Pelargonium X Hortorum Research Articles

Antimicrobial Activity of Isolated Bacterial Endophytes from Cichorium intybus L, Pelargonium hortorum, and Portulaca oleracea Against Human Nosocomial Bacterial Pathogens

Background: Bacterial endophytes are colonizers of the inner plant tissues in which they do not normally cause any substantial morphological changes or disease symptoms. Endophytic bacteria are safe microorganisms that reside within the plant hosts and are known to enhance the growth and development of host plants, probably by secreting growth hormones. These bacteria are known to enhance growth and products of plants by fixing atmospheric nitrogen, solubilization of phosphate, production of phytohormones and siderophores, and possession of antagonistic activity, as well as reducing the level of stress ethylene in host plants. Objectives: In this descriptive study, we focused on the isolation of bacterial endophytes from three medicinal plants Cichorium intybus L, Pelargonium hortorum, and Portulaca oleracea and screened them for activities against nosocomial isolates of Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeroginosa, and Acinetobacter baumannii. Methods: Random samples from asymptomatic leaves and branches of three medicinal plants (Cichorium intybus L, Pelargonium hortorum, and Portulaca oleracea) were collected. To isolate the endophytic bacteria, the disinfected portions of the plants were distributed onto the isolation media. To examine endophytic bacterial contents, bioassays were conducted using growing colonies in PA and YEA, inactivating them by chloroform. To test the antibacterial activity of the endophytic bacterial culture broth, filter-sterilized supernatants were poured into cylinders on each bacterial plate. Results: A total of 24 phenotypically distinguishable bacterial endophytes were isolated in pure form from three medicinal plants. In part of the chloroform-inactivated colonies of all 24 isolated endophytes, the most effective herb was C. intybus L, followed by Po. oleracea, and in part of the supernatant culture broth, the most effective herb was Po. oleracea, followed by C. intybus L. Conclusions: Endophytic microorganisms residing in Cichorium intybus L, Portulaca oleracea, and Pelargonium hortorum are a very promising source for production of bioactive compounds. In general, most isolated endophytes had an acceptable effect against indicator bacterial pathogens.

Antimicrobial Activity of Isolated Bacterial Endophytes from Cichorium intybus L, Pelargonium hortorum, and Portulaca oleracea Against Human Nosocomial Bacterial Pathogens

Background: Bacterial endophytes are colonizers of the inner plant tissues in which they do not normally cause any substantial morphological changes or disease symptoms. Endophytic bacteria are safe microorganisms that reside within the plant hosts and are known to enhance the growth and development of host plants, probably by secreting growth hormones. These bacteria are known to enhance growth and products of plants by fixing atmospheric nitrogen, solubilization of phosphate, production of phytohormones and siderophores, and possession of antagonistic activity, as well as reducing the level of stress ethylene in host plants. Objectives: In this descriptive study, we focused on the isolation of bacterial endophytes from three medicinal plants Cichorium intybus L, Pelargonium hortorum, and Portulaca oleracea and screened them for activities against nosocomial isolates of Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeroginosa, and Acinetobacter baumannii. Methods: Random samples from asymptomatic leaves and branches of three medicinal plants (Cichorium intybus L, Pelargonium hortorum, and Portulaca oleracea) were collected. To isolate the endophytic bacteria, the disinfected portions of the plants were distributed onto the isolation media. To examine endophytic bacterial contents, bioassays were conducted using growing colonies in PA and YEA, inactivating them by chloroform. To test the antibacterial activity of the endophytic bacterial culture broth, filter-sterilized supernatants were poured into cylinders on each bacterial plate. Results: A total of 24 phenotypically distinguishable bacterial endophytes were isolated in pure form from three medicinal plants. In part of the chloroform-inactivated colonies of all 24 isolated endophytes, the most effective herb was C. intybus L, followed by Po. oleracea, and in part of the supernatant culture broth, the most effective herb was Po. oleracea, followed by C. intybus L. Conclusions: Endophytic microorganisms residing in Cichorium intybus L, Portulaca oleracea, and Pelargonium hortorum are a very promising source for production of bioactive compounds. In general, most isolated endophytes had an acceptable effect against indicator bacterial pathogens.

