Effect of temperature on seed germination of queen palm Syagrus romanzoffiana (Cham.) glassman (Arecaceae)

The Syagrus romanzoffiana is a specie of the Arecaccae family, native of Brazil, frequently used in landscape architecture. Its propagation is by seeds, however, there is little information in the literature about seed germination of this ornamental palm. The objective of this work was to study the effects of temperatures on seed germination of Syagrus romanzoffliana. The experimental design used was entirely randomized, with six temperatures (20 degrees C, 25 degrees C, 30 degrees C and 35 degrees C, constant and 20-30 degrees C and 25-35 degrees C alternated), photoperiod of 12 hours, and five replications of 20 seeds each. The seeds were placed in plastic boxes with sand, counting daily germination until 43(th) day. The percentage of seed germination (43(th) day) and the speed germination index (SGI) were evaluated. The conclusion was that there was no germination at a constant temperature of 20 degrees C and in the alternated temperature of 20-30 degrees C; the higher germination percentages were verified in the constant temperatures of 30 degrees C and 35 degrees C that didn't differ statistically from the temperature of 25-35 degrees C. The germination was faster at a constant temperature of 30 degrees C.

EFFECT OF DROUGHT AND DEFOLIATION STRESS IN THE FIELD ON SOYBEAN SEED-GERMINATION AND VIGOR

Although drought and defoliation stress have been shown to reduce soybean [Glycine max (L.). Merr.] yield, little information has been published regarding their effects on soybean seed quality. Field experiments were conducted in 1986, 1987, and 1989 to evaluate the effect of drought and defoliation (1989 only) stress during soybean seed development on seed germination and vigor. Essex (MG [maturity group] V) and Union (MG III) were grown in 1986 and 1987, and Harper (MG III) and McCall (MG 00) in 1989. Moisture treatments were either well watered or drought stressed during seed development (R5 to R7). In 1989, a total defoliation treatment was also imposed at R6 as an additional stress factor. There were significant reductions in yield and yield components following drought stress in all 3 yr and following defoliation in 1989. Leaf conductance and transpiration also decreased in the drought stress treatments. There was no effect of drought stress on seed germination or seed vigor as measured by accelerated aging germination and the cold test across the four cultivars (determinate and indeterminate) and 3 yr. In 1989 slight changes in 3-d germination and conductivity occurred for some drought stress treatments. Most of this response, however, was related to increased occurrence of hard seed, which does not represent an indication of a change in vigor. Seed germination and vigor were significantly reduced for small, flat, shriveled, and underdeveloped seeds that only occurred following defoliation. These seeds represented a small portion of the seed lot that would normally be removed during conditioning. The data suggest that drought stress would have no effect on seed germination or vigor, unless the stress was severe enough to produce shriveled, flat, underdeveloped seeds.

Electrical conductivity of soybean seed and correlation with seed coat lignin content

The effects of soybean genotype and seed coat lignin content on bulk electrical conductivity were investigated. Seeds of nine soybean cultivars were hand harvested at R8 maturation stage in Londrina, PR., Brazil in 1995/96. Seeds were electrical conductivity tested using four replicates of 50 seeds per cultivar soaked in 75 mi of deionized water at 25 degrees C for 24 hours. Seed coat lignin content was determined using the potassium permanganate method. There was a significant relationship (R-2 = 0.84**) between electrical conductivity and seed coat lignin content, the latter being a characteristic that varies among soybean genotypes; the higher the amount of lignin in the seed coat, the lower the levels of seed exudates to the soaking solution and consequently the lower the electrical conductivity. It was concluded that seed soaking electrical conductivity is influenced by the seed coat lignin content, which is a characteristic that varies among soybean genotypes. Additionally, the EC test can be used as a valuable tool in the screening process for this characteristic, which is desirable for genetically improving soybean seed quality.

Temperature effect on seed germination in Canna indica L. (Cannaceae)

Comm indica L. is an herbaceous species with ornamental and medicinal value, having seeds with a hard seed coat. This study aimed to test the influence of constant temperatures ranging from 5 to 45 C, at 5 C intervals, on the germination of scarified seeds. Data obtained were analyzed through the model of enthalpy of activation in order to obtain the optimum temperature range for germination. The species showed seed germinability in a wide temperature range (10-40 degrees C) being the optimal temperature range between 13.84 and 34.41 degrees C, determined by the enthalpy of activation.

