Norma de Magalhães Erismann

Lead uptake and tolerance of Ricinus communis L.

Phytoextraction is an important technique used for the decontamination of areas polluted by lead. Consequently, an understanding of the physiological responses to tolerance of tropical species subjected to increasing levels of contamination is fundamental before considering their use as phytoextractors in contaminated areas. The objective of this study was to assess the lead (Pb) uptake and the tolerance of Ricinus communis L. The plants were cultivated in nutrient solution in a greenhouse under controlled conditions. Lead was tested at concentrations of 0, 100, 200 and 400 µmol L-1. The experimental set-up was a block design, using a 4 x 1 factorial scheme, with three replicates. Biometric analyses, photosynthesis rates, and Pb content in the nutritive solution as well as in roots and shoots were performed. In conclusion, R. communis L is a hyperaccumulator species for Pb and presents tolerance properties in lead light concentration.

Capacidade fotossintética de genótipos de amendoim em ambiente natural e controlado

Photosynthetic capacity of runner peanuts (Arachis hypogaea L.) cv. IAC-Caiapo and cv. Runner IAC-886 was evaluated under controlled condition, in plants grown on pots maintained in a greenhouse, and in irrigated plants grown on soil-filled tanks made of concrete, and exposed to natural ambient condition. CO2 net assimilation rate (A) response in relation to photosynthetic photon flux density (DFFF) was better in controlled condition, but in both conditions the same maximum A of ca. 28 µmol m -2 s -1 was reached. Under controlled condition, light saturation was about 1,000 µmol m -2 s -1 , although under natural condition, saturation occurred at higher DFFF. Leaf temperature between 23 and 36°C did not affect A, and leaf to air vapor pressure difference caused partial stomatal closing, decreasing A, when above 3.0 kPa. Photosynthetic capacities of the two cultivars were similar. Both cultivars showed good adaptation to daily changes of environmental conditions that occur during summer, showing dynamic photoinhibition of photosynthesis in the beginning of the afternoon (13-14h), as revealed by a reversible decrease in the maximum quantum efficiency (Fv/Fm) of photosystem II.

Cadmium Accumulation by Jack-Bean and Sorghum in Hydroponic Culture

Among the technologies used to recuperate cadmium (Cd) contaminated soils, phytoextraction are particularly important, where the selection of suitable plants is critical to the success of the soil remediation. Thus, the objectives of this study were to evaluate the responses of jack-bean and sorghum to Cd supply and to quantify Cd accumulation by these species grown in hydroponic culture. The plants were subjected to 0, 15, 30, or 60 μmol Cd L−1 in the nutrient solution, and gas exchange, plant growth and Cd accumulation were measured at 25 days after starting Cd treatments. The Cd supply severely reduced growth of shoots and roots in both species. In jack-bean, Cd decreased photosynthesis by 56–86%, stomatal conductance by 59–85% and transpiration by 48–80%. The concentrations and amounts of Cd accumulated in the plant tissues were proportional to the metal supply in the nutrient solution. Sorghum was more tolerant than jack-bean to Cd toxicity, but the latter showed a greater metal concentration and accumulation in the shoot. Therefore, jack-bean would be more suitable than sorghum for use in Cd phytoremediation programs based on phytoextraction.

Gas exchanges in peach palms as a function of the spad chlorophyll meter readings

