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Robert G. Laport - One of the best experts on this subject based on the ideXlab platform.
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pollinator assemblage and pollen load differences on sympatric diploid and tetraploid cytotypes of the desert dominant Larrea tridentata
American Journal of Botany, 2021Co-Authors: Robert G. Laport, Robert L. Minckley, Diana PilsonAbstract:PREMISE Whole-genome duplication (polyploidy) is an important force shaping flowering-plant evolution. Ploidy-specific plant-pollinator interactions represent important community-level biotic interactions that can lead to nonrandom mating and the persistence of mixed-ploidy populations. METHODS At a naturally occurring diploid-tetraploid contact zone of the autopolyploid desert shrub Larrea tridentata, we combined flower phenology analyses, collections of bees on plants of known cytotype, and flow cytometry analyses of bee-collected pollen loads to investigate whether (1) diploid and tetraploid plants have unique bee pollinator assemblages, (2) bee taxa exhibit ploidy-specific visitation and pollen collection biases, and (3) specialist and generalist bee taxa have ploidy-specific visitation and pollen collection biases. RESULTS Although bee assemblages overlapped, we found significant differences in bee visitation to co-occurring diploids and tetraploids, with the introduced honeybee (Apis mellifera) and one native species (Andrena species 12) more frequently visiting tetraploids. Consistent with bee assemblage differences, we found that diploid pollen was overrepresented among pollen loads on native bees, while pollen loads on A. mellifera did not deviate from the random expectation. However, mismatches between the ploidy of pollen loads and plants were common, consistent with ongoing intercytotype gene flow. CONCLUSIONS Our data are consistent with cytotype-specific bee visitation and suggest that pollinator behavior contributes to reduced diploid-tetraploid mating. Differences in bee visitation and pollen movement potentially contribute to an easing of minority cytotype exclusion and the facilitation of cytotype co-occurrence.
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Polyploidy in creosote bush (Larrea tridentata) shapes the biogeography of specialist herbivores.
Journal of Biogeography, 2019Co-Authors: Timothy K. O’connor, Robert G. Laport, Noah K. WhitemanAbstract:Aim Whole-genome duplication (polyploidy) can influence the biogeography and ecology of plants that differ in ploidy level (cytotype). Here, we address how two consequences of plant polyploidy (parapatry of cytotypes and altered species interactions) shape the biogeography of herbivorous insects. Location Warm deserts of North America. Taxa Gall midges (Asphondylia auripila group, Diptera: Cecidomyiidae) that attack three parapatric cytotypes of creosote bush (Larrea tridentata, Zygophyllaceae). Methods We surveyed Asphondylia species diversity at 177 sites across a 2300-km extent. After noting a correspondence between the distributions of eight Asphondylia species and L. tridentata cytotypes, we fine-mapped Asphondylia species range limits with transects spanning cytotype contact zones. We then tested whether plant-insect interactions and/or abiotic factors explain this coincidence by (1) comparing attack rates and gall midge communities on alternative cytotypes in a narrow zone of sympatry and (2) using species distribution models (SDMs) to determine if climatically suitable habitat for each midge species extended beyond cytotype contact zones. Results The range limits of 6/17 Asphondylia species (including two novel putative species confirmed with COI sequencing) perfectly coincided with the contact zone of diploid and tetraploid L. tridentata. One midge species was restricted to diploid host plants while five were restricted to tetraploid and hexaploid host plants. Where diploid and tetraploid L. tridentata are sympatric, cytotype-restricted midge species more frequently attacked their typical host and Asphondylia community structure differed markedly between cytotypes. SDMs predicted that distributions of cytotype-restricted midge species were not constrained by climatic conditions near cytotype contact zones. Main conclusions Contact zones between plant cytotypes are dispersal barriers for many Asphondylia species due to plant-insect interactions. The distribution of L. tridentata cytotypes therefore shapes herbivore species ranges and herbivore community structure across North American deserts. Our results demonstrate that polyploidy in plants can affect the biogeography of ecological communities.
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assessing water use variation among the cytotypes of the autopolyploid southwestern desert creosotebush Larrea tridentata dc coville zygophyllaceae
Madroño, 2017Co-Authors: Robert G. Laport, Purity Muhia, Carter Kennell, Haydar HasanAbstract:Genome duplication, or polyploidy, has played an important role in the diversification of flowering plants, but the ecological and evolutionary consequences of polyploidy still remain unclear. Polyploidy is known to either cause or facilitate phenotypic changes, and ploidy-specific phenotypic differences may lead to the exploitation of novel niche space. Many studies reporting phenotypic variation between cytotypes have been observational, and may not reflect ecological adaptation by diploids and polyploids to different habitat. One such trait, water use, may play an outsized role in survival and population expansion into novel habitat. To test whether water use differs among ploidy levels, we grew field-collected diploid, autotetraploid, and autohexaploid cytotypes of the characteristic North American desert plant, Larrea tridentata (DC.) Coville, under greenhouse conditions. We measured whole plant water use gravimetrically over six wk, standardizing water use with measures of total stomatal area. We found that water use was positively correlated with stomatal area, but the cytotypes had similar total stomatal areas and did not differ significantly in mean water use/total stomatal area. Cytotype-specific water use responses through time were also not significantly different. Taken together, these results suggest that the cytotypes have similar water relationships, and possibly fitness outcomes, with respect to water use in common environments.
