Effect of oxygen on the germination and culturability of Bacillus atrophaeus spores

The effect of oxygen on the germination and culturability of aerobic Bacillus atrophaeus spores was investigated in this study. Under oxic or anoxic conditions, various nutritional and non-nutritional germinants were utilized to induce germination. Tb3+-dipicolinic acid fluorescence assay and phase-contrast microscopy were used to track the germination process. The final germination level, germination half time, and germination speed were used to define germination kinetics. Colony-forming unit enumeration was used to assess the culturability of germinated spores germinated with or without oxygen. The results show that in the absence of oxygen, the final germination level was unaffected, germination half time decreased by up to 35.0%, germination speed increased by up to 27.4%, and culturability decreased by up to 95.1%. It is suggested that oxygen affects some germinant receptor-dependent germination pathways, implying that biomolecules engaged in these pathways may be oxygen-sensitive. Furthermore, spores that have completed the germination process in either anoxic or oxic conditions may have different culturability. This research contributed to a better understanding of the fundamental mechanism of germination.

Interruption of Seed Dormancy and In Vitro Germination of the Halophile Emerging Crop Suaeda edulis (Chenopodiaceae)

Suaeda edulis (Flores Olvera & Noguez) is a halophile species that grows in saline environments, with concomitant difficulties to germinate and reproduce. Once a null germination under a salinity gradient or fresh water was observed, a plant-growth bioregulator (BioR) was applied to interrupt dormancy and improve germination in vitro. This BioR is composed of gibberellins and adjuvant regulators; and 12.5, 25.0, and 37.5 mg L−1 of gibberellins with immersion at 24, 48, and 72 h were assayed. Most of the normality and homoscedasticity tests were favorable, except in three of 24 cases. On the germination percentage (transformed values), the dose 25.0 mg L−1 reflected the highest values of 5.5 and 6.0 units at 48 and 72 h. For the mean germination time, the highest level of 37.5 mg L−1 at 24 h reflected the best response. For the germination rate, the best one was 25 mg L−1 at 48 h, reaching 12% per day, but for the germination speed coefficient, the best value was observed with 25.0 mg L−1 at 24 h. It was concluded that to improve germination of S. edulis seeds, it is necessary to assess a dose-gradient of gibberellins, starting at 25.0 mg L−1, with higher values to break dormancy.

Effects of high dilutions of Cymbopogon winterianus Jowitt (citronella) on the germination and growth of seedlings of Sida rhombifolia

The effects of high dilutions of Cymbopogon winterianus (citronella) on the growth and germination of Sida rhombifolia are analyzed; 5 homeopathic dilutions (3cH, 6cH, 12cH, 24cH, 30cH) and a control (water) were used, with 5 repetitions. Variables analyzed were the primary growth of the root system, length of the shoot, fresh mass total, germination percentage and germination speed index. All dilutions stimulated the primary growth of the root. Dilutions 3cH, 6cH, 12cH and 30 cH stimulated the growth of the aerial parts and 24cH inhibited it. Dilutions 6cH, 12cH, 24cH and 30cH stimulated a larger production of fresh mass than 3cH. Dilution 12cH resulted in the largest germination percentage while 24cH in the lowest. Dilution 12cH resulted in the highest score in the germination speed index, while 3cH and 24cH in the lowest. Keywords: Homeopathic dilutions; Plants; Germination; Growth; Cymbopogon winterianus; Sida rhombifolia.  Efeitos de altas diluições de Cymbopogon winterianus Jowitt (citronella) na germinação e crescimento de sementes de Sida rhombifolia Resumo Os efeitos de altas diluições de Cymbopogon winterianus (citronella) no crescimento e germinação de Sida rhombifolia são analisados; 5 diluições ho´meopáticas (3cH, 6cH, 12cH, 24cH, 30cH) e um controle (água) foram utilizados, com 5 repetições. As variáveis analisadas foram: crescimento primário do sistema da raiz, longitude do broto, massa fresca total, porcentagem de germinação e índice de velocidade de germinação. As diluições 3cH, 6cH, 12cH e 30cH estimularam o crescimento das partes aéreas, que foi inibido pela diluição 24cH. As diluições 6cH, 12cH e 30cH estimularam uma maior produção de massa fresca que a diluição 3cH. A diluição 12cH mostrou a porcentagem máxima de germinação, enquanto 24cH mostrou a mínima. Igualmente, a diluição 12cH resultou no máximo índice de velocidade de germinação, enquanto as diluições 3cH e 24cH, os mínimos. Palavras-chave: Diluições Homeopática; Plantas; Germination; Crescimento; Cymbopogon winterianus; Sida rhombifolia.  Efectos de altas diluciones de Cymbopogon winterianus Jowitt (citronella) en la germinación y crecimiento de semillas de Sida rhombifolia Resumen Los efectos de altas diluciones de Cymbopogon winterianus (citronella) en el crecimiento y germinación de Sida rhombifolia son analizados; 5 diluciones homeopáticas (3cH, 6cH, 12cH, 24cH, 30cH) y un control (agua) fueron utilizados, con 5 repeticiones. Las variables analizadas fueron: crecimiento primario del sistema de la raíz, largura del brote, masa fresca total, porcentaje de germinación e índice de velocidade de germinación. Las diluciones 3cH, 6cH, 12cH y 30cH estimularon el crecimiento de las partes aéreas, mientras que éste fue inhibido por la dilución 24cH. Las diluciones 6cH, 12cH, 24cH y 30cH estimularon una mayor producción de masa fresca que la dilución 3cH. La dilución 12cH mostró el máximo porcentaje de germinación, mientras que la dilución 24cH, el mínimo. Igualmente, la dilución 12cH resultó en el máximo índice de velocidad de germinación, mientras que las diluciones 3cH y 24cH, los mínimos. Palabras-clave: Diluciones homeopáticas; plantas; germinación, crecimiento, Cymbopogon winterianus; Sida rhombifolia.  Correspondence author: Carlos Moacir Bonato, [email protected], State University of Maringá-SP, Brazil How to cite this article: Marques RM, Marques-Silva GG, Bonato CM. Effects of high dilutions of Cymbopogon winterianus Jowitt (citronella) on the germination and growth of seedlings of Sida rhombifolia. Int J High Dilution Res [online]. 2008 [cited YYYY Mmm DD]; 7(22): 31-35. Available: http://journal.giri-society.org/index.php/ijhdr/article/view/208/342. ÂÂÂ

