Salt stress on physiology, biometry and fruit quality of grafted Passiflora edulis / Estresse salino na fisiologia, biometria e qualidade dos frutos de Passiflora edulis enxertada

The production of grafted passion fruit is an alternative for plant adaptation to saline environments. The objective of this study was to evaluate the effect of salt stress on physiology, biometry and fruit quality of P. edulis grafted on Passiflora spp. The experiment was conducted in completely randomized design, in a 3 x 2 factorial scheme, corresponding to three species of Passiflora (P. edulis, P. gibertii and P. cincinnata) with P. edulis scion and two levels of irrigation water salinity (0.5 - control and 4.5 dS m-1), with four repetitions. Water salinity compromises gas exchanges (CO2 assimilation raste and transpiration) and physiological variables (total chlorophyll and total water consumption) in grafted P. edulis. The interaction between the factors (water salinity x species) compromised only the growth in plant height and number of leaves. In relation to the species, auto-grafted P. edulis stood out from the other species, with higher internal CO2 concentration, number of leaves, stem dry mass, peel thickness, total soluble solids (TSS) of the pulp and TSS/TA ratio (titratable acidity). Auto-grafted P. edulis under saline conditions develops vital mechanisms (TSS and TSS/TA), which attenuates the effects of salt stress on the physico-chemical quality of the fruits.

A produção de maracujazeiro enxertado é uma alternativa para adaptação das plantas a ambientes salinos. Objetivou-se avaliar o efeito do estresse salino na fisiologia, biometria e qualidade de frutos de P. edulis enxertado em espécies de Passiflora spp. O delineamento utilizado foi inteiramente casualizado, em esquema fatorial 3 x 2, sendo três espécies de Passiflora (P. edulis, P. gibertii e P. cincinnata) tendo como copa P. edulis e dois níveis de salinidade de água de irrigação (0,5 ­ testemunha e 4,5 dS m-1), com quatro repetições. A salinidade da água compromete as trocas gasosas (taxa de assimilação de CO2 e transpiração) e variáveis fisiológicas (clorofila total e consumo hídrico total) em P. edulis enxertado. A interação entre os fatores (salinidade da água x espécie) compromete apenas o crescimento em altura de plantas e número de folhas. Em relação às espécies, o P. edulis auto enxertado se destaca em relação as demais espécies apresentando maior concentração interna de CO2, número de folhas, massa seca de caule, espessura da casca do fruto, sólidos solúveis totais (SST) da polpa e razão sólidos solúveis totais por acidez titulável (SST/AT). O P. edulis auto enxertado sob condições de salinidade, desenvolve mecanismos vitais (SST e SST/AT), que atenuam os efeitos do estresse salino na qualidade físico-química dos frutos.

Water salinity and nitrogen fertilization in the production and quality of guava fruits / Salinidade da água e adubação nitrogenada na produção e qualidade de frutos de goiabeira

Using nitrogen (N) to increase plant tolerance to salinity has been tested in many species. However, in addition to controversial results, most studies are conducted with annual species and/or in the initial growth stage and there are almost no studies with perennial fruit crops in the production stage. Thus, this study aimed to evaluate the production components and post-harvest quality of 'Paluma' guava irrigated with water of increasing salinity in soil fertilized with N. The experiment was carried out for two years in drainage lysimeters in an experimental area of the Federal University of Campina Grande (UFCG), Pombal, PB, Brazil. The experimental design was in randomized blocks, in 5 x 4 factorial scheme, with of five levels of water salinity ­ ECw (NaCl)(0.3, 1.1, 1.9, 2.7 and 3.5 dS m-1) and four N doses (ureia) (70, 100, 130 and 160% of the recommended dose - 541.1 mg of N dm-3 of soil per year), with three replicates. Number of fruits, mean fruit weight, production per plant, polar and equatorial diameters of fruit and contents of soluble solids and ascorbic acid (vitamin C) decreased linearly with the increase in irrigation water salinity from 0.3 dS m-1. The interaction between water salinity and N doses and the isolated action of N did not interfere statistically with the studied variables.