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ecological distributions phenological isolation and genetic structure in sympatric and parapatric populations of the Larrea tridentata polyploid complex
American Journal of Botany, 2016Co-Authors: Robert G. Laport, Robert L. Minckley, Justin RamseyAbstract:PREMISE OF THE STUDY Polyploidy is widely recognized as a mechanism of diversification. Contributions of polyploidy to specific pre- and postzygotic barriers-and classifications of polyploid speciation as "ecological" vs. "non-ecological"-are more contentious. Evaluation of these issues requires comprehensive studies that test ecological characteristics of cytotypes as well as the coincidence of genetic structure with cytotype distributions. METHODS We investigated a classical example of autopolyploid speciation, Larrea tridentata, at multiple areas of cytotype co-occurrence. Habitat and phenological differences were compared between diploid, tetraploid, and hexaploid populations on the basis of edaphic, community composition, and flowering time surveys. Frequency of hybridization between diploids and tetraploids was investigated using a diploid-specific chloroplast DNA (cpDNA) marker; genetic structure for all cytotypes was assessed using amplified fragment length polymorphisms (AFLPs). KEY RESULTS Across contact zones, we found cytotypes in habitats distinguished by soil and vegetation. We observed modest differences in timing and production of flowers, indicating a degree of assortative mating that was asymmetric between cytotypes. Nonetheless, cpDNA analyses in diploid-tetraploid contact zones suggested that ∼5% of tetraploid plants had hybrid origins involving unilateral sexual polyploidization. Genetic structure of AFLPs largely coincided with cytotype distributions in diploid-tetraploid contact zones. In contrast, there was little structure in areas of contact between tetraploids and hexaploids, suggesting intercytotype gene flow or recurrent hexaploid formation. CONCLUSIONS Diploid, tetraploid, and hexaploid cytotypes of L. tridentata are segregated by environmental distributions and flowering phenology in contact zones, with diploid and tetraploid populations having corresponding differences in genetic structure.
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morphometric analysis of the north american creosote bush Larrea tridentata zygophyllaceae and the microspatial distribution of its chromosome races
Plant Systematics and Evolution, 2015Co-Authors: Robert G. Laport, Justin RamseyAbstract:Polyploidy is a major mechanism of chromosome evolution and speciation in flowering plants. Delineation of polyploid populations as species or subspecies is complicated because of the uncertainties of distinguishing closely related diploids and polyploids in field conditions. Here we evaluate the practical identification of polyploids—using geographic distributions and morphological features—in the North American creosote bush (Larrea tridentata, Zygophyllaceae). Regarded as a classical autopolyploid complex, L. tridentata comprises diploids, tetraploids, and hexaploids distributed throughout the Chihuahuan, Sonoran, and Mojave Deserts. Transect sampling on cytotype range boundaries revealed strong spatial structuring of the chromosome races, and infrequent sympatry, over small spatial scales (<50 km). Inter-cytotype hybrids were rare, with putative triploids and pentaploids comprising <1 % of the sampled plants (N = 1,197). In morphometric analyses of stem, flower, and leaf characteristics (N = 14 traits), we found significant ploidy effects in several cytotype comparisons; reproductive structures and foliage characteristics were particularly discriminatory. Significant transect and ploidy × transect effects for most traits suggest, however, that environmental and genic factors influence plant architecture and morphology. Nonetheless, discriminant function analysis with a combined morphometric data set correctly assigned 68.9 % of plants to ploidal level. Pollen diameters increased significantly with ploidal level, providing another potentially informative trait for comparisons of reproductive plants. Taken together, the spatial distribution and morphometric data presented here suggest that the majority of L. tridentata plants could, in principle, be assigned to cytotype in the field. However, because of potential misclassifications, we suggest recognition of the L. tridentata cytotypes as subspecies.
Chávez Solis, Aarón Leobardo - One of the best experts on this subject based on the ideXlab platform.
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Evaluación de extracto de gobernadora Larrea tridentata (D. C) Coville (L.) en el control de cenicilla Podosphaera xanthii (sin. Sphaerotheca fuliginea) del melón Cucumis melo L.