Phytoremediation of EMS Induced Brassica juncea Heavy Metal Hyperaccumulator Genotypes

Buriganga, an economically important river of Dhaka, Bangladesh, is highly polluted by different toxic heavy metals. In this study, phytoremediation of EMS induced Indian mustard (Brassica juncea L) genotypes against three pollutants viz. lead (Pb), chromium (Cr) and cadmium (Cd) of Buriganga riverbank soil was assessed in field condition. Among 1-, 2- and 3% EMS induced genotypes, better seed germination rate, germination speed and plant survival rate were observed in 1% EMS induced genotype, BE21. The highest concentration of Pb, Cr and Cd were also obtained in the leaf of BE21 genotype and therefore was considered as a super-hyperaccumulator genotype. Concentration of Pb in the next generation of this genotype was approximately two-fold higher in the root (91.53 mg/kg dry weight, DW); three-fold higher in the shoot (33.31 mg/kg DW) and leaf (28.35 mg/kg DW), and more in the fruit (5.59 mg/kg DW) than the control. Concentration of Cr was approximately two-fold in the root (57.02 mg/kg DW), shoot (18.51 mg/kg DW) and leaf (14.98 mg/kg DW), and more in the fruit (6.15 mg/kg DW) of BE21 genotype compared to the control. Cd concentration was more in the root (1.96 mg/kg DW), leaf (0.52 mg/kg DW) and fruit (0.19 mg/kg DW) and less in the shoot (0.19 mg/kg DW) of BE21 genotype than the control. Root, shoot, leaf and fruit of BE21 altogether accumulated 98-, 73- and 87% Pb, Cr and Cd, respectively and can thus be utilized to remove heavy metals of Buriganga River. As like root, shoot and leaf, fruit also accumulated heavy metals; hence those plants which are used in phytoremediation should not be used as food or fodder. To the best of our knowledge, this is the first report of developing EMS induced hyperaccumulator genotype of B. juncea for phytoremediation of Buriganga riverbank soil of Bangladesh.

Germination and vigor of lettuce seeds (Lactuca sativa L.) pelleted with homeopathic preparations Alumina and Calcarea carbonica subjected to toxic levels of aluminum.