O uso de nitrogênio como forma de aumentar a tolerância das plantas à salinidade tem sido testado em muitas espécies. No entanto, além de resultados controversos, se observa que a maioria dos estudos são realizados com espécies anuais e, ou na fase inicial de crescimento, sendo praticamente inexistentes estudos com frutíferas perenes em fase de produção. Nessa direção, o trabalho teve como objetivo avaliar os componentes de produção e a qualidade pós-colheita de goiabeira 'Paluma' irrigada com águas de salinidade crescente no solo com nitrogênio. O experimento foi conduzido durante dois anos em lisímetros de drenagem numa área experimental da Universidade Federal de Campina Grande (UFCG), Pombal, PB. O delineamento experimental foi em blocos casualizados, em esquema fatorial 5 x 4, com salinidades de água ­ CEa (NaCl) de 0,3, 1,1, 1,9, 2,7 e 3,5 dS m-1 e quatro doses de nitrogênio (ureia) de 70, 100, 130 e 160% da dose recomendada de 541,1 mg de N dm-3 por ano, com três repetições. A interação salinidade da água x doses de nitrogênio e ação isolada de N não influenciaram estatisticamente as variáveis estudadas. O número de frutos, a massa média de frutos, a produção por planta, o diâmetro polar e equatorial dos frutos, os teores de sólidos solúveis e ácido ascórbico (vitamina C), decresceram linearmente com o aumento da salinidade da água de irrigação a partir de 0,3 dS m-1.

Production of tomato seedlings using seeds pelleted with Natrum muriaticum and submitted to saline stress

The development and yield of plants is directly related to the effects of salinity. There are several reports in scientific studies of significant reduction in the growth and production of tomato in soils with high electrical conductivity. The correction or recovery of salinized soils, although technically possible, is a slow and very expensive process, making it necessary to develop new technologies. The objective of this study is to evaluate the production of tomato (Solanum lycopersicon L.) seedlings using seeds pelleted with a homeopathic preparation of Natrum muriaticum (Nat-m) submitted to saline stress. The treatments consisted of the pelletization of tomato seeds with six dynamizations of Nat-m (3cH, 5cH, 7cH, 9cH, 11cH and 13cH). Coated or uncoated seeds (controls) were placed in phenolic foam blocks, kept in plastic trays previously moistened with 50 mM NaCl saline solution (2.922 g.L-1 of NaCl, electrical conductivity = 4.5 dSm-1) and nutrient solution (0.15 dS.m-1) at half the ionic strength, containing 4, 1, 2, 1, 0.5, and 0.5 mmol.L-1 of N, P, K, Ca, Mg and S, and 17.5, 9.5, 10.5, 2, 0.45 and 0.35 mmol.L-1 of Fe, Mn, Zn, Cu and Mo, respectively. The variables evaluated were percentage of emerged plants, emergence speed index, shoot length, leaf area, number of leaves, root volume, root dry matter, and shoot dry matter. The treatments pelleted seeds/talc Nat-m 5cH and pelleted seeds/talc Nat-m 7cH increased all variables evaluated. They differed statistically from the controls, with a positive response for the development of tomato seedlings under disequilibrium conditions. (AU)

Effects of NaCl on plant growth and antioxidant activities in fenugreek (Trigonella Foenum Graecum L. ) / Efeitos da NaCl no crescimento e capacidade antioxidante por feno-grego (Trigonella Foenum Graecum L. )

Fenugreek is used as a spice, vegetable and a important medicinal crops cultivated throughout the world. Since antioxidant properties have been linked to health benefits of natural products, such properties were studied salt concentrations (0, 50, 100,150 and 200 mM NaCl) effect on plant growth mineral contents composition, antioxidant responses and phenolilc contents. Results showed a reduction of dry weights of leaves stems and roots growth. These changes were associated with decreased in water content, K+ and Ca2+ concentrations and a highly increased in Na+ and Clcontents in different organs. Catalase, guaiacol peroxidase activities and total phenolic content significantly increased in fenugreek leaves. Data reported here revealed the variation of phenolic compound contents at different organs in the presence of salt, who suggested the use of Fenugreek in commercial and economic applications.

O feno-grego é usado como especiaria, vegetal e uma importante cultura medicinal cultivada em todo o mundo. Como as propriedades antioxidantes têm sido associadas aos benefícios à saúde dos produtos naturais, tais propriedades foram estudadas quanto ao efeito das concentrações de sal (0, 50, 100, 150 e 200 mM de NaCl) no crescimento das plantas, composição do conteúdo mineral, respostas antioxidantes e teores fenólicos. Os resultados mostraram uma redução do peso seco dos caules das folhas e crescimento das raízes. Essas alterações foram associadas à diminuição do conteúdo de água, concentrações de K+ e Ca2+ e um aumento nos teores de Na+ e Cl- em diferentes órgãos. As atividades de catalase e da peroxidase do guaiacol e o teor de fenólicos totais aumentaram significativamente em folhas de feno-grego. Os dados aqui relatados revelaram a variação do conteúdo de compostos fenólicos em diferentes órgãos na presença de sal, que sugeriu o uso do feno-grego em aplicações comerciais e econômicas.

Saline stress onto growth and physiology of trifoliate citrus hybrids during rootstock formation / Estresse salino no crescimento e fisiologia de híbridos trifoliados de citros enquanto porta-enxertos

High salts concentrations in soil and water are common in semi-arid regions, which reduces the growth and development of crops, especially sensitive plants, such as citrus, being important to identify tolerant materials as well as to study the physiology of these plants. An experiment was conducted evaluate the growth and physiology of citrus trifoliate citrus hybris during their early stage of development (seedling stage) under salt stress conditions. These hydrids were obtained through the Citrus Breeding Program of Embrapa Cassava & Fruits consisting of 'Common sunki' mandarin x 'Argentina' citrange - 019, 'Common sunki' mandarin x ('Rangpur' lime x Poncirus trifoliata) - 040, Trifoliate hybrids - 069, 116 and 127, distributed in a randomized block design with three replications. Nucellar seedlings of the genotypes were grown in an hydroponic system using Leonard jars. The application of nutrient solution with saline water started 90 days after sowing, extending to 120 days, when the seedlings were evaluated for plant growth and physiology. The genotypes common 'Sunki' mandarin x 'Argentina' citrange - 019, Common 'Sunki' mandarin x ('Rangpur' lime x P. trifoliata) - 040 and Trifoliate hybrid - 069 showed the greater tolerance to salinity, while the Trifoliate hybrid - 116 and 127 were found to be the less tolerant.

Altas concentrações de sais no solo e na água são comuns em regiões semiáridas, o que reduz o crescimento e o desenvolvimento das culturas, notadamente as sensíveis, como os citros, sendo importante a identificação de materiais tolerantes assim como o estudo da fisiologia destes. Assim, realizou-se um experimento para avaliar o crescimento e a fisiologia de híbridos de Poncirus trifoliata durante a formação de porta-enxertos sob condições de estresse salino. O experimento foi realizado usando um esquema factorial, 2 x 5, correspondendo a dois níveis de salinidade na solução nutritiva (2,6 e 6,3 dS m-1) e cinco híbridos de citros. Tais híbridos foram obtidos a partir do programa de melhoramento genético de citros da Embrapa Mandioca e Fruticultura, PMG ­ Citrus, a saber: tangerineira 'Sunki Comum' x citrange 'Argentina' ­ 019; tangerineira 'Sunki Comum' x (limoeiro 'Cravo' x Poncirus trifoliata) ­ 040 e os híbrido trifoliados ­ 069, 116 e 127. Os tratamentos foram distribuídos em delineamento experimental de blocos ao acaso, com três repetições. As plantas de origem nucelar dos genótipos foram cultivadas em sistema hidropônico por meio de vasos de Leonard. A aplicação das soluções nutritivas com águas salinas começaram aos 90 dias após a semeadura, se extendendo até os 120 dias, quando as plantas foram avaliadas em relação ao crescimento e a fisiologia. Os genótipos tangerineira 'Sunki Comum' x citrange 'Argentina' - -19, tangerineira Sunki Comum x x (limoeiro 'Cravo' x Poncirus trifoliata) ­ 040 e o híbrido trifoliado ­ 069 tiveram maior tolerância à salinidade, enquanto os híbridos trifoliados 116 e 127 foram os menos tolerantes.

The use of high throughput DNA sequence analysis to assess the endophytic microbiome of date palm roots grown under different levels of salt stress

Date palms are able to grow under diverse abiotic stress conditions including in saline soils, where microbial communities may be help in the plant’s salinity tolerance. These communities able to produce specific growth promoting substances can enhance date palm growth in a saline environment. However, these communities are poorly defined. In the work reported here, the date palm endophytic bacterial and fungal communities were identified using the pyrosequencing method, and the microbial differential abundance in the root upon exposure to salinity stress was estimated. Approximately 150,061 reads were produced from the analysis of six ribosomal DNA libraries, which were prepared from endophytic microorganisms colonizing date palm root tissues. DNA sequence analysis of these libraries predicted the presence of a variety of bacterial and fungal endophytic species, some known and others unknown. The microbial community compositions of 30% and 8% of the bacterial and fungal species, respectively, were significantly (p ≤ 0.05) altered in response to salinity stress. Differential enrichment analysis showed that microbe diversity indicated by the Chao, Shannon and Simpson indices were slightly reduced, however, the overall microbial community structures were not significantly affected as a consequence of salinity. This may reflect a buffering effect by the host plant on the internal environments that these communities are colonizing. Some of the endophytes identified in this study were strains that were previously isolated from saline and marine environments. This suggests possible interactions with the plant that are favorable to salinity tolerance in date palm (AU)