Oviposition pattern and within-season spatial and temporal variation of pre-dispersal seed predation in a population of Mimosa bimucronata trees

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Alveolar process preservation at implants installed immediately into extraction sockets using deproteinized bovine bone mineral - an experimental study in dogs

Aim To evaluate the soft tissue and the dimensional changes of the alveolar bony crest at sites where deproteinized bovine bone mineral (DBBM) particles, concomitantly with the placement of a collagen membrane, were used at implants installed into sockets immediately after tooth extraction. Material and methods The pulp tissue of the mesial roots of 3P3 was removed in six Labrador dogs, and the root canals were filled. Flaps were elevated bilaterally, the premolars hemi-sectioned, and the distal roots removed. Recipient sites were prepared in the distal alveolus, and implants were placed. At the test sites, DBBM particles were placed in the residual marginal defects concomitantly with the placement of a collagen membrane. No treatment augmentation was performed at the control sites. A non-submerged healing was allowed. Impressions were obtained at baseline and at the time of sacrifice performed 4 months after surgery. The cast models obtained were analyzed using an optical system to evaluate dimensional variations. Block sections of the implant sites were obtained for histological processing and soft tissue assessments. Results After 4 months of healing, no differences in soft tissue dimensions were found between the test and control sites based on the histological assessments. The location of the soft tissue at the buccal aspect was, however, more coronal at the test compared with the control sites (1.8 +/- 0.8 and 0.9 +/- 0.8 mm, respectively). At the three-dimensional evaluation, the margin of the soft tissues at the buccal aspect appeared to be located more apically and lingually. The vertical dislocation was 1 +/- 0.6 and 2.7 +/- 0.5 mm at the test and control sites, respectively. The area of the buccal shrinkage of the alveolar crest was significantly smaller at the test sites (5.9 +/- 2.4 mm2) compared with the control sites (11.5 +/- 1.7 mm2). Conclusion The use of DBBM particles concomitantly with the application of a collagen membrane used at implants placed into sockets immediately after tooth extraction contributed to the preservation of the alveolar process.

Seed dispersal by fishes in tropical and temperate fresh waters: The growing evidence

Fruit-eating by fishes represents an ancient (perhaps Paleozoic) interaction increasingly regarded as important for seed dispersal (ichthyochory) in tropical and temperate ecosystems. Most of the more than 275 known frugivorous species belong to the mainly Neotropical Characiformes (pacus, piranhas) and Siluriformes (catfishes), but cypriniforms (carps, minnows) are more important in the Holarctic and Indomalayan regions. Frugivores are among the most abundant fishes in Neotropical floodplains where they eat the fruits of a wide variety of trees and shrubs. By consuming fruits, fishes gain access to rich sources of carbohydrates, lipids and proteins and act as either seed predators or seed dispersers. With their often high mobility, large size, and great longevity, fruit-eating fishes can play important roles as seed dispersers and exert strong influences on local plant-recruitment dynamics and regional biodiversity. Recent feeding experiments focused on seed traits after gut passage support the idea that fishes are major seed dispersers in floodplain and riparian forests. Overfishing, damming, deforestation and logging potentially diminish ichthyochory and require immediate attention to ameliorate their effects. Much exciting work remains in terms of fish and plant adaptations to ichthyochory, dispersal regimes involving fishes in different ecosystems, and increased use of nondestructive methods such as stomach lavage, stable isotopes, genetic analyses and radio transmitters to determine fish diets and movements. (C) 2011 Elsevier Masson SAS. All rights reserved.

Natural Infection with Cryptosporidium galli in Canaries (Serinus canaria), in a Cockatiel (Nymphicus hollandicus), and in Lesser Seed-Finches (Oryzoborus angolensis) from Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

PLANT-TO-SEED TRANSMISSION of CURTOBACTERIUM FLACCUMFACIENS pv. FLACCUMACIENS IN A DRY BEAN CULTIVAR

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The influence of the caruncle on the germination of castor seed under high salinity or low soil water content

The caruncle is a structure present in the micropylar region of Euphorbiaceae seeds. This structure has the ecological function of promoting seed dispersal by ants (myrmecochory), but it is debated whether it also has an agronomical importance influencing seed germination. The influence of the caruncle on castor (Ricinus communis) seed germination was evaluated under low soil water content and high soil salinity. Seeds were germinated at soil water storage capacities varying from 22 to 50% and salinities (NaCl) varying from 0 to 10 dS m(-1) The germination (%) increased following the increments in soil moisture. hut the caruncle had no influence on this process at any moisture level. In one genotype. more root dry mass was produced when caruncle was excised. Increasing salinity reduced the percentage and speed of germination of castor seeds, but no influence of caruncle was detected. No evidence of caruncle influencing castor seed germination was found under low soil water content and high salinity.

