scholarly journals Germination constraints of dicarpic cypselae of Bidens pilosa L.

2019 ◽  
Vol 79 (3) ◽  
pp. 383-394
Author(s):  
P. R. M. Souza-Filho ◽  
M. Takaki
Keyword(s):  
De Novo ◽  
Growth Potential ◽  
Behavioral Differences ◽  
Weed Species ◽  
Bidens Pilosa ◽  
Hormonal Stimulation ◽  
Central Type ◽  
Chemical Inhibitors ◽  
Peripheral Type ◽  
Physical And Chemical

Abstract Bidens pilosa L. is a heterocarpic weed species with two cypselae types that present morpho-physiological differences, being the peripheral type smaller and slower to germinate than the central one. We aimed to verify how the germination mechanism varied between types. We focused on two mechanisms: (1) pericarp constraints (physical and chemical) and (2) hormonal stimulation (Abcisic acid [ABA] and Gibberellin [GA]). Both cypselae types are physically constrained by the pericarp, for when it is excised both seed types increase their germination, but behavioral differences still remain. The pericarp of the peripheral type also has chemical inhibitors that effectively inhibited germination of the intact central cypsela. To test the hormonal effects, we focused on the ABA:GA control. Both cypselae responded to an exogenous ABA concentration gradient, however there is no variation between types on the sensitivity to it. Also, both cypselae types were indifferent to Fluridone (ABA inhibitor), which indicates that the dormancy is not maintained by de novo ABA synthesis. Cypselae types had different sensitivity to an exogenous GA3 gradient, the central type being more sensitive to the treatment than the peripheral one. But when the endogenous GA synthesis was blocked by Paclobutrazol, both types responded equally to same GA3 concentrations. This indicates that endogenous GA synthesis may be related to differences observed on germination of cypselae types. To conclude, seed types differ on their growth potential to overcome the pericarp resistance: while the inhibitor in the peripheral pericarp reduces growth potential, GA increases it.

scholarly journals Pre-emergence application of (thio)urea analogues compromises the development of the weed species Bidens pilosa, Urochloa brizantha, and Urochloa decumbens

2019 ◽  
Vol 17 ◽  
pp. 95-102
Author(s):  
Dandara R. Muniz ◽  
Janaina S. Garcia ◽  
Taniris C. Braga ◽  
Ângelo de Fátima ◽  
Luzia V. Modolo
Keyword(s):  
Weed Species ◽  
Bidens Pilosa ◽  
Urochloa Decumbens ◽  
Urochloa Brizantha

scholarly journals Allelopathy of aqueous Pachyrhizus erosus L. extracts on Euphorbia heterophylla and Bidens pilosa

2018 ◽  
Vol 48 (1) ◽  
pp. 59-65
Author(s):  
Jaqueline de Araujo Barbosa ◽  
Silvio Douglas Ferreira ◽  
Adriana Cologni Salvalaggio ◽  
Neumárcio Vilanova da Costa ◽  
Márcia de Moraes Echer
Keyword(s):  
Germination Rate ◽  
Germination Percentage ◽  
Tuberous Root ◽  
Allelopathic Effect ◽  
Root Extract ◽  
Weed Species ◽  
Bidens Pilosa ◽  
Randomized Design ◽  
Pachyrhizus Erosus ◽  
Dry Biomass

ABSTRACT Allelopathy contributes to the sustainable management of weeds in growing areas, due to its ability to inhibit the development of weed species. This study aimed to evaluate the allelopathic effect of Pachyrhizus erosus extract on Euphorbia heterophylla and Bidens pilosa germination. The experiment was carried out in a completely randomized design, in a 2 x 2 x 4 factorial scheme, with four replications. The first factor corresponded to the plant portion (shoot and tuberous root), the second to the extract preparation method (water at room temperature and boiling) and the third to the extract concentrations (0 %, 25 %, 50 % and 100 %). Phytochemical analyses were performed to identify the presence of secondary metabolites. The variables germination percentage, germination rate index and dry biomass decreased with increasing aqueous extract concentrations for both E. heterophylla and B. pilosa. When applied a P. erosus crude shoot extract (boiling), decreases of 18 % and 92 % were observed in the E. heterophylla and B. pilosa germination, respectