Showing papers in "Phyton-international Journal of Experimental Botany in 2016"
TL;DR: The resistance profile of isolates of S. agalactiae was independent of host origin and typical of the species, ensuring the existence of phenotypic variability amongisolates from the same host.
Abstract: Plants contain numerous constituents and are valuablesources of new biologically active molecules. Avocado (Perseaamericana Mill.) is cultivated and used as food in most tropical andsubtropical countries. Its high nutritional value and biological activities,as antioxidant, antimicrobial and analgesic properties, have beenthoroughly investigated. Interest in plant extracts with antimicrobialproperties has increased as a result of the indiscriminate use ofantibiotics, leading to the emergence of resistant bacterial strains.Among bacterial species with clinical importance to multiple hosts,Streptococcus agalactiae is outstanding, as it can cause infections especiallyin humans, fish and cattle. The current study aimed to evaluatethe antimicrobial activity of two extracts (ethanol and dichloromethane)from avocado seeds, ‘Margarida’ variety, against isolates of S.agalactiae. Extracts were diluted in ethanol / water (1:1) at a concentrationof 100 mg/mL. Antimicrobial activity was tested by thedisk diffusion method (antibiogram) against isolates of S. agalactiaeof human and fish origin.The ethanol extract showed antimicrobialactivity only for some isolates of S. agalactiae of human origin. Thedichloromethane extract showed activity against all isolates of S. agalactiaeof both origins. A comparison of the results obtained with dichloromethaneextract from isolates of S. agalactiae of human or fishorigin demonstrated the existence of phenotypic variability amongisolates from the same host. However, when comparing measurementsobtained in each of the groups, they were statistically similar,showing a lack of interpopulation variability. Thus, it can be verifiedthat the resistance profile of isolates of S. agalactiae was independentof host origin and typical of the species.
19 citations
TL;DR: The application of MBX to tomato plants at transplanting time provided good protection against M. incognita under greenhouse conditions and the efficiency of the microencapsulation was verified by the difference between the initial and final concentrations of protein release.
Abstract: Antagonistic bacteria used as biological control agentmay loss effectiveness at the field due to environmental factors suchas UV radiation, dryness and high temperature. An inexpensive alternativeto protect antagonistic bacteria against such factors is theuse of microencapsulating agents. In this work, the effect of microencapsulationof Bacillus subtilis with commercial gums on theirantagonistic capacity against Meloidogyne incognita was evaluated.The efficiency of the microencapsulation was verified by the differencebetween the initial and final concentrations of protein release.The effectiveness as antagonist was evaluated against M. incognita intomato under greenhouse conditions. The microcapsules based oncarboxymethylcellulose (MBC) and xanthan (MBX) were morphologicallydifferent. The MBX showed a higher bacterial release efficiency(90.2%) compared to that of MBC (76.6%). Plants inoculatedwith MBX showed a significant decrease in galls and M. incognitaeggs in comparison to control plants, but this decrease did not occuron those inoculated with non-microencapsulated B. subtilis. The applicationof MBX to tomato plants at transplanting time providedgood protection against M. incognita under greenhouse conditions.
10 citations
TL;DR: In this paper, the authors examined the effect of willow trees (Salix fragilis L.) invasion of grassland riparian environments in the Argentinean Pampas on the runoff reduction, sedimentation and glyphosate retention in the riparian vegetationstrip (RVS).
Abstract: In this study, we examined some aspects regarding theeffect of willow trees (Salix fragilis L.) invasion of grassland riparianenvironments in the Argentinean Pampas on the runoff reduction,sedimentation and glyphosate retention in the riparian vegetationstrip (RVS). To assess the influence of willows on the filtering mechanisms,we performed runoff simulation experiments in plots of 1.5 x2.5 m, in coastal environments characterized by the presence of willowsor the lack of trees. Despite the short length of the experimentalplots, the retention of glyphosate in the controls, with no trees, washigher and reached almost 74%. Nevertheless, sediment retentiondid not differ significantly between the tree areas and the grassycontrols. The runoff reduction in plots with willows was of 63%.The presence of willow trees significantly altered the measured biophysicalproperties, such as soil moisture and aboveground biomass,compared to areas without trees. Analysis of partial correlations forenvironments with and without trees showed that the reduction inrunoff volume increased significantly with the soil sand content andthe groundwater table depth, while it decreased with bulk density,soil moisture and the riparian slope. Sediment retention increasedsignificantly with aboveground biomass, litter and root biomass;and decreased with the riparian slope. In turn, glyphosate retentionincreased significantly with sediment retention and decreased withthe riparian slope and litter biomass. The mechanisms involving theeffect of willows could not be well explained. Due to the increasedintensification of agriculture, treeless RVS are important to reduceglyphosate concentration in streams and their sinks. Nevertheless,the presence of trees is also important in the context of agroecosystemsand agricultural landscapes, as they contribute to reduce therunoff flow.
8 citations
TL;DR: In this article, the authors reviewed the current risk of extinction of all African cycads species using the IUCN (International Union of Conservation of Nature) red list of threatened species 2014 version.
Abstract: Over a long period of time, cycads endemic to Africa have been facing high risk of extinction. Several conservation efforts have been made to reduce the risk of losing these highly endangered species. In this study we review the current risk of extinction of allAfrican cycads species. We calculated the percentages of each category of species found in African cycads using the IUCN (International Union of Conservation of Nature) red list of threatened species 2014 version. We compared our result with that of Donaldson (2003) on percentages of different categories of IUCN for cycads in Africa which was carried out a decade ago. We also calculated the percentage of population trend in African cycads. When comparing these results, we discovered that over one decade there was no improvement in cycads conservation despite several conservation efforts that were made during this period. The results of the populationtrend also showed that the majority of African cycads are experiencing population decreases. These results highlight that the risk of extinction of African cycads is still very high and much conservation effort is still required to properly tackle ecological factors pushing these endangered species to extinction.