Colegio de Postgraduados (COLPOS), 2012Co-Authors: Chávez Solis, Aarón LeobardoAbstract:El estudio se realizó la región de Ceballos del municipio de Mapimí, Durango. Donde se evaluó la efectividad del extracto de gobernadora (Larrea tridentata (D.C.) coville (L.)). en el control de cenicilla en la producción de melón. El cultivo se estableció en una parcela de 2,500 m2 en un diseño de bloques en arreglo de parcelas sub sub divididas, donde las parcelas grandes fueron las variedades de melón (Crusier y Navigator), las parcelas medianas fueron las formulaciones del extracto de gobernadora (agua, hidroalcohólico 50% agua y 50% alcohol y, etanolico 96%) y las parcelas chicas correspondieron a las dosis (0, 1000, 5000 y 10000 mg de planta por litro de agua). Se evaluó la severidad de infección de cenicilla Podosphaera xanthii mediante una escala ajustada H-B obtenida de DOSLOG v.1.0 la cual se evaluó a los 37,45,53 y 61 días después de la siembre donde a los datos obtenidos se les realizo un análisis de área bajo la curva la cual se utilizó para determinar cuáles fueron los mejores tratamientos. De acuerdo a los resultados, no hubo diferencia en la mayoría de los factores analizados en términos de área bajo la curva del progreso de la enfermedad (ABCPE), excepto para el factor dosis, donde se observó que al usarse de 1000 a 5000 mg de planta litro de agua disminuyó significativamente la severidad de la cenicilla. De acuerdo al análisis gráfico de distribución espacial, se pudo observar que los focos con mayor severidad de infección fueron aquellas que se ubicaban en donde se encontraban la dosis 0(testigo) y 10,000 mg de planta por litro de agua. También se evaluó la variable producción donde los frutos fueron clasificados en fruto de primera y rezaga, Para el factor fruto de primera no existió diferencia significativa ya que todos los tratamientos fueron estadísticamente iguales. Para el caso de fruto de rezaga es notorio el efecto que existió entre los diferentes tratamientos, donde la variedad Navigator tuvo un mejor comportamiento al tener menor fruto de rezaga con un valor medio de 20.729 kg. para fruto de rezaga. La mejor formulación fue el extracto acuoso que tuvo el valor de 21.864 Kg. de fruto de rezaga, teniendo la media más baja en cuanto a cantidad de fruto de rezaga. Para la interacción entre Navigator y formulación, los mejores tratamientos fueron Navigator y extracto acuoso seguida por Navigator y extracto hidroalcohólico con valores de 16.350 y 21.333 kg. de fruto de rezaga respectivamente, mostraron que fueron las interacciones que tuvieron menor de fruto de rezaga. Las mejores dosificaciones de goberanadora (Larrea tridentata (D.C.) Coville (L.).) fueron las de 1,000 y 5,000 mg de planta litro de agua, ya que produjeron 22.815 y 23.072 frutos de rezaga. En el caso de la interacción variedad-dosis, las mejores interacciones fueron las dadas por Navigator con dosis de 1,000 mg de planta de gobernadora y Navigator con dosis de 5,000 mg de planta de gobernadora con valores de 15.687 y 18.511 kg de fruto de rezaga respectivamente, por lo que los mejores comportamientos fueron la mezcla de la variedad Navigator con las dosis de 1,000 y 5,000 mg de planta de gobernadora (Larrea tridentata (D.C.) coville (L.).) por litro-1 de agua. La interacción de los tres factores mostró que las mejores interacciones fueron Navigator con la formulación agua y 1,000 mg de planta de gobernadora seguida por Navigator con formulación agua y 5,000 mg de planta de gobernadora, Navigator con formulación hidroalcohólica y 5,000 mg, Navigator formulación hidroalcohólica y 10,000 mg y Crusier con la formulación agua y 10,000 mg de planta de gobernadora con valores de 9.600, 11.333, 15.833, 16.066 y 17.133 kg. de fruto de rezaga, respectivamente. Finalmente la cantidad de solidos solubles en fruto al momento de la cosecha fue evaluada para cada tratamiento. Para el caso de grados Brix en el fruto, la interacción variedad Crusier y dosis de 10,000 mg de planta, fue la más baja (6.877), respecto al resto, que fueron significativamente mayores. _______________ ABSTRACT: Research was carried out at Ceballos, Mapimí Durango. Which evaluated the effectiveness of the extract of creosote bush (Larrea tridentata (DC) Coville (L.)) In controlling powdery mildew in the production of melon. Crop was established on area of 2.500 m2 in split-split plot designe, where the big plots were the varieties of melon (Crusier and Navigator), medium plots were the Crosote bush extract formulations (water, hydroalcoholic 50% of water 50% of alcohol and ethanolic 96%) and the small plots corresponded to dosages of Creosote bush tissue, (0, 1000, 5000 and 10000 mg plant per liter of water). Severity of powdery mildew infection due Podosphaera xanthii was adjusted by H-B obtained by DOSLOG v.1.0, which was measured at 37, 45, 53 and 61 days after to sowing. Data were performed an analysis of area under disease progress curve which was used to determine which treatments were the best. Dosage effect was found when used 1000 to 5000 mg of plant per liters of water, which decreased area under disease progress curve, with values of 7.9 y 8.7 %-days respectively. Agree with graphical analysis of spatial distribution, it was observed that more severe outbreaks of infection were those that were located where the doses were 0 (control) and 10,000 mg of plant per liter of water. We also evaluated the production variable where the fruits were classified into fruit of high quality and fruit waste, effect was not identified in the production of fruit of high quality, however for fruit waste the Navigator was the best effect because produce the minor amount (20.7 kg). The best formulation was the watery extract had the value of 21,864 kg fruit waste having the lowest average in quantity of fruit waste. For the interaction between Navigator and formulation the best treatments were Navigator and watery extract followed by Navigator and hydroalcoholic extract with values 16,350 and 21,333 fruit waste respectively, showed that the interactions were had lower fruit waste. Best Creosote bush dosages (Larrea tridentata (DC) Coville (L.).) Were 1.000 and 5.000 mg of plant per liter of water, as produced 22,815 and 23,072 fruit waste. In the case of the variety-dosage interactions, best interactions were those given by Navigator and dosage of 1.000 mg of plant of Creosote bush and Navigator and dosage of 5.000 mg of plant of Creosote bush with values of 15,687 and 18,511 kg fruit waste respectively, so that the best performances were the mixture of the variety Navigator with doses of 1.000 and 5.000 mg of plant Creosote bush (Larrea tridentata (DC) Coville (L.).) per liter of water. The interaction of three factors showed that the best interactions were Navigator with water and 1.000 mg formulation plant followed by Navigator with water and formulated with 5,000 mg of Creosote bush, Navigator hydroalcoholic formulation and 5.000 mg of Creosote bush, formulation hydroalcoholic formulation Navigator and 10,000 mg, formulation Crusier with water and 10,000 mg of plant Creosote bush with values of 9,600, 11,333, 15,833, 16,066 and 17,133 kg. fruit waste, respectively. Finally the amount of soluble solids in fruit at harvest time was evaluated for each treatment. In the case of Brix degree in the fruit, the Crusier range interaction and dose of 10,000 mg of plant, was minor (6,877), with respect of the other dosages, which were significantly higher
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Evaluación de extracto de gobernadora Larrea tridentata (D. C) Coville (L.) en el control de cenicilla Podosphaera xanthii (sin. Sphaerotheca fuliginea) del melón Cucumis melo L.