No disponible

Haloalkalitolerant Actinobacteria with capacity for anthracene degradation isolated from soils close to areas with oil activity in the State of Veracruz, Mexico

The use of native strains of microorganisms from soils is an excellent option for bioremediation. To our knowledge, until now there has been no other group working on the isolation of Actinobacteria from contaminated soils in Mexico. In this study, samples of soils close to areas with oil activity in the State of Veracruz, Mexico, were inoculated for the isolation of Actinobacteria. The strains isolated were characterized morphologically, and the concentrations of NaCl and pH were determined for optimal growth. Strain selection was performed by the detection of a phylogenetic marker for Actinobacteria located at the 23S rRNA gene, followed by species identification by sequencing the 16S rRNA gene. Several haloalkalitolerant Actinobacteria were isolated and identified as: Kocuria rosea, K. palustris, Microbacterium testaceum, Nocardia farcinica and Cellulomonas denverensis. Except for C. denverensis, the biomass of all strains increased in the presence of anthracene. The strains capacity to metabolize anthracene (at 48 h), determined by fluorescence emission, was in the range of 46-54%. During this time, dihydroxy aromatic compounds formed, characterized by attenuated total reflectance Fourier transform infrared spectroscopy bands of 1205 cm-1 and 1217 cm-1. Those Actinobacteria are potentially useful for the bioremediation of saline and alkaline environments contaminated with polycyclic aromatic hydrocarbon compounds (AU)

No disponible

Geología, hidrología y protección de las aguas subterráneas del balneario / The geology, the hydrogeology and the protection of its medicinal groundwaters

Se ha estudiado la microbiota autóctona y alóctona del agua mineral del Balneario Villa de Olmedo (Valladolid). El número total de microorganismos en el agua ha sido de 4,5 x 103/mL y el número de bacterias viables heterótrofas menor de 5 ufc/mL. No se han encontrado indicadores fecales ni microorganismos patógenos por lo que estas aguas cumplen con la normativa española de aguas de consumo. La microbiota autóctona está constituida, principalmente, por bacilos Gram negativos de la clase Gammaproteobacteria (68,5%) y, en menor proporción, por cocos Gram positivos (14,3%). La especie más frecuente ha sido Pseudomonas stutzeri (37,2%). Se han detectado bacterias con actividades amonificantes, nitrificantes, proteolíticas y amilolíticas en 100 mL de agua, que contribuyen a la autodepuración del agua

The autochthon and alocthon microbiota of the mineral water of the Villa de Olmedo Spa have been studied. The total number of microorganisms in the water was of 4.5 x103/mL and the number of heterotrophic viable bacteria was lower than 5 cfu/mL. Neither faecal indicators nor pathogenic microorganisms were found; therefore these waters comply with the Spanish regulations on drinking water. The autochthon microbiota mostly belongs to Gram negative bacilli, from the Class Gammaproteobacteria (68.5%) and in smaller percentage to the Gram positive cocci (14.3%). The most frequently found species was Pseudomonas stutzeri. Moreover ammonifying, nitrifiying, proteolytic and amylolytic bacteria have been detected in 100 mL of water, all of them involved in self-purification process of wáter

Germinação de sementes de marmelo: temperatura, luz e salinidade / Germination of the quince

Neste trabalho objetivou-se avaliar a ecofisiologia da germinação de sementes de Alibertia edulis (Rich) A. Rich. ex DC. (marmelo) sob diferentes condições ambientais. Dois experimentos foram realizados no Laboratório de Nutrição e Metabolismo de Plantas da UFGD. O experimento I avaliou quatro temperaturas (15, 20, 25 e 30°C) e duas condições de iluminação (presença e ausência de luz) e o experimento II o efeito de soluções salinas de KCl , NaCl e CaCl2 nos potenciais osmóticos de 0,0 (controle); -0,4; -0,8; -1,2; -1,6; -2,0 MPa na germinação das sementes. As sementes apresentam fotoblástismo neutro e não germinam a 15°C. A 25°C foi observada maior porcentagem e índice de velocidade de germinação e comprimento de parte aérea de plântulas. As sementes são sensíveis salinidade causada por NaCl, KCl e CaCl2, que afetam negativamente a germinação das sementes e no crescimento das plântulas.

The target of this study was to evaluate seed ecophysiology germination of Alibertia edulis (Rich) A. Rich. ex DC. (quince) at different environmental condition. Two experiments were done at the Laboratory of Nutrition and Metabolism of Plant from UFGD (Universidade Federal da Grande Dourados). Experiment I evaluated 4 temperatures (15, 20, 25 e 30°C) and two light conditions (absence and presence of light); experiment II evaluated the salt effect of KC1, NaCl and CaCl2 at osmotic potencial of 0,0 (control); -0,4; -0,8; -1,2; -1,6; -2,0 MPa seed germination. The seeds are photoblastism neutral and do not germinate at 15 ° C. The 25 ° C showed a higher rate of speed and percentage of germination and shoot length of seedlings. The seeds are sensitive to salinity caused by NaCl, KCl and CaCl2, which negatively affect seed germination and seedling growth.

