Physiological and biochemical characterization of the assai palm (Euterpe oleracea Mart.) during seed germination and seedling growth under aerobic and anaerobic conditions

Physiological and biochemical aspects of assai palm during seed germination and early seedling growth were investigated. Seeds collected from plants growing in flooded and upland forests were used to determine the influence of normoxic (aerobic) and anoxic (anaerobic) conditions in germination and the initial and average time of development in the roots and shoots. After 75 days, seedlings germinated under normoxia were transferred to trays and submitted to flooding. Seed reserves (lipids, proteins, soluble sugars and starch) were monitored for quiescent and germinated seeds maintained under normoxic and anoxic conditions, as well as after 5, 10 and 20 days of seedling growth. Alcohol dehydrogenase (ADH) activity was quantified in roots and leaves of seedlings without or with flooding (partial and total). Seeds were not able to germinate under anoxia. Different strategies of storage mobilization of lipids, proteins, soluble sugars and starch were observed in seeds of each environment. ADH activity was induced by anoxia, with the highest level observed in the leaves. This study showed that, under normoxic conditions, the best developmental performance of assai palm seeds, from flooded or upland forest areas, during germination was associated with primary metabolites mobilization and seedling flooding tolerance with increased ADH activity. We conclude that the assai palm is well adapted to the anoxic conditions provoked by flooding.

Localization of the cotyledon reserves of Theobroma grandiflorum (Willd. ex Spreng.) K. Schum., T. subincanum Mart., T. bicolor Bonpl. and their analogies with T. cacao L.

Cotyledon mesophyll cell morphology and lipid and protein synthesis of T. grandiflorum, T. subincanum and T. bicolor were analyzed and compared with T. cacao. These species possess foliar cotyledons folded around the hypocotyl radicle axis, typical of Sterculiaceae. Fruit size, morphology and weight are very distinct amongst the four species and so are the respective seeds. The main axis of the T. grandiflorum and T. bicolor seeds measured about 30 mm, while T. subincanum and T. cacao seeds measured 17 mm and 26 mm respectively. The seed weights of T. grandiflorum, T. bicolor, T. subincanum and T. cacao were 11.6 g, 9.4 g, 2.1 g and 3.0 g, respectively. The cotyledon mesophylls of the four species contained mainly polysaccharides and lipid-protein reserve cells. Theobroma cacao, T. grandiflorum and T. subincanum were composed of greater than 50% lipids. For the four species, lipid globules gradually accumulated adjacent to the cell wall, and these globules measured from 1 to 3 µm. TEM showed low-density proteins inside the central vacuole of the young mesophyll cells of T. cacao. The protein reserves of the mature cells were densely scattered amongst the lipid bodies, and a few starch granules occurred together with the cotyledon mesophyll of the four species. Polyphenolic cells were found throughout the mesophyll cells or aligned with the respective vascular bundles. Immature cells demonstrated the capacity to synthesize all these reserves, but gradually the pre-determined cells produced mainly lipid-protein reserves. Besides the unique characteristics of the T. cacao products, the lipid-protein synthesis capacities of T. grandiflorum, T. subincanum and T. bicolor suggest various possibilities for new industrialized food, pharmaceutical and cosmetic products.

Mobilization of reserves and germination of seeds of Erythrina velutina Willd. (Leguminosae - Papilionoideae) under different osmotic potentials

Some environmental factors, including water availability, may influence seed germination. This study investigated the germination of E. velutina seeds submitted to different osmotic potentials and mobilization of reserves during water-stress. Scarified seeds were arranged in paper rolls and soaked in solutions of Polyethylene Glycol (PEG) prepared in osmotic potentials 0.0, -0.2, -0.4, -0.6, and -0.8 MPa and kept into a seed germinator, at 25 °C, and 12/12 h photoperiod (L/D), during 10 days. The percentage, mean time, mean speed, germination speed index; as well as the germination uniformity coefficient were assessed. During germination process the total soluble sugars, reducing sugars, soluble protein, and total amino acids were quantified in the cotyledon, hypocotyl and radicle of soaked seeds and cotyledons of quiescent seeds (control). There was influence of osmotic potential on E. velutina seed germination. The germination percentage remained at high levels until -0.6 MPa and above this osmotic potential there has been no germination. The mobilization of stored reserves of carbon and nitrogen in E. velutina seeds was also influenced by water-stress. There was sensitiveness between -0.2 and -0.6 MPa; however, the degradation and the mobilization of reserves was slower when the osmotic potential decreased.