The close relationship between the chlorophyll-meters readings and the total chlorophyll and nitrogen contents in leaves, has allowed their evaluation both in annual and perennial species. Besides, some physiological events such as the CO2 assimilation have also been estimated by chlorophyll meters. This work was carried out aiming to evaluate the gas exchanges of peach palms as a function of the chlorophyll SPAD-Meter readings. Three year-old peach palms from Yurimaguas, Peru were studied in Ubatuba, SP, Brazil, spaced 2 x 1 m in area under a natural gradient of organic matter which allowed four plots to be considered, according to the peach palms leaves colors, from light yellow to dark green. The SPAD readings and the stomatal frequency of leaflets were evaluated. The photosynthetic photon flux density (PPFD, μmol m-2 s-1), the leaf temperature (Tleaf, oC), the CO2 assimilation (A, μmol m-2 s-1), the stomatal conductance (gs, mol m-2 s-1), the transpiration (E, mmol m-2 s-1) and the intercellular CO2 concentration (Ci, μmol mol-1) were evaluated with a portable infrared gas analyzer (LCA-4, ADC BioScientific Ltd., Great Amwell, U.K.). A linear increase in the CO2 assimilation as a function of the SPAD readings (y = -0.34 + 0.19x, R2 = 0.99), indicates that they can be a rapid and cheap complementary method to evaluate in peach palms some important physiological events, such as CO2 assimilation.

PREPARO DE SEMENTES PARA DETERMINAÇÃO DO TEOR DE ÓLEO PELO MÉTODO DE RMN EM SEIS VARIEDADES DE ALGODOEIRO

No presente trabalho, foram realizados estudos comparativos de metodos de preparacao de sementes de algodoeiro, com a finalidade de selecionar aquele com melhores condicoes para determinacao do teor de oleo por ressonância magnetica nuclear (RMN). Os metodos estudados foram os seguintes: o deslintamento quimico com acido sulfurico concentrado, o da flambagem e o da semente com linter, que foi utilizada como parâmetro sem tratamento. Dos tres, optou-se pelo tratamento quimico, por eliminar a interferencia do linter. Por esse metodo, determinaram-se os teores de oleo em sementes de seis variedades do algodoeiro herbaceo - obtidas do Ensaio Nacional de Variedades, sendo doze realizados no ano agricola de 1994/95 e doze, em 1995/96: CNPA Precoce 2, IAPAR 71 PR3, CNPA 7H, CS 50, IAC 20 e IAC 22. O teor de oleo foi determinado pela tecnica de RMN. As variedades estudadas apresentaram valores medios decrescentes no teor de oleo, na seguinte ordem: IAPAR71 PR3, IAC 20, CNPA 7H, CS 50, IAC 22 e CNPA Precoce 2.

CARACTERIZAÇÃO TECNOLÓGICA DE HÍBRIDOS DE AGAVE

Fiber production per plant and leaf dry matter content as well as leaf fiber and non-fibrous fraction levels have been scored in 152 Agave hybrids, and the results compared with those of Agave sisalana (common species). Those hybrids were derived from the backcross (A. amaniensis x A. angustifolia) x A. amaniensis. Fiber production (0.2 to 2.5 kg/plant), leaf dry matter content (142.3 to 216.0 g/kg), leaf fiber (189.9 to 361.9 g/kg) and leaf non-fibrous fraction (219.2 to 365.1 g/kg) varied sharply among the hybrids tested, as compared with the values obtained in Agave sisalana. Average fiber production (1.4 kg/plant) from the 58 highest yielding hybrids significantly outscored that of the common species (0.7 kg/plant).

Teor de óleo e composição de ácidos graxos em sementes de diferentes genótipos de algodoeiro

Cottonseed is a by-product of the production of fibre and an important raw material for the edible oil industry and for biodiesel production. The aim of this study was to evaluate the genetic diversity of the cotton cultivars and strains available in Brazil, with respect to the oil characteristics. The oil content and fatty acid composition were determined in the seeds of 18 cotton genotypes, cultivated in three distinct localities in Brazil. The oil was extracted from the seeds using hexane, and the fatty acids analysed by gas chromatography after methylation. The analyses of variance of the results for oil content and fatty acid composition revealed highly significant differences between the genotypes and locations and for the genotypes x locations interactions. The average oil content from the three distinct localities varied from 23 to 27% amongst the genotypes. The fatty acids presented the following ranges: linoleic (55.6-59.0%); palmitic (22.7-24.8%); oleic (13.4-15.8%) and stearic (1.83-2.14%). Although statistically significant, the range of genetic diversity for the fatty acids was not sufficiently wide to carry out genetic improvement programs. The genotypes FMT 523, FIBERMAX 966, IAC 06/205 and LD CV 22 stood out from the others for having higher oleic and palmitic acid contents and lower linoleic acid contents, thus being more suitable for biodiesel production and for use as frying oil, due to the greater oxidative stability provided by this composition.