Effects of asafoetida, geranium and walnut leaves essential oils on nutritional indices and progeny reduction on Rhyzopertha dominica adults (Coleoptera: Bostrychidae)

In this study, the efficiency of essential oils from asafoetida, Ferula assa foetida L., geranium, Pelargonium hortorum L.H. Bailey and walnut leaves, Juglans regia F. was investigated on nutritional indices of Rhyzopertha dominica (F.) adults. Wheat grains were treated with different concentrations of the oils. The nutritional indices: relative growth rate (RGR), relative consumption rate (RCR), efficiency of conversion of ingested food (ECI) and feeding deterrence index (FDI) were measured at 28 ± 2 °C, 65 ± 5% R. H. in continuous darkness. RGR, RCR and ECI deceased as the concentration level was increased. While, FDI percent increased significantly as the concentration level increased. Asafoetida oil had the most efficiency on nutritional indices and 28.61 ppm of the oil was enough to decrease RGR, RCR and ECI% to 0.032 mg/mg/day, 0.444 mg/mg/day and 6.994%, respectively. FDI percent of adults exposed to 6.5 ppm of asafoetida oil was 13.31% which increased upto 64.62% at the concentration of 28.61 ppm. In the second experiment, the effect of tested essential oils was evaluated on F1 progeny reduction of R. dominica. Walnut and asafoetida leaves essential oils significantly suppressed progeny production by (59.92%) and (53.2%) respectively.

Effects of elemental sulphur on heavy metal uptake by plants growing on municipal sewage sludge

In this study experiment was carried out to determine the phytoextraction potential of six plant species (Conium maculatum, Brassica oleraceae var. oleraceae, Brassica juncea, Datura stramonium, Pelargonium hortorum and Conyza canadensis) grown in a sewage sludge medium amended with metal uptake promoters. The solubility of Cu, Cd and Pb was significantly increased with the application of elemental S due to decrease of pH. Faecal coliform number was markedly decreased by addition of elemental sulphur. The extraction of Cu, Cr and Pb from sewage sludge by using B. juncea plant was observed as 65%, 65% and 54% respectively that is statistically similar to EDTA as sulphur. The bioaccumulation factors were found higher (>1) in the plants tested for Cu and Pb like B. juncea. Translocation index (TI) calculated values for Cd and Pb were greater than one (>1) in both C. maculatum and B. oleraceae var. oleraceae. The results cleared that the amendment of sludge with elemental sulphur showed potential to solubilize heavy metals in phytoremediation as much as EDTA.

GROWTH, FLOWERING AND PHOTOSYNTETIC PIGMENTS OF PELARGONIUM × HORTORUM L.H. BAILEY ‘SURVIVOR HOT PINK’ AND ‘GRAFFITI FIRE’ GROWN IN SUBSTRATES CONTAINING SEWAGE SLUDGE COMPOST

The aim of this study was to assess usability of composts made of sewage sludge and either straw or leaves used as substrates for growing zonal pelargoniums. The study plants ‘Hot Pink’ cv. of Survivor group and ‘Fire’ cv. of Graffiti group were grown in 5 different substrates. The control substrate was high peat (100%) deacidified with chalk and dolomite up to pH 5.8–6.0 and supplemented with 2.5 g·dm-3 of Azofoska multicomponent fertilizer. The other four substrates contained two types of composts: SSRS – sewage sludge, straw (1:1, v/v) and SSL – sewage sludge, leaves (1:1, v/v), mixed with high peat at two different proportions, 1:3 (v/v) and 1:7 (v/v). Chemical composition of the substrates was investigated and they were supplemented with nitrogen and potassium as recommended for pelargoniums. Plant morphological parameters were evaluated during flowering. They included plant height and diameter, number of shoots and leaves, leaf assimilation area and leaf weight. Leaf chlorophyll and carotenoid content was also estimated. Inflorescence related parameters included inflorescence diameter and inflorescence stem length, number of flowers per inflorescence and flower diameter. All inflorescences formed over 10 weeks of flowering were counted. Plant ornamental value was assessed using a five-score bonitation scale. The investigated composts were found to be useful components of the substrates for zonal pelargonium production. Irrespective of the compost share, the tested substrates significantly affected most of the evaluated morphological traits. The substrate containing the compost made of sewage sludge and straw (SSRS) and peat (1:3, v/v) was found the most beneficial for pelargonium foliage, i.e. the number of leaves, their fresh weight and assimilation area. Leaf chlorophyll and carotenoid content in the pelargoniums grown in the substrates containing either dose of SSRS compost did not differ from the control plants. Substrate type did not affect bonitation score of ‘Survivor Hot Pink’ cultivar. The bonitation score of ‘Graffiti Fire’ cultivar was the highest for plants growing in the substrates with either SSRS or SSL compost plus peat in 1:3 ratio (v/v).