8 citations
TL;DR: Selenium (Se) content in Azolla plants increased significantly withincreasing Se concentrations in the culture media up to 5 ppm, indicating thatAzolla plants were a good accumulator for Se, and effects change from beneficial totoxic, as reflected in the metabolism and growth of the plants.
Abstract: Plants of Azolla caroliniana were treated with differentselenium concentrations (0, 1, 2, 5, 7, 10 ppm) for seven days.Selenium (Se) content in Azolla plants increased significantly withincreasing Se concentrations in the culture media up to 5 ppm. Thisindicated that Azolla plants were a good accumulator for Se. Seleniumaccumulation determined changes in Azolla biomass, doublingtime and relative growth rates. Treatment of Azolla plants with lowconcentrations of Se (1 ppm) resulted in a significant increase in biomass.This was accompanied by a reduction in hydrogen peroxide andmalondialdehyde (MDA) contents; the decrease percentages were78% and 60%, respectively at 1 ppm Se in comparison with the control.At higher Se concentrations (>5 ppm), there was a significantincrease in H2O2 and MDA contents, these increases were 3.2- and2.8-fold at 10 ppm Se in comparison to controls, respectively. Comparedto that in controls, total ascorbate as well as total glutathionecontents, were significantly increased. The activity of the GR enzymewas significantly increased in Azolla plants with addition of differentconcentrations of Se. The increase was 2.2- and 3.4-fold at 2 and7 ppm Se, respectively. The addition of high concentrations of Se(>5 ppm) to the growth media resulted in a significant increase inthe GSH-PX and APX activities in Azolla plants. Thus, addition ofSe affects Azolla plants, and these effects change from beneficial totoxic, as reflected in the metabolism and growth of the plants.
7 citations
TL;DR: Morphology analysis of guava was performed taking data from seventy nine individuals out of thirtysix orchards, while RAPD was performed on a subset of twentysix individuals, and combined data of RAPD and morphology showed similarity greater than 80%.
Abstract: Guava fruit produced in Calvillo, Aguascalientes(Mexico) is considered to be of the best quality in this country. Nevertheless,growers from this place empirically know that there is anoticeable variation among individual trees within the same orchard,and variation among individuals from different orchards. In orderto have a clear evidence of this, morphology analysis of guava wasperformed taking data from seventy nine individuals out of thirtysix orchards, while RAPD was performed on a subset of twentysix individuals. Similarity was found for morphology data rangingfrom 87-100%, while similarity from RAPD data ranged from 30-100%. Combined data of RAPD and morphology showed similaritygreater than 80%. Clades from combined data sorted genotypes intoclearly defined groups according to fruit shapes and banding pattern.These markers could be used as helper tools for breeding programsfor guava genotypes of Mexico. Furthermore, these may help on theclaims from growers when checking origin authenticity if packedguava from somewhere else is labeled as guava from Calvillo.
6 citations
TL;DR: During the entire rainy season, thenet input (kg/hm2) of nutrients in the Pinus densata forest was Na>Si>Ca>Mg>Zn>Fe>S>Cu>P>Mn>N, and the net input of N was negative.
Abstract: Precipitation, throughfall and stemflow were monitoredand collected through the rainy season on a natural forest ecosystemof Pinus densata in the Gongbu Nature Reserve in Tibet. Theconcentrations of N, P, K, Na, Ca, Mg, Si, Mn, Fe, S, Zn and Cuwere analyzed in the precipitation, throughfall and stemflow waters,Thereafter, and according to the amount of water of precipitation,throughfall and stemflow, the net input was calculated for each nutrientin the forest. The results showed that: (1) During the entirerainy season, the average concentration of different nutrients in theprecipitation of the Pinus densata forest was ranked in the followingorder: N>K>Na>Ca>Mg>Si>P>Mn>Fe>S>Zn>Cu. The concentrationof N 29.6145 mg/L, and that of Cu was only 0.1017 mg/L.(2) The average concentration of these nutrients in throughfall followedthe order: N>Na>Ca>K>Mg>Si>P>Mn>Fe>S>Zn>Cu. Thehighest concentration was 11.2843 mg/L for N, and the lowest wasonly 0.0937 mg/L for Cu; the difference between the two was 120.4times. (3) The order of N>K>Ca>Na>Mg>Zn>P>Si>Mn>Fe>Cu>Swas found for the nutrient concentration in stemflow. The concentrationof N (20.5096 mg/L) was 105.2 times higher than that ofthe lowest nutrient (S: 0.1949 mg/L). (4) As a whole, every nutrientwas quite different on average for the stemflow, throughfall andprecipitation. The concentration of Na, Ca, Mg and Zn followed stemflow>throughfall>precipitation. During the entire rainy season, thenet input (kg/hm2) of nutrients in the Pinus densata forest was Na>Si>Ca>Mg>K>Zn>Fe>S>Cu>P>Mn>N, and the net input of N wasnegative.
6 citations
TL;DR: Fluorescence imaging was used to indicate that Cd2+ waslocalized in cytoplasm in the epidermis of the basal parts of root and vascular tissues after Cd treatment, and autophagy was active.
