight seeds each, were sowed to germinate for 21 days in expanded polystyrene trays filled with substrate. The percentage, speed index, average germination time and 50% germination time of the plantlets were evaluated. The reserve proteins (albumin, globulin, prolamin and glutelin) contents were also determined. There was influence of the position of the seed in the fruit on germination and reserve proteins contents. The proximal/median position showed excellent results, having correlations of albumin, globulin and glutelin concentrations with some germinative parameters. Therefore, the use of proximal/median position of the seeds is recommended for C. pulcherrima propagation.

Análise biométrica multidimensional com tratamentos pré-germinativos em sementes e caracterização morfológica de plântulas de Mimosa bimucronata (De Candolle) Otto Kuntze

Mimosa bimucronata is a plant species that can be used in reforestation programs, and initial studies for the production of seedlings are needed. Due to the importance of this plant species and the scarcity of information on seed germination, this research was carried out with the objective of evaluate i) the biometric characteristics of the seeds by multivariate analysis, ii) the effect of seed pretreatment on germination, and iii) to characterize morphologically the different stages of germination and seedling. The biometry and seed mass and eight pre-germination treatments were analyzed: control; sulfuric acid (98%) for two; five and 10 min; hot water at 70 to 80 °C for 2 min; mechanical scarification and distilled water for 24 h. The different stages of seed development were evaluated until seedling formation. The seeds were exposed to two environments - laboratory and greenhouse. The percentage of germination and emergence were evaluated; germination and emergence speed index; and average time of germination and emergence. According to the multivariate analysis, the seeds were classified into three groups, with classes II and III being the most suitable for seedling production. Germination with sulfuric acid and sandpaper were the most indicated. The species presents 10 stages of development.

Períodos de exposição e diferentes concentrações de GA3 na germinação de sementes de Corymbia citriodora Hill & Johnson (Myrtaceae)

The germination of Corymbia citriodora was evaluated in five periods of exposure under different concentrations of GA3. The treatments were: distilled water and gibberellic acid at 5, 10 and 20 mg L-1, added to four batches of 100 seeds each. Soaking was carried out in periods of 30, 60, 120 and 180 min. The obtained data were used to calculate the Germinability (G%), Germination Speed Index (GSI) and Average Germination Time (AGT). The analysis of the results show that, compared to G%, the best averages were obtained for the interaction occurred by exposure of seeds for 30 minutes at a concentration of 20 mg L-1 GA3. With respect to the GSI, the best interaction occurred between the concentration of 5 mg L-1 GA3 in 120 minutes of exposure. For AGT, the best interaction occurred between the concentration of 5 mg L-1 GA330 minutes of exposure.

Recovery and germinative response of Amaranthus deflexus L. seeds under different levels of water stress and luminosities

The objective of this work was to evaluate, in two experiments, the effect of water stress and luminosity on the germinative behavior and vigor of Amaranthus deflexus L seeds. The seeds were sown in Petri dishes containing two sheets of filter paper moistened with distilled water, in the control treatment. Using this treatment-control configuration, as a standard of comparison, two assays were performed using subsamples from the same A. deflexus seed population. In the first experiment (experiment 1), solutions of polyethylene glycol 6000 (PEG 6000) were used, providing osmotic potentials of -0.3; -0.6; -0.9; -1.2 and -1.5 MPa; however, in the second trial (experiment 2) osmotic potentials of -0.1; -0.2; -0.3; -0.4 and -0.5 MPa were used. At the end of the test, the ungerminated seeds for each treatment were washed and germinated on a filter paper moistened with water. The germination and vigor of the seeds were evaluated through the first germination count, germination test, germination speed index and average germination time. The experimental design was completely randomized, in a 2 x 6 factorial scheme, totaling twelve treatments, with four replicates of 50 seeds each, in both trials. Water stress negatively affects the performance of A. deflexus seeds, reducing germination and vigor from -0.1 MPa. Seed germination was compromised by the absence of light, regardless of the applied stress levels. There was an increase in seed germination after application of the same at higher levels of water stress.

Alelopatic Effects of Tectona grandis L.F. in the Germination and Initial Development of Lettuce (Lactuca sativa L.)

This study aimed to evaluate the allelopathic effects of aqueous extracts of Tectona grandis L.F. in various concentrations produced from leaves and flowers. Seeds of lettuce (Lactuca sativa L.) and germitest paper as substrate were used, the germitest paper was moistened with distilled water, and aqueous extract in concentrations of 100%, 75%, 50%, 25% and 0% (distilled water). The extracts were homogeneously deposited on twenty-five seeds evenly distributed in gerbox-type boxes. The materials used in the experiment were previously sterilized with alcohol (70%). A completely randomized experimental design with four replicates was used and the experiment was conducted under natural conditions of temperature and humidity. The tests were carried out in the laboratory, the experiment was watched for 10 days always at the same hour and the variables analyzed were Germination Percentage (%G), Speed of Germination Index (SGI), Mean germination time (MGT) and Mean speed of germination (MSG). The data were submitted to Analysis of Variance and compared by Tukey test considering 95% of probability. It was observed that there were no significant differences in leaf and flower extracts for the variables %G, MGT and MSG, however, in SGI aqueous leaf extract differed significantly at the highest concentrations (75% and 100%). It was concluded that aqueous extracts of leaves and flowers of T. grandis had no inhibitory potential in relation to the percentage and average germination time of lettuce seeds at any of the concentrations.

GERMINATION AND INITIAL GROWTH OF Sesbania punicea (Cav.)Benth.: INFLUENCE OF SALINITY, FLOODING AND LIGHT1

ABSTRACT Sesbania punicea (Cav.) Benth. has been recommended for the recovery of degraded areas. This study aimed at verifying the effect of salinity in the germination of S. punicea seeds in different hydric and luminosity conditions and assessing the influence of salinity and flooding on the growth and concentration of photosynthetic pigments. After the morphometric measurements of the fruits and seeds, we performed germination tests in different salt concentrations (0,5, 10 and 15gL-1 NaCl), keeping the seeds in a humid substrate (normoxy) or submerged (flooding), in the presence or absence of luminosity. There was a decrease in the percentage of germination and germination speed index (GSI) of seeds that were kept submerged in the dark. The average germination time (AGT) decreased up to the concentration of 10gL-1NaCl when the seeds were submitted to submersion in the presence of light. The growth and the production of leaves of seedlings exposed to flooding decreased as the salt concentration increased. The concentrations of photosynthetic pigments of seedlings of S. punicea did not differ among the treatments. Therefore, the colonization and occupation of new degraded areas by S. punicea may be limited by the presence of salts concentrations in the soil.