Efficacy of chemical retardants on growth and flowering in potted zonal pelargonium

A pot experiment was conducted under glasshouse conditions with completely randomized block design where growth and flowering responses of two cultivars of Pelargonium × hortorum were studied using spray treatments of chlormequat or chlorocholine chloride or cycocel (CCC @ 500, 1000, 1500 ppm) and ethephon (350, 600, 1000 ppm). CCC at 1000–1500 ppm was found most effective in producing desirable and presentable potted pelargoniums where 15% dwarfing effect on plant height reduction was obtained along with an early flowering of 10–12 days as compared to control. Ethephon at 600–1000 ppm resulted in maximum height retardation (18.31%) in plants with more number of side shoots and 50% more plant spread as compared to the control. All ethephon treated plants resulted in delayed flowering. Both growth retardants have beneficial implications in large scale commercial production of potted zonal pelargoniums where axillary branching can be achieved with ethephon followed by cycocel foliar sprays to retard plant height and advance flowering.

Disease resistance and growth responses in Pelargonium × hortorum plants to brief pulses of UV-C irradiation

Data collected from the current experiments showed that brief pulses of UV-C irradiation (i.e. 0.5–10.0kJm−2) on Pelargonium×hortorum L.H. Bail (zonal geraniums) plants of cvs ‘Victor’ and ‘Glacis’ significantly (P<0.05) reduced Botrytis cinerea infection. This inducible defence response peaked 24h post UV-C treatment and caused 47% reduction in lesion diameters after artificial inoculation with B. cinerea. All UV-C doses applied on both geranium cultivars were significantly (P<0.05) effective and the lower-most effective dose, 2.5kJm−2 was suggested for future and possible commercial use. Between the two cultivars tested, cv ‘Victor’ responded better against B. cinerea infection, while cv ‘Glacis’ displayed specific morphological changes associated with growth and flowering. Irradiated cv ‘Glacis’ plants showed significantly (P<0.05) higher number of inflorescences, number of leaves and plant heights compared to the non-irradiated controls. For the first time, the effects of brief pulses of UV-C irradiation on photosynthetic activity of ornamental plants were tested. A significant (P<0.05) rise in CO2 assimilation (As), stomatal conductance (gs) and transpiration (E) was recorded immediately after UV-C irradiation. However, this increase was only temporary as As, gs and E values returned to normal (i.e. at control levels) within the next 24h. We suggest that brief pulses of UV-C on geranium plants may facilitate growth and development by inducing photomorphogenic responses.

Influence of leaf trichome type and density on the host plant selection by the greenhouse whitefly, Trialeurodes vaporariorum (Hemiptera: Aleyrodidae)

Host selection by the adult greenhouse whitefly Trialeurodes vaporariorum (Westwood) was assessed on two pelargonium plant cultivars, Pelargonium × domesticum Bailey (regal) and P. × hortorum Bailey (zonal), using Petri dish bioassay chambers in choice and no-choice tests. Plant characteristics which could influence the oviposition preference of the whitefly, i.e., type and density of trichomes on the abaxial leaf surface, was determined. A strong host preference was observed for the regal compared to the zonal pelargonium by the adult whiteflies. In no-choice tests, adults laid a significantly higher number of eggs on regal than on zonal leaves both at 24 and 48 h post-exposure, respectively. After exposure to the adult whitefly, the number of eggs in choice tests were similar between cultivars at 24 h, but were higher for regal at 48 and 72 h. The total number of trichomes (sng, straight non-glandular + sg, straight glandular) per 0.50 cm2 was significantly less on regal [mean (sng + sg) ± SE; 43.1 ± 1.5) than on zonal leaves (60.5 ± 1.2); however, the sng trichomes were significantly higher on the zonal (49.5 ± 1.2) than the regal leaves (28.6 ± 1.0). Also, the number of sg trichomes was slightly higher for the regal cultivar leaves compared to the zonal, being 14.4 ± 1.2 and 11.2 ± 0.5, respectively. Results suggest that the trichome density, type, and ability to express glandular exudates can affect adult whitefly Pelargonium cultivar preference and plays an important role in their host plant selection for oviposition.