Abstract: Allium cepa var. agrogarum L. seedlings are sensitive toCd stress. We used fluorescence imaging to indicate that Cd2+ waslocalized in cytoplasm in the epidermis of the basal parts of rootand vascular tissues after Cd treatment. The nucleoli and the cellwalls were the first storage sites of Cd2+. When Cd exposure wasprolonged, severe irregularly-shaped nuclei were induced. We usedsilver nitrate staining to analyze the effects of different concentrations(1–300 μM) of cadmium chloride on chromosome, nucleolus andnucleolus organizer regions (NORs) in root tip cells. Cd2+ inducedc-mitosis, chromosome bridges, chromosome stickiness and micronuclei.More than 100 μM Cd2+ could induce nucleolar materialextruded from the nucleus into the cytoplasm. The abnormal phenomenaof the nucleolar cycle during mitosis induced by Cd stresscontained the nucleoli, which did not exist normally and meltedgradually. More silver-stained particles were seen on chromosomes atthe metaphase; more silver-stained particulates were localized on thesticky chromosomes, chromosome bridges and cytoplasm. Nucleolarreconstruction was inhibited at the telophase, NORs were localizedon chromosomes of c-mitosis. The LysoTracker red stained resultsindicated that autophagy was active. The number of autolysosomesin roots of Cd-treated plants was more than that on control plant.
5 citations
TL;DR: In this paper, the conditions for extracting polysaccharides from sweet corncobs (SCP) were studied, and four parameters (ratio of waterto raw material, compound enzyme concentration, temperature ofenzymolysis and duration of enzymatic activity) were optimized using response surface methodology (RSM).
Abstract: The conditions for extracting polysaccharides fromsweet corncobs (SCP) were studied. Four parameters (ratio of waterto raw material, compound enzyme concentration, temperature ofenzymolysis and duration of enzymolysis) affecting the extraction ofSCP were optimized using response surface methodology (RSM).Under the optimized conditions, the yield of SCP was 17.58 %. SCPhad inhibitory effects on α-amylase and α-glucosidase activities, andthe IC50 was 20.91 mg/mL and 12.47 mg/mL. SCP may thereforehave prevention and treatment effects on postprandial hyperglycemiain diabetes. The inhibitory effects of SCP were improved afterfractionation, and were strongest in the fraction SCP80. The fractionof SCP belong to β-glycosides heteropolysaccharides with a pyrangroup.
5 citations
TL;DR: Ambas especies carecen de mecanismos de dormicion bajo lascondiciones experimentales, lo que sumado al hecho de that crecen enambientes disturbados y son endemicas, las hace excelentes candidataspara trabajos de restauracion ecologica.
Abstract: Asteraceae es la familia de plantas vasculares mas diversaa nivel mundial y la mas numerosa de Argentina, incluyendo26% de especies endemicas. Muchas asteraceas son pioneras, facilitandoel establecimiento de otras especies, y varias se han utilizadoen restauracion. Dada la importancia de conocer las caracteristicas delas semillas y de la germinacion para su utilizacion en proyectos derestauracion, se indaga sobre aspectos fisiologicos basicos de la germinacionde Gutierrezia solbrigii Cabrera y Senecio subulatus D. Donex Hook. & Arn. var. erectus Hook. & Arn., arbustos endemicos deArgentina distribuidos en zonas aridas de Patagonia. El material provinode la Reserva Provincial Auca Mahuida (NE de Neuquen), enel Distrito Fitogeografico de Payunia (ecotono Monte-Estepa). Alli,la actividad hidrocarburifera ha generado areas degradadas dondeestas especies podrian utilizarse para revegetacion. Se evaluo el porcentajede germinacion (G), el tiempo medio de germinacion (TMG)y los dias hasta el inicio de la germinacion (IG) de un control y detratamientos pre-germinativos: estratificacion humeda fria de 15 dias(EHF15), escarificacion mecanica con lija (EML) para las dos especies,y estratificacion humeda fria de 30 dias (EHF30) y escarificacionmecanica con bisturi (EMB) para S. subulatus. Para los tratamientos losporcentajes de germinacion fueron elevados (G. solbrigii: 77% EHF15,81% EML; S. subulatus: 88% EHF15, 89% EHF30, 84% EML, 94%EMB) y similares a los controles (G. solbrigii: 82%,S. subulatus: 88%).Solo se registraron diferencias entre EMB y EML para S. subulatus: Ge IG fueron mayores en EMB y el TGM menor, posiblemente porquecon EML las semillas no son escarificadas uniformemente. En conclusion,ambas especies carecen de mecanismos de dormicion bajo lascondiciones experimentales, lo que sumado al hecho de que crecen enambientes disturbados y son endemicas, las hace excelentes candidataspara trabajos de restauracion ecologica.
4 citations
TL;DR: This is the first report of occurrence of the TuMV virus on kale in Ordu, Turkey, and suggested that the virus might be an important threat for the kalecrops in the province.
Abstract: Brassica oleracea var. acephala L. (kale) is widely grownin the Black Sea Region of Turkey. Kale growing has not been commonin the other regions of Turkey. A number of diseases can seriouslyaffect Brassica crop production. Field surveys were done todetermine the occurrence of viruses in kale-growing areas in Ordu in2013-2014. Leaf samples were collected from kale plants and testedfor the presence of Turnip mosaic virus (TuMV), Cauliflower mosaicvirus (CaMV), Turnip yellow mosaic virus (TYMV), and Cucumbermosaic virus (CMV) by DAS-ELISA and bioassays. Result of serologicaland biological tests showed that 7.7% of these samples wereinfected with TuMV. However, CaMV, CMV, and TYMV were notdetected in any of the tested kale plants. The occurrence of TuMVsuggested that the virus might be an important threat for the kalecrops in the province. This is the first report of occurrence of the viruson kale in Ordu, Turkey.
TL;DR: A general model for N-P fertilization in the area that also quantified diammonium phosphate effect and its interactions with N-urea, applied at sowing or tillering, as compared with triple superphosphate (TSP) was developed.
