Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| deactivation of gibberellin by 2-oxidation during germination of photoblastic lettuce seeds. | gibberellin (ga) plays an important role in the induction of germination of photoblastic lettuce (lactuca sativa l. cv. grand rapids) seeds. we have previously shown that gene expression of a ga 3-oxidase (ls3h1) increased after a red light treatment, resulting in an increase in the endogenous content of ga1, bioactive ga. since the metabolism of gas is also important for determining the endogenous levels of bioactive gas, cdnas encoding ga 2-oxidases (lsga2ox1 and lsga2ox2, for l. sativa ga 2-o ... | 2003 | 12913300 |
| incidence of parasites found on vegetables collected from markets and vegetable gardens in taegu area. | a parasitic survey on vegetables collected from markets and vegetable gardens in taegu area was conducted for the discovery of human parasitic eggs and larvae. three species of vegetable, lettuce (lactuca sativa), young radish(raphanus sapivus) and chinese cabbage (brassica pekinensis) were selected. all vegetable leaves were washed with a hard brush, and then species of parasites and the approximate mean number of parasitic eggs per 200 grams of vegetable leaves were investigated. when vegetabl ... | 1972 | 12913510 |
| environmental cadmium levels increase phytochelatin and glutathione in lettuce grown in a chelator-buffered nutrient solution. | phytochelatins are enzymatically synthesized peptides involved in metal detoxification and have been measured in plants grown at very high cd concentrations, but few studies have examined the response of plants at lower environmentally relevant cd concentrations. using an ethylenediaminetetraacetic acid (edta)-buffered nutrient medium, we have varied cd exposure and measured phytochelatin and glutathione concentrations in romaine lettuce (lactuca sativa l. var. longifolia lam. var. parris island ... | 2013 | 12931891 |
| [microbiological and parasitological contamination of lettuce (lactuca sativa) from self service restaurants of niterói city, rj]. | thirty samples of lettuces from self service restaurants of niterói were analyzed to detect bacteriological and parasitological contamination. sixteen samples presented fecal coliform, 16 mesophilic aerobic microorganisms greater than 10(7) ufc/g and 3 cysts of entamoeba coli. these data suggest the need of better orientation for food handlers regarding the hygiene of processed vegetables. | 2003 | 12937736 |
| [structure of outgrowths produced by lactuca sativa l. (belle de mai variety) under the action of the ethyl ester of 2,-4 d]. | 1953 | 13067405 | |
| essential oils from mediterranean lamiaceae as weed germination inhibitors. | the essential oils obtained from rosemary (rosmarinus officinalis l.), thyme (thymus vulgaris l.), and savory (satureja montana l.) and the four monoterpenes that are their major constituents have been analyzed by gc and gc-ms and tested for their allelopathic properties on the seeds of three different annual weeds (chenopodium album, portulaca oleracea, and echinochloa crus-galli) and three crops (raphanus sativus, capsicum annuum, and lactuca sativa), with the aim to evaluate in vitro their po ... | 2003 | 14518938 |
| lignans and neolignans from brassica fruticulosa: effects on seed germination and plant growth. | five lignans, five neolignans, two sesquilignans, and a dilignan were identified from a phytotoxic extract of brassica fruticulosa l. compounds 8, 9, 12, and 13 have been isolated for the first time. structures were determined on the basis of their spectroscopic features. their effects on the germination and growth of two dicotyledons, lactuca sativa (lettuce) and lycopersicon esculentum (tomato), and a monocotyledon, allium cepa (onion), as standard target species have been studied. | 2003 | 14518939 |
| ethylene promotes the induction by auxin of the cortical microtubule randomization required for low-ph-induced root hair initiation in lettuce (lactuca sativa l.) seedlings. | transverse cortical microtubule (cmt) arrays in lettuce root epidermal cells randomize soon after a shift from ph 6.0 to ph 4.0, and this randomization is essential for root hair initiation. we investigated the hormonal regulation of cmt randomization. at ph 4.0, 1 micro m of the auxin competitive inhibitor 2-(p-chlorophenoxy)-2-methylpropionic acid (pcib), 0.1 micro m of the ethylene biosynthesis inhibitor aminoethoxyvinylglycine (avg) or 0.1 micro m of the ethylene action inhibitor ag(+) suppr ... | 2003 | 14519775 |
| inhibition of endogenous trypsin- and chymotrypsin-like activities in transgenic lettuce expressing heterogeneous proteinase inhibitor sapin2a. | sapin2a, a proteinase inhibitor ii from american black nightshade (solanum americanum mill.) is highly expressed in the phloem and could be involved in regulating proteolysis in the sieve elements. to further investigate the physiological role of sapin2a, we have produced transgenic lettuce (lactuca sativa l.) expressing sapin2a from the camv35s promoter by agrobacterium-mediated transformation. stable integration of the sapin2a cdna and its inheritance in transgenic lines were confirmed by sout ... | 2004 | 14574575 |
| [frequency of intestinal parasites in samples of lettuce (lactuca sativa) commercialized in lavras, minas gerais state]. | the aim of this study was to evaluate the parasitological contamination in samples of lettuce (lactuca sativa) commercialized in lavras city, minas gerais. the samples of lettuce showed low hygienic conditions, indicated by the presence of parasites of animal or human origin and high concentration of fecal coliforms. | 2003 | 14576879 |
| chemical stimulants of leaf-trenching by cabbage loopers: natural products, neurotransmitters, insecticides, and drugs. | larvae of the cabbage looper, trichoplusia ni (lepidoptera: noctuidae), often transect leaves with a narrow trench before eating the distal section. the trench reduces larval exposure to exudates, such as latex, during feeding. plant species that do not emit exudate, such as plantago lanceolata, are not trenched. however, if exudate is applied to a looper's mouth during feeding on p. lanceolata, the larva will often stop and cut a trench. dissolved chemicals can be similarly applied and tested f ... | 2003 | 14584674 |
| cinnamic acid amides from chenopodium album: effects on seeds germination and plant growth. | seven cinnamic acid amides have been isolated from chenopodium album. the structures have been attributed by means of their spectral data. one of them, n-trans-4-o-methylferuloyl 4'-o-methyldopamine, is described for the first time. their effects on germination and growth of dicotyledons lactuca sativa l. (lettuce) and lycopersicon esculentum l. (tomato) and of monocotyledon allium cepa l. (onion) as standard target species have been studied in the range concentration 10(-4)-10(-7) m. | 2003 | 14630003 |
| effect of hypobaric conditions on ethylene evolution and growth of lettuce and wheat. | elevated levels of ethylene occur in enclosed crop production systems and in spaceflight environments, leading to adverse plant growth and sterility. there are engineering advantages in growing plants at hypobaric (reduced atmospheric pressure) conditions in biomass production for extraterrestrial base or spaceflight environments. objectives of this research were to characterize the influence of hypobaria on growth and ethylene evolution of lettuce (lactuca sativa) and wheat (triticum aestivum). ... | 2003 | 14658387 |
| snp-based codominant markers for a recessive gene conferring resistance to corky root rot (rhizomonas suberifaciens) in lettuce (lactuca sativa). | the analysis of f2 progeny and derived f3 families of lactuca sativa segregating for resistance to corky root rot caused by rhizomonas suberifaciens permitted the identification of restriction fragment length polymorphism (rflp) and single nucleotide polymorphism (snp) markers linked to the recessive resistance gene cor. pcr-based markers were identified by bulked segregant analysis (bsa). allele-specific primers were generally designed with the 3 terminal base coinciding with an snp, matching o ... | 2003 | 14663524 |
| transfer of salmonella and campylobacter from stainless steel to romaine lettuce. | the degree of transfer of campylobacter jejuni and salmonella enterica serovar typhimurium was evaluated from a stainless steel contact surface to a ready-to-eat food (lettuce). stainless steel coupons (25 cm2) were inoculated with a 20-microl drop of either c. jejuni or salmonella typhimurium to provide an inoculum level of approximately 10(6) cfu/28 mm2. wet and dry lettuce (lactuca sativa var. longifolia) pieces (9 cm2) were placed onto the inoculated stainless steel surface for 10 s after th ... | 2003 | 14672218 |
| abscisic acid in the thermoinhibition of lettuce seed germination and enhancement of its catabolism by gibberellin. | germination of lettuce (lactuca sativa l. cv. 'grand rapids') seeds was inhibited at high temperatures (thermoinhibition). thermoinhibition at 28 degrees c was prevented by the application of fluridone, an inhibitor of abscisic acid (aba) biosynthesis. at 33 degrees c, the sensitivity of the seeds to aba increased, and fluridone on its own was no longer effective. however, a combined application of fluridone and gibberellic acid (ga3) was able to restore the germination. exogenous ga3 lowered en ... | 2004 | 14676289 |
| volatile allelopathy in velvet bean (mucuna pruriens [correction of pruiens] l.) and gravity. | allelopathy caused by volatile compounds was studied with velvet bean (mucuna pruriens [correction of prueiens] l.). preparatory experiment was conducted to identify the relationship between action of volatiles and gravity. the experimental protocol was defined and tested to study on volatile allelopathy of velvet bean. root growth of lettuce (lactuca sativa l.) seedlings was inhibited by volatile gas from velvet bean seedlings planted in agripot. in this study, it was shown that ten-day velvet ... | 2003 | 14676381 |
| effects of monoterpenoids, acting alone or in pairs, on seed germination and subsequent seedling growth. | we compared the potential allelopathic activity of 47 monoterpenoids of different chemical groups, by estimating their effect on seed germination and subsequent growth of lactuca sativa seedlings. apart from individual compounds, eleven pairs at different proportions were also tested. as a group, the hydrocarbons, except for (+)-3-carene, were the least inhibitory. of the oxygenated compounds, the least inhibitory were the acetates; whenever the free hydroxyl group of an alcohol turned into a ca ... | 2003 | 14682512 |
| isolation and structural characterization of a water-soluble germination inhibitor from scotch thistle (onopordum acanthium) cypselas. | cypsela dormancy in scotch thistle (onopordum acanthium) may be affected by the presence of chemical inhibitors. to investigate this phenomenon, a leachate from o. acanthium cypselas was tested for its ability to inhibit germination of the cypselas from which it was derived (i.e., autoinhibition). leachates varied in their degree of autoinhibition, depending on the cypsela population from which they were prepared. overall, removal of leachate from a group of o. acanthium cypselas increased their ... | 2003 | 14682524 |
| alkylperoxyl radical scavenging activity of red leaf lettuce (lactuca sativa l.) phenolics. | although lettuce may provide relatively low levels of antioxidative phytochemicals which may contribute to human health, lettuce leaf extracts in fact contained compounds with high specific peroxyl radical scavenging activities. after determining the extraction conditions that minimized phenolic oxidation and produced the highest oxygen radical absorbance capacity (orac) values, the phenolic compounds from red leaf lettuce were separated by reverse-phase high-performance liquid chromatography (h ... | 2003 | 14705882 |
| determining toxicity of lead and zinc runoff in soils: salinity effects on metal partitioning and on phytotoxicity. | when assessing cationic metal toxicity in soils, metals are often added to soil as the chloride, nitrate, or sulfate salts. in many studies, the effects of these anions are ignored or discounted; rarely are appropriate controls included. this study used five soils varying in ph, clay content, and organic matter to determine whether salinity from counter-ions contributed to or confounded metal phytotoxicity. varying rates of pb and zn were applied to soils with or without a leaching treatment to ... | 2003 | 14713044 |
| a simple and efficient method for testing lettuce mosaic virus resistance in in vitro cultivated lettuce. | the potential of a new in vitro inoculation and propagation method developed for lettuce mosaic virus (lmv) on lettuce (lactuca sativa l.) was evaluated by studying lmv infection on in vitro cultivated seedlings or on newly regenerated plantlets. lettuce cultivars differing by their lmv-resistance status were inoculated with various natural lmv isolates as well as with green fluorescent protein (gfp)-tagged recombinant virus isolates. a good correlation was observed between the known resistance ... | 2004 | 14738978 |
| joint effects of elevated levels of ultraviolet-b radiation, carbon dioxide and ozone on plants. | there is growing interest regarding the joint effects of elevated levels of surface ultraviolet b (uv-b) radiation, carbon dioxide (co2) and ozone (o3) on plants. our current knowledge of this subject is too limited to draw any specific conclusions, although one might state that such effects are likely to be highly species dependent and may be more than additive, additive or less than additive. there are a number of uncertainties associated with the experimental protocols used and the conclusion ... | 2003 | 14743861 |
| effects of se and zn supplementation on the antagonism against pb and cd in vegetables. | the antagonistic effects of supplementation of zn and se to the soil on vegetables were studied in this work. in the pot experiment, se (se4+) and zn (zn2+) were applied, respectively, to the soil, in which the chinese cabbage (brassica rapa) and the lettuce (lactuca sativa l.) were planted. as a result, se and zn were enriched evidently in the two vegetables. the contents of pb and cd in the two vegetables were decreased markedly while contents of some healthy mineral elements, like mn and mg, ... | 2004 | 14749105 |
| structure elucidation and phytotoxicity of c13 nor-isoprenoids from cestrum parqui. | twelve c(13) nor-isoprenoids have been isolated from the leaves of cestrum parqui (solanaceae). the structure (2r,6r,9r)-2,9-dihydroxy-4-megastigmen-3-one has been assigned to the new compound. all the structures have been determined by spectroscopic means and chemical correlations. the compounds showed phytotoxic effect on the germination and growth of lactuca sativa l. | 2004 | 14759548 |
| inheritance of resistance to the root-knot nematode meloidogyne javanica in lettuce. | resistance to the root-knot nematodes meloidogyne spp. would be a valuable attribute of lettuce lactuca sativa l. cultivars grown in tropical regions. the looseleaf lettuce 'grand rapids' is resistant to both m. incognita and m. javanica. resistance to m. incognita has a high heritability, under the control of a single gene locus, in which the 'grand rapids' allele, responsible for resistance (me), has predominantly additive gene action, and has incomplete penetrance and variable expressivity. w ... | 2002 | 14963814 |
| comparative analysis of nbs domain sequences of nbs-lrr disease resistance genes from sunflower, lettuce, and chicory. | plant resistance to many types of pathogens and pests can be achieved by the presence of disease resistance (r) genes. the nucleotide binding site-leucine rich repeat (nbs-lrr) class of r-genes is the most commonly isolated class of r-genes and makes up a super-family, which is often arranged in the genome as large multi-gene clusters. the nbs domain of these genes can be targeted by polymerase chain reaction (pcr) amplification using degenerate primers. previous studies have used pcr derived nb ... | 2004 | 15019616 |
| the effect of ph, time and dietary source of cadmium on the bioaccessibility and adsorption of cadmium to/from lettuce (lactuca sativa l. cv. ostinata). | this study evaluated the influence of three variables in the effectiveness of an in vitro digestion protocol used to determine bioaccessibility of cadmium from the diet. the percentage of solubilized metal was measured in relation to digestion time, ph of each digestion phase and the dietary source of the metal in the diet. because it would be convenient to add the metal to the diet before digestion instead of growing contaminated vegetables, the importance of metal incorporation in the plant in ... | 2004 | 15046830 |
| dredged illinois river sediments: plant growth and metal uptake. | sedimentation of the illinois river in central illinois has greatly diminished the utility and ecological value of the peoria lakes reach of the river. consequently, a large dredging project has been proposed to improve its wildlife habitat and recreation potential, but disposal of the dredged sediment presents a challenge. land placement is an attractive option. previous work in illinois has demonstrated that sediments are potentially capable of supporting agronomic crops due to their high natu ... | 2004 | 15074796 |
| uptake of perchlorate in terrestrial plants. | cucumber (cucumis sativus l.), lettuce (lactuca sativa l.), and soybean (glycine max) were used to determine uptake of the perchlorate anion (100 ppb) from sand. plants were watered with different ratios of hydrosol (a diluted solution of peters all-purpose plant food) to milli-q water (18 momega) to determine if the presence of other nutrients (such as nitrate) influenced perchlorate uptake. perchlorate concentrations in sand and plant tissues were determined weekly. perchlorate uptake was obse ... | 2004 | 15087162 |
| yield loss assessments for cultivars of broccoli, lettuce, and onion exposed to ozone. | the effects of the photochemical oxidant air pollutant ozone (o(3)) on growth and yield of three garden crops, broccoli (brassica oleracea l.), lettuce (lactuca sativa l.), and onion (allium cepa l.) were studied in an open-top chamber experiment conducted in the field in southern california. four cultivars each of leaf lettuce, broccoli, and globe onion were exposed to charcoal-filtered air (cf), non-filtered (nf) air, or nf plus 1.5 times ambient o(3) concentration from 4 weeks after germinati ... | 1990 | 15092228 |
| effect of sludge-processing mode, soil texture and soil ph on metal mobility in undisturbed soil columns under accelerated loading. | the effect of sludge processing (digested dewatered, pelletized, alkaline-stabilized, composted, and incinerated), soil type and initial soil ph on trace metal mobility was examined using undisturbed soil columns. soils tested were hudson silt loam (glossaquic hapludalf) and arkport fine sandy loam (lamellic hapludalf), at initial ph levels of 5 and 7. sludges were applied during four accelerated cropping cycles (215 tons/ha cumulative application for dewatered sludge; equivalent rates for other ... | 2000 | 15092904 |
| linking plant tissue concentrations and soil copper pools in urban contaminated soils. | copper tissue concentrations of radish (raphanus sativa cv. cherry belle), lettuce (lactuca sativa cv. buttercrunch) and ryegrass (lolium perenne cv. barmultra) grown in a greenhouse in urban contaminated soils are compared to total, soluble and free ion copper pools. the tissue concentrations of copper vary between 8.1 and 82.6 mg cu kg(-1) dry tissue and the total soil copper content varies between 32 and 640 mg cu kg(-1) dry soil. the linear regressions with cupric ion activity and total soil ... | 1996 | 15093501 |
| zapoteca formosa: sulfur chemistry and phytotoxicity. | chemical analysis of zapoteca formosa extracts show that a variety of volatile sulfur-containing components, including cyclic polysulfides, are responsible for the distinctive odor of its germinating seeds and young plants. the major sulfur-containing compounds include acetyl djenkolic acid, djenkolic acid, taurine, cystine, benzothiazole, dimethyl disulfide, 2,4-dithiapentane, 2-hydroxyethylmethylsulfide, trithiane, 1,2,4-trithiolane, and 1,2,4,6-tetrathiepane. decreased amounts of djenkolic ac ... | 2004 | 15112733 |
| analgesic and anti-inflammatory activity of lactuca sativa seed extract in rats. | lactuca sativa (lettuce) is a member of compositae family. in folk medicine of iran, the seeds of this plant were used for relieving of inflammation and osteodynia. in this study, anti-nociceptive and anti-inflammatory activities of a crude methanol/petroleum ether (70/30, v/v) extract of the seeds have been evaluated. the extract exhibited a time- and dose-dependent analgesic effect in formalin test and also a dose-dependent anti-inflammatory activity in a carrageenan model of inflammation. the ... | 2004 | 15138019 |
| extractability of metals and ecotoxicity of soils from two old wood impregnation sites in finland. | four metal-contaminated soil samples were classified using physical methods, extracted by selective extraction procedures and analyzed for chemical concentrations. de-ionized water, 0.01 mol/l barium chloride, 1 mol/l ammonium acetate and concentrated nitric acid were used as extraction solutions. ecotoxicity of water extracts and soil samples was analyzed in order to describe the bioavailability of the contaminants. samples from old wood impregnation plants contained high amounts of as, cu, cr ... | 2004 | 15142767 |
| allelopathic potential of citrus junos fruit waste from food processing industry. | the allelopathic potential of citrus junos fruit waste after juice extraction was investigated. aqueous methanol extracts of peel, inside and seeds separated from the fruit waste inhibited the growth of the roots and shoots of alfalfa (medicago sativa l.), cress (lepidium sativum l.), crabgrass (digitaria sanguinalis l.), lettuce (lactuca sativa l.), timothy (pheleum pratense l.), and ryegrass (lolium multiflorum lam.). the inhibitory activity of the peel extract was greatest and followed by tha ... | 2004 | 15158515 |
| phytotoxins from the leaves of ruta graveolens. | bioassay-guided fractionation of the ethyl acetate extract of ruta graveolens (common rue) leaves led to the isolation of the furanocoumarins 5-methoxypsoralen (5-mop), 8-methoxypsoralen (8-mop), and the quinolone alkaloid graveoline as phytotoxic constituents. graveoline and 8-mop substantially inhibited growth of lactuca sativa (lettuce) seedlings and reduced chlorophyll content at 100 microm; this effect was not due to a direct effect on chlorophyll synthesis. radical growth of l. sativa was ... | 2004 | 15161195 |
| photoinduced toxicity of fluoranthene on germination and early development of plant seedling. | the influence of light on phytotoxicity of increased concentration (2, 5, 10 mg/l) of intact fluoranthene (flt) and photomodified fluoranthene (phflt) diluted in experimental solutions was investigated. the germination rate of lettuce (lactuca sativa l.), onion (allium cepa l.) and tomato (lycopersicum esculentum l.) seeds and some parameters of seedlings primary growth of these plant species were used as laboratory indicators of phytotoxicity. among them a length of root and shoot, their dry we ... | 2004 | 15184002 |
| arudonine, an allelopathic steroidal glycoalkaloid from the root bark of solanum arundo mattei. | bioassay-guided fractionation of the methanol extract of the root bark of solanum arundo mattei led to the isolation of a steroidal glycoalkaloid, designated arudonine, which was elucidated to be solasodine o-alpha-l-rhamnopyranosyl-(1-->2)-[beta-d-xylopyranosyl-(1-->3)], [alpha-l-rhamnopyranosyl-(1-->4)]-beta-d-glucopyranoside. this steroidal glycoalkaloid inhibited the growth of lettuce seedlings (lactuca sativa). | 2004 | 15184013 |
| environmental and potential health effects of growing leafy vegetables on soil irrigated using sewage sludge and effluent: a case of zn and cu. | the use of sewage sludge and effluent as a source of nutrients and water for crop production is increasing worldwide. a study was conducted in 2001 at pension farm (near harare) to determine the effect of long term (>30 yrs) application of sewage sludge and effluent on zn and cu accumulation in top soil, uptake of these metals by lettuce (lactuca sativa l.) and mustard rape (brassica juncea l.), and dry matter yield. application of sewage sludge/effluent significantly (p<0.001) increased total z ... | 2004 | 15186034 |
| low molecular weight phenols from the bioactive aqueous fraction of cestrum parqui. | the aqueous fraction of fresh leaves of cestrum parqui and its organic fractions have been assayed for their phytotoxicity on lactuca sativa, lycopersicon esculentum, and allium cepa. the tests showed that the bioactivity was retained in the organic fractions. chromatographic processes led to isolation and characterization of the n-(p-carboxymethylphenyl)-p-hydroxybenzamide together with 17 low molecular weight phenols and 2 flavones. the phytotoxicity tests showed a good activity of these compo ... | 2004 | 15212454 |
| toxicity assessment of contaminated soils from an antitank firing range. | explosives are released into the environment at production and processing facilities, as well as through field use. these compounds may be toxic at relatively low concentrations to a number of ecological receptors. a toxicity assessment was carried out on soils from an explosive-contaminated site at a canadian forces area training center. toxicity studies on soil organisms using endpoints such as microbial processes (potential nitrification activity, dehydrogenase activity, substrate-induced res ... | 2004 | 15223256 |
| do earthworms mobilize fixed zinc from ingested soil? | a wide range of organisms inhabit the soil and has to deal with soil-bound metals. the bioavailable fraction of metals may be estimated explicitly using the isotopic dilution technique. in the present paper, we evaluated the isotopic exchange technique for assessing the bioavailability of soil zn (using 65zn) to earthworms. to validate the technique, the worms were first exposed to various 65zn levels, and errors due to soil entrained in the gut were evaluated. this exposure indicated no effect ... | 2004 | 15224732 |
| assessment of the use of industrial by-products to remediate a copper- and arsenic-contaminated soil. | two water treatment sludges (wts-a, wts-b), two red muds (rm), and red gypsum (rg), all rich in iron oxy-hydroxides, were added to a soil highly polluted with as and cu at 2% (w/w) to reduce metal bioavailability. because the amendments increased soil ph to approximately 6, a lime treatment to the same ph and an unamended treatment were included for comparison. all the amendments had significant positive effects on the soil microbial biomass and growth of ryegrass (lolium multiflorum lam. cv. av ... | 2004 | 15224926 |
| isolation and characterisation of a class of carbohydrate oxidases from higher plants, with a role in active defence. | in a search for novel plant-derived antimicrobial proteins, we screened extracts from salicylic acid (sa)-treated lettuce and sunflower leaves. these extracts displayed very potent antimicrobial activity against a set of phytopathogens. characterisation of these extracts revealed that in both extracts, proteins of approximately 60 kda were responsible for the antimicrobial activity. further characterisation of these proteins and cloning of the respective cdnas revealed close homology to a range ... | 2004 | 15225281 |
| response to ozone in two lettuce varieties on chlorophyll a fluorescence, photosynthetic pigments and lipid peroxidation. | the effect of different o3 concentrations on two lettuce (lactuca sativa l.) varieties (valladolid and morella) was investigated through chlorophyll (chl) a fluorescence parameters, photosynthetic pigments (chl a, b and total carotenoid), lipid peroxidation and crop yield. ozone fumigation caused: a decrease in maximum quantum yield of photosystem ii (psii) photochemistry (fv/fm) in mature leaves, a reduction in the non-cyclic electron flow (phipsii) and a lower capacity to reoxidize the qa pool ... | 2004 | 15246069 |
| distribution and population development of nasonovia ribisnigri (homoptera: aphididae) in iceberg lettuce. | a field study was conducted to determine the distribution and development of aphid nasonovia ribisnigri (mosley) (homoptera: aphididae) populations in iceberg lettuce, lactuca sativa l. 'salinas'. lettuce plants were transplanted and caged individually in the field and inoculated with apterous n. ribisnigri at 0, 1, 2, 3, and 4 wk after transplanting in spring and fall 2002. plants were harvested 15-50 d after inoculations; numbers of alates and apterous n. ribisnigri were counted or estimated o ... | 2004 | 15279267 |
| effects of compost and phosphate on plant arsenic accumulation from soils near pressure-treated wood. | leaching of arsenic (as) from chromated copper arsenate (cca)-treated wood may elevate soil arsenic levels. thus, an environmental concern arises regarding accumulation of as in vegetables grown in these soils. in this study, a greenhouse experiment was conducted to evaluate as accumulation by vegetables from the soils adjacent to the cca-treated utility poles and fences and examine the effects of soil amendments on plant as accumulation. carrot (daucus carota l.) and lettuce (lactuca sativa l.) ... | 2004 | 15325459 |
| stomatal conductance of lettuce grown under or exposed to different light qualities. | the objective of this research was to examine the effects of differences in light spectrum on the stomatal conductance (gs) and dry matter production of lettuce plants grown under a day/night cycle with different spectra, and also the effects on gs of short-term exposure to different spectra. | 2004 | 15347557 |
| isolation and phytotoxicity of apocarotenoids from chenopodium album. | two new compounds (1, 2) and 16 apocarotenoids (3-18) were isolated from the weed chenopodium album. the structures of new apocarotenoids were determined to be (3r,6r,7e,9e,11e)-3-hydroxy-13-apo-alpha-caroten-13-one (1) and (6s,7e,9e,11e)-3-oxo-13-apo-alpha-caroten-13-one (2) by spectroscopic, nmr, and ms analysis. five of the known compounds (5, 6, 13, 15, and 17) were previously reported only as synthetic compounds. effects of these compounds on germination and growth of lactuca sativa (lettuc ... | 2004 | 15387648 |
| multiple genetic processes result in heterogeneous rates of evolution within the major cluster disease resistance genes in lettuce. | resistance gene candidate2 (rgc2) genes belong to a large, highly duplicated family of nucleotide binding site-leucine rich repeat (nbs-lrr) encoding disease resistance genes located at a single locus in lettuce (lactuca sativa). to investigate the genetic events occurring during the evolution of this locus, approximately 1.5- to 2-kb 3' fragments of 126 rgc2 genes from seven genotypes were sequenced from three species of lactuca, and 107 additional rgc2 sequences were obtained from 40 wild acce ... | 2004 | 15494555 |
| effect of different washing procedures on phenolic metabolism of shredded, packaged iceberg lettuce during storage. | different washing treatments applying chlorinated, ozonated, and tap water were examined for their effect on the phenolic metabolism of minimally processed iceberg lettuce (lactuca sativa l.) during storage in consumer-sized bags at 4 degrees c for up to 9 days. to eliminate problems associated with raw material inhomogeneity, processing was conducted on a pilot-plant scale under operating conditions of industrial practice. inherent product heterogeneity caused by diverse lettuce leaf tissues wa ... | 2004 | 15537312 |
| chryseobacterium formosense sp. nov., isolated from the rhizosphere of lactuca sativa l. (garden lettuce). | a yellow-pigmented bacterial strain (cc-h3-2t), isolated from the rhizosphere of lactuca sativa l. (garden lettuce) in taiwan, was investigated using a polyphasic taxonomic approach. the cells were gram-negative, rod-shaped and non-spore-forming. phylogenetic analyses using the 16s rrna gene sequence of the isolate indicated that the organism belongs to the genus chryseobacterium, with the highest sequence similarity to the type strains of chryseobacterium indoltheticum (97.7 %), chryseobacteriu ... | 2005 | 15653912 |
| genetic analysis and mapping of resistance to lettuce dieback: a soilborne disease caused by tombusviruses. | a diverse collection of modern, heirloom and specialty cultivars, plant introduction (pi) accessions, and breeding lines of lettuce were screened for susceptibility to lettuce dieback, which is a disease caused by soilborne viruses of the family tombusviridae. susceptibility was evaluated by visual symptom assessment in fields that had been previously shown to be infested with lettuce necrotic stunt virus. of the 241 genotypes tested in multiple field experiments, 76 remained symptom-free in inf ... | 2005 | 15672259 |
| structure-activity relationships (sar) studies of benzoxazinones, their degradation products and analogues. phytotoxicity on standard target species (sts). | benzoxazinones 2,4-dihydroxy-7-methoxy-(2h)-1,4-benzoxazin-3(4h)-one (dimboa) and 2,4-dihydroxy-(2h)-1,4-benzoxazin-3(4h)-one (diboa) have been considered key compounds for understanding allelopathic phenomena in gramineae crop plants such as corn (zea mays l.), wheat (triticum aestivum l.), and rye (secale cereale l.). the degradation processes in the environment observed for these compounds, in which soil microbes are directly involved, could affect potential allelopathic activity of these pla ... | 2005 | 15686399 |
| cadmium, lead and mercury in fresh and boiled leafy vegetables grown in lagos, nigeria. | vegetables, eaten fresh or boiled, are an important diet relished in many local nigerian cuisines and delicacies. increasing their production has therefore become a prime focus of governments in nigeria. in the process of production, metals capable of impairing the health of consumers are inadvertently picked up. studies were therefore conducted to determine the presence of cadmium (cd), lead (pb) and mercury (hg) in fresh and boiled leafy vegetables grown in farms close (proximal) to highways ( ... | 2004 | 15691197 |
| effects of several applications of digested sewage sludge on soil and plants. | sewage sludge production has significantly increased during the last years in european union (eu) countries, being primarily used for agricultural purposes. in this study, digested sewage sludge was applied to greenhouse soil over a three-year period (2001--2003), with three sludge treatments in the first two years (2, 4, and 6 kg m(-2)) and three more applications using a greater quantity in the last year (6, 8, and 10 kg m(-2)). the effects of sewage sludge application on soil and on a leafy c ... | 2005 | 15717786 |
| isotopic discrimination of zinc in higher plants. | * the extent of isotopic discrimination of transition metals in biological processes is poorly understood but potentially has important applications in plant and biogeochemical studies. * using multicollector inductively coupled plasma (icp) mass spectrometry, we measured isotopic fractionation of zinc (zn) during uptake from nutrient solutions by rice (oryza sativa), lettuce (lactuca sativa) and tomato (lycopersicon esculentum) plants. * for all three species, the roots showed a similar extent ... | 2005 | 15720681 |
| the lettuce infectious yellows virus (liyv)-encoded p26 is associated with plasmalemma deposits within liyv-infected cells. | cytological, immunological, and mutagenesis approaches were used to identify the viral factors associated with the formation of plasmalemma deposits (plds) in whole plants and protoplasts infected by lettuce infectious yellows virus (liyv). transmission electron microscopy and immunogold labeling using polyclonal antibodies to four of the five liyv rna 2-encoded large proteins, capsid protein (cp), minor capsid protein (cpm), hsp70 homolog (hsp70h), and p59, showed specific labeling of liyv viri ... | 2005 | 15721368 |
| the application of bioassays as indicators of petroleum-contaminated soil remediation. | bioremediation has proven successful in numerous applications to petroleum contaminated soils. however, questions remain as to the efficiency of bioremediation in lowering long-term soil toxicity. in the present study, the bioassays spirotox, microtox, ostracodtoxkit f, umu-test with s-9 activation, and plant assays were applied, and compared to evaluate bioremediation processes in heavily petroleum contaminated soils. six higher plant species (secale cereale l., lactuca sativa l., zea mays l., ... | 2005 | 15722101 |
| new fusarium wilts on vegetable crops in italy. | three fusarium wilts recently observed in italy on lettuce (lactuca sativa), wild (diplo taxis spp.) and cultivated (eruca sativa) rocket and lamb's lettuce (valerianella olitoria) emerged as major production problems in lumbardy (north-western italy). aspects of biology and epidemiology of the three diseases and some possibilities of disease management are discussed. | 2004 | 15756819 |
| biological and molecular characterization of lettuce mosaic virus from tehran province in iran. | in this study, lettuce samples having lmv infection symptoms were collected from tehran fields during 2003. samples tested for lmv infection by immuno printing. three positive samples in immuno printing collected and their characteristics were determined. in mechanical inoculation, these isolates produced symptoms on chenopodium quinoa, c. amaranticolor, gomphrena globosa, nicotiana benthamiana, lactuca sativa cv. mantilia and cv. terocadero (which contains the mol1 resistance gene and susceptib ... | 2004 | 15756833 |
| host-associated populations in the lettuce root aphid, pemphigus bursarius (l.). | pemphigus bursarius is a host-alternating aphid in which annual rounds of sexual reproduction on its primary host, populus nigra, are interspersed with parthenogenesis on a range of secondary hosts. evidence was sought for the existence of genetically distinct populations, associated with different secondary hosts, in p. bursarius. microsatellite markers revealed that genetically distinct populations were present on three different secondary host species. microsatellites were also used, in conju ... | 2005 | 15785781 |
| effects of kaurane diterpene derivatives on germination and growth of lactuca sativa seedlings. | kaurenoic and grandiflorenic acid, isolated from wedelia paludosa (asteraceae), some derivatives from these acids (alcohols, esters, amides, lactones, oximes) and other naturally occurring kaurane diterpenes were tested for their action on the growth of radical and shoot of lactuca sativa. gibberellic acid, ga3, a commercially available phytohormone, belonging to the same class of diterpenes, was also tested. some of the tested substances showed a remarkable activity either in the inhibition or ... | 2012 | 15787248 |
| purification and biochemical properties of glutathione s-transferase from lactuca sativa. | a glutathione s-transferase (gst) from lactuca sativa was purified to electrophoretic homogeneity approximately 403-fold with a 9.6% activity yield by deae-sephacel and glutathione (gsh)-sepharose column chromatography. the molecular weight of the enzyme was determined to be approximately 23,000 by sds-polyacrylamide gel electrophoresis and 48,000 by gel chromatography, indicating a homodimeric structure. the activity of the enzyme was significantly inhibited by shexylgsh and s-(2,4-dinitropheny ... | 2005 | 15826502 |
| plant growth inhibition by cis-cinnamoyl glucosides and cis-cinnamic acid. | spiraea thunbergii sieb. contains 1-o-cis-cinnamoyl-beta-d-glucopyranose (cg) and 6-o-(4'-hydroxy-2'-methylene-butyroyl)-1-o-cis-cinnamoyl-beta-d-glucopyranose (bcg) as major plant growth inhibiting constituents. in the present study, we determined the inhibitory activity of cg and bcg on root elongation of germinated seedlings of lettuce (lactuca sativa), pigweed (amaranthus retroflexus), red clover (trifolium pratense), timothy (phleum pratense), and bok choy (brassica rapa var chinensis) in c ... | 2005 | 15898503 |
| evaluation of the role of genes encoding for dehydrin proteins (lea d-11) during drought stress in arbuscular mycorrhizal glycine max and lactuca sativa plants. | in this study, it has been determined whether the arbuscular mycorrhizal (am) symbiosis is able to alter the pattern of dehydrin (lea d-11 group) transcript accumulation under drought stress, and whether such a possible alteration functions in the protection of the host plants against drought. two dehydrin-encoding genes have been cloned from glycine max (gmlea 8 and gmlea 10) and one from lactuca sativa (lslea 1) and they have been analysed for their contribution to the response against drought ... | 2005 | 15911559 |
| [pesticide detection in costarican vegetables based on the inhibition of serum and erythrocytic human cholinesterases]. | a simple and low cost method able to detect the presence of pesticides, organophosphates and carbamates based on the inhibition of serum and erythrocytic cholinesterases, was used in lettuce (lactuca sativa), cilantro (coriandum santivum) and celery (apium graveolens) obtained from the ferias del agricultor from valle central of costa rica. the percentage inhibition of cholinesterases is related to the presence of plaguicide in the vegetable. thirteen percent of the analyzed samples were positiv ... | 2004 | 15969271 |
| accumulation and perchlorate exposure potential of lettuce produced in the lower colorado river region. | the colorado river is contaminated with perchlorate concentrations of 1.5-8 microg/l, an anion linked to thyroid dysfunction. over 90% of the lettuce (lactuca sativa l.) consumed during the winter months in the united states is produced in the lower colorado river region. studies were conducted in this region to survey the potential for lettuce perchlorate accumulation and estimate potential human exposure to perchlorate from lettuce. total uptake of perchlorate in the above-ground plant of iceb ... | 2005 | 15969537 |
| structural analysis of xyloglucans in the primary cell walls of plants in the subclass asteridae. | the structures of xyloglucans from several plants in the subclass asteridae were examined to determine how their structures vary in different taxonomic orders. xyloglucans, solubilized from plant cell walls by a sequential (enzymatic and chemical) extraction procedure, were isolated, and their structures were characterized by nmr spectroscopy and mass spectrometry. all campanulids examined, including lactuca sativa (lettuce, order asterales), tenacetum ptarmiciflorum (dusty miller, order asteral ... | 2005 | 15975566 |
| cadmium phytotoxicity: quantitative sensitivity relationships between classical endpoints and antioxidative enzyme biomarkers. | in this work, cadmium phytotoxicity and quantitative sensitivity relationships between different hierarchical endpoints in plants cultivated in a contaminated soil were studied. thus, germination rate, biomass growth and antioxidative enzyme activity (i.e. superoxide dismutase, peroxidase, catalase and glutathione reductase) in three terrestrial plants (avena sativa l., brassica campestris l. cv. chinensis, lactuca sativa l. cv. hanson) were analyzed. plant growth tests were carried out accordin ... | 2006 | 15982719 |
| ozonated water extends the shelf life of fresh-cut lettuce. | the use of ozonated water as a sanitizer to extend the shelf life of fresh-cut lettuce and the effect on the antioxidant constituents (polyphenols and vitamin c) were investigated. fresh-cut iceberg lettuce (lactuca sativa l.) was washed at 4 degrees c using three different ozonated water dips [10, 20, and 10 activated by ultraviolet c (uv-c) light mg l(-1) min total ozone dose], and the dips were compared with water and chlorine rinses. treated lettuce was packaged in air or active modified atm ... | 2005 | 15998129 |
| systematic silencing of a tobacco nitrate reductase transgene in lettuce (lactuca sativa l.). | a population of 50 independent transgenic lettuces transformed with a nitrate reductase coding sequence under the control of the 35s promoter was studied. none of them showed significantly lower nitrate levels when compared with the untransformed plants, despite the presence of nitrate reductase (nr) activity that derives from the transgene in at least four of the transformants. no repercussion on total nr activity (endogenous+transgenic) was detected in these plants. nevertheless, 28% of the tr ... | 2005 | 16014365 |
| adaptations required for mitochondrial import following mitochondrial to nucleus gene transfer of ribosomal protein s10. | the minimal requirements to support protein import into mitochondria were investigated in the context of the phenomenon of ongoing gene transfer from the mitochondrion to the nucleus in plants. ribosomal protein 10 of the small subunit is encoded in the mitochondrion in soybean and many other angiosperms, whereas in several other species it is nuclear encoded and thus must be imported into the mitochondrial matrix to function. when encoded by the nuclear genome, it has adopted different strategi ... | 2005 | 16040655 |
| three-dimensional organization of higher-plant chloroplast thylakoid membranes revealed by electron tomography. | the light-harvesting and energy-transducing functions of the chloroplast are performed within an intricate lamellar system of membranes, called thylakoid membranes, which are differentiated into granum and stroma lamellar domains. using dual-axis electron microscope tomography, we determined the three-dimensional organization of the chloroplast thylakoid membranes within cryo-immobilized, freeze-substituted lettuce (lactuca sativa) leaves. we found that the grana are built of repeating units tha ... | 2005 | 16055630 |
| uptake and transport of radioactive nickel and cadmium into three vegetables after wet aerial contamination. | knowledge of radionuclide or trace element retention and translocation to plants following an aerial contamination event, for example, sprinkling with contaminated water, is necessary for the evaluation of human exposure through consumption of contaminated vegetables. the fate of 63ni and 109cd in all plant parts of three different vegetables after wet deposition on leaves or on fruits was studied. lettuce (lactuca sativa l.), radish (raphanus sativus l.), and bean (phaseolus vulgaris l.) grown ... | 2005 | 16091602 |
| ecotoxicity of sodium fluoroacetate (compound 1080) to soil organisms. | sodium fluoroacetate (compound 1080) is applied as a vertebrate pesticide in new zealand for control of introduced mammalian pests. despite its widespread use, little is known about the soil ecotoxicity of 1080. therefore, the hazard of 1080 to soil invertebrates, plants, and soil microorganisms was evaluated in a series of controlled laboratory tests. no earthworm (eisenia fetida) mortality was reported with 1080 exposures up to 865 mg/kg soil. the lowest-observable-effect concentration and the ... | 2005 | 16111002 |
| [the dynamic of calcium distribution during megasporegenesis of lettuce (lactuca sativa l.)]. | potassium antimonite was used to deposit calcium in the young ovule of lettuce (lactuca sativa l.) at megasporogenesis stage to study the relationship between calcium and megaspore degeneration. at the megaspore mother cell stage, few calcium granules were formed in the cell (plate i-1, 2). after meiosis of megaspore mother cell and forming an arrayed tetrad in a line (plate i-3), three megaspores degenerated one by one from the micropyle end. in the process of degeneration, the numbers of calci ... | 2005 | 16121008 |
| dioxygen uptake by isolated thylakoids from lettuce (lactuca sativa l.): simultaneous measurements of dioxygen uptake, ph change of the medium and chlorophyll fluorescence parameters. | the setup has been elaborated for the simultaneous measurements of dioxygen uptake, ph changes, and chlorophyll a fluorescence parameters of an isolated thylakoid suspension. using this equipment we have found at least three kinetically distinguishable components in the response of dioxygen uptake and ph increase to light intensity in the range of 0-1600 microe m(-2) s(-1). the ph changes were not observed in the presence of uncouplers (2 microm valinomycin plus 2 microm nigericin) while o(2) up ... | 2005 | 16143918 |
| quantitative trait loci associated with seed and seedling traits in lactuca. | seed and seedling traits related to germination and stand establishment are important in the production of cultivated lettuce (lactuca sativa l.). six seed and seedling traits segregating in a l. sativa cv. salinas x l. serriola recombinant inbred line population consisting of 103 f8 families revealed a total of 17 significant quantitative trait loci (qtl) resulting from three seed production environments. significant qtl were identified for germination in darkness, germination at 25 and 35 degr ... | 2005 | 16177902 |
| bioactive metabolites from the fungus nectria galligena, the main apple canker agent in chile. | the phytopathogenic fungus nectria galligena bres. is the most common canker disease agent of hardwood trees. the terpenoids colletochlorin b, colletorin b, ilicicolin c, e, and f, as well as the phytotoxin alpha,beta-dehydrocurvularin have been isolated from liquid cultures of n. galligena obtained from the xylem of infected apple trees in central chile. ilicicolin c and f and alpha,beta-dehydrocurvularin were active against pseudomonas syringae with ic50 values of 28.5, 28.5, and 14.2 microg/m ... | 2005 | 16190620 |
| arabidopsis thaliana: a new test species for phytotoxic bioassays. | lettuce seeds (lactuca sativa l.) and other crop species are often used in phytotoxic bioassays that are designed to detect allelochemicals. the seeds of these species are considered ideal because they are readily available, germinate rapidly and uniformly, and are routinely used in laboratories around the world. despite their common use, however, the seeds of these species are often not as sensitive or responsive to some phytotoxic chemicals as are the seeds of other species. while searching fo ... | 2005 | 16222813 |
| hydroxamic acid content and toxicity of rye at selected growth stages. | rye (secale cereale l.) is an important cover crop that provides many benefits to cropping systems including weed and pest suppression resulting from allelopathic substances. hydroxamic acids have been identified as allelopathic compounds in rye. this research was conducted to improve the methodology for quantifying hydroxamic acids and to determine the relationship between hydroxamic acid content and phytotoxicity of extracts of rye root and shoot tissue harvested at selected growth stages. det ... | 2005 | 16222814 |
| [the dynamics of calcium distribution in stigma and style of lettuce (lactuca sativa l.) before and after pollination]. | potassium antimonite was used to deposit calcium in the stigma and style of lettuce (lactuca sativa l.) before and after pollination. the stigma of lettuce is two splits. abundant calcium granules are displayed in the wall of papillae on the receptive surface of stigma before and after pollination, which may facilitate pollen germination. however, a few calcium granules in the wall of epidermis cell on no-receptive surface. calcium distribution in style presents a gradient in transmitting tissue ... | 2005 | 16231693 |
| stable plastid transformation in lettuce (lactuca sativa l.). | although plastid transformation in higher plants was first demonstrated in the early 1990s it is only recently that the technology is being extended to a broader range of species. to date, the production of fertile transplastomic plants has been reported for tobacco, tomato, petunia, soybean, cotton and lesquerella fendleri (brassicaceae). in this study we demonstrate a polyethylene glycol-mediated plastid transformation system for lettuce that generates fertile, homoplasmic, plastid-transformed ... | 2005 | 16240172 |
| new type of dual-channel pam chlorophyll fluorometer for highly sensitive water toxicity biotests. | a new type of dual-channel pam chlorophyll fluorometer has been developed, which is specialised in the detection of extremely small differences in photosynthetic activity in algae or thylakoids suspensions. in conjunction with standardised algae cultures or isolated thylakoids, the new device provides an ultrasensitive biotest system for detection of toxic substances in water samples. in this report, major features of the new device are outlined and examples of its performance are presented usin ... | 2002 | 16245142 |
| cadmium, copper, nickel, and zinc availability in a biosolids-amended piedmont soil years after application. | concerns over the possible increase in phytoavailability of biosolids-applied trace metals to plants have been raised based on the assumption that decomposition of applied organic matter would increase phytoavailability. the objectives of this study were to assess the effect of time on chemical extractability and concentration of cd, cu, ni, and zn in plants on plots established by a single application of biosolids with high trace metals content in 1984. biosolids were applied to 1.5 by 2.3 m co ... | 2017 | 16275727 |
