Genetic control of iron concentration in Mesoamerican and Andean common bean seeds

The objective of this work was to evaluate the main differences in the genetic control of the iron concentration in Mesoamerican and Andean common bean seeds, in early generations, and to select recombinants with a high iron concentration in the seeds. F1, F1 reciprocal, F2, F2 reciprocal, and backcross (BC11 and BC12) generations were produced by crosses between Mesoamerican (CNFP 10104 x CHC 01-175) and Andean (Cal 96 x Hooter) inbred lines. The expression of significant maternal effect was observed for the Mesoamerican gene pool. Iron concentration was higher in the seed coat of Mesoamerican common bean seeds (54.61 to 67.92%) and in the embryo of Andean common bean seeds (69.40 to 73.44%). High broad-sense heritability was obtained for iron concentration in Mesoamerican and Andean common bean seeds. Gains with the selection of higher magnitude, from 20.39 to 24.58%, are expected in Mesoamerican common bean seeds. Iron concentration in common bean seeds showed a continuous distribution in F2, which is characteristic of quantitative inheritance in Mesoamerican and Andean common bean seeds. Recombinants with high iron concentration in seeds can be selected in both Mesoamerican and Andean common bean hybrids.

Influence of internal seedborne Fusarium semitectum on cotton seedlings

Fusarium semitectum was found to be the major seed colonizing fungus in the commercial acid delinted cotton (Gossypium hirsutum) seed lots. There was no correlation, however, between its incidence and seedling emergence and disease symptoms on the emerged seedlings in autoclaved sand. Inoculation technique simulating internally seedborne nature of the fungus showed that the observed non-correlation might be related to the threshold level of seed coat colonization. The internally seedborne inoculum besides reducing seedling emergence, incited an array of symptoms on the emerged seedlings, which ranged from negative geotropism, leaf tearing, collar rot leading to dry root rot and seedling mortality. The dry root rot continued to develop on the plants surviving the seedling phase. The collar rot symptoms can be confused with those caused by Rhizoctonia solani.

Morphology and anatomy of the developing fruit of Maclura tinctoria, Moraceae

(Morphology and anatomy of the developing fruit of Maclura tinctoria, Moraceae). Maclura tinctoria (L.) D. Don ex Steudel was selected for the present study due of its economic and medicinal importance. The purpose of this investigation is to present a detailed description of the fruit development, specially by: (a) defining the fruit type presented by the species, and (b) characterizing the seed type of the species based upon the presence or not of mechanical tissue on the seed-coat. The fruit originates from the subglobose female inflorescence which consists of small unipistillate flowers with superior ovary, unilocular and uniovular apical placentation. The mature fruit is multiple, constituted of small drupes. The ovule is ana-campylotropous, suspended, bitegmic and crassinucellate. The mature seed is flattened, slightly ovated, cream colored, with unspecialized membrane coat with thin-walled cells more or less crushed. The seed has parenchymatic endosperm with lipophilic content. The embryo is straight, with two cotyledons of the same size. Ontogenetic studies reveal that the fruits are infrutescences. The fleshy edible part is derived from the perigone and inflorescence axis. The drupes consist of a single pyrene of macrosclereids.

Viability and vigor of jamun (Syzygium cumini) seeds

Jamun (Syzygium cumini L. Skeels) (Black plum, Damson plum) fruits weigh between 2-5 g at maturity. Fresh seeds represented 20-80% of the total fruit weight; the seed coat and cotyledons contributed 6% and 94% to the total seed weight respectively, while the weight of the embryonic axis was insignificant. Only the embryonic axis stained with Tetrazolium, not the cotyledons. The seeds are polyembryonic with up to four embryos, of which at most three germinate. Decoated seeds germinated faster than coated seeds under nursery conditions, with high significant germination percentages, dry matter production rates and vigor indices. The lack of staining of the cotyledon by tetrazolium was probably due to the presence of an impermeable layer. Decoating seeds for faster germination is recommended.