Abstract: In the southwest of Buenos Aires Province (Argentina),nitrogen (N) and phosphorus (P) deficiencies are importantwheat yield limiting factors. There is an information gap regardingdifferences between single element and binary N-P sources. The objectiveof this paper was to develop a general model for N-P fertilizationin the area that also quantified diammonium phosphate (DAP)effect and its interactions with N-urea, applied at sowing or tillering,as compared with triple superphosphate (TSP). Between 1984 and1985, 13 experiments were carried out in farmer’s fields N. Withthe yield data for each experiment, a yield function was fitted whichincluded terms for single effects of urea (0, 30 and 60 kg N/ha) and80 kg/ha of either DAP or TSP. Yield response variables were derivedfrom the equation. Measured site variables were pH, organicmatter (OM) and soil extractable phosphorus (Bray-P). Categoricalvariables of soil texture, wheat cycle and previous soil use were alsoincluded. Regressions were developed between dependent and sitevariables. The set of equations constituted a model that explained 31to 75% of the variation in the yield response variables. Agronomicefficiency of N-urea for soils with agricultural use was around 12 kgwheat/kg N for both times of application. Response to DAP andTSP was related to Bray-P and soil texture. The bridging experimentsbetween these two P sources estimated a superiority of DAPof around 180 and 90 kg wheat/ 80 kg of fertilizer on coarse and mediumtextured soils, respectively. Although it is physically impossibleto isolate N-P effects in a binary fertilizer, this may be attributed toadditional N. The data also suggested synergism between DAP andurea applied at sowing after their interaction in the soil.
TL;DR: La hilera de frutales intercalados genero un microambiente particular y complemento la productividaddel agrosistema, debido a que se asocio de manera significativa y positiva with las asociaciones triples mas eficientes y of mayor eficienciaproductiva.
Abstract: El agrosistema mesoamericano ‘milpa’ es la asociacionde maiz, frijol (Phaseolus sp.) y calabaza (Cucurbita sp.) en el mismo espacioy tiempo. Dicho sistema se caracteriza por la produccion de unagran diversidad de especies en pequenas extensiones, y su uso tiende adecrecer por efecto de introducciones tecnologicas de monocultivos.En este trabajo se evaluo el rendimiento y eficiencia productiva de laasociacion de maiz, frijol y calabaza intercalada con frutales en dos localidadesde Puebla, Mexico, a traves de 32 tratamientos agrupados entres agrosistemas: asociaciones triples maiz-frijol-calabaza intercaladascon frutales, asociaciones dobles maiz-frijol sin frutales, y monocultivoscon y sin frutales intercalados, distribuidos en bloques al azar con tresrepeticiones. En el analisis de varianza se detectaron diferencias significativas(P 2,0). La hilera de frutales intercaladosgenero un microambiente particular y complemento la productividaddel agrosistema, debido a que se asocio de manera significativa y positiva(r>0,3) con las asociaciones triples mas eficientes y de mayor eficienciaproductiva, tanto en la localidad de San Andres Calpan con manzanacomo en San Lorenzo Chiautzingo con durazno.
TL;DR: The results showed that adding Si increased Cd tolerance in T. dolabrata, but that the mechanism was specifical, suggesting that Cd-chelation combined with Si-induced phenolics were involved in Cd detoxification.
Abstract: We conducted pot experiments on the cypress Thujopsisdolabrata (Linn. f.) Sieb. et Zucc. in order to study the interactionof silicon (Si) and root exudates on cadmium (Cd) bioavailabilityin the rhizosphere,. Each variety was planted with 100 mg/kg Cdand/or 400 mg/kg Si for 210 days. The results showed that addingSi increased Cd tolerance in T. dolabrata, but that the mechanismwas specifical. In T. dolabrata, Si did not prevent Cd translocationfrom roots to shoots, and it significantly enhanced Cd accumulationwithout inhibiting growth. Moreover, Si mobilized Cd from therhizospheric soil by stimulating phenolic exudation from the roots,suggesting that Cd-chelation combined with Si-induced phenolicswere involved in Cd detoxification.
TL;DR: In this article, the interrelation between hydrochemistry and hydrodinamics was analyzed in the basin of El Divisorio stream in order to gain undestanding in the magnitude, distribution of toxicions (As, F) and behaviour in the discharge of main nutrients (P,N) contributing to the eutrofication of Paso de las Piedras Dam.
Abstract: The interrelation between hydrochemistry and hydrodinamicswas analyzed in the basin of El Divisorio stream. Thiswas to gain undestanding in the magnitude, distribution of toxicions (As, F) and behaviour in the discharge of main nutrients (P,N) contributing to the eutrofication of Paso de las Piedras Dam.During two years, 47 sites were sampled determining several parameters:geographical position for each sampling point, phreaticlevel depth, and As, F, PO4 and N-NO3 concentrations. Repeatedmeasures, Fisher test, correlation and regression analysis were appliedto all variables. Highly significant space and time differences(P<0.01) with increments of 0.3 m were detected for isohypses. Atevery site, differences with a variable degree of significance wererecognized for chemical parameters (As, F, PO4 and N-NO3). Hydrodinamicsbehaves mainly in accord with the seasonal rainfallcontribution; run off affects some of the hydrochemical parametersgiving rise to a variability that influences water quality. N-NO3 andPO4 concentrations are the main factors that cause eutroficationexpressed through algae bloom episodes and deterioration of storedwater quality. P is the critical element and in the dry periods thehighest contribution is through groundwater flux and to a lesserextent by the continuous discharge of surface water. In the periodof greater runoff, these elements incorporated to the sedimentarycharge as a result of soil erosion, and coming by fertilizers and pesticidesare transported in suspension towards the reservoir.