Growth Regulators and KNO3 on Seed Germination of Angelonia salicariifolia

Angelonia salicariifolia is an herbaceous perennial native to Brazil with ornamental potential as garden plant, cut-flower and potted plant. It has blue flowers 1.0 to 1.4 cm long, in 10-30 cm long terminal racemes. In previous studies seeds of A. salicariifolia showed a positive photoblastic behavior under constant temperatures of 10, 15, 20, 25, 30 and 35 degrees C. The present study evaluated the effects of growth regulators (100, 200, 300, 400, 500 mg L-1 of gibberellic acid and 2.25, 11.3, 22.5 mg L-1 of 6-benzylamino-purine) and potassium nitrate (0.2 and 1.0 %) on promoting its seed germination. The experiment was conducted in a completely randomized design with six replications of 25 seeds, for each treatment. Seeds from dehiscent capsules were sown on one layer of filter paper and moistened with growth regulators or KNO3 solutions. Germination was carried out at 25 degrees C +/- 1 degrees C, under continuous light or darkness. Germination (protusion of the radicle) was observed daily for 20 days. In the dark, only gibberellic acid promoted seed germination. The percentage of germination and the speed of germination index at 400 mg L-1 (47.3%; 0.86) and 500 mg L-1 (52.0%; 0.95) were significantly higher compared to 100 mg L-1 (27.8%; 0.38) and 200 mg L-1 (32.3%; 0.49). The mean germination time at 500 mg L-1 (10.0 days) was significantly smaller compared to 100 mg L-1 (11.9 days) and 200 mg L-1 (11.5 days). Under light, treatments did not differ among each other or from the control, except for 22.5 mg L-1 of 6-benzylamino-purine and potassium nitrate (1.0%), which decreased the percentage of germination and the speed of germination index compared to control. The application of growth regulators or potassium nitrate under light condition is not necessary, since these treatments did not improve germination percentage or the speed of germination index.

Big fish are the best: Seed dispersal of Bactris glaucescens by the pacu fish (Piaractus mesopotamicus) in the Pantanal, Brazil

We studied the potential role as seed disperser of the pacu fish (Piaracrus mesopotamicus, Characidae) in the Pantanal of Brazil. The most important food item in the diet of the pacu in the wet season was fruits of the palm Bactris glaucescens found in the guts of 73 percent of all fishes collected (N = 70). We found a positive relationship between fish length, weight, and gape size and the number of intact seeds in their gut. Therefore, large pacus are especially important in dispersing B. glaucescens seeds within the studied system. Since the best seed dispersers are the largest fishes, which are preferred by commercial fisheries, we predict that the ongoing over fishing in freshwater ecosystems will have major impacts on the dispersal system of fish-dependent plants. We suggest that it is paramount to change the attitudes in fisheries management of fruit-eating fishes and urgent to evaluate the impact of fishing on forest regeneration.

Use of Natural Products for Post-Harvest Preservation of 'Vega' Cut Roses

Use of natural products as floral preservatives has helped to reduce the indiscriminate use of chemical products in flower preservation. In this study, we tested the ability of certain natural products to maintain the quality and to increase the commercial durability of 'Vega' cut roses. We employed a randomized factorial design with six post-harvest treatments and four evaluation dates. The following treatments were tested: 1) distilled water; 2) methyl jasmonate (350 mu M) applied in a four-hour pulse; 3) methyl jasmonate (500 mu M) spraying; 4) mint oil (100 ppm); 5) ginger oil (100 ppm); and 6) propolis (0.05%) as a maintenance solution. Flowers were kept at 20+/-2 degrees C and 67+/-3% RH. Physiological and qualitative evaluations were conducted. Natural products had a beneficial effect on the shelf life of the flowers. However, for all evaluated parameters, the methyl jasmonate spray was the most efficient treatment to maintain floral quality, resulting in less fresh-mass loss and a lower flower respiratory rate. Methyl jasmonate spray also improved the maintenance of coloration, relative water content and concentration of reducing sugars, thus extending the shelf life of roses.