The influence of light spectra, UV-A, and growth regulators on the in vitro seed germination of Senecio cineraria DC.

This study was carried out to investigate the effects of light spectra, additional UV-A, and different growth regulators on the in vitro germination of Senecio cineraria DC. Seeds were surface-sterilized and inoculated in MS medium to evaluate the following light spectra: white, white plus UV-A, blue, green, red or darkness. The maximum germinability was obtained using MS0 medium under white light (30%) and MS + 0.3 mg L-1 GA3 in the absence of light (30.5%). S. cineraria seeds were indifferent to light. Blue and green lights inhibited germination. Different concentrations of gibberellic acid (GA3) (0.1; 0.4; 0.6; 0.8; 1.0 and 2.0 mg L-1) and indole-3-acetic acid IAA (0.1; 0.3 and 1.0 mg L-1) were evaluated under white light and darkness. No concentration of GA3 enhanced seed germination percentage under white light. However, when the seeds were maintained in darkness, GA3 improved germination responses in all tested concentrations, except at 1.0 mg L-1. Under white light, these concentrations also increased the germination time and reduced germination rate. Germination rate, under light or darkness, was lower using IAA compared with GA3.

Production of basic potato seed minitubers in substrate and different nitrogen rates

The optimal dose of nitrogen (N) in potato crop depends on the production system. The objective of this study was to determine the optimal dose of N for the production of basic potato seed minitubers and evaluate the effect of N rates on physiological and nitrogen indices in the youngest fully developed leaf (fourth leaf) and in the oldest leaf of the plants at 60 days after planting. The experiment was conducted in a greenhouse at the Departamento de Fitotecnia da Universidade Federal de Viçosa. The treatments consisted of five N rates (0, 45, 90, 180 and 360 mg dm-3), with 10% of each dose applied at planting and the remainder through irrigation water, daily, for 30 days. The nitrogen rates positively influenced the physiological indices (length, width, leaf area, number of leaves, fresh mass and dry mass) and nitrogen (level and content of N and N-NO³ in the dry mass and SPAD) both in the fourth leaf and in the oldest leaf. Likewise, the N rates positively influenced the number and mass of harvested tubers. The largest number (5.44 tubers/plant) and the maximum mass of tubers (243.5 g/plant) were obtained with 360.0 and 332.9 mg N dm-3, respectively. Therefore, the mass and number of tubers were not optimized by the same N rate. The critical SPAD index was 38.8 in the fourth leaf, which was more sensitive to the effect of N rates than the oldest leaf.

Chilling requirement for seed germination and phenological observations on peach cultivars

In subtropical climate areas, the models and methods proposed to evaluate the chilling requirement of temperate fruit crops often do not provide satisfactory results, thus calling for the development of alternative techniques. The aim of this study was to evaluate the correlations between some phonological traits and chilling requirement for seed germination of 18 peach cultivars and one nectarine cultivar. Two experiments were installed separately for the correlation studies. In experiment 1, the phenological traits were observed in the field, while in experiment 2, the chilling requirement for 50 and 100% seed germination of each cultivar was assessed. The number of days for beginning of bloom (r = 0.70**, 0.61**) and full bloom (r = 0.72**, 0.76**) were both significantly correlated with the number of chilling units for 50% and 100% germination of seeds. The number of days for beginning of budding and dormancy break were both significantly correlated with the number of chilling units for 50% and 100% germination (r = 0.48*, 0.50*, respectively). However, the same significant effect for these phenological traits was not found between chilling units and 50% germination of seeds, as well as between chilling units and harvest dates.