TL;DR: Having higher genetic diversity in restored provenancesthan in the provenance that originated the seeds can be favorable asthe conditions in the site change in the future due to the expected increase in the urban heat island effect as the nearby city expands.
Abstract: To quantify the effect on genetic diversity of restoringtree populations in an area under the influence of an urban heatisland, we evaluated the genetic diversity of 72 Ceiba aesculifoliaindividuals, from a restoration experiment established from 2170to 2260 m a.s.l. Reintroduced individuals were compared with theprovenance from which the seeds were obtained, and two externalprovenances, for a total of 123 individuals. Samples were analyzedwith three AFLP primer combinations. Polymorphisms of 38.4 to62.5% were obtained. Genetic diversity estimated with the Simpsonindex ranged from 0.14 to 0.2. The provenances in the restorationsite had higher diversity than the provenance that originated theseeds. Groups formed with provenances with similar genetic diversity(no statistical differences) also shared similar Bayesian mixtureproportions. Having higher genetic diversity in restored provenancesthan in the provenance that originated the seeds can be favorable asthe conditions in the site change in the future due to the expectedincrease in the urban heat island effect as the nearby city expands.
TL;DR: Esta investigacioncontribuye a enriquecer el conocimiento sobre the actividad biologica de hongos anamorficos nativos de los cenotes de Yucatan y su potencial usoen aplicaciones biotecnologicas en the agricultura.
Abstract: En la actualidad, es altamente necesario encontrar nuevosy mas seguros productos agroquimicos. En este sentido, los micromicetosson una fuente importante de productos naturales los cuales puedenser usados en el control de enfermedades vegetales. Con el objetivo decontribuir a la busqueda de productos con aplicaciones antimicrobianas,un total de 49 cepas fungicas fueron aisladas de dos cenotes de lapeninsula de Yucatan. Estas cepas se cultivaron en arroz fermentado, seobtuvieron sus respectivos extractos organicos macerados en acetato deetilo (EAE) y metanol (EM) y se evaluaron contra cinco fitopatogenosde importancia agricola. Estos patogenos incluyeron a los hongos Alternariachrysanthemi, Colletotrichum gloeosporioides, Mycosphaerella fijiensisy las bacterias Erwinia carotovora y Xanthomonas campestris, utilizandoel bioensayo en microdilucion. El 69% de los extractos fungicos evaluadosmostraron actividad antifungica y/o antibacteriana contra al menosuno de los patogenos evaluados a concentraciones de 2000 y 200 μg/mL, respectivamente. Las cepas de Penicillium sp. OSE-61, Fusariumsp. OH2-30, Hypocrea lixii OSN-37 y Rhizoctonia solani OSE-73mostraron actividad contra al menos tres de los fitopatogenos en estudio.Los extractos de EAE mas promisorios fueron particionados obteniendotres fracciones de baja (A), media (B) polaridad y un precipitado (C),los cuales fueron evaluados contra los patogenos estudiados. La fraccionA de Fusarium KS-15 fue la mas efectiva presentando la mas baja ConcentracionMinima Inhibitoria (MIC ≤25 μg/mL) y efecto bactericidacontra X. campestris. La fraccion B de Penicillium sp. OSE-61 contraA. chrysanthemi fue relativamente mayor (MIC ≤500 μg/mL); mientrasla fraccion B de H. lixii OSN-37 mostro efecto antifungico contra C.gloeosporioides y M. fijiensis (MIC = 1000 μg/mL). Esta investigacioncontribuye a enriquecer el conocimiento sobre la actividad biologica dehongos anamorficos nativos de los cenotes de Yucatan y su potencial usoen aplicaciones biotecnologicas en la agricultura.
TL;DR: This is the first report of Phytophthora cactorum onlemon verbena in Iran, and based on morphological features, it is likely that this plant has been infected with this fungus before.
Abstract: Lemon verbena (Lippia citriodora) is a medicinal plantfrom the Verbenacea family. Its plantation and medicinal use in Iranhas risen greatly in recent years. Crown and root rot symptoms wereobserved on this plant in some farms and greenhouses of Kermanprovince during November 2012. The infected plants were taken tothe laboratory. Then, samples of infected root tissues were removedand were surface sterilized with 0.5% sodium hypochlorite and culturedonto CMA-PARPH medium. Based on morphological features,the isolated fungus was identified as Phytophthora cactorum.Pathogenicity test was performed using inoculated wheat seeds. Toour knowledge this is the first report of Phytophthora cactorum onlemon verbena in Iran.
TL;DR: The anatomical studies ofphyllaries in Asteraceae remain relatively poor in the literature and future studies for comparing the physiological and biochemical activities of the RuBisCO among the IB of the primitive, male-fertile lines and modern sunflower genotypes will help to define magnitude of their importance as a morphological trait to be considered in future plans of sunflower breeding.
Abstract: The involucral bracts (IB or phyllaries) of the sunflower(Helianthus annuus L.) capitulum constitute an example of photosynthesizingorgans that contribute to the photosynthesis budget duringthe generation of crop yield. The anatomy of IB was analyzed in twodomesticated primitive sunflower genotypes, Havasupai and Hopi, inthe sunflower line HA89B, in the wild Helianthus annuus ssp. annuus,in the sunflower male-fertile line R013 and in the commercial hybridDKOP3845. Stomata and trichomes were counted on the adaxial andabaxial epidermis. In all cases, the IB showed a one-layered adaxialand abaxial epidermis, secretory ducts and parenchymatic cells withabundant chloroplast. The vascular system was similar to that of thenomophylls; however, their bundles were smaller, with an abaxial surfaceshowing abundance of glandular and non-glandular trichomesand stomata. IB of Havasupai, Hopi and the male-fertile line strainshowed higher number of adaxial hypodermic strata than those ofHA89B, DKOP3845 and wild sunflower (2-3 vs. 1), and one mesophyllwith inverted polarity with respect to a foliage leaf: the presenceof a spongy parenchyma on the adaxial side was observed with arudimentary palisade parenchyma on the abaxial side. Stomatal densityof the IB was significantly higher in Hopi and Havasupai than inHA89B and DKOP3845, with values ranging from 132 to 156 vs 73to 110 stomata/mm2, respectively. Like the modern commercial hybrid,the IB of male-fertile line showed lower stomatal density (83stomata/mm2) and scarce abaxial trichomes. The anatomical studies ofphyllaries in Asteraceae remain relatively poor in the literature. Fromthe functional point of view, sunflower breeding produced undesiredchanges in the IB anatomy. Future studies for comparing the physiological(photosynthesis and respiration) and biochemical activities ofthe RuBisCO among the IB of the primitive (Havasupai and Hopi),male-fertile lines and modern sunflower genotypes will help to definethe magnitude of their importance as a morphological trait to be consideredin future plans of sunflower breeding.
TL;DR: Results indicate that the differences among the populations of wild pepper were due to genetic differences among them, and the variation pattern observed in these traits suggests adaptation to local climate conditions.
Abstract: Wild pepper (Capsicum annuum L. var. glabriusculum)is a valuable genetic resource for food and agriculture. The patternsof variation of 12 morphological traits of 17 populations ofwild pepper collected across a latitudinal and climate gradients innorthwestern Mexico were analyzed in a uniform greenhouse experiment.The morphological traits data were axamined by univariateand multivarite analysis. The relationship between phenotypicvariation and latitude of population origen was tested using linearregression analysis. We found high variation within and amongpopulations for most of the measured traits. Populations wereclearly differentiated by univariate analysis of variance and principalcomponent analysis. Because plants grew in a uniform environment,these results indicate that the differences among the populationswere due to genetic differences among them. Plant height,number of fruits, fruit weight, number of seeds per fruit, numberof seeds per plant showed a clinal pattern of variation across latitudinalgradients. Plants from northern populations were shorter,produced more fruits, fruits were heavier, more seeds per fruit andmore seeds per plant than plants from southern populations. Thevariation pattern observed in these traits suggests adaptation to localclimate conditions. The variation of the other traits (stem diameter,leaf length and width, number of branches, fruit length andwidth and seed weight) was not significantly related to latitude deorigin. It is possible that the observed differentiation in these traitswas the result of different regimens of selection (and nonclinal) ineach population, or a consequence of genetic drift.
TL;DR: It is observed that A. amurensis did not go through summer dormancy, but started producing mixed buds on rhizomes soon after the aboveground parts had died, and allometric analyses of growth rates in length and diameter indicated that in general diameter increased with length at a slower rate.
Abstract: Spring ephemeroid plants complete their abovegroundreproduction and growth during the short growing season, and maygo dormant subsequently underground. Little is known about theunderground dormancy and biological activities of the plants. In thisstudy, we observed organogenesis and growth rhythm of rhizomebuds of Adonis amurensis Regel et Radde, a spring ephemeroid plantfrom the Changbai Mountains in northeastern China. Our resultsshowed that A. amurensis did not go through summer dormancy, butstarted producing mixed buds on rhizomes soon after the abovegroundparts had died. The buds grew in length and diameter followingan exponential model with significantly slower rates in theearly organogenesis stages, and faster rates before winter dormancy.Allometric analyses of growth rates in length and diameter indicatedthat in general diameter increased with length at a slower rate. Energyallocation, and adaptation to the environment, might play animportant role in the growth dynamics and allometric relationshipsin A. amurensis.
TL;DR: Results showed that species diversity explained less than 7% of the total variability in total aboveground plant biomass, which agrees with the idiosyncratic response hypothesis which suggests that ecosystem function changes when species diversity changes, but the magnitude and direction of these changes are unpredictable.
Abstract: Fil: Zhou, C.. School of Life Sciences. Liaoning University; China. Key Laboratory for Vegetation Ecology. Ministry of Education. Institute of Grassland Science. Northeast Normal University; China
TL;DR: Evidence is provided that besides having a negative influence on aboveground plant growth, grazing also impacted emergence/growth of annual plants and also reduced the nutrient use efficiency of native plant species.
Abstract: This study investigated spatial and temporal patterns of aboveground biomass and nutritive value of rangeland species in perspective of influence of grazing and soil moisture The research was conducted over two years at Tomagh Research Station, near Sanjawi, Ziarat District, Balochistan, Pakistan This area is protected from grazing since 1998; however, some of the area is open for grazing Three sites were selected for research purpose; protected plain, protected hilly, and unprotected plain area Sampling was carried out during spring, summer and autumn seasons Results reveal that soil moisture was greater in protected sites as compared to unprotected site The aboveground plant biomass was 66% to 76% lower at unprotected site as compared to protected sites The biomass of annual plant species was nearly 0 at grazed site In the grazed area the concentrations of all nutrients were higher than un-grazed and hilly area and this pattern was consistent over all species sampled This finding indicates for lower nutrient use efficiency of plants in grazed site as compared to the plants at protected sites This research provided evidence that besides having a negative influence on aboveground plant growth, grazing also impacted emergence/growth of annual plants and also reduced the nutrient use efficiency of native plant species Moreover, 11 years of protection from grazing increased significantly the biomass of plants, enhanced their nutrient use efficiency and allowed annual plants to grow
TL;DR: It was found that the pre-treatment would significantly improve the efficiency for nodularcalli induction in both varieties, although it was easier on explantsof L. sativus than on those of L. cicera, and the protocol would be useful for further expanding the propagation and Agrobacterium-mediated genetic transformation to obtain low β-ODAP varieties.