Discovering herbalism through art. Plants in Polish symbolic painting (1890–1914)

Summary The article focuses on the historical link between herbalism and art at the turn of the twentieth century. The aim of this investigation is to recognize medicinal plants shown as symbols in Polish painting between 1890 and 1914 and find some cultural context of their presence in artworks. In this qualitative study online art galleries and museum collections were analyzed to select Polish symbolists’ artworks including plant images. Next, their botanical classification and medicinal context were examined. Twenty wild-growing plant species were recognized. Some of them had been used in traditional medicine (Alcea rosea, Angelica archangelica, Artemisia abrotanum, Betula pendula, Carduus marianus, Convallaria majalis, Crocus sativus, Lilium candidum, Matricaria chamomilla, Nuphar lutea, Paeonia officinalis, Papaver somniferum, Pelargonium hortorum, Populus nigra, Primula veris, Sorbus aucuparia, Taraxacum officinale, and Verbascum thapsus) and two species grown in the Carpathians (Digitalis purpurea, Lilium bulbiferum) at the time. Used to paint realistic objects, the symbolists made free-hand drawings in nature and in this way they recorded some wild-growing plants typical for surroundings of the town of Cracow and the Carpathian Mountains. Artistic images of plants were not intentionally aimed at taxonomic identification, however, sometimes classification was possible.

Validation of a Fertilizer Potential Acidity Model to Predict the Effects of Water-soluble Fertilizer on Substrate pH

Two experiments were run to validate a “Nitrogen Calcium Carbonate Equivalence (CCE)” model that predicts potential fertilizer basicity or acidity based on nitrogen (N) form and concentration for floriculture crops grown with water-soluble fertilizer in containers with minimal leaching. In one experiment, nine bedding plant species were grown for 28 days in a peat-based substrate using one of three nutrient solutions (FS) composed of three commercially available water-soluble fertilizers that varied in ammonium to nitrate (NH4+:NO3–) ratio (40:60, 25:75, or 4:96) mixed with well water with 130 mg·L−1 calcium carbonate (CaCO3) alkalinity. Both the ammonium-nitrogen (NH4-N) content of the FS and plant species affected substrate pH. Predicted acidity or basicity of the FS for Impatiens walleriana Hook.f. (impatiens), Petunia ×hybrida E. Vilm. (petunia), and Pelargonium hortorum L.H. Bailey (pelargonium) from the Nitrogen CCE model was similar to observed pH change with an adjusted R2 of 0.849. In a second experiment, water alkalinity (0 or 135.5 mg·L−1 CaCO3), NH4+:NO3– ratio (75:25 or 3:97), and N concentration (50, 100, or 200 mg·L−1 N) in the FS were varied with impatiens. As predicted by the N CCE model, substrate pH decreased as NH4+ concentration increased and alkalinity decreased with an adjusted R2 of 0.763. Results provide confidence in the N CCE model as a tool for fertilizer selection to maintain stable substrate pH over time. The limited scope of these experiments emphasizes the need for more research on plant species effects on substrate pH and interactions with other factors such as residual limestone and substrate components to predict pH dynamics of containerized plants over time.

Effects of cytokinins on antioxidant enzymes in in vitro grown shoots of Pelargonium hortorum L. H. Bayley

