Phytoremediation capacity, growth and physiological responses of Crambe abyssinica Hochst on soil contaminated with Cd and Pb.

The search for vegetal species regarding effectiveness in the phytoremediation of soils is of great importance, mainly in function of the great environmental problems, such as soil contamination with heavy metals, the necessity of producing more food, among others that mankind face today. This work aimed (i) to evaluate phytoremediation capacity of Crambe abyssinica Hochst and its growth in soil artificially contaminated with Cd and Pb, and (ii) to evaluate the possible impacts of crambe cultivation in contaminated soil conditions, in order to evaluate, to test, and to question the Brazilian CONAMA 420, providing important information that can be useful for governmental and environmental purposes. Two simultaneous experiments were developed, one for each metal. The soils were contaminated with salts of CdCl2 and PbCl2H2O in five doses based on the investigation values (IV) of CONAMA Resolution 420, resulting in 0; 1.5; 3; 9 and 30 mg kg-1 for Cd and 33; 90; 180; 540 and 1800 mg kg-1 for Pb. Gaseous exchange, development, nutritional composition and production of plant components, as well as phytoavailability of metals, were evaluated. The contamination with metals reduced photosynthesis, increased breathing as well as leading to a negative effect on the mineral nutrition and productivity in general; Plants cultivated in soil with Cd presented higher phytoavailability when compared to those cultivated in the Pb conditions, being found metals in all parts of the crambe plants from 1.5 mg kg- 1 of Cd in the soil; and Pb was retained only in roots, not being translocated in the plant. Cd showed higher phytoavailability, being found in all parts of the plant and Pb was retained only in the roots. Cd showed a higher phytoavailability when compared to Pb, also being found in all parts of crambe plants from dose 1.5 mg kg-1 of Cd in soil, which is an environmental problem, since in these concentrations the cultivation of crops is allowed by Brazilian legislation CONAMA 420.

Peroxidase activity as an indicator of water deficit tolerance in soybean cultivars / Atividade de peroxidase como indicativo de tolerância à deficiência hídrica em cultivares de soja

This study had as purpose to test the hypothesis that peroxidase enzyme activity could be used as an indicator of tolerance to water deficit in soybean cultivars. The experiment was carried out in pots containing 20-L of a Rhodic Hapludox soil in greenhouse conditions. Treatments were arranged in a randomized block design in a 2 × 4 factorial: two water regimes (with and without water deficit) and four soybean cultivars (CD 204, CD 215, CD 225RR and CD 226RR), with four replications. Soybean plants were grown until the beginning of flowering (R1-R2) with soil moisture content near at the field capacity, and then, it started the differentiation of treatments under water deficit by the suspension of water supply. Changes in relative water content (RWC) in leaves, protoplasmic tolerance, peroxidase activity, and plant growth were measured after four days of drought stress and 4-d recovery. The soybean cultivars used in this study have different responses under water deficit conditions. The CD 215 cultivar was the most sensitive to water deficit in the beginning of flowering stage. Soybean cultivars presented variable responses to the peroxidase enzyme activity, and this variable can be used in the selection of soybean genotypes with greater tolerance to drought.

Este estudo teve como objetivo testar a hipótese de que a atividade das enzimas peroxidase poderia ser utilizada como um indicativo de tolerância à deficiência hídrica em cultivares de soja. O experimento foi realizado em vasos contendo 20L de um Latossolo vermelho argiloso em condições de casa-de-vegetação. Os tratamentos foram dispostos no delineamento de blocos casualizados em esquema fatorial 2 × 4, constituído de dois regimes hídricos (sem e com déficit hídrico) e quatro cultivares de soja (CD 204, CD 215, CD 225RR and CD 226RR), com quatro repetições. A soja foi cultivada até o início do florescimento com teor de água no solo próximo a capacidade de campo, e então, iniciouse a diferenciação dos tratamentos com déficit hídrico, mediante a suspensão do fornecimento de água. Alteração no conteúdo relativo de águas nas folhas, tolerância protoplasmática, atividade das enzimas peroxidade e crescimento das plantas foram avaliados após quatro dias de exposição ao déficit hídrico e após quatro dias de recuperação das plantas em condições controle. As cultivares de soja utilizadas neste estudo apresentam respostas distintas em condições de déficit hídrico. A cultivar CD 215 foi mais sensível ao déficit hídrico imposto no inicio do florescimento. As cultivares de soja apresentaram respostas variáveis à atividade das enzimas peroxidase, e esta variável pode ser utilizada na seleção de genótipos de soja com maior tolerância à seca.

Rapid identification of bacterial isolates from wheat roots by high resolution whole cell MALDI-TOF MS analysis.

Whole-cell mass spectrometry analysis is a powerful tool to rapidly identify microorganisms. Several studies reported the successful application of this technique to identify a variety of bacterial species with a discriminatory power at the strain level, mainly for bacteria of clinical importance. In this study we used matrix-assisted laser desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) to assess the diversity of wheat-associated bacterial isolates. Wheat plants cultivated in non-sterile vermiculite, under greenhouse conditions were used for bacterial isolation. Total cellular extracts of 138 isolates were analyzed by MALDI-TOF MS and the mass spectra were used to cluster the isolates. Taxonomic identification and phylogenetic reconstruction based on 16S rRNA gene sequences showed the presence of Pseudomonas, Pantoea, Acinetobacter, Enterobacter and Curtobacterium. The 16S rRNA gene sequence analyses were congruent with the clusterization from mass spectra profile. Moreover, MALDI-TOF whole cell mass profiling allowed a finer discrimination of the isolates, suggesting that this technique has the potential of differentiating bacterial isolates at the strain level.

Sistema desponte na produção de figos verdes 'Roxo de Valinhos' / Lopping system in the production of 'Roxo de Valinhos' green fig

O objetivo deste trabalho foi estudar o efeito do sistema desponte sobre o desenvolvimento e a produção de figos verdes 'Roxo de Valinhos'. O experimento utilizando plantas de quatro anos de idade, com espaçamento 3 x 2m, foi conduzido de julho de 2007 a março de 2008, em Quatro Pontes, Paraná (PR). O delineamento utilizado foi em blocos ao acaso, com quatro blocos, e os tratamentos foram arranjados em fatorial 2 x 5, tomando por fatores o número de ramos produtivos (plantas conduzidas com seis ou 12 ramos) e o número de despontes (um, dois, três ou quatro, além do controle sem desponte). No sistema desponte, após a emissão da 16a folha, o ramo foi despontado (gema apical removida), selecionando-se duas brotações por ramo produtivo. Novos despontes foram realizados posteriormente, sempre após a emissão da sexta folha. Em cada parcela, constituída de três plantas úteis, foram coletados dados no ciclo de produção 2007/08. A maior produção (2.208,87g planta-1) e produtividade estimada (3.681,19kg ha-1) observada de figos verdes foram obtidas quando as plantas foram conduzidas com 12 ramos produtivos, efetuando-se três despontes.

The objective of this research was to study the effect of the lopping system on the development and production of green figs 'Roxo de Valinhos'. The experiment using plants of four years of age, with spaced 3 x 2m, was conducted from July/2007 to March/2008 in Quatro Pontes, PR. The design was randomized blocks with four blocks, and the treatments arranged in a 2 x 5, taking as factors the number of productive branches (plants conducted with six or twelve branches) and the number of loppings (one, two, three or four, besides the control without lopping). In the lopping system, after the emission of the 16th leaf, the branch was blunted (apical bud removed), selecting two sprouting per productive branches. New lopping was accomplished later, always after the emission of sixth leaf. In each plot, consisting of the three plants, data were collected in the production cycles 2007/2008. The highest yield (2,208.87g planta-1) and estimated yield (3,681.19kg ha-1) observed of green figs were obtained when plants were conducted with twelve branches of production, effecting three loopings.

Avaliação de mudas de beterraba em função do substrato e do tipo de bandeja / Evaluation of substrate and tray types for beet seedlings

Visando avaliar o efeito de três substratos, Plantimax, Mogimax, Gioplanta, e bandejas de poliestireno expandido com 128 e 200 células, na produção de mudas de beterraba da cultivar “Early Wonder”, realizou-se um experimento no período de abril a maio de 1998 em Piracicaba- SP. A avaliação foi realizada 40 dias após a semeadura e as variáveis estudas foram altura da planta, comprimento do sistema radicular, massa seca total, massa seca da parte aérea, massa seca de raiz e determinada a razão entre a massa seca da parte aérea e a massa seca das raízes (RPAR). O delineamento experimental utilizado foi de blocos casualizados, em esquema fatorial 3 x 2, com 4 repetições. Em todas as variáveis estudas foi observada diferença significativa para substratos e recipientes. Para massa seca da parte aérea, massa seca total e RPAR foram observadas interações significativas entre tipo de substrato e bandeja. Plantimax e Mogimax mostraram-se superiores para maioria dos parâmetros avaliados. A bandeja com 128 células proporcionou a produção de mudas de melhor qualidade, com maior acúmulo de massa seca, quando comparada às mudas produzidas em bandejas de 200 células, sendo a mais indicada para produção de mudas de beterraba.

The experiment was carried out from April to May of 1998 in Piracicaba- SP, with the objective of evaluating three substrates: Plantimax, Mogimax and Gioplanta, and two recipient trays: one with 128cells and other with 200 cells, in beet seedling production of cultivar "Early Wonder". The evaluationwas accomplished 40 days after sowing by the following parameters: plant height, root length, total drymass, root dry mass, shoot dry mass and the shoot/root relation. The experimental design was randomized blocks in 3 x 2 outline factorial with 4 replications. In all evaluated parameters, there were found significant differences among substrates and trays. Also, it was observed significant interaction in total dry mass, shootdry mass and shoot/root relation. Plantmax and Mogimax were superior for the most of the evaluated parameters.Recipient tray with 128 cells was better than 200 cells, being more indicated for beet seedling production

Uso de bioestimulante na formação de mudas de maracujazeiro amarelo / Use of bioestimulant in yellow passion fruit seedlings

A produção de mudas de alta qualidade torna-se uma estratégia importante para o sucesso de uma cultura. Desta forma, o presente trabalho teve como objetivo avaliar o efeito de diferentes doses de bioestimulante Stimulate na formação de mudas de maracujazeiro. O experimento foi conduzido em casa de vegetação, em delineamento experimental em blocos casualizados, com parcelas subdivididas no tempo, com seis tratamentos e quatro repetições, sendo cada parcela composta de 24 plantas. Os tratamentos foram constituídos de diferentes doses de bioestimulante: (água destilada), 4, 12, 16, e 20 mL kg-1 sementes. Foram coletadas duas plantas por parcela aos 15, 22, 29, 36, 43 e 50 dias após a emergência. As características avaliadas foram altura de plantas, área foliar, massa seca de folhas, parte aérea, raízes, massa seca total, razão raiz/parte aérea, taxa de crescimento absoluto e relativo, taxa assimilatória líquida, razão de área foliar e área foliar específica. Verificou-se efeito positivo do bioestimulante sobre a maioria das variáveis avaliadas, em relação à testemunha. Doses entre 4 e 6 mL de Stimulate kg-1 de sementes promoveram maior equilíbrio entre o sistema radicular e a parte aérea, o que pode favorecer o estabelecimento da muda no campo

The production of seedlings of high quality becomes an important strategy for the success of a crop.The present research had the objective of evaluating the effect of different bioestimulant doses,Stimulate®, in the formation of passion fruit seedlings. The experiment was carried out in greenhouseconditions, in randomize complete blocks experimental design with six treatments and four replications,with 24 plants per plots. The treatments were constituted of different bioestimulante doses: 0 (distilledwater), 4, 12, 16 and 20 mL kg-1 seeds. Plants were collected 15, 22, 29, 36, 43 and 50 days after theemergency. Evaluations were plant height, leaf area, dries mass of leaves, shoot, root and total dry mass;root/shoot relation, absolute and relative growth rate, net assimilate rate, leaf area ratio and specific leafarea. Positive effect of the bioestimulant was verified on most of the appraised variables, in relation tothe control. Doses between 4 and 6 mL of Stimulate® kg-1 of seeds promoted better balance between theroot and shoot, which can improve the establishment of the seedlings in the field