Abstract: The grass pea (Lathyrus sativus L.) and flatpod peavine(Lathyrus cicera L.) are the most economically important and widelycultivated Lathyrus species. However, their utilization is limiteddue to the presence of their endogenous toxin β-N-oxalyl-L-α,β-diaminopropionic acid (β-ODAP). Thus, a β-ODAP free varietyshould be developed through some plant breeding techniquelike either mutational breeding or genetic-manipulation. In thiscircumstance, the plant regeneration of Lathyrus species becomes abottleneck. In the present study, an efficient system for in vitro regenerationof L. sativus with high β-ODAP levels, and L. cicera withlow β-ODAP levels, was developed from different explants (axillarybuds, leaves and stems). At first, the green nodular calli were inducedfrom sterile seedlings. It was found that the pre-culture of sterileseedlings with 15 mg/L 6-benzyladenine (BA) was necessary for L.cicera, but not for L. sativus. All of these calli were able to differentiateinto adventitious shoot formation when cultured further. Amongthose explants, leaf segments were the optimum because of their easyobtainment and high regeneration efficiency (i.e., 66.48% in L. sativusand 62.13% in L. cicera). Furthermore, it was found that thepre-treatment would significantly improve the efficiency for nodularcalli induction in both varieties, although it was easier on explantsof L. sativus than on those of L. cicera. When these in vitro-derivedplantlets of the two Lathyrus species were planted on half-strengthMurashige and Skoog medium (MS) medium with α-naphthaleneacetic acid (NAA) supplemented, 60% of them developed severalroots. After being transplanted into soil, above 85% of each Lathyrusspecies grew well. The protocol would be useful for further expandingthe propagation and Agrobacterium-mediated genetic transformationto obtain low β-ODAP varieties.
TL;DR: A synchronous behavior between both predator and prey was observed in the four study varieties of rose, although only the cultivars Royal and Samuray presented a signi"cant correlation".
Abstract: Spatial and vertical distributions, and population !uctuationsof Tetranychus urticae and its predator Phytoseiulus persimiliswere determined in four varieties of rose (Royal, Samuray, Red Baiserand Keiro) under greenhouse conditions. Nine samples for the pestand 8 samples for the predator were obtained. From 20 Septemberto 18 November 2013, T. urticae and P. persimilis presented an aggregateddistribution pattern during most of the sampling dates. At thesame time, P. persimilis did not change the vertical distribution of T.urticae. A synchronous behavior between both predator and prey wasobserved in the four study varieties, although only the cultivars Royaland Samuray presented a signi"cant correlation (r= -0.708, P<0.05;r= 0.702, P<0.05, respectively).
TL;DR: This population in Palmas de Tapihue had a low richness of accompanying species and a higher species richness of introduced and therophytes species than other populations of J. chilensis, but it should be necessary to develop an active rehabilitation strategy to aid the recovery of this southernmost J. Chilensis population.
Abstract: Jubaea chilensis (Molina) Baill. (Chilean palm) is anendemic species in Chile. It has been classified as a vulnerable speciesbecause of the reduction and the fragmentation of its populationnumbers, the exploitation of the palms for the production of syrup,the indiscriminate harvest of seed for human consumption, and thereduction of the accompanying native vegetation cover. The southernmostlimit of its natural distribution is located in Palmas de Tapihue(Pencahue, Maule region). The objective of this study was to benchmarkthe conservation status of this population and its accompanyingvegetation. The population of J. chilensis in Tapihue was divided inthree areas. The cover of all vascular plants was recorded with 8 plots(16 x 16 m), and the structure of the vegetation was evaluated with3 plots (50 x 20 m). A total of 35 adult specimens of J. chilensis werefound in the population, and a regeneration density of 0.2 seedlings/ha, values that are lower than those in other populations. Seedlingswere only found under the protection of Peumus boldus Molina. Therewere 75 species found on the accompanying vegetation, of which58.6% were classified as introduced species and 52.0% correspondedto therophytes. This population in Palmas de Tapihue had a low richnessof accompanying species and a higher species richness of introducedand therophytes species than other populations of J. chilensis.We conclude that the J. chilensis population in Palmas de Tapihue andits accompanying vegetation showed a degraded conservation status.Therefore, it should be necessary to develop an active rehabilitationstrategy to aid the recovery of this southernmost J. chilensis populationand its accompanying vegetation.
TL;DR: La relacion tiempo-temperaturaafecto significativamente la concentracion de inulina y fructanos extraidos,siendo la combinacion optima 80 °C durante 60 minutos, resulto no significativa para this mismo proposito.
Abstract: La dalia (Dahlia coccinea Cav.) es una planta que hasido cultivada y mejorada geneticamente con fines ornamentales; noobstante, su sistema radical almacena carbohidratos de reserva bajo laforma de inulina y otros fructanos. La inulina forma parte de la fibradietetica de diversos vegetales, y es considerada como un compuestoprebiotico. Este polisacarido se extrae principalmente de la achicoriay la alcachofa mediante metodos de separacion muy variados, siendola raiz de la dalia una opcion interesante de utilizacion industrial.Los objetivos de este estudio fueron (1) proponer un metodo simplede extraccion de inulina de la raiz de dalia, y (2) evaluar el efecto delcultivo de dalias silvestres sobre su contenido de inulina, fructanos,fructosa y glucosa. Se realizaron colectas de dalia silvestre y se propusoun metodo de extraccion de inulina. Las semillas de los ejemplaresrecolectados fueron cultivadas y a las raices obtenidas se les determinola concentracion de fructanos, inulina, fructosa y glucosa, y seestimo el grado de polimerizacion. La relacion tiempo-temperaturaafecto significativamente la concentracion de inulina y fructanos extraidos,siendo la combinacion optima 80 °C durante 60 minutos. Lainfluencia del pH resulto no significativa para este mismo proposito.Por otro lado, el cultivo de las dalias silvestres aumento significativamenteel contenido de inulina y fructanos de sus raices. Sin embargo,el grado de polimerizacion, estimado a partir de la relacion fructosa/glucosa, disminuyo.