The leaves of green plants as well as a cyanobacterium, a red alga, and fungi contain insulin-like antigens

We report the detection of insulin-like antigens in a large range of species utilizing a modified ELISA plate assay and Western blotting. We tested the leaves or aerial parts of species of Rhodophyta (red alga), Bryophyta (mosses), Psilophyta (whisk ferns), Lycopodophyta (club mosses), Sphenopsida (horsetails), gymnosperms, and angiosperms, including monocots and dicots. We also studied species of fungi and a cyanobacterium, Spirulina maxima. The wide distribution of insulin-like antigens, which in some cases present the same electrophoretic mobility as bovine insulin, together with results recently published by us on the amino acid sequence of an insulin isolated from the seed coat of jack bean (Canavalia ensiformis) and from the developing fruits of cowpea (Vigna unguiculata), suggests that pathways depending on this hormone have been conserved through evolution.

LENTIL TANNIN-GLOBULIN INTERACTIONAND AND IN VITRO HYDROLYSIS

Protein fractions were isolated from lentil cotyledons and tannins were isolated and purified from lentil seed coats. The globulin fraction corresponded to 42.7% of the total lentil flour nitrogen, representing the major protein fraction. Acetone:water (7:3) was the best extractant for seed coat tannins compared to methanol or methanol-HCl 1%. Native and heated (99oC/15 min.) isolated lentil globulin and casein were hydrolyzed with trypsin and pepsin in the absence of tannins and at 1:40, 1:20, 1:10, 1:5 and 1:2.5 tannin-to-protein ratios. The tryptic and peptic hydrolysis of the unheated proteins were reduced with increasing tannin-to-protein ratios. Unheated casein showed to be more susceptible to trypsin than globulin and the opposite effect was observed with pepsin. Heating followed by tannin interaction and hydrolysis had a more pronounced effect on tryptic than peptic digestion for both proteins.

Methods for overcoming dormancy in Dinizia excelsa Ducke seeds

The impermeability of seed coat to water is common mechanism in Fabaceae seeds. Treatments to overcome hardseededness include scarification with sulphuric acid, scarification on abrasive surface and soaking in water among others. The objective of this study was to identify an effective method to overcome dormancy in Dinizia excelsa seeds. A pre-test (untreated seed) and three experiments were carried out: immersion of seeds in acid sulphuric for 10, 20, 30, 40, 50 and 60min (experiment 1); scarification on abrasive surface at the positions distal end, near of the mycrophyle and on the lateral tissue and tegument clipping at 1mm of the distal end, near of the mycrophyle and on the lateral tissue (experiment 2); scarification on abrasive surface and immersion in water for 0, 12, 24 and 48h (experiment 3). The experimental design was completely with four replications of 50 seeds for each treatment. The statistical analysis was carried out by ANOVA and regression analysis. Seedlings emergence on untreated seeds started on the 8th day after sowing and reached 52.5% on the 1,709th day. In general, the treatments to overcome dormancy increase emergence. Emergence was higher for seeds treated with sulphuric acid for 20 and 30min with emergence of 93.6% and 86.6%, respectively. For seeds scarified on abrasive surface higher emergences were recorded for scarification on distal end, near of the mycrophyle and on the lateral, 82.7%, 74.3% and 75.7%, respectively. Seeds scarified manually showed higher emergence when not immersed in water (75%), or when immersed for 12 and 24h (75%, 73.6% and 65.6%, respectively). Immersion seeds in sulphuric acid for 20 and 30min and scarification on abrasive surface of distal end are effective to overcome dormancy in D. excelsa.

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.

Tentativa de evidenciar o Trypanosoma cruzi no sangue periférico de pacientes com doença de Chagas, em fase crônica, por meio do Quantitative Buffy Coat (QBC)

Valorizando a sensibilidade do sistema Quantitative Buffy Coat (QBC), documentada em modelo experimental murino, estando os animais com infecção aguda pelo Trypanosoma cruzi houve tentativa de evidenciar esse parasita no sangue periférico de 100 pacientes com doença de Chagas, em fase crônica. Com o emprego desse método, nenhuma positividade ocorreu, evidentemente em virtude das pequenas parasitemias, não reveláveis pela técnica, pelo menos conforme o verificado através da casuística considerada.

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.

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.

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.