Colegio de Postgraduados (COLPOS), 2012Co-Authors: Chávez Solis, Aarón LeobardoAbstract:El estudio se realizó la región de Ceballos del municipio de Mapimí, Durango. Donde se evaluó la efectividad del extracto de gobernadora (Larrea tridentata (D.C.) coville (L.)). en el control de cenicilla en la producción de melón. El cultivo se estableció en una parcela de 2,500 m2 en un diseño de bloques en arreglo de parcelas sub sub divididas, donde las parcelas grandes fueron las variedades de melón (Crusier y Navigator), las parcelas medianas fueron las formulaciones del extracto de gobernadora (agua, hidroalcohólico 50% agua y 50% alcohol y, etanolico 96%) y las parcelas chicas correspondieron a las dosis (0, 1000, 5000 y 10000 mg de planta por litro de agua). Se evaluó la severidad de infección de cenicilla Podosphaera xanthii mediante una escala ajustada H-B obtenida de DOSLOG v.1.0 la cual se evaluó a los 37,45,53 y 61 días después de la siembre donde a los datos obtenidos se les realizo un análisis de área bajo la curva la cual se utilizó para determinar cuáles fueron los mejores tratamientos. De acuerdo a los resultados, no hubo diferencia en la mayoría de los factores analizados en términos de área bajo la curva del progreso de la enfermedad (ABCPE), excepto para el factor dosis, donde se observó que al usarse de 1000 a 5000 mg de planta litro de agua disminuyó significativamente la severidad de la cenicilla. De acuerdo al análisis gráfico de distribución espacial, se pudo observar que los focos con mayor severidad de infección fueron aquellas que se ubicaban en donde se encontraban la dosis 0(testigo) y 10,000 mg de planta por litro de agua. También se evaluó la variable producción donde los frutos fueron clasificados en fruto de primera y rezaga, Para el factor fruto de primera no existió diferencia significativa ya que todos los tratamientos fueron estadísticamente iguales. Para el caso de fruto de rezaga es notorio el efecto que existió entre los diferentes tratamientos, donde la variedad Navigator tuvo un mejor comportamiento al tener menor fruto de rezaga con un valor medio de 20.729 kg. para fruto de rezaga. La mejor formulación fue el extracto acuoso que tuvo el valor de 21.864 Kg. de fruto de rezaga, teniendo la media más baja en cuanto a cantidad de fruto de rezaga. Para la interacción entre Navigator y formulación, los mejores tratamientos fueron Navigator y extracto acuoso seguida por Navigator y extracto hidroalcohólico con valores de 16.350 y 21.333 kg. de fruto de rezaga respectivamente, mostraron que fueron las interacciones que tuvieron menor de fruto de rezaga. Las mejores dosificaciones de goberanadora (Larrea tridentata (D.C.) Coville (L.).) fueron las de 1,000 y 5,000 mg de planta litro de agua, ya que produjeron 22.815 y 23.072 frutos de rezaga. En el caso de la interacción variedad-dosis, las mejores interacciones fueron las dadas por Navigator con dosis de 1,000 mg de planta de gobernadora y Navigator con dosis de 5,000 mg de planta de gobernadora con valores de 15.687 y 18.511 kg de fruto de rezaga respectivamente, por lo que los mejores comportamientos fueron la mezcla de la variedad Navigator con las dosis de 1,000 y 5,000 mg de planta de gobernadora (Larrea tridentata (D.C.) coville (L.).) por litro-1 de agua. La interacción de los tres factores mostró que las mejores interacciones fueron Navigator con la formulación agua y 1,000 mg de planta de gobernadora seguida por Navigator con formulación agua y 5,000 mg de planta de gobernadora, Navigator con formulación hidroalcohólica y 5,000 mg, Navigator formulación hidroalcohólica y 10,000 mg y Crusier con la formulación agua y 10,000 mg de planta de gobernadora con valores de 9.600, 11.333, 15.833, 16.066 y 17.133 kg. de fruto de rezaga, respectivamente. Finalmente la cantidad de solidos solubles en fruto al momento de la cosecha fue evaluada para cada tratamiento. Para el caso de grados Brix en el fruto, la interacción variedad Crusier y dosis de 10,000 mg de planta, fue la más baja (6.877), respecto al resto, que fueron significativamente mayores. _______________ ABSTRACT: Research was carried out at Ceballos, Mapimí Durango. Which evaluated the effectiveness of the extract of creosote bush (Larrea tridentata (DC) Coville (L.)) In controlling powdery mildew in the production of melon. Crop was established on area of 2.500 m2 in split-split plot designe, where the big plots were the varieties of melon (Crusier and Navigator), medium plots were the Crosote bush extract formulations (water, hydroalcoholic 50% of water 50% of alcohol and ethanolic 96%) and the small plots corresponded to dosages of Creosote bush tissue, (0, 1000, 5000 and 10000 mg plant per liter of water). Severity of powdery mildew