TL;DR: In this paper, the authors evaluate the calidad fitoquimica de frutos de tomate producidos endiferentes sustratos organicos bajo condiciones de invernadero, and the results obtenidos mostraron diferencia significativa (P≤0,05) for el rendimiento, contenidos de clorofila y fenolico,y capacidad antioxidante.
Abstract: El objetivo del presente estudio fue evaluar la producciony calidad fitoquimica de frutos de tomate producidos endiferentes sustratos organicos bajo condiciones de invernadero. Lostratamientos aplicados (sustratos organicos) fueron: T1 (80% Arena+ 20% Vermicompost; T2 (90% Arena + 10% Compost); T3 Testigocon Solucion Steiner (80% Arena + 20% Perlita); T4 (80% Arena +5% Suelo + 15% Vermicompost); T5 (85% Arena + 15% EstiercolSolarizado), y T6 (80% Arena + 5% Suelo + 15% Estiercol Solarizado).Se utilizo un diseno experimental completamente al azar,con cuatro repeticiones de tratamientos. Las variables evaluadas fueronrendimiento, contenido relativo de clorofila en hojas (unidadesSPAD), contenido fenolico total, contenido de licopeno, y capacidadantioxidante. Los resultados obtenidos mostraron diferencia significativa(P≤0,05) para el rendimiento, contenidos de clorofila y fenolico,y capacidad antioxidante. Los resultados de rendimiento mostraronque el Tratamiento con solucion Steiner obtuvo un rendimientode 8,75 kg/m2, mientras que el Tratamiento 4 obtuvo un rendimientoestadisticamente igual (8,70 kg/m2, P>0,05). Por otra parte, la capacidadantioxidante del tomate producido fue de 142,28-276,57 μmolTrolox/g ms, y el contenido fenolico fue de 16,4-28,9 mg equiv. deAc. galico/100 g de fruto fresco. Asimismo, el contenido de licopenoen el tomate producido con los sustratos organicos fue de 2,05-2,77mg/100 g de tomate fresco, mientras que el fruto producido bajofertilizacion quimica (Solucion Steiner) fue de 2,93 mg/100 g detomate fresco. Los resultados obtenidos indican que los sustratos organicosevaluados pueden ser utilizados para la produccion de tomatecon alta calidad fitoquimica.
TL;DR: In this article, the effects of different Cd concentrations (0, 1, 10, 100, and 300 μM CdCl2) on Allium plantlets were investigated.
Abstract: This study aimed to determine the effects of differentCd concentrations (0, 1, 10, 100, and 300 μM CdCl2) on Alliumplantlets. To achieve this goal, we examined the (1) dynamics of Cd2+flux in the rhizosphere, (2) partitioning of Cd between roots andleaves, (3) formation of reactive oxygen species (ROS), (4) levels ofH2O2 and chlorophyll, and (5) translocation of several macro- andmicronutrients. A strong net Cd2+ influx was observed in the rootapex after exposure to 100 μM Cd for 24 h. Exposure to either 1 or10 μM Cd for 96 h presented no evident influence on root growth.However, treatments with 100 to 300 μM Cd for 72 h significantlyinhibited root growth. ROS levels increased in roots and leaves withincreasing Cd concentrations. The concentration of photosyntheticpigments, except for carotenoids on day 4, increased with increasingCd concentrations and treatment duration. Cd accumulationdecreased photosynthetic carbon assimilation but exerted no effectson diurnal patterns. Cd accumulated in roots and leaves, but a largercontent was detected on roots than on leaves. Several macro- andmicronutrients showed tissue- and concentration-specific responsesto Cd.
TL;DR: In this article, the dynamics of production of dry matter (DM) and leaf area were obtained, and growth rates were calculated per plant in a semiarid region under greenhouse conditions andin an organic substrate.
Abstract: The aim of this study was to establish the dynamics ofgrowth and allocation of photosynthates in squash (Cucurbita pepoL.) cultivated in a semiarid region under greenhouse conditions andin an organic substrate. Squash seeds were sown in two substrates(one mineral and other organic). The first consisted of a mixture ofsand and pumice on a volume basis, while the organic consisted ofsand and pumice mixed with vermicompost, both in plastic pots.The substrates were for two treatments [Inorganic (IT) and OrganicTreatment (OT)] with sixteen repetitions on a completely randomizeddesign. After emergence, plants were fertilized according to thecorresponding treatment. The dynamics of production of dry matter(DM) and leaf area were obtained, and growth rates were calculatedper plant. The results of the estimates and different measurements inthe experiment (sample) were subjected to analysis of variance andTukey (P≤0.05), and different regressions. The results showed thatleaf area chemical treatment throughout the cycle was greater thanthe organic treatment; also, the accumulation of biomass in vegetativeand reproductive organs had statistically significant differencesbetween treatments. Growth rates between treatments showed statisticallysignificant differences. It is concluded that growth of Cucurbitapepo L. plants and biomass allocation to different vegetativeand reproductive organs, when grown in organic substrates undergreenhouse conditions, are no better than those obtained in inertsubstrates and inorganic nutrient solutions under the same conditions.