Study of seed-germination and etiolation of seedlings in Emilia-sonchifolia (l) dc and Emilia-fosgerbii nicolson (Asteraceae)

The germination of seeds of Emilia sonchifolia (2n) and E. fosgerbii (4n) was analysed and our results indicate that the former present light insensitive seeds and the latter germinated only under continuous white light. The germination of seeds under shade light presented no differences between both species, However under continuous white light, which maintain 70% of Pfr, the velocity of germination was greater in Emilia sonchifolia when compared to Emilia fosbergii, indicating that the threshold of 4n seeds were greater than 2n seeds. The analysis of the fluence response curves for etiolating process indicated that the process presented no differences between both species. The same was observed for the effect of the shade light in the etiolating process.

Seed dispersal and germination of Cryptocarya moschata Nees & Martius Ex Nees, Ocotea catharinensis Mez and Endlicheria paniculata (Sprengel) Macbride (Lauraceae)

Data of seed dispersal and germination of the studied species are presented, comparing both observations from the wild and nursery. Fruits were collected from Carlos Botelho State Park (24 degrees 44' to 24 degrees 03'S, 47 degrees 46' to 48 degrees 10'W), south of São Paulo State, Brazil. O. catharinensis had low germination percentage, both in the wild and in nursery, and did not tolerate seed storage at low temperature. In nursery, diaspores with removed mesocarp of E. paniculata presented greater germination than those in entire fruits. The high levels of seedling mortality beneath mother-trees of C. moschata, when in comparison to those observed to established seedlings from diaspores dispersed by muriquis (Brachyteles arachnoides E. Geoffroy 1806, Cebidae, Primates), allied to the absence of juveniles in the understory, are in accord with the escape model of Janzen-Connel. In nursery, diaspores of C. moschata dispersed by the primates had greater germination, in smaller time, than those collected from mother-trees.

Morpho-anatomical aspects of Paepalanthus hilairei Koern (Eriocaulaceae) from Serra do Cipo MG

The morphological characteristics of seedlings and the anatomical characteristics of vegetative organs and floral scape of P. hilairei (Eriocaulaceae) were analyzed to investigate the ecological and taxonomic implications for the species. P. hilairei is a perennial plant with an aerial stem and it grows in recently decomposed stony, sandy soils of the Serra do Cipo, in the State of Minas Gerais, Brazil. It is found both on wet and dry soils, exposed to constant winds, high light intensities and extreme daily fluctuations of temperature. The results show that the seeds have operculum and the initial seedling development stages are the same for other Eriocaulaceae. During the germination period, the undifferentiated axis of the embryo becomes apparent. The observation of the development of this axis, shows first, the growth of the leaves and later that of the adventitious root. Attention is focused on the apical stem region which presents sterelis lateral branching with adventitious roots in its base which will develop into paraclades (system of florescences). Both of them rise out of the pericycle and characterize its vegetative growth. The occurrence of a special leaf substomatal chamber may be related to an efficient protection for the gaseous exchange and may be considered an important characteristic of the Eriocaulaceae.

Use of reduced concentrations of tetrazolium solutions for the evaluation of the viability of peanut seed lots

The possibility of reducing the concentration of the working solution used in the tetrazolium test for peanut seeds (Arachis hypogaea L.) with or without seedcoats was studied. Tetrazolium solutions of different concentrations (0.05%, 0.075% and 0.1%) were tested at the temperatures of 35 and 40 degrees C, for determining the time needed for the seeds to reach proper staining. The efficiency of the selected treatments in evaluating the viability potential of the seeds was determined by comparing the results of the tetrazolium tests with those obtained by standard germination (using sand and rolled paper towel as substrata) and seedling emergence in the field tests. Staining the seeds without seedcoat in 0.05% tetrazolium solution for three hours at 40 degrees C yielded efficient results. on the other hand, reduced concentrations can be employed in the staining process of seeds with seedcoat; however, this method requires a higher consumption of tetrazolium salt, longer staining time as well as a higher ability and availability of time for embryo evaluation, since the cross-cutting of seeds is much more difficult in the presence of the seedcoat and the occurrence of damage to the outer surface of the cotyledons cannot be determined.

Ontogenic development of Guazuma ulmifolia (Sterculiaceae) sapplings

Guazuma ulmifolia is as popular reforestation tree all over Latin America. It is characteristic of the initial stages of the secondary sucession and presents potential utility in the restoring of degraded areas. There is no information about fruit,seed and seedling morphology, which is of fundamental importance for identification, extraction, management and seed germination as well as for the characterization of post-seminal development and normal seedling pattern. To obtain such information, external fruit, and external and internal seed structures were studied considering shape, size, micropile and embryo localization; and tegumentar structures. All stages of this work were conduced in the Universidade Estadual Paulista (UNESP), Campus of Jaboticabal city. The fruits were collected in a mixed plantation in Jaboticabal city, State of São Paulo, Brazil. For the bio metric study eight repetitions of ten fruits and eight repetitions of 100 seeds were utilized. For seed internal traits study, 50 seeds were drenched in a distiled water, cut, and observed with a scanning electron microscope and a stereomicroscope, For post-seminal study ten repetitions of seven seeds were scarificated chemically with sulphuric acid during 50 min, and placed to germinate ina culture medium, at 30 degrees C, and eight hours of photoperiod. We found elipsoid, woody, indehiscent, pentacarpelar fruits, with a mean lenght of 22.61 mm (diameter 24.88 mm) and 64.0 seeds per fruit. Seed shape varies, mean length is 3.07 mm (width of 2.36 mm). The seed is bitegumented, tegmic, with a continuous, axial and curved embryo. The germination is epigeal and the seedlings are fanerocotiledoneus. Drawings of all stages are included.

Efeito da porosidade do substrato casca de pínus no desenvolvimento de mudas de grumixameira

Aiming to evaluate the effect of the pine bark substrate porosity on the development of the grumixama plant (Eugenia brasiliensis Lam.), an experiment was conducted in a greenhouse of the Escola Superior de Agricultura "Luiz de Queiroz"/USP, Piracicaba, Brazil. The treatments were: 100% ground pine bark without separation of particles; 100% pine bark of <= 0,1mm; 75% pine bark of <= 0,1mm + 25% between 0,1-4,0 mm; 50% of pine bark <= 0,1mm + 50% between 0,1-4,0 mm; 25% pine bark of <= 0,1mm + 75% between 0,1-4,0 mm and 100% pine bark of 0,1-4,0 mm. The evaluations (stem diameter, length and average dry weight of seedlings) were performed on the 90, 120 and 150(th) days after sowing. The low water absorption in the early stages and the low aeration of the roots promoted by the substrate, affect the development of the grumixama plant seedlings, that grow best when the total pore space of the substrate is less than 90% (v / v).

Crescimento de mudas micropropagadas da bananeira cv. Nanicão, em diferentes substratos e fontes de fertilizante

With the objective of evaluating the effect of different substrates combined with fertilizers in the growth of micropropagated seedlings of Cavendish banana (Musa spp. AAA), ail experiment was conducted in a randomized block design, in a 5 x 3 factorial scheme, with four repetitions. The substrates used were: S1 - subsoil land + carbonized rice hull + Rendmax Floreira (R); S2 - subsoil land + carbonized rice hull + Organifol (R); S3 - subsoil land + carbonized rice hull + Organifol (R) 9% SiO; S4 - Technes Vivatto (R); S5 - thick sand + carbonized rice hull + Rendmax Floreira (R). The fertilizer sources were: SA - without fertilizer; LL - slow-release fertilizer - Osmocote (R) 3M 14-14-14 (5.0 kg m(-3)) inixed in the substrate; and LN - normal-release fertilizer, 14-14-14 (7.5 g seedling(-1)) applied in covering. The height, collar diameter, leaf number, leaf area and dry matter were determined. Based on the differences of growth, substrates S 1, S2, S3 and S4 can be used with fertilizer 14-14-14, with slow (5.0 kg m(-3)) or normal (7.5 g seedling(-1)) release of nutrients.

Interferência e estudo fitossociológico da comunidade infestante na cultura da beterraba transplantada

The objective of this research was to Study the phytosociological and critical interference periods of weed communities Oil transplanted beets. The treatments consisted of increasing weekly weedy/weed-free periods, starting it the second week after seedling transplanting. The weed community was evaluated based oil the number of individuals and their corresponding accumulated dry mass, for each weed population and evaluated period. The beets were harvested 91 days after transplanting, followed by evaluation of the cross-sectional diameter and marketable yield. The weed communities were composed mainly of Amaranthus viridis, Coronopus didymus, Galinsoga parviflora, Nicandra physaloides and Solanum americanum, and the populations were very similar. The period before weed interference and the total period of weed interference prevention were 51 and 35 days after transplanting, respectively. The beet yield in the weed-free treatment was 44.92 t ha(-1) and the reduction from weed interference was more than 70%.