infection due Podosphaera xanthii was adjusted by H-B obtained by DOSLOG v.1.0, which was measured at 37, 45, 53 and 61 days after to sowing. Data were performed an analysis of area under disease progress curve which was used to determine which treatments were the best. Dosage effect was found when used 1000 to 5000 mg of plant per liters of water, which decreased area under disease progress curve, with values of 7.9 y 8.7 %-days respectively. Agree with graphical analysis of spatial distribution, it was observed that more severe outbreaks of infection were those that were located where the doses were 0 (control) and 10,000 mg of plant per liter of water. We also evaluated the production variable where the fruits were classified into fruit of high quality and fruit waste, effect was not identified in the production of fruit of high quality, however for fruit waste the Navigator was the best effect because produce the minor amount (20.7 kg). The best formulation was the watery extract had the value of 21,864 kg fruit waste having the lowest average in quantity of fruit waste. For the interaction between Navigator and formulation the best treatments were Navigator and watery extract followed by Navigator and hydroalcoholic extract with values 16,350 and 21,333 fruit waste respectively, showed that the interactions were had lower fruit waste. Best Creosote bush dosages (Larrea tridentata (DC) Coville (L.).) Were 1.000 and 5.000 mg of plant per liter of water, as produced 22,815 and 23,072 fruit waste. In the case of the variety-dosage interactions, best interactions were those given by Navigator and dosage of 1.000 mg of plant of Creosote bush and Navigator and dosage of 5.000 mg of plant of Creosote bush with values of 15,687 and 18,511 kg fruit waste respectively, so that the best performances were the mixture of the variety Navigator with doses of 1.000 and 5.000 mg of plant Creosote bush (Larrea tridentata (DC) Coville (L.).) per liter of water. The interaction of three factors showed that the best interactions were Navigator with water and 1.000 mg formulation plant followed by Navigator with water and formulated with 5,000 mg of Creosote bush, Navigator hydroalcoholic formulation and 5.000 mg of Creosote bush, formulation hydroalcoholic formulation Navigator and 10,000 mg, formulation Crusier with water and 10,000 mg of plant Creosote bush with values of 9,600, 11,333, 15,833, 16,066 and 17,133 kg. fruit waste, respectively. Finally the amount of soluble solids in fruit at harvest time was evaluated for each treatment. In the case of Brix degree in the fruit, the Crusier range interaction and dose of 10,000 mg of plant, was minor (6,877), with respect of the other dosages, which were significantly higher.Tesis (Maestría en Ciencias, especialista en Fitopatología).- Colegio de Postgraduados, 2012.Consejo Nacional de Ciencia y Tecnología (CONACYT)
Solange I Mussatto - One of the best experts on this subject based on the ideXlab platform.
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Solid-state fermentation as a strategy to improve the bioactive compounds recovery from Larrea tridentata leaves.
Applied Biochemistry and Biotechnology, 2013Co-Authors: Silvia Martins, Jose A Teixeira, Solange I MussattoAbstract:Chemical composition of Larrea tridentata leaves was determined and elevated content of lignin (35.96 % w/w) was found. The present study was proposed in order to evaluate the extraction of bioactive compounds, particularly phenolic compounds, by solid-state fermentation (SSF) of L. tridentata leaves. The basidiomycete Phanerochaete chrysosporium was used in the experiments due to its ability to degrade lignin. The concentration of total phenolic compounds in the extracts produced by SSF was determined. Additionally, the extracts were characterized regarding the concentration of flavonoids, quercetin, kaempferol, and nordihydroguaiaretic acid and antioxidant activity. SSF was not an efficient process to recover phenolic compounds from L. tridentata leaves. However, this process was very efficient when used as a pretreatment before the plant extraction with organic solvent (methanol). By submitting the plant to SSF and subsequently to extraction with 90 % (v/v) methanol, the recovery of phenolic compounds was improved by 33 % when compared to the results obtained by methanolic extraction of the non-fermented plant. Scanning electron microscopy micrographs revealed a major disorganization and porosity of the plant structure after fermentation, and Fourier transform infrared spectroscopy spectra indicated a possible solubilization of some constituents of lignocellulose fraction after this process, which may have favored the solvent action in the later stage.