Production of peptide antibiotics by Bacillus sp: GU 057 indigenously isolated from saline soil

A total of 112 soil samples were taken from differents areas of district D.I.Khan and Kohat (KPK) Pakistan and screened for production of antibiotics against the Micrococcus luteus and Staphylococcus aureus. Widest zone of inhibition (18mm) was produced by microorganism isolated from saline soil. The strain was later identified as Bacillus GU057 by standard biochemical assays. Maximum activity (18mm inhibition zone) was observed against Staphylococcus aureus after 48 hours of incubation at pH 8 and 4% concentration of glucose. The antibiotic was identified by autobiography as bacitracin. The Bacillus strain GU057 was confirmed as good peptide antibiotic producer and can effectively be indulged as biocontrol agent.

Biodegradation of petroleum hydrocarbons in hypersaline environments

Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review.

Bacterial exopolysaccharide and biofilm formation stimulate chickpea growth and soil aggregation under salt stress

To compensate for stress imposed by salinity, biofilm formation and exopolysaccharide production are significant strategies of salt tolerant bacteria to assist metabolism. We hypothesized that two previously isolated salt-tolerant strains Halomonas variabilis (HT1) and Planococcus rifietoensis (RT4) have an ability to improve plant growth, These strains can form biofilm and accumulate exopolysacharides at increasing salt stress. These results showed that bacteria might be involved in developing microbial communities under salt stress and helpful in colonizing of bacterial strains to plant roots and soil particles. Eventually, it can add to the plant growth and soil structure. We investigated the comparative effect of exopolysacharide and biofilm formation in two bacterial strains Halomonas variabilis (HT1) and Planococcus rifietoensis (RT4) in response to varying salt stress. We found that biofilm formation and exopolysaccharide accumulation increased at higher salinity. To check the effect of bacterial inoculation on the plant (Cicer arietinum Var. CM-98) growth and soil aggregation, pot experiment was conducted by growing seedlings under salt stress. Inoculation of both strains increased plant growth at elevated salt stress. Weight of soil aggregates attached with roots and present in soil were added at higher salt concentrations compared to untreated controls. Soil aggregation was higher at plant roots under salinity. These results suggest the feasibility of using above strains in improving plant growth and soil fertility under salinity.

Interspecific variation of the bacterial community structure in the phyllosphere of the three major plant components of mangrove forests

Mangrove forests encompass a group of trees species that inhabit the intertidal zones, where soil is characterized by the high salinity and low availability of oxygen. The phyllosphere of these trees represent the habitat provided on the aboveground parts of plants, supporting in a global scale, a large and complex microbial community. The structure of phyllosphere communities reflects immigration, survival and growth of microbial colonizers, which is influenced by numerous environmental factors in addition to leaf physical and chemical properties. Here, a combination of culture-base methods with PCR-DGGE was applied to test whether local or plant specific factors shape the bacterial community of the phyllosphere from three plant species (Avicenia shaueriana, Laguncularia racemosa and Rhizophora mangle), found in two mangroves. The number of bacteria in the phyllosphere of these plants varied between 3.62 x 10(4) in A. schaeriana and 6.26 x 10³ in R. mangle. The results obtained by PCR-DGGE and isolation approaches were congruent and demonstrated that each plant species harbor specific bacterial communities in their leaves surfaces. Moreover, the ordination of environmental factors (mangrove and plant species), by redundancy analysis (RDA), also indicated that the selection exerted by plant species is higher than mangrove location on bacterial communities at phyllosphere.

Influência da salinidade sobre o crescimento e a produção de ácido indol acético de Burkholderia spp. endofíticas de cana-de-açúcar / Salinity influence on the growth and production of indole acetic acid by endophytic Burkholderia spp. from sugarcane