Lignification of the plant and seed quality of RR soybeans sprayed with herbicide glyphosate

Differences in levels of lignin in the plant between conventional and transgenic cultivars RR has been reported by several authors, however, there are few studies evaluating the influence of spraying of glyphosate on the lignin in the plant and RR soybean seeds. The aim of this study was to evaluate the physiological quality of RR transgenic soybean seeds and the lignin contents of plants sprayed with the herbicide glyphosate. The assays were conducted both in greenhouse and field in the municipality of Lavras, MG, in the agricultural year 2007/08. The experiment was arranged in a splitplot design with four replicates, considering the treatments hand weeding and herbicide glyphosate as plots, and five RR soybean cultivars (BRS 245 RR, BRS 247 RR, Valiosa RR, Silvânia RR and Baliza RR) as splitplots. In the greenhouse, the cultivars tested were BRS 245 RR and Valiosa RR in a randomized block design with four replicates. The sprayings were carried out at stages V3, V7 and early R5 (3L/ha). The 1000 seed weight, mechanical injury, germination and germination velocity index, emergence velocity index, accelerated aging, electrical conductivity and water soaking seed test, lignin content in the seed coat, in the stem and legumes were determined. The spraying of glyphosate herbicide, in greenhouse and field, did not alter the physiological quality of seeds and the lignin contents in the plant.

Chemical composition, toxicity and larvicidal and antifungal activities of Persea americana (avocado) seed extracts

The present study had the aim of testing the hexane and methanol extracts of avocado seeds, in order to determine their toxicity towards Artemia salina, evaluate their larvicidal activity towards Aedes aegypti and investigate their in vitro antifungal potential against strains of Candida spp, Cryptococcus neoformans and Malassezia pachydermatis through the microdilution technique. In toxicity tests on Artemia salina, the hexane and methanol extracts from avocado seeds showed LC50 values of 2.37 and 24.13mg mL-1 respectively. Against Aedes aegypti larvae, the LC50 results obtained were 16.7mg mL-1 for hexane extract and 8.87mg mL-1 for methanol extract from avocado seeds. The extracts tested were also active against all the yeast strains tested in vitro, with differing results such that the minimum inhibitory concentration of the hexane extract ranged from 0.625 to 1.25mg L-¹, from 0.312 to 0.625mg mL-1 and from 0.031 to 0.625mg mL-1, for the strains of Candida spp, Cryptococcus neoformans and Malassezia pachydermatis, respectively. The minimal inhibitory concentration for the methanol extract ranged from 0.125 to 0.625mg mL-1, from 0.08 to 0.156mg mL-1 and from 0.312 to 0.625mg mL-1, for the strains of Candida spp., Cryptococcus neoformans and Malassezia pachydermatis, respectively.

Small mammal abundances in isolated and non-isolated primary forest reserves near Manaus, Brazil

Abundances of msmall terrestrial mammals were estimated in 10 and 100-ha, isolated and non-isolated primary forest reserves near, Manaus, Brazil between October 1983 and March 1984. The smalt mammal abundance pattern In a 10 ha reserve isolated fan appoximately three years differed significantly from that in othen reserves, primarily due to higher capture rates of Marmosa cinerea, Rhipidomys mastacalis, and Onyzomys paricola in the isolated reserve. Viet type and re-invasion potential may be important factors the small mammal communities in forest patches. Variation the small mammal community among othen reserves was pnimanlty due to variatton In the abundances of Proechimys and 0. capito. At least pant of this vantation was attributable to temporal efects, but variation due to reserve effects also was suggested. Small mammals were much more abundant in the reserves during the present study than in 1982.

On the occurrence of cyanolipids In Paullinia carpopodea cambess And P. cupana Kunth seed oils

Paullinia carpopodea seed oil contains 70% type Icyanolipids with cyanogenetic properties, as proven by chemical and spectrometric techniques. P. cupana seed oil also contains cyanogenic type I cyanolipids, according to its 1Ή-NMR spectrum. The existing controversy in the literature about the presence and/or type of cyanolipids in P. cupana seed oil is probably due to the low amount of these compounds (0.2%) in the seeds.