Background: aluminum toxicity is the most important factor limiting the growth of plants in acid soils, whereas current treatments are unfeasible. For this reason, alternatives are sought for, among which homeopathic treatment. Aims: this study aimed at evaluating the influence of homeopathic preparations Alumina 6cH, Alumina 12cH, Calcarea carbonica 6cH and Calcarea carbonica 12cH on the germination and vigor of lettuce seeds subjected to toxic levels of aluminum in paper-solution. At the same time, it was sought to develop a new procedure to apply homeopathic preparations in plants (pelleting). Methods: the statistical design was entirely randomized (CRD) with 6 treatments and 4 repetitions. Treatments included: 1) pelleted seeds/talc + Alum 6 cH; 2) pelleted seeds/talc + Alum 12cH; 3) pelleted seed/talc + Calc 6cH; 4) pelleted seeds/talc + Calc 12cH; 5) pelleted seeds/talc + distilled water; 6) non pelleted seeds (control). Variables evaluated were: germination percentage (GP), germination speed index (GSI) and radicle length (RL). Results: there was significant difference in GSI and RL – variables that reflect the vigor of seeds - between the samples treated with homeopathic preparations and the controls Conclusions: homeopathic preparations Alumina 6cH and 12cH and Calcarea carbonica 6cH and 12cH had significant effect on the vigor of lettuce seeds subjected to stress conditions.

High dilutions of Magonia pubescens hidrogel affect germination variables in Sorghum bicolor L. Moench

Introduction: In science homeopathic diseases or physiological disorders are not considered just a result of abiotic and biotic factors, but rather a consequence of loss of organic system homeostasis. Homeopathic science is currently being used efficiently in the control of plagues[1], plant diseases[2], in the increase of medicinal plants’ active principles[3] and in plant metabolism[4,5]. Although actual results, both in the academic and field-level, very little is known about physiological mechanisms action of homeopathic medicine on germination process[6]. This work aims to study the effect of M. pubescens hydrogel, on some physiological variables of sorghum germination (Sorghum bicolor L. Moench). Material and methods: The experiment was conducted at Homeopathy and Plant Physiology of Biology Department at UEM in the period from 04/05/06 to 30/12/06. M. pubescens (tingui) seeds were obtained from the region of Montes Claros - Minas Gerais. The M. pubescens hidrogel was obtained from the external centrals wrappers of 4 dry seeds, after they have been disposed in petri dishes with distilled water for a period of 36 hours of soaking (25oC). The hydrogel mother tincture was prepared according to Manual of Technical Standards for Homeopathic Drugstore[7] 3rd ed (2003), in the proportion of a hidrogel part (5g) to ten parts (50g) of absolute alcohol 70% and stored in a glass amber (capped and protected from light). After 15 days of maceration, the solution was filtered and after 48h at rest, the mother tincture was considered ready for use. The dilution 1cH (Centesimal Hahnemannian) was obtained by adding 0.2 ml of the mother tincture in 19.8 ml of distilled water (1/100) and sucussioned 100 times (33 sucussions s-1) by mechanical arm dynamizer with automatic stop (Model Denise 50 - AUTIC). The subsequent dilutions (2cH to 30cH) were obtained from the same procedure, starting from the dilution 1cH. Bioassay: In petri dish containing 15 seeds of sorghum in a circular distributed were added 10 ml with their dilutions (3, 6, 9, 12, 15, 20 and 30cH) and the control containing distilled water. The petri dishes were placed in a growth chamber (type BOD), temperature of (25 ± 2)°C and photoperiod of 16h. The variables were analyzed by germination period of 73.5h as described below: · Germination (%G): %G = (∑ni.N-1)x100 , where ∑ni, is the total number of germinated seeds in relation to the number of seeds put to germinate, expressed in percentage; · Germination average time (GAT): GAT = ∑ni . ti / ∑ni , where ni is the number of germinated seeds within a certain interval of time ti-1 and ti; expressed in hours. · Germination average speed (GAS), expressed in hours): GAS = ∑ni / ∑ni . ti · Germination speed index (GSI): IVG = G1 / N1 + G2 / N2 + ........ Gn / Nn , where G1, G2....Gn is the number of germinated seeds and N1, N2, ... Nn is the number of hours after sowing. The total number of germinated seeds, at each time (12h) was also analyzed. Seeds were considered germinated when the radicle had 1 to 2 mm of lengths. Experimental design: The experimental design was randomized block with 4 replications, totaling 32 experimental units. It was adopted the double-blind methodology, to avoid possible interference or direction by the researcher. Statistical Analysis: The data were analyzed by ANOVA and the averages compared by Scott-Knott test (p≤0.05). The twinning combined data were analyzed for interaction germination x time (G x T) by F test to 5% of probability. Results and discussion: The homeopathy of Magonia pubescens hydrogel affected on the germination kinetic variables of sorghum seeds, when compared with the control (Fig. 1). This effect was most observed in the initial process of germination (from 13h). Research accomplished by Salgado-Labouriau (1973) [8] showed that the hydrogel formed from the external wrapper Magonia pubescens seeds, does not contain inhibiting, but contains factors that accelerate the germination process. Apparently, these results seem contradictory. However, for the homoeopathic optics, some used medicines in a considered way might have determined effect. Already in high diluted doses this behavior can be reversed, as it happens with some drugs. This behavior in pharmacokinetics is denomined Hormesis. When diluted and given dynamism, the product of hydrogel, instead of stimulating, it can delay the germination for the same phenomenon. Hormesis is not yet explained by science. Homeopathy of the Magonia pubescens gel significantly increased the germination average time (GAT) of sorghum seeds and reduced the germination average speed (GAS) and the germination speed index (GSI) (Fig. 2A, B and C). The values of these variables suggest that homeopathy, somehow slowed the speed of sorghum seeds soaking. Conclusion: The results here presented suggest that high dilutions of Magonia pubescens hidrogel can be used in future experiment such as bioherbicide.