A cana-de-açúcar é uma fonte importante de alimento e bioenergia. Assim, o estudo da interação com bactérias endofíticas que fixam o nitrogênio atmosférico (FBN) e produzem o ácido indol acético (AIA) vem sendo amplamente explorado. Porém, devido à sensibilidade bacteriana, tanto a produção de AIA, como a FBN, podem sofrer o impacto de fatores edafoclimáticos. O objetivo deste trabalho foi avaliar a influência de diferentes concentrações de NaCl sobre o crescimento bacteriano, a FBN e a produção de AIA in vitro de linhagens bacterianas do gênero Burkholderia, isoladas endofiticamente de plantas de cana-de-açúcar, cultivadas no estado de Pernambuco. Para tanto, duas linhagens bacterianas endofíticas das espécies Burkholderia gladioli e B. heleia foram inoculadas em meio TSA (com L-triptofano) acrescido de cinco concentrações de NaCl: 0,1; 1; 10; 25 e 50 g.L-1 e incubadas sob agitação. O crescimento bacteriano e a produção de AIA foram avaliados através de um espectrofotômetro por 48 horas. Para o teste de fixação de nitrogênio, as linhagens foram inoculadas em meio LGI-P semi-sólido acrescido de cinco concentrações de NaCl: 0,1; 1; 10; 25 e 50 g.L1 e incubadas a 28ºC por 10 dias. Foi possível observar que altas concentrações de NaCl influenciaram negativamente o crescimento bacteriano e a produção do AIA in vitro por B. glaidoli e B. heleia. E que, concentrações de NaCl acima de 25 g.L-1 inibiram a capacidade de fixar nitrogênio, de ambas as linhagens.

The sugarcane is an important source of food and bioenergy. So, the study of its interaction with endophytic bacteria that fix atmospheric nitrogen (BNF) and produce indole acetic acid (IAA) has been widely explored. However, due to bacterial sensitivity, both the production of IAA as the BNF may suffer the impact of soil and climatic factors. The goal of this study was to evaluate the influence of the NaCl different concentrations on the bacterial growth, on the BNF and on the IAA production in vitro by endophytic bacterial strains of the genus Burkholderia isolated from sugarcane plants grown in the Pernambuco State. In this study, two endophytic bacterial strains of Burkholderia gladioli and B. heleia species were inoculated in TSA (with L-tryptophan) added of five NaCl concentrations: 0.1, 1, 10, 25 and 50 g.L-1 and incubated under agitation. Bacterial growth and IAA production were assessed using a spectrophotometer for 48 hours. The nitrogen fixation test was carried out by the inoculation of the bacteria in semi-solid LGP-I added of five NaCl concentrations: 0.1, 1, 10, 25 and 50 g.L-1 and incubated at 28°C during 10 days. It was observed that high concentrations of NaCl influenced negatively the bacterial growth and indole acetic acid production in vitro by B. glaidoli and B. heleia. Nevertheless, NaCl concentrations above 25 g.L-1 inhibited the ability to fix nitrogen in both strains.

Sepia 200cH at 1: 1000 dilution ameliorates salt stress in cowpea seedlings but its medium 90% ethanol proves ineffective at the same dilution

Soil salinity severely affects crop yield all over the world. In a recent study we observed that Natrum mur 200cH, a homeopathic remedy, improved growth in germinating cowpea seeds. In the present study we have tested another remedy Sepia, which is complementary to Natrum mur, on cowpea seedlings under salt stress. Cowpea seedlings grown over moist filter paper in petridishes were divided into 4 groups: (1) control in sterile water, (2) in 50mM NaCl solution, (3) seeds pretreated with 90% ethanol diluted with water 1:100 and then transferred to 50mM NaCl solution, (4) seeds pretreated with Sepia 200cH diluted with water 1:100 and transferred to 50mM NaCl solution. In another experiment the groups were same, but the dilution of 90% ethanol and Sepia 200cH was 1:1000 instead of 1:100. The purpose was to further reduce the ethanol content in both the drug and its vehicle 90% ethanol, so that the alcohol effect is minimized or abolished. The data were analysed by ANOVA followed by t-test. Sepia 200cH at both 1:100 and 1:1000 dilutions significantly increased growth, sugar, chlorophyll, protein and water content in seedlings as compared to the untreated salt-stressed group. The effect with the1000th dilution of Sepia 200cH was more pronounced than with its 100th dilution. The vehicle 90% ethanol at 1:100 dilution produced some positive effect on the seedlings, but the 1000th dilution of the vehicle produced no such effect. It is, therefore, concluded that Sepia 200cH could ameliorate salt stress in cowpea seedlings and that the 1000th dilution is more effective than its 100th dilution. The alcohol effect is totally eliminated with the 1000th dilution of 90% ethanol. Thus the 1000th dilution could retain the drug effect and eliminate the vehicle effect. (AU)