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antibacterial activity of crude methanolic extract and fractions obtained from Larrea tridentata leaves
Industrial Crops and Products, 2013Co-Authors: Silvia Martins, Elba Lucia Cavalcanti De Amorim, Tadeu Jose Da Silva Peixoto Sobrinho, Antonio Marcos Saraiva, Maria Nelly Caetano Pisciottano, J A Teixeira, Solange I MussattoAbstract:a b s t r a c t The emergence of new infections and increase of bacteria drug-resistance rise up the urgent need for the development of new antibacterial agents from natural sources. This study was designed to evaluate the antibacterial activity of the crude methanolic extract (CME) and fractions (hexane (H), dichloromethane (DCM), ethyl acetate (EA) and ethanol (Et)) obtained from Larrea tridentata (Sesse & Moc. Ex DC.) Cov- ille leaves. The antibacterial activity was determined by the agar diffusion method against six strains of Gram-positive and Gram-negative bacteria. The micro-dilution method was applied for the deter- mination of the minimal inhibitory concentration (MIC) of selected bacteria strains. HPLC analyses of tested samples were also carried out. The antibacterial activity of the samples was more effective inhibit- ing the growth of Gram-positive bacteria comparing with Gram-negative bacteria, mainly for the CME, DCM and EA fractions. EA fraction showed the highest antibacterial activity against methicillin-resistant Staphylococcus aureus isolated from secretion; with a MIC value (31.3 g/mL) lower than the reference antibiotic tetracycline (64 g/mL). Low MIC values (62.5 g/mL) were also obtained for the CME and DCM fraction. CME and EA fraction presented the highest concentrations of quercetin, kaempferol and nordihydroguaiaretic acid. These compounds have important biological activities and could be respon- sible for at least part of the antibacterial activity of the CME, DCM and EA fractions. EA fraction from L. tridentata leaves was the most efficient to inhibit the growth of the bacterial strain methicillin-resistant S. aureus, which represents an important step for the search and development of a new antibacterial agent.
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Bioactive compounds (phytoestrogens) recovery from Larrea tridentata leaves by solvents extraction
Separation and Purification Technology, 2012Co-Authors: Silvia Martins, Jose A Teixeira, Solange I MussattoAbstract:Methanol, ethanol, and acetone at four different concentrations (90%, 70%, 50%, and 30% v/v) were used for extraction of phytoestrogens (nordihydroguaiaretic acid (NDGA), kaempferol, and quercetin) from Larrea tridentata leaves. Besides the phytoestrogens extraction, the antioxidant potential, and the contents of total phenols, flavonoids, and protein in the produced extracts were also determined. The solvent and concentration used for extraction strongly affected the phytoestrogens recovery. The highest NDGA, quercetin, and kaempferol contents (46.96 ± 3.39, 10.46 ± 1.01, and 87.00 ± 6.43 mg/g DW plant, respectively) were recovered using 90% (v/v) methanol. All the produced extracts showed antioxidant capacity, but those obtained using 70% and 90% (v/v) methanol had significantly higher (p < 0.05) FRAP (ferric reducing antioxidant power) values (2.55 ± 0.09 and 2.73 ± 0.11 mM FE(II)/g DW plant, respectively) than the remaining ones. Extract produced by using 90% (v/v) methanol contained also the highest contents of total flavonoids (19.29 ± 0.79 mg QE/g DW plant) and protein (131.84 ± 6.23 mg/g DW plant), and elevated total phenols concentration (263.60 ± 25.78 mg GAE/g DW plant).
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nordihydroguaiaretic acid recovery from Larrea tridentata by microwave assisted extraction
Semana de Engenharia 2010, 2010Co-Authors: Silvia Martins, Cristobal N Aguilar, Solange I Mussatto, Iliana M De La Garzarodriguez, Jose A TeixeiraAbstract:Nordihydroguaiaretic acid (NDGA) is a powerful antioxidant with biological activities of great interest in several health areas, including antiviral, cancer chemopreventive, and antitumorgenic. Little information is available on extraction methods of NDGA from Larrea tridentata . Hence, the aim of this study was to develop a rapid and effective microwave-assisted extraction (MAE) method for NDGA recovery from Larrea tridentata leaves, and to compare the results obtained with those found using conventional heatreflux extraction (HRE).
Justin Ramsey - One of the best experts on this subject based on the ideXlab platform.