&lt;p&gt;The aim of this study was to determine the influence of &lt;em&gt;meta&lt;/em&gt;-topolin (&lt;em&gt;m&lt;/em&gt;T) and 6-benzyl-aminopurine (BAP) on the hydrogen peroxide (H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;) level and antioxidant enzymes activities in relation to the shoot formation and senescence process in &lt;em&gt;Pelargonium hortorum&lt;/em&gt; cultivars, which differ in their susceptibility to leaf yellowing under &lt;em&gt;in vitro&lt;/em&gt; conditions.&lt;/p&gt;&lt;p&gt;In an early senescing cultivar ‘Grand Prix’, the addition of an aromatic cytokinin &lt;em&gt;m&lt;/em&gt;T to abscisic acid (ABA)-enriched Murashige and Skoog (MS) basal medium more efficiently inhibited leaf yellowing than BAP. In both genotypes, &lt;em&gt;meta&lt;/em&gt;-topolin was also the most effective in shoot formation. It was found that &lt;em&gt;Pelargonium&lt;/em&gt; species varying in their susceptibility to senescence differ in H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; production and antioxidant enzymes activities. Generally, &lt;em&gt;meta&lt;/em&gt;-topolin more effectively enhanced H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2 &lt;/sub&gt;production and POD activity than BAP and control medium, but its effect depended on genotype. The highest H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; production stimulated by &lt;em&gt;m&lt;/em&gt;T was observed on day 5 of subculture in late senescing cv. ‘Bergpalais’. In both geranium genotypes, superoxide dismutase (SOD) and catalase (CAT) levels were highest at the beginning of the subculture period, during the initiation of shoot formation. SOD showed the highest activity on day 5 of subculture on the medium without cytokinin and generally being higher in cv. ‘Bergpalais’ than in cv. ‘Grand Prix’. CAT activity was positively regulated by both cytokinins. POD activity was most effectively enhanced by &lt;em&gt;m&lt;/em&gt;T, but on different days of subculture - on the 2&lt;sup&gt;nd&lt;/sup&gt; day of subculture in cv. ‘Bergpalais’ and on the 22&lt;sup&gt;nd&lt;/sup&gt; day of subculture in cv. ‘Grand Prix’. The enhanced activity of POD in the presence of &lt;em&gt;m&lt;/em&gt;T, 4-fold higher than on control medium, at the end of subculture in &lt;em&gt;P. hortorum &lt;/em&gt;‘Grand Prix’ coincided with the inhibition of leaf senescence.&lt;/p&gt;

Regeneration of whole plants of geranium from petioles cultured in vitro

Studies were made on the morphogenetic potential of petioles of &lt;em&gt;Pelargonium hortorum&lt;/em&gt; (1 variety, 2 clones) and &lt;em&gt;Pelargonium peltatum&lt;/em&gt; (1 variety, 1 clone) grown on the medium of Murashige and Skoog (MS) supplemented with auxins (IAA, IBA, NAA) and cytokinins (KIN, BAP, zeatin). The most intensive growth of callus of both species was observed on medium supplemented with 0.1 mg/l NAA and 10 mg/l KIN, both under constant illumination and in darkness. Differentiation of callus and regeneration of plants occurred in &lt;em&gt;P. peltatum&lt;/em&gt; variety "PAC Dresdner Amethyst" and in &lt;em&gt;P. hortorum&lt;/em&gt; clone 3766/4 on medium containing 1 mg/l BAP, 1 mg/l IAA and exposed to a photoperiod (L:D = 16:8).

Gasified Rice Hull Biochar Affects Nutrition and Growth of Horticultural Crops in Container Substrates

This research was conducted to determine if gasified rice hull biochar (GRHB), inherently high in phosphorus and potassium content, could be used as an amendment to container substrates to eliminate the need for other phosphorus and potassium fertilizers. Geranium (Pelargonium xhortorum ‘Maverick Red’), pansy (Viola xwittrockiana ‘Mammoth Blue Deep Dazzle’), sunflower (Helianthus annus ‘Pacino Gold’), zinnia (Zinnia elegans ‘Oklahoma White’), and tomato (Lycopersicon lycopersicum ‘Mega Bite’) were grown in a standard commercial soilless substrate composed of sphagnum peat moss:perlite (85:15, by vol) and amended with 0, 5, or 10% GRHB (by vol). A group of plants labeled as NPK-fertilized controls were fertilized with 7.1 mM nitrogen (N), 0.7 mM phosphorus (P), and 1.4 mM potassium (K) derived from ammonium nitrate (NH4NO3) and potassium phosphate (K2HPO4). Other treatments received 0, 5, or 10% GRHB and fertilized with 7.1 mM N using NH4NO3. Gasified rice hull biochar had little effect on substrate pH over the course of the experiment. While pH was higher with 10% GRHB than NPK-fertilized controls by 6 weeks after potting (WAP), the difference was only 0.19 pH units. The GRHB used in this study provides a source of readily available phosphate and potassium when incorporated at 5 or 10%. While the five crops grown in this study were of similar size and lacked any signs of nutrient deficiency when amended with GRHB, foliar concentrations of P and K were low when their only source was from pre-incorporated GRHB.