Introdução: A salinidade do solo afeta seriamente a produtividade das culturas no mundo todo. Num estudo recente, observamos que o medicamento homeopático Natrum muriaticum 200 Ch melhorou o crescimento de sementes de feijão-fradinho Vigna unguiculata (L.) Walp] em germinação. Objetivo: Nesse trabalho, testamos o medicamento homeopático Sepia succus, complementar de Nat-m, em plântulas de feijão-fradinho submetidas a estresse salino. Métodos: Plântulas de feijão-fradinho desenvolvidas sobre papel de filtro umedecido em placas de Petri foram divididas em 4 grupos: (1) controle em água estéril, (2) em solução de NaCl 50 mM, (3) sementes pré-tratadas com etanol a 90% diluído 1:100 em água e após transferido a solução de NaCl 50mM, e (4) sementes pré-tratadas com Sep 200 cH diluídas 1:100 em água e após transferidas a solução de NaCl 50 mM. Num segundo experimento, os grupos foram os mesmos, mas a diluição do etanol a 90% e de Sep 200 cH foi 1:1.000 ao invés de 1:00 para reduzir ainda mais o teor de etanol em ambos, medicamento e veículo a fim de minimizar ou abolir o efeito do álcool. Os dados foram analisados através de ANOVA seguida de teste t de Student. Resultados: As duas diluições de Sep 200 cH, 1:100 e 1:1.000, aumentaram significativamente o crescimento, teor de açúcar, clorofila, proteína e água das plântulas por comparação ao grupo submetido a estresse salino não tratado. O efeito da 1.000ª diluição de Sep 200 cH foi mais pronunciado que o da 100ª diluição. O veículo etanol a 90% em diluição 1:100 induziu alguns efeitos positivos nas plântulas, mas a diluição 1:1.000 não apresentou esses efeitos. Conclusões: Sep 200 cH reverteu o efeito de estresse salino nas plântulas de feijão-fradinho, sendo que a 1.000ª diluição foi mais efetiva que a 100ª. O efeito do álcool foi totalmente eliminado com a 1.000ª diluição do etanol a 90%. Portanto, a 1.000ª conservou o efeito do medicamento e eliminou o efeito do veículo. (AU)

Sepia 200cH at 1: 1000 dilution ameliorates salt stress in cowpea seedlings but its medium 90 por cento ethanol proves ineffective at the same dilution

Soil salinity severely affects crop yield all over the world. In a recent study we observed that Natrum mur 200cH, a homeopathic remedy, improved growth in germinating cowpea seeds. In the present study we have tested another remedy Sepia, which is complementary to Natrum mur, on cowpea seedlings under salt stress. Cowpea seedlings grown over moist filter paper in petridishes were divided into 4 groups: (1) control in sterile water, (2) in 50mM NaCl solution, (3) seeds pretreated with 90% ethanol diluted with water 1:100 and then transferred to 50mM NaCl solution, (4) seeds pretreated with Sepia 200cH diluted with water 1:100 and transferred to 50mM NaCl solution. In another experiment the groups were same, but the dilution of 90% ethanol and Sepia 200cH was 1:1000 instead of 1:100. The purpose was to further reduce the ethanol content in both the drug and its vehicle 90% ethanol, so that the alcohol effect is minimized or abolished. The data were analysed by ANOVA followed by t-test. Sepia 200cH at both 1:100 and 1:1000 dilutions significantly increased growth, sugar, chlorophyll, protein and water content in seedlings as compared to the untreated salt-stressed group. The effect with the1000th dilution of Sepia 200cH was more pronounced than with its 100th dilution. The vehicle 90% ethanol at 1:100 dilution produced some positive effect on the seedlings, but the 1000th dilution of the vehicle produced no such effect. It is, therefore, concluded that Sepia 200cH could ameliorate salt stress in cowpea seedlings and that the 1000th dilution is more effective than its 100th dilution. The alcohol effect is totally eliminated with the 1000th dilution of 90% ethanol. Thus the 1000th dilution could retain the drug effect and eliminate the vehicle effect.

Introdução: A salinidade do solo afeta seriamente a produtividade das culturas no mundo todo. Num estudo recente, observamos que o medicamento homeopático Natrum muriaticum 200 Ch melhorou o crescimento de sementes de feijão-fradinho Vigna unguiculata (L.) Walp] em germinação. Objetivo: Nesse trabalho, testamos o medicamento homeopático Sepia succus, complementar de Nat-m, em plântulas de feijão-fradinho submetidas a estresse salino. Métodos: Plântulas de feijão-fradinho desenvolvidas sobre papel de filtro umedecido em placas de Petri foram divididas em 4 grupos: (1) controle em água estéril, (2) em solução de NaCl 50 mM, (3) sementes pré-tratadas com etanol a 90% diluído 1:100 em água e após transferido a solução de NaCl 50mM, e (4) sementes pré-tratadas com Sep 200 cH diluídas 1:100 em água e após transferidas a solução de NaCl 50 mM. Num segundo experimento, os grupos foram os mesmos, mas a diluição do etanol a 90% e de Sep 200 cH foi 1:1.000 ao invés de 1:00 para reduzir ainda mais o teor de etanol em ambos, medicamento e veículo a fim de minimizar ou abolir o efeito do álcool. Os dados foram analisados através de ANOVA seguida de teste t de Student. Resultados: As duas diluições de Sep 200 cH, 1:100 e 1:1.000, aumentaram significativamente o crescimento, teor de açúcar, clorofila, proteína e água das plântulas por comparação ao grupo submetido a estresse salino não tratado. O efeito da 1.000ª diluição de Sep 200 cH foi mais pronunciado que o da 100ª diluição. O veículo etanol a 90% em diluição 1:100 induziu alguns efeitos positivos nas plântulas, mas a diluição 1:1.000 não apresentou esses efeitos. Conclusões: Sep 200 cH reverteu o efeito de estresse salino nas plântulas de feijão-fradinho, sendo que a 1.000ª diluição foi mais efetiva que a 100ª. O efeito do álcool foi totalmente eliminado com a 1.000ª diluição do etanol a 90%. Portanto, a 1.000ª conservou o efeito do medicamento e eliminou o efeito do veículo.

Comparative study of the pathogenicity of seabed isolates of Fusarium equiseti and the effect of the composition of the mineral salt medium and temperature on mycelial growth

The pathogenicity of seven strains of Fusarium equiseti isolated from seabed soil was evaluated on different host plants showing pre and post emergence damage. Radial growth of 27 strains was measured on culture media previously adjusted to different osmotic potentials with either KCl or NaCl (-1.50 to - 144.54 bars) at 15º, 25º and 35º C. Significant differences and interactive effects were observed in the response of mycelia to osmotic potential and temperature.

Capacidad de bacterias halófilas para capturar sodio in vitro y su posible aplicación en bioremediación en suelos salinos-sódicos / Ability of halophile bacteria to capture in Vitro sodium and its possible application in bioremediation of saline-sodic soil

Las prácticas agrícolas inadecuadas han sido la causa del aumento de los suelos salinos–sódicos en todo el planeta. Su recuperación se ha hecho principalmente cambiando el sodio por otro catión, generalmente calcio, remediando en forma mecánica y usando plantas halotolerantes. Aunque estas prácticas controlan en alguna medida el problema, no se ha podido hacer una recuperación efectiva en estos suelos. Este trabajo presenta como alternativa, el uso de bioremediación con bacterias halófilas. El objetivo de la investigación fue evaluar la capacidad de cinco especies de bacterias halófilas para capturar iones sodio in vitro y diseñar una propuesta para su posible aplicación en bioremediación de suelos sódicos y salinos. La captura del sodio se demostró comparando la concentración inicial de la solución de sodio sin inocular y la concentración de la misma con la bacteria inoculada a través de la técnica de espectroscopia de absorción atómica. Las bacterias que demostraron la capacidad de captura de sodio in vitro fueron: Vibrio alginolyticus, Vibrio metschnikovii, Flavimonas oryzihabitans y Agrobacterium tumefasciens. Serratia marcescens no demostró captura. La comprobación de la captura de sodio permitió hacer dos propuestas: diseñar un bioreactor con un consorcio microbiano que incluya las bacterias que capturaron sodio en el experimento y bacterias autóctonas presentes en los suelos salinos y sódicos; utilizar ingeniería genética para implantar el gen de bomba de sodio de la especie con mejor captura, en especies nativas existentes en este tipo de suelos.

Biodegradación de hidrocarburos de la comunidad bacteriana en condiciones de alta concentración en sales de sulfato

El Cordón Forestal es un suelo que pertenece a la formación Patagonia y que ha sufrido procesos de salinización, por la circulación de aguas subterráneas de elevada salinidad y en los últimos veinte años, por una deficiente planificación. El objetivo del trabajo es conocer las posibilidades de uan comunidad bacteriana adaptada a la alta salinidad del suelo del que proviene, de biodegradar hidrocarburos en condiciones salinas óptimas

Biodegradación de hidrocarburos de la comunidad bacteriana en condiciones de alta concentración en sales de sulfato

El Cordón Forestal es un suelo que pertenece a la formación Patagonia y que ha sufrido procesos de salinización, por la circulación de aguas subterráneas de elevada salinidad y en los últimos veinte años, por una deficiente planificación. El objetivo del trabajo es conocer las posibilidades de uan comunidad bacteriana adaptada a la alta salinidad del suelo del que proviene, de biodegradar hidrocarburos en condiciones salinas óptimas