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ecological distributions phenological isolation and genetic structure in sympatric and parapatric populations of the Larrea tridentata polyploid complex
American Journal of Botany, 2016Co-Authors: Robert G. Laport, Robert L. Minckley, Justin RamseyAbstract:PREMISE OF THE STUDY Polyploidy is widely recognized as a mechanism of diversification. Contributions of polyploidy to specific pre- and postzygotic barriers-and classifications of polyploid speciation as "ecological" vs. "non-ecological"-are more contentious. Evaluation of these issues requires comprehensive studies that test ecological characteristics of cytotypes as well as the coincidence of genetic structure with cytotype distributions. METHODS We investigated a classical example of autopolyploid speciation, Larrea tridentata, at multiple areas of cytotype co-occurrence. Habitat and phenological differences were compared between diploid, tetraploid, and hexaploid populations on the basis of edaphic, community composition, and flowering time surveys. Frequency of hybridization between diploids and tetraploids was investigated using a diploid-specific chloroplast DNA (cpDNA) marker; genetic structure for all cytotypes was assessed using amplified fragment length polymorphisms (AFLPs). KEY RESULTS Across contact zones, we found cytotypes in habitats distinguished by soil and vegetation. We observed modest differences in timing and production of flowers, indicating a degree of assortative mating that was asymmetric between cytotypes. Nonetheless, cpDNA analyses in diploid-tetraploid contact zones suggested that ∼5% of tetraploid plants had hybrid origins involving unilateral sexual polyploidization. Genetic structure of AFLPs largely coincided with cytotype distributions in diploid-tetraploid contact zones. In contrast, there was little structure in areas of contact between tetraploids and hexaploids, suggesting intercytotype gene flow or recurrent hexaploid formation. CONCLUSIONS Diploid, tetraploid, and hexaploid cytotypes of L. tridentata are segregated by environmental distributions and flowering phenology in contact zones, with diploid and tetraploid populations having corresponding differences in genetic structure.
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morphometric analysis of the north american creosote bush Larrea tridentata zygophyllaceae and the microspatial distribution of its chromosome races
Plant Systematics and Evolution, 2015Co-Authors: Robert G. Laport, Justin RamseyAbstract:Polyploidy is a major mechanism of chromosome evolution and speciation in flowering plants. Delineation of polyploid populations as species or subspecies is complicated because of the uncertainties of distinguishing closely related diploids and polyploids in field conditions. Here we evaluate the practical identification of polyploids—using geographic distributions and morphological features—in the North American creosote bush (Larrea tridentata, Zygophyllaceae). Regarded as a classical autopolyploid complex, L. tridentata comprises diploids, tetraploids, and hexaploids distributed throughout the Chihuahuan, Sonoran, and Mojave Deserts. Transect sampling on cytotype range boundaries revealed strong spatial structuring of the chromosome races, and infrequent sympatry, over small spatial scales (<50 km). Inter-cytotype hybrids were rare, with putative triploids and pentaploids comprising <1 % of the sampled plants (N = 1,197). In morphometric analyses of stem, flower, and leaf characteristics (N = 14 traits), we found significant ploidy effects in several cytotype comparisons; reproductive structures and foliage characteristics were particularly discriminatory. Significant transect and ploidy × transect effects for most traits suggest, however, that environmental and genic factors influence plant architecture and morphology. Nonetheless, discriminant function analysis with a combined morphometric data set correctly assigned 68.9 % of plants to ploidal level. Pollen diameters increased significantly with ploidal level, providing another potentially informative trait for comparisons of reproductive plants. Taken together, the spatial distribution and morphometric data presented here suggest that the majority of L. tridentata plants could, in principle, be assigned to cytotype in the field. However, because of potential misclassifications, we suggest recognition of the L. tridentata cytotypes as subspecies.
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Phylogeny and Cytogeography of the North American Creosote Bush (Larrea tridentata, Zygophyllaceae)
Systematic Botany, 2012Co-Authors: Robert G. Laport, Robert L. Minckley, Justin Ramsey, Chrissen E.c. GemmillAbstract:The North American creosote bush (Larrea tridentata, Zygophyllaceae) is a widespread and ecologically dominant taxon of North American warm deserts. The species is comprised of diploid, tetraploid, and hexaploid populations, and touted as a classical example of an autopolyploid taxonomic complex. Here we use flow cytometry and DNA sequence data (non-coding cpDNA and nuclear ribosomal DNA) to evaluate spatial and evolutionary relationships among cytotype races, as well as the origins of the species from its South American ancestors. We find the geographic distribution of North American cytotypes to be highly structured, with limited co-occurrence within populations. Diploids reside only in the Chihuahuan Desert, as reported in previous biosystematic surveys, but tetraploid and hexaploid populations interdigitate along the margins of the Sonoran and Mojave Deserts. In phylogenetic analyses, North American plants comprise a monophyletic grouping that is sister to the South American diploid species, L. divaricata. North American populations exhibit genetic signatures of rapid demographic expansion, including a star-shaped genealogy, unimodal distribution of pairwise haplo- type differences, and low genetic structure. Nonetheless, polyploid cytotypes are consistently distinguished from diploid cytotypes by a cpDNA indel character, suggesting a single origin of tetraploidy in the species. These findings suggest a recent origin of the North American creosote bush via long distance dispersal, with establishment of polyploid populations accompanying its rapid spread through the Northern Hemisphere.
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Solid-state fermentation as a strategy to improve the bioactive compounds recovery from Larrea tridentata leaves.