| phytotoxic, clastogenic and bioaccumulation effects of the environmental endocrine disruptor bisphenol a in various crops grown hydroponically. | the effects of the endocrine disruptor bisphenol a (bpa) at concentrations of 10 and 50 mg l(-1) were evaluated on the germination and morphology, micronuclei (mn) content in root tip cells and bpa bioaccumulation of hydroponic seedlings of broad bean (vicia faba l.), tomato (lycopersicon esculentum mill.), durum wheat (triticum durum desf.) and lettuce (lactuca sativa l.) after 6 and 21 days of growth. in general, bpa at any dose used did not inhibit germination and early growth (6 days) of see ... | 2006 | 16292569 |
| how does glutamine synthetase activity determine plant tolerance to ammonium? | the wide range of plant responses to ammonium nutrition can be used to study the way ammonium interferes with plant metabolism and to assess some characteristics related with ammonium tolerance by plants. in this work we investigated the hypothesis of plant tolerance to ammonium being related with the plants' capacity to maintain high levels of inorganic nitrogen assimilation in the roots. plants of several species (spinacia oleracea l., lycopersicon esculentum l., lactuca sativa l., pisum sativ ... | 2006 | 16292661 |
| humic substances can modulate the allelopathic potential of caffeic, ferulic, and salicylic acids for seedlings of lettuce (lactuca sativa l.) and tomato (lycopersicon esculentum mill.). | the capacity of a leonardite humic acid (lha), a soil humic acid (sha), and a soil fulvic acid (sfa) in modulating the allelopathic potential of caffeic acid (ca), ferulic acid (fa), and salicylic acid (sa) on seedlings of lettuce (lactuca sativa l.) and tomato (lycopersicon esculentum mill.) was investigated. lettuce showed a sensitivity greater than that of tomato to ca, fa, and sa phytotoxicity, which was significantly reduced or even suppressed in the presence of sha or sfa, especially at th ... | 2005 | 16302757 |
| toxicity identification evaluation of five metals performed with two organisms (daphnia magna and lactuca sativa). | when trying to identify the main toxicants in effluents, natural waters, sediments, soil leachates, and leachates from products, the toxicity identification evaluation (tie) procedure has proven useful. to enhance the use of this procedure for soil, sewage, and sediment samples, we wanted to evaluate this tie procedure, regarding metal toxicity, for the 96-h root elongation test performed with lactuca sativa (lettuce) seeds. we also wanted to evaluate the effect of tie treatment on the toxicity ... | 2006 | 16328613 |
| a note on the measurement of genetic diversity within genebank accessions of lettuce (lactuca sativa l.) using aflp markers. | this paper discusses a statistical approach for measuring genetic diversity within genebank accessions of a self-fertilising species. this approach is applied to lettuce (lactuca sativa l.), using aflp marker data on a set of 1,390 accessions, representing six different lettuce types. knowledge of the within-accession genetic diversity is important for decisions about the way accessions have to be maintained by genebanks. it is argued that if the within-accession diversity is small, as can be ex ... | 2006 | 16333613 |
| a detailed linkage map of lettuce based on ssap, aflp and nbs markers. | molecular markers based upon a novel lettuce ltr retrotransposon and the nucleotide binding site-leucine-rich repeat (nbs-lrr) family of disease resistance-associated genes have been combined with aflp markers to generate a 458 locus genetic linkage map for lettuce. a total of 187 retrotransposon-specific ssap markers, 29 nbs-lrr markers and 242 aflp markers were mapped in an f(2) population, derived from an interspecific cross between a lactuca sativa cultivar commonly used in europe and a wild ... | 2006 | 16341837 |
| [the character of calcium distribution in developing anther of lettuce (lactuca sativa l.)]. | potassium antimonite was used to locate calcium in the anther of lettuce (lactuca sativa l) during its development. at the early stage of anther development there were few calcium granules in microspore mother cells and the cells of anther wall. after meiosis of microspore mother cells, calcium granules first appeared in the tapetal cells in which some small secretive vacuoles containing many calcium granules were formed and secreted into locule. then, the tapetal cells began to degenerate. at t ... | 2005 | 16363117 |
| biochemical study of leaf browning in minimally processed leaves of lettuce (lactuca sativa l. var. acephala). | a series of biochemical parameters, including the concentration of total ascorbic acid (asa(tot)) and the activities of phenylalanine ammonia lyase (pal), polyphenol oxidase (ppo), and peroxidases (pods), was investigated during cold storage (72 h at 4 degrees c in the dark) in fresh-cut (minimally processed) leaves of two lettuce (lactuca sativa l. var. acephala) cultivars differing in the susceptibility to tissue browning: green salade bowl (gsb), susceptible, and red salade bowl (rsb), resist ... | 2005 | 16366683 |
| phytotoxicity and accumulation of anthracene applied to the foliage and sandy substrate in lettuce and radish plants. | the effects of anthracene (ant) on the growth of two species of vegetable plants (lactuca sativa l. and raphanus sativus l.), which play an important role in the human diet, were studied. ant was applied to the leaves of these plants by foliar deposition, in aerosol form, and to the sandy substrate in which the plants were grown in a greenhouse. it was found that ant affected plant biomass, especially root biomass, in the case of both foliar and soil application. under conditions of induced chem ... | 2007 | 16368141 |
| isolation and characterization of new lignans from the leaves of cestrum parqui. | three new compounds, a sesquilignans, an oxyneolignan and a norlignan, have been isolated from the aqueous fraction of cestrum parqui. all of the compounds have been identified on the basis of their spectroscopic properties and tested on the species lactuca sativa and lycopersicon esculentum to evaluate their phytotoxic activity. | 2006 | 16401562 |
| phytotoxic components produced by pathogenic fusarium against morning glory. | a pathogenic isolate of fusarium, f. oxysporum f. sp. batatas o-17 (pf), causes wilt disease in leaf etiolation in sweet potato (ipomoea batatas) and morning glory (ipomoea tricolor). extracts from pf cultures were screened for phytotoxic components using a growth inhibition assay with morning glory seedlings. the extracts were fractionated using differential solvent extraction and two active compounds, ergosterol and fusalanipyrone, were isolated from the less-polar fraction. growth inhibition ... | 2013 | 16402546 |
| terpenoids and phenol derivatives from malva silvestris. | a sesquiterpene and a tetrahydroxylated acyclic diterpene as well as two known monoterpenes, 6 c(13)nor-terpenes and 11 aromatic compounds were isolated from the water extract of malva silvestris. the structures of the compounds were determined by spectroscopic nmr and ms analysis. effects of these compounds on germination and growth of dicotyledon lactuca sativa l. (lettuce) were studied in the 10(-4)-10(-7)m concentration range. | 2006 | 16403542 |