Fisheries and fishing effort at the Indigenous Reserves Ashaninka/Kaxinawá, river Breu, Brazil/Peru

This article aimed to describe the subsistence fisheries of traditional populations of three ethnic groups, one Ashaninka and two Kaxinawá, lying on the banks of the River Breu. Initially, monitors were trained to fill logbooks with data from fisheries of the villages during an annual cycle (august/1995 august/1996). Based on these data, it was realized an inventory of the most common fish species caught as well as one about the fishing environment. The following results were obtained: i) Indians prefer to use pools, locally known as "poços", for fishing; ii) the most common caught species are the "mandis" (35%, Pimelodidae), armored catfishes (Loricariidae), specially Hypostomus sp. (25%), the "curimatá" (9%, Prochilodus sp.) and the "saburus" (8%, Curimatidae), among others; iii) the fishing gears that lead to a high rate of fishing are the native "tingui", nets and bow and arrows; iv) fisheries are more intensive during summer; v) the fishing effort and their associated factors statistically significant in predicting the catches in the Indian Reserve were f1 = number of fishermen, f2 = (number of fishermen*total time devoted to fishing), f3 = [(number of fishermen)*(total time devoted to fishing)-(the time displacement)] and the factor villages and fishing gears; vi) although almost all the fisheries are done by walking to the fishing places, catches increase when paddle boats are used; and vii) the most active fishermen belong to Kaxinawá tribe.

Taxonomic relevance of seed and seedling morphology in two Amazonian species of Entada (Leguminosae)

We carried out a comparative morphological study to evaluate the taxonomic value of seed and seedling traits of Entada polystachya and E. simplicata (Leguminosae, Mimosoideae, Mimoseae). Seeds of both species were collected from wild populations in Roraima State, Brazil. Our results show consistent quantitative and qualitative differences between these species regarding their seeds and seedlings. Testa fracture lines, funiculus impression, lens characters, radicle shape and length, and cotyledon lobes length, seedling morphology group, number of pinnae at first node, and hypocotyl length permit a straightforward distinction of E. polystachya from E. simplicata, supporting a recent treatment of the latter taxon as a distinct species, endemic to Roraima State, northern Amazonia, Brazil.

Effects of foliar fertilization of common bean (Phaseolus vulgaris, L.) during the seed-filling stage

An experiment was carried out with common bean (Phaseolus vulgaris, L.) in a Red Yellow Latossol, sandy phase, in order to study the influence of foliar spraying of the Hanway nutrient solution (NPKS) at grain filling stage on: 1) grain yield; 2) the uptake of fertilizer and soil nitrogen by this crop through the root system and 3) the efficiency of utilization of the nitrogen in the foliar spray solution by the grain. The results of this experiment showed that the foliar application of the Hanway solution with ammonium nitrate at the pod filling period caused severe leaf burn and grain yield was inferior to that of the plants which received a soil application of this fertilizer at the same stage. These facts can be attributed to the presence of ammonium nitrate in the concentration used. The composition of final spray was: 114,28 Kg NH4NO3 + 43,11 Kg potassium poliphosphate + 12,44 Kg potassium sulphate per 500 litres. The uptake of nitrogen fertilizer through the root system and the efficiency of its utilization was greater than that through the leaves.

The Phlebotominae sand fly (Diptera: Psychodidae) fauna of two Atlantic Rain Forest Reserves in the State of Rio de Janeiro, Brazil

During two consecutive years, studies on the sand fly fauna in Poço das Antas and Fazenda Bom Retiro, two Atlantic Rain Forest Reserves from the State of Rio de Janeiro, were performed using Shannon traps, CDC light traps and human bait collections. Eleven species were identified; Lutzomyia longipalpis, L. migonei, L. edwardsi, L. intermedia, L. whitmani, L. fischeri, L. shannoni, L. ayrozai, L. hirsuta, L. monticola and L. misionensis (first occurrence in the State of Rio de Janeiro). L. intermedia and L. whitmani were the predominant anthropophilic species around houses, while L. hirsuta predominated in the forest.