Composition and insecticidal activity of the essential oil of Pelargonium hortorum flowering aerial parts from China against two grain storage insects

The aim of this research was to determine chemical composition and insecticidal activity of the essential oil of Pelargonium hortorum Bailey (Geraniaceae) flowering aerial parts against the booklouse (Liposcelis bostrychophila Badonnel) and maize weevils (Sitophilus zeamais Motschulsky). The essential oil of P. hortorum flowering aerial parts was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 36 components of the essential oil were identified. The principal compounds in the essential oil were 1,8-cineole (23.01%), α-terpineol (13.22%), α-pinene (8.13%) and camphor (8.12%) followed by 4-terpineol (4.63%), β-myrcene (4.56%) and β-caryophyllene (4.08%). The essential oil exhibited contact toxicity against L. bostrychophila and S. zeamais with LD50 values of 149.78 μg/cm2 and 14.41 µg/adult, respectively. The essential oil also possessed fumigant toxicity against L. bostrychophila and S. zeamais adults with LC50 values of 1.31 mg/L air and 7.22 mg/L air, respectively. The results indicated that the essential oil of P. hortorum showed potential in terms of contact and fumigant toxicity against grain storage insects. Key words: Pelargonium hortorum, Liposcelis bostrychophila, Sitophilus zeamais, contact toxicity, fumigant, essential oil composition.

Total phenolic contents and antioxidant capacities of 51 edible and wild flowers

Antioxidant capacities of 51 edible and wild flowers from China were systemically evaluated using ferric-reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity (TEAC) assays, and their total phenolic contents were measured by Folin–Ciocalteu method. The lipophilic components of flowers were extracted with tetrahydrofuran, and the hydrophilic ones were extracted with a methanol–acetic acid–water (50:3.7:46.3, v/v/v) mixture. The results showed that different flowers had diverse antioxidant capacities and phenolic compounds were a major contributor to their antioxidant activities. Rosa rugosa, Limonium sinuatum, Pelargonium hortorum, Jatropha integerrima and Osmanthus fragrans were found to have the highest antioxidant capacities. Homogentisic acid, cyanidin-3-glucoside, protocatechuic acid, catechin, gallic acid and epicatechin were quantified in these flowers using HPLC analysis. These flowers should save as potential rich resources of natural antioxidants for use as functional food ingredients or pharmaceuticals for control of diseases caused by oxidative stress.

Exogenous Applications of Benzyladenine and Gibberellic Acid Inhibit Lower-leaf Senescence of Geraniums during Propagation

After postharvest shipping, the lower leaves of zonal geranium (Pelargonium ×hortorum) cuttings often turn chlorotic and necrotic during rooting in a propagation environment. Our objective was to quantify the efficacy of spray applications of the plant growth regulators (PGRs) benzyladenine (BA) and/or gibberellic acid (GA) at various stages in propagation to reduce lower-leaf senescence and evaluate effects on subsequent rooting. In Expt. 1, cuttings of ‘Patriot White’ geraniums were harvested and treated with BA (2.5 or 5.0 mg·L−1), BA + GA4+7 (2.5 or 5.0 mg·L−1 each), or GA3 (0.5 or 2.0 mg·L−1) either before or after a 2-day storage period simulating commercial shipping. Post-shipment application of all PGRs eliminated leaf yellowing compared with cuttings treated pre-shipment, but rooting was inhibited. In Expt. 2, the promotion of rooting from a rooting hormone preceding treatment with BA (1.25 to 5.0 mg·L−1), BA+GA4+7 (1.25 to 5.0 mg·L−1 each), or GA3 (0.25 to 2.0 mg·L−1) was evaluated on ‘Patriot White’ geranium cuttings after a 2-day simulated shipping. Applying rooting hormones increased the percentage of fully rooted cuttings treated with BA and/or GA from 16.4% to 51.8%. In Expt. 3, cuttings of different geranium cultivars from a commercial producer varied in susceptibility and suppression of leaf yellowing after BA + GA4+7 applications. We conclude that foliar applications of BA + GA4+7 can suppress lower-leaf senescence and rooting during propagation of some geranium cultivars, and the inhibition of rooting can be at least partially overcome with an application of rooting hormone.