DESFIBRAMENTO DE CAVACOS LAMINADOS DE BAMBUSA VULGARIS SCHRAD VISANDO À EXTRAÇÃO DE AMIDO

In this paper, laminated chips of Bambusa vulgaris Schrad with reduced thickness (0.5 mm) were shredded for starch extraction as well as fibrous and residual fraction separations. The chip shredding system was performed in a domestic liquefier provided with an inverted cup. The results varied from 52.16 to 69.36 g/kg for starch, from 774.53 to 798.26 g/kg for fibrous fraction and from 72.50 to 112.44 g/kg for residual fraction. The utilization of laminated chips with thickness ranging from 0.403 to 0.489 mm, improved the starch extraction, as they eliminate the need of softening pre-treatment of the chips.

CRESCIMENTO DE MUDAS DE PUPUNHEIRA ( Bactris gasipaes Kunth) UTILIZANDO RESÍDUO DE MINERAÇÃO DE AREIA COMO COMPONENTE DE SUBSTRATOS

O objetivo deste trabalho foi avaliar o crescimento de mudas de pupunheira quando utilizado o residuo fino de mineracao de areia na composicao de substratos. O experimento constou de cinco tratamentos, sendo quatro composicoes de diferentes proporcoes de residuo de mineracao de areia e casca de arroz carbonizada: 1:0; 3:1; 1:1; 1:3 e um substrato padrao composto por latossolo amarelo podzolico alico e esterco de bufalo curtido, na proporcao 3:1. Utilizou-se o delineamento experimental de blocos ao acaso com cinco repeticoes e 10 mudas por parcela. Repicou-se uma plântula de pupunheira por recipiente (sacos plasticos de polietileno preto de 8 x 20 cm, volume 1,1 L), os quais foram preenchidos com os diferentes substratos. Foram determinadas mensalmente as variaveis diâmetro do coleto, altura da haste, numero de folhas e taxa de crescimento relativo e, apos 180 dias da repicagem, os valores SPAD (Soil and Plant Analysis Development), din âmica da assimilacao de CO2, da transpiracao e da condutividade estomatica. O residuo de mineracao de areia puro como substrato nao proporcionou mudas de qualidade, visto que esse material apresenta alta densidade e baixa granulometria. Seu uso pode ser indicado como um dos componentes de substratos, pois as plantas que cresceram nas misturas de residuo e casca de arroz carbonizada apresentaram resultados semelhantes ao do considerado padrao.

DETERMINAÇÃO DO NÚMERO E DO ÂNGULO DE CONVOLUÇÃO DA FIBRA DE ALGODÃO E SUA RELAÇÃO COM PROPRIEDADES TECNOLÓGICAS DA FIBRA E DO FIO

A linhagem de algodoeiro IAC 20-233 e as variedades comerciais IAC 21 e IAC 22 foram caracterizadas morfologicamente pelo numero e pelo ângulo de convolucao de suas fibras, utilizando-se microscopia optica. A variedade IAC 21 apresentou fibras com menor numero e ângulo de convolucao que a IAC 20-233 e a IAC 22, enquanto estas foram semelhantes entre si. Os tres genotipos apresentaram fibras de maturidade similar. O indice Micronaire (medida do complexo finura + maturidade) da variedade IAC 21 foi maior que o dos demais, correspondendo, portanto, a fibras mais grossas. Isso pode ter contribuido para diminuir o numero e o ângulo de convolucao e, como consequencia, deprimido a elongacao da fibra e do fio de algodao produzido.