Morphology of the dental carinae in Mariliasuchus amarali (Crocodylomorpha, Notosuchia) and the pattern of tooth serration among basal Mesoeucrocodylia.

Carinated teeth are common in Mesoeucrocodylia, and the occurrence of denticles over the carinae is related to high predacious species, often referred as ziphodont. This characteristic is broadly recognized as homoplastic. Carinae morphology is cryptic, difficult to be studied under common techniques, and Scanning Electronic Microscopy (SEM) allows the access to detailed information, offering a higher degree of confidence. Previous SEM study allowed the recognition of true/false ziphodont patterns, according to the morphology of the denticles, but such studies on gondwanan mesoeucrocodyles are uncommon. Mariliasuchus amarali is an Upper Cretaceous notosuchian mesoeucrocodyle from South America (Bauru Group, Brazil), with carinated teeth and specialized dentition. Its geological and biochronological distribution are reappraised. SEM study of two teeth shows carinae composed of isolated tuberous anisomorphic true denticles, supporting previous study. Enamel ornamentation does not develop over the carinae, and fabric becomes anastomosed in middle and posterior teeth. Carinae only occur in posterior molariform teeth, related to food processing. Morphological variability of Mariliasuchus is commented, focusing on dentition. Overall characteristics, molariform morphology and wear planes support a non-predacious habit for Matiliasuchus. Matiliasuchus pattern could not be related to true/false ziphodont patterns, either by morphology or function, and is defined as ziphomorph. Ziphomorph pattern is evaluated within the range of mesoeucrocodyles. The detailed study of homoplastic characteristics, such as dental carinae, may provide useful apomorphic information for cladistic analysis.

The action of the testa upon the germination of seeds of Cucumis anguria L.

In negatively photoblastic seeds of Cucumis anguria L. the scarification of micropyle overcame the inhibitory effect of white light , although far-red radiation inhibited the germination in both intact and scarified seeds. The moistened testa powder transmitted more far-red than red radiation. Thus the testa could act as a filter of radiation and maintain a high far-red/red ratio at the photosensitive site of the embryo, which must be localized near the micropyle. © 1988 Academia.

Effect of water stress on seed germination and seedling growth in Oryza sativa L.

The effect of water stress induced by application of polyethylene glycol 6000 during seed germination and seedling growth of Oryza sativa L. cv. IAC 165 was analysed. The seed germination was inhibited by the decrease in the water potential of the medium, the inhibition being greater under white light than under continuous darkness. When the seedling was submitted to water stress (-0.51 MPa) white light inhibited growth of root, coleoptile-and leaf, while under no stress conditions white light caused increase in growth of root and leaf and only inhibition of coleoptile growth. © 1990 Kluwer Academic Publishers.

Asymmetry of the Aharonov-Bohm diffraction pattern and Ehrenfests theorem

The electron-diffraction pattern for two slits with magnetic flux confined to an inaccessible region between them is calculated. The Aharonov-Bohm effect gives a diffraction pattern that is asymmetric but has a symmetric envelope. In general, both the expected displacement and the kinetic momentum of the electron are nonzero as a consequence of the asymmetry. Nevertheless, Ehrenfests theorems and the conservation of momentum are satisfied. © 1992 The American Physical Society.

Electrical conductivity of soybean soaked seeds. I. Effect of genotype

During the period from October/92 to September/94 experiments were carried out at the Seed Laboratory, FCAV/UNESP, Jaboticabal, SP, Brazil, using soybean seeds of different genotypes in order to evaluate the effect of genotype on the electrical conductivity (bulk conductivity) of soaked seeds. Seed moisture content (105 ± 3°C, 24 h), standard germination (four 50-seed samples, paper towel, 30°C), and vigor-accelerated aging (42°C, 48 h) were first determined. Undamaged soybean seeds were soaked in deionized water (four 50-seed samples, 75 ml, 25°C, 24 h) and electrical conductivity (μmhos.cm+1.g+1) was measured. Significant differences in conductivity were observed among genotypes having the same pattern of germination and vigor. The results have showed that electrical conductivity can be significantly influenced by genotype.

On the germination and dormancy of dispersal units of Brachiaria decumbens staff

The effect of light and temperature on germination of Brachiaria decumbens as well as the action of some dormancy breaking chemicals were tested. Two seed batches stored different times were used. The results show that seeds failed to respond to alternating temperature regimes and different light qualities. Seeds were indifferent to white light at 25°C. KNO3, ethanol and H2SO4 failed to break seed dormancy, whereas KCN and H2O2 partially reduced dormancy of two month stored seeds. The results suggest a metabolic character of dormancy in new (freshly collected) seeds and confirm the occurence of two types of dormancy in B. decumbens seeds.