Applied Biochemistry and Biotechnology, 2013Co-Authors: Silvia Martins, Jose A Teixeira, Solange I MussattoAbstract:Chemical composition of Larrea tridentata leaves was determined and elevated content of lignin (35.96 % w/w) was found. The present study was proposed in order to evaluate the extraction of bioactive compounds, particularly phenolic compounds, by solid-state fermentation (SSF) of L. tridentata leaves. The basidiomycete Phanerochaete chrysosporium was used in the experiments due to its ability to degrade lignin. The concentration of total phenolic compounds in the extracts produced by SSF was determined. Additionally, the extracts were characterized regarding the concentration of flavonoids, quercetin, kaempferol, and nordihydroguaiaretic acid and antioxidant activity. SSF was not an efficient process to recover phenolic compounds from L. tridentata leaves. However, this process was very efficient when used as a pretreatment before the plant extraction with organic solvent (methanol). By submitting the plant to SSF and subsequently to extraction with 90 % (v/v) methanol, the recovery of phenolic compounds was improved by 33 % when compared to the results obtained by methanolic extraction of the non-fermented plant. Scanning electron microscopy micrographs revealed a major disorganization and porosity of the plant structure after fermentation, and Fourier transform infrared spectroscopy spectra indicated a possible solubilization of some constituents of lignocellulose fraction after this process, which may have favored the solvent action in the later stage.
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antibacterial activity of crude methanolic extract and fractions obtained from Larrea tridentata leaves
Industrial Crops and Products, 2013Co-Authors: Silvia Martins, Elba Lucia Cavalcanti De Amorim, Tadeu Jose Da Silva Peixoto Sobrinho, Antonio Marcos Saraiva, Maria Nelly Caetano Pisciottano, J A Teixeira, Solange I MussattoAbstract:a b s t r a c t The emergence of new infections and increase of bacteria drug-resistance rise up the urgent need for the development of new antibacterial agents from natural sources. This study was designed to evaluate the antibacterial activity of the crude methanolic extract (CME) and fractions (hexane (H), dichloromethane (DCM), ethyl acetate (EA) and ethanol (Et)) obtained from Larrea tridentata (Sesse & Moc. Ex DC.) Cov- ille leaves. The antibacterial activity was determined by the agar diffusion method against six strains of Gram-positive and Gram-negative bacteria. The micro-dilution method was applied for the deter- mination of the minimal inhibitory concentration (MIC) of selected bacteria strains. HPLC analyses of tested samples were also carried out. The antibacterial activity of the samples was more effective inhibit- ing the growth of Gram-positive bacteria comparing with Gram-negative bacteria, mainly for the CME, DCM and EA fractions. EA fraction showed the highest antibacterial activity against methicillin-resistant Staphylococcus aureus isolated from secretion; with a MIC value (31.3 g/mL) lower than the reference antibiotic tetracycline (64 g/mL). Low MIC values (62.5 g/mL) were also obtained for the CME and DCM fraction. CME and EA fraction presented the highest concentrations of quercetin, kaempferol and nordihydroguaiaretic acid. These compounds have important biological activities and could be respon- sible for at least part of the antibacterial activity of the CME, DCM and EA fractions. EA fraction from L. tridentata leaves was the most efficient to inhibit the growth of the bacterial strain methicillin-resistant S. aureus, which represents an important step for the search and development of a new antibacterial agent.
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Bioactive compounds (phytoestrogens) recovery from Larrea tridentata leaves by solvents extraction
Separation and Purification Technology, 2012Co-Authors: Silvia Martins, Jose A Teixeira, Solange I MussattoAbstract:Methanol, ethanol, and acetone at four different concentrations (90%, 70%, 50%, and 30% v/v) were used for extraction of phytoestrogens (nordihydroguaiaretic acid (NDGA), kaempferol, and quercetin) from Larrea tridentata leaves. Besides the phytoestrogens extraction, the antioxidant potential, and the contents of total phenols, flavonoids, and protein in the produced extracts were also determined. The solvent and concentration used for extraction strongly affected the phytoestrogens recovery. The highest NDGA, quercetin, and kaempferol contents (46.96 ± 3.39, 10.46 ± 1.01, and 87.00 ± 6.43 mg/g DW plant, respectively) were recovered using 90% (v/v) methanol. All the produced extracts showed antioxidant capacity, but those obtained using 70% and 90% (v/v) methanol had significantly higher (p < 0.05) FRAP (ferric reducing antioxidant power) values (2.55 ± 0.09 and 2.73 ± 0.11 mM FE(II)/g DW plant, respectively) than the remaining ones. Extract produced by using 90% (v/v) methanol contained also the highest contents of total flavonoids (19.29 ± 0.79 mg QE/g DW plant) and protein (131.84 ± 6.23 mg/g DW plant), and elevated total phenols concentration (263.60 ± 25.78 mg GAE/g DW plant).
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nordihydroguaiaretic acid recovery from Larrea tridentata by microwave assisted extraction
Semana de Engenharia 2010, 2010Co-Authors: Silvia Martins, Cristobal N Aguilar, Solange I Mussatto, Iliana M De La Garzarodriguez, Jose A TeixeiraAbstract:Nordihydroguaiaretic acid (NDGA) is a powerful antioxidant with biological activities of great interest in several health areas, including antiviral, cancer chemopreventive, and antitumorgenic. Little information is available on extraction methods of NDGA from Larrea tridentata . Hence, the aim of this study was to develop a rapid and effective microwave-assisted extraction (MAE) method for NDGA recovery from Larrea tridentata leaves, and to compare the results obtained with those found using conventional heatreflux extraction (HRE).