Germination of palm seeds under periods of rehydration

Palm seeds are indicative of being recalcitrant species. Seeds germination for many species, is slow and uneven, even in favorable conditions, often due to the resistance of the woody endocarp that makes them impermeable to water. Most species also have the characteristic of not tolerating the drying process at low moisture levels, thus losing their viability. In view of these considerations, the objective was to evaluate the effect of different periods of rehydration on the germinative process of seeds of royal palm, dwarf palm and jeriva. Seeds were homogenized and immersed in water containing 3 times their volume, with daily replacement. The experimental design used was completely randomized, with 5 treatments (0, 3, 6, 9, and 12 days of rehydration), with 4 replications of 25 seeds. The seeds were placed in transparent “gerbox” plastic boxes containing medium vermiculite as substrate and placed in BOD with a photoperiod of 16-hour of light and their respective optimum temperatures for each species. The number of germinated seeds was counted every 2 days until germination stabilized. The variables analyzed were germination percentage, germination speed index (GSI), average germination time (AGT) and distribution of germination over the days. Rehydration for 3 days increased the germination rate of royal palm seeds. For dwarf and jeriva species, rehydration did not influence the analyzed variables. The GSI and AGT were negatively influenced by the rehydration periods for royal palm. Rehydration prolonged the peak of germination of the studied species.

ACTIVATED CHARCOAL APPLICATION FOR THE MICROPROPAGATION OF Cattleya crispata (Thunb.) Van den Berg

Micropropagation is an alternative for the genetic conservation and propagation of endemic species from “Campo Rupestre Ferruginoso”, such as the orchid Cattleya crispata. The aim of the present study is to assess the influence of activated charcoal on the in vitro germination, multiplication and elongation phases of C. crispata. Seeds extracted from mature capsules were used for inoculation in the culture medium that was adopted to assess the effect of supplementation, or not, with activated charcoal. Data about germination speed, seedling number, length, vigor, oxidation and contamination (bacterial and/or fungal) were assessed through these phases. Based on the results obtained, the use of activated charcoal was efficient in the in vitro germination and multiplication phases of C. crispata, providing greater speed and percentage of germination, less contamination and oxidation of the tissues, greater number, length and vigor of shoots, being effective for the genetic conservation and production of seedlings of the species. Culture medium without the supplementation of activated charcoal provided the best results for the in vitro elongation, with greater length, vigor and less oxidation of shoots.

Evaluation of Trichoderma spp. Isolates in Cocoa Seed Treatment and Seedling Production

Isolates of Trichoderma spp., a soil fungus, has been used to control diseases and promote plant growth, reducing the use of chemicals in the production of seedlings of different plant species. We evaluated the effect of some Trichoderma spp. isolates on seed treatment and seedling production of Theobromacacao. Five isolates from the Amazon region were tested. In laboratory, the following variables were evaluated for seed treatments: germination, germination speed index, radicle and hypocotyl lengths, and fungi incidence. In nursery, the following forms of application were tested: via seeds; in the substrate at pre-planting; monthly in post-planting substrate, and also their combination. The following was evaluated: height, diameter, number of leaves, root length, leaf area, and shoot dry mass and root system. Inoculation with Trichoderma increased the length of the radicle and hypocotyl and showed no fungi in the seeds. In seedlings, some treatments increased height and plant root dry mass. The use of Trichoderma was beneficial for seeds and appeared favorable for T. cacao production.