Teste de envelhecimento acelerado em sementes de quiabo

The objective of this research was to study the accelerated aging test to evaluate the okra vigor seed. Were used four okra seed lots cv. "Santa Cruz". The initial seed lot quality was evaluate by the moisture content, germination, first germination count, speed of germination index and seedling emergence. The experiment was carried out in two phases: the first one the seeds were submitted to the accelerate aging with and without NaCl salt solution aging periods of 48, 72, 96 and 120 hours, at 41 and 45(0) C temperature. The second phase the best procedures as for as accelerated aging and temperatures were repeated. The period of 72h and 41 C with and without NaCl saturated solution was the most adequate for the lot classification in distint vigor levels.

Do Terrestrial Tank Bromeliads in Brazil Create Safe Sites for Palm Establishment or Act as Natural Traps for Its Dispersed Seeds ?

This study shows for the first time that terrestrial tank bromeliads from Brazilian restinga can act as natural traps for dispersed palm Euterpe edulis seeds. Such bromeliads, which are shade intolerant, gain benefits by limiting palm recruitment since they hinder canopy formation and, consequently, increase luminosity over its aggregates.

Efeitos dos danos mecânicos e fisiológicos na colheita e beneficiamento de sementes de soja

The objective of this study was to evaluate the effect of mechanical damage and physiological events in harvesting and processing of soybean cv. Mosoy RR 8000. The samples were taken during harvest manual, mechanical harvesting and during processing (receipt, pre-cleaning, cleaning, spiral separator, classification and gravity table). The physiological and physical quality was analized through the purity, germination, vigor (first germination count, seedling dry matter, accelerated aging, electrical conductivity, tetrazolium, mechanical damages and seedling field emergence) tests. The statistical design used was a entirely randomized with nine treatments (9 sampling points) with 4 replications, being the means compared by the Tuckey test at 5% probability. In the purity and seedling field emergence were observed highly significative difference between the sampling process, also this differences were obtained the first germination count, seedling dry weight matter, accelerated aging and electrical conductivity which showed smaller results for the mechanical harvesting when compared with the manual harvesting. The germination was obtained differences at 5% for the manual harvesting in relation to the mechanical harvesting were obtained smaller results, being the main cause of reducing the soybean seed quality, when compared with the manual harvesting.

Biological activity of Gomphrena elegans Mart. Var. Elegans (Amaranthaceae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Cryopreservation of Dendrobium hybrid seeds and protocorms as affected by phloroglucinol and Supercool X1000

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Consórcio de espécies nativas da floresta estacional semidecidual com mandioca (Manihot sculenta Crantz) para restauração de mata ciliar

Intercropping of trees and annual crops could be an important alternative for promoting forest restoration in small farms. The objective of this study was to evaluate the intercropping of cassava (Manihot sculenta Crantz) with native trees for restoration of natural forest in riparian areas in the western São Paulo State, Brazil. The experimental design was randomized blocks with six replications for comparing two restoration systems: pure afforestation and afforestation intercropped with cassava. It was evaluated the variables related to seedling development (height, crown diameter, crown cover, and height/crown diameter ratio), mortality and the economic impact were assessed for using cassava. No differences were found between treatments for any dendrometrical variable and mortality. Economic impact of the intercroppoing treatment was positive because costs for establishment of intercropped system were partially reduced by the income from the cassava crop, which covered 32% of total costs. Cassava income made final costs 19% lesser than restoration in the pure afforestation system.

Emergence and initial growth of rambutan seedlings as a function of seed storage conditions

Introduction. Rambutan is a tropical fruit species with recalcitrant seeds. Despite the expansion of exotic fruit cultivation in Brazil, lots of which fruit species, including rambutan, need basic information, especially in relation to propagation and storage of seeds, which are important for genetic improvement studies, maintenance of genetic sources and seedling production. Materials and methods. A completely randomized design was adopted with treatments distributed in a factorial arrangement, 3 x 4, referring to three seed storage conditions [room temperature conditions; a dry chamber with (18 +/- 2) degrees C and 60% relative humidity; and a cold chamber with (10 +/- 2) degrees C and 70% relative humidity] and four storage times ( 0, 7, 14 and 21 d). Each treatment of 10 seeds was replicated five times. Data on seedling emergence, emergence rate, plant height, number of leaves and length of main root were submitted to variance analysis and means were separated using Tukey's test. Correlation analysis between seed moisture and seedling emergence was performed. Results and discussion. Our results indicated that dry chamber conditions promoted the statistically significantly highest seedling emergence after 7 d of storage. Cold chamber conditions promoted an extremely low seedling emergence independently of time. Conclusion. Rambutan seeds can be stored in a dry chamber for 7 d without losing viability; after 14 d of storage the loss of emergence is 60%.