Metacarpophalangeal pattern profile in Marfan syndrome and Marfan-like patients

Marfan syndrome (MFS) is an autosomal dominant trait due to mutations in the fibrillin gene (FBN1). The MFS expressivity is variable, and its diagnosis relies completely on clinical criteria. Atypical cases and Marfan- like (marfanoid) clinical presentations are commonly found. The metacarpophalangeal pattern profile (MCPP), a radiological method in which the 19 tubular hand bones are assessed, has been used in the diagnosis of various syndromes. To investigate whether the MCPP was adequate to discriminate between MFS and Marfan-like subjects, we studied 38 patients who were referred to our service because they had an MFS diagnosis, diagnostic hypothesis, or differential diagnosis or had arachnodactyly with dolichostenomelia. Two groups were formed: 1) MFS: 21 patients with a mean age of 18.3 (10.8 S.D.) years and 2) Marfan-like syndromes: 16 patients who did not meet the current criteria, with a mean age of 14.6 (4.6 S.D.) years. The MCPP was performed in each case following the classical technique, and a characteristic mean profile was obtained for group I (MFS), with Z scores ranging from 0.69 to 2.73 (1.80 ± 0.50; mean ± S.D.). In group I, three cases had no correlation with the typical MFS pattern. In group II, three cases had an MFS pattern. The correlation with the mean MCPP of MFS permitted the differential diagnosis of MFS and marfanoid syndromes with 86% sensitivity, 81% specificity, and 86% positive and 81% negative predictive values. The results suggest that MCPP can be used effectively as an auxiliary tool in the nosology of these conditions and, because there is no change in MCPP with age, can be helpful in early diagnosis.

Inhibitory effects of jackbean (Canavalia ensiformis L.) leaf residues on germination and vigour of crops and weeds

The effects of jackbean leaf residues incorporated in the soil on germination and seedlings growth of cucumber, radish and some weeds was examined. Trials were carried out under greenhouse conditions to (a) determine the amount of incorporated residue that is inhibitory to two test plants, (b) to determine if decomposition time changes the inhibitory levels of jackbean residues on test plants and (c) to determine the amount of residue that is inhibitory to the weed species. Jackbean leaf residues incorporated in soil at concentration of 2% or higher and allowed to decompose for a period of 0 to 2 weeks before sowing, reduced the initial growth of cucumber and radish and at different concentrations, reduced germination and growth of three weed species. These results suggest the presence of allelopathic components in Jackbean leaves that could affect seed germination and seedling development.

Effect of soil moisture content and the irrigation frequency on the sugarcane germination

The aim of this work was to observe the interaction between soil moisture and irrigation time intervals on the germination of sugarcane cv. RB785148 sets in semi-controlled conditions. One-bud sets of the variety RB785148 were germinated in ceramic pots filled with soil under a transparent PVC cover using soil humidity levels of 22, 25 and 30%, that were restored at intervals of 7, 14 and 21 days. The experiment was carried out at three different periods of the year: May-June/94; Oct.-Nov./94; and Mar.-Apr./95. The results indicate that the germination decreased mainly in function of the decrease in soil humidity, whereas irrigation interval have no statistical effect on germination. An interaction between humidity level and irrigation interval was observed. A variation of the timecourse of the germination could be observed when the results of the experiments installed at different dates were compared.

Heterochromatic banding pattern in two Brazilian populations of Aedes aegypti

We analysed samples of Aedes aegypti from Sao Jose do Rio Preto and Franca (Brazil) by C-banding and Ag-banding staining techniques. C-banding pattern of Ae. aegypti from Sao Jose do Rio Preto examined in metaphase cells differed from Franca. The chromosomes 2, 3 and X showed centromeric C-bands in both populations, but a slightly stained centromeric band in the Y chromosome was observed only in Sao Jose do Rio Preto. In addition, the X chromosome in both populations and the Y chromosome of all individuals from Sao Jose do Rio Preto showed an intercalary band on one of the arms that was absent in Franca. An intercalary, new band, lying on the secondary constriction of chromosome 3 was also present in mosquitoes of both populations. The comparison of the present data with data in the literature for Ae. aegypti from other regions of the world showed that they differ as to the banding pattern of sex chromosomes and the now described intercalary band in chromosome 3. The observations suggested that the heterochromatic regions of all chromosomes are associated to constitute a single C-banded body in interphase cells. Ag-banding technique stained the centromeric regions of all chromosomes (including the Y) and the intercalary C-band region of the X chromosome in both populations. As Ae. aegypti populations are widespread in a great part of the world, the banding pattern variations indicate environmental interactions and may reveal both the chromosome evolutionary patterns in this species and the variations that may interfere with its vector activity.

Effect of five substrates and three seed types on Calendula officinalis (Asteraceae) germination and seedling development

The investigation was carried out during May - June 1996 in Agronomical Sciences College - UNESP, Campus de Botucatu. The objective was to study the effect of seed types (carenate, alate and orbicular) and different substrates (vermiculite, sand, soil, commercial mixture and producer's mixture) on Calendula officinalis germination and seedling development. The design was in randomized blocks, with 4 replications. The germination index of the seeds was evaluated, as well as the development of aerial part and root system of the seedlings. Results showed that seed types have no relation with seedling development, therefore, germination was better on alate and orbicular seeds in C. officinalis. With reference to the substrates, the producer's mixture and the commercial mixture gave better germination and seedling development.

Desarrollo ontogénico de plántulas de Guazuma ulmifolia (Sterculiaceae)

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 considenng 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 biometric 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 in a culture medium, at 30°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.

Influence of light, plant density and disinfection in spore germination of fern blechnum brasiliense desv. blechnaceae

The present assay had as objective evaluating spore germination of Blechnum brasiliense in relation to light, plant density and disinfection. The assay was carried out at Jaboticabal, Sào Paulo State, Brazil, from February, 22 to June, 30, 1996. The experimental design was randomized blocks on a factorial scheme (3x2x2), consisting of 12 treatments, three environments (shade-house, dark-house and germination camera), 2 densities (0.005 grs and 0.010 grs of spores/treatment) and presence or absence of disinfection. The leaf coverage area (130 days) and the number of days necessary to germinate were evaluated. The germination camera data were not analysed because they were insignificant; consequently, the remining data were analysed on a 2×2×2 scheme. The shade-house provided larger green covering area and a faster germination. The density of 0.0 lOg of spore/treatments presented the largest green covering area. The supply of partial light was necessary for good germination. The interaction between the environment and the density had significant effect on the green covering area.

Evaluation of naturally and artificially aged seeds of Phaseolus vulgaris L.

Seed ageing is natural phenomenon that occurs in all seeds, including those stored in dry and low temperature rooms. Phaseolus vulgaris L. cv. 'Carioca' seeds harvested in five different years were stored in at 15°C. Seed samples were germinated and evaluated according to The Brazilian Rules for Testing Seeds. The newest seed sample was submitted to artificial ageing. Small (∼1g) samples of all materials (naturally and artificially aged) were ground and proteins extracted. Equal quantities of protein were loaded onto the gels and electrophoresis carried out. Although seeds submitted to 24, 48, 72 and 96 hours of artificial ageing did not show any statistical difference (5%) in relation to unaged seeds in physiological parameters related to emergence, some statistically different parameters related to dry matter and length of shoots and roots occurred. A 24 h of artificial ageing at 41°C improved these factors. Protein patterns were changed after 72 h of artificial ageing and naturally aged seeds showed alterations after two years storage at 15°C. Aged seeds, naturally and artificially, had decreasing germination, vigour, and changes in the characteristic banding pattern of proteins. Physiological parameters and electrophoresis examination showed that for naturally aged seeds physiological parameters were more sensitive while artificially aged seeds, (41°C/100% RH), had electrophoretic profiles that were more efficient for seed lot discrimination.

Phytochrome and light influence on germination and vigor of ocimum gratissimum L. (Lamiaceae) seeds under high irradiance conditions

Ocimum gratissimum seed germination (% germination and vigor) has been found as phytochrome dependent, having a typical High Irradiant Response (HIR). Seven treatments were tested: daylight (DL), red (R), far-red (FR), blue (B), green (G), dark (DK), and reversible (RVB). No statistical difference among the DL, R, FR, B, and G were found. DK and RVB were statistically equal and presented the lowest results. The germination also occurred in the DK treatment but in non-useful rates, and it was nonreversible in the RVB treatment. It allows these seeds to be classified as positively photoblastic. The minimum energy need to initiate the germination was evaluated by a fluency-response curve. It plotted four different exposition times to R light (1 second, 60 seconds, 1 hour, and 13 hours) against percent germination. Useful germination occurred only after 1 hour, confirming the high energy needed to incite the process. The germination rate increased with the raise of the photoequilibrium (j). The high positive correlation index found confirms the phytochrome influence in this process. Facing all the results presented here, it is suggested to sow these seeds under direct and highly intense sunlight. It is preferable to avoid places exposed to variations in the shading, because inhibition induced by dense shade effects (low R/FR ration and consequently low j established) were demonstrated irreversible, and it can lead to undesirable loss of the germination power.