Evaluation of the activity of Guatemalan medicinal plants against cancer cell lines and microbes

Medicinal plants are used by rural Guatemalan villagers to treat a variety of ailments, and a better understanding of their effectiveness against common diseases is warranted. Acetone and methanol extracts of 73 medicinal plant species from 44 families were bio-assayed against breast, cervical, skin, and tongue cancers, and Staphylococcus aureus, Escherichia coli, Streptococcus mutans, Lactobacillus acidophilus, and Candida albicans. Half-maximum inhibitory concentrations (IC50) and half-maximum cytotoxicity concentrations (CC50) were determined against cancerous and non-cancerous cell lines, respectively. Minimum inhibitory concentrations (MIC) were determined for active extracts. Bursera simaruba (L.) Sarg. (Burseraceae), Byrsonima crassifolia (L.) Kunth (Malpighiaceae), Guazuma ulmifolia Lam. (Malvaceae), and Quercus acatenangensis Trel. (Fagaceae) were inhibitory to one or more cancer cell lines and yielded promising IC50 and CC50 values. Eucalyptus globulus Labill. (Myrtaceae), Liquidambar styraciflua L. (Altingiaceae), Pelargonium hortorum L.H. Bailey (Geraniaceae), and Psidium guajava L. (Myrtaceae) were inhibitory to one or more microbes and had MIC’s of 250 µg/ml or less against one or more microbes. The activity of these species against cancer and pathogenic microbes indicates that they are valuable resources that should be conserved and considered for future research. Key words: Anticancer, antimicrobial, IC50, CC50, minimum inhibitory concentrations (MIC), Guatemala.

Gasified Rice Hull Biochar is a Source of Phosphorus and Potassium for Container-Grown Plants2

Biochar materials have been reported to improve the chemical, physical, and biological properties of mineral soils and soilless substrates. The objective of this research was to determine the effect of gasified rice hull biochar (GRHB) on available nutrients in a container substrate. Two experiments were conducted in a glasshouse with geranium (Pelargonium xhortorum ‘Maverick Red’) in 10 cm (4 in) pots. Geranium were potted in commercial soilless medium (Sunshine Mix #2) amended with 0 to 10% GRHB. Control pots were fertilized with a commercial complete liquid fertilizer (20N-4.4P-16.6K-0.15Mg-0.02B-0.01Cu-0.1Fe-0.05Mn-0.01Mo-0.05Zn), while GRHB-amended crops were fertilized with ammonium nitrate. Additional GRHB substrates were amended with either 0 or 0.9 kg·m−3 (1.5 lb·yd−3) micronutrient package (Micromax). The GRHB amendment had little or no effect on substrate pH. Amendment with GRHB increased available phosphate and potassium in substrate leachates compared to the commercially fertilized controls. Substrates amended with GRHB alone were chlorotic and grew less than those amended with GRHB and micronutrients. These data demonstrate that GRHB provides sufficient P and K to support a six week production cycle of geranium, but lacks either the correct concentration or balance of micronutrients for healthy growth.

Overexpression of mannitol dehydrogenase in zonal geranium confers increased resistance to the mannitol secreting fungal pathogen Botrytis cinerea

The sugar alcohol mannitol is a carbohydrate with well-documented roles in both metabolism and osmoprotection in plants and fungi. In addition, however, mannitol is an antioxidant, and current research suggests that pathogenic fungi can secrete mannitol into the plant’s extracellular spaces during infection to suppress reactive oxygen-mediated host defenses. In response to pathogen attack, plants have been shown to secrete the normally symplastic enzyme, mannitol dehydrogenase (MTD). Given that MTD converts mannitol to the sugar mannose, extracellular MTD may be an important defense against mannitol-secreting fungal pathogens. Previous work demonstrated that overexpression of MTD in tobacco did, in fact, provide increased resistance to the mannitol-secreting fungal pathogen Alternaria alternata. In the present work we demonstrate that the fungal pathogen Botrytis cinerea also can secrete mannitol, and that overexpression of MTD in zonal geranium (Pelargonium × hortorum) in turn provides increased resistance to B. cinerea. These results are not only an important validation of previous work, but support the idea that MTD-overexpression might be used to engineer a broad variety of plants for resistance to mannitol-secreting fungal pathogens like B. cinerea for which specific resistance is lacking.

In vitro cultures of Vitis vinifera L. cv. Chardonnay synthesize the phytoalexin nerolidol upon infection by Phaeoacremonium parasiticum

Fil: Escoriaza, Maria Georgina. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Cuyo Mendoza - San Juan. Estacion Experimental Agropecuaria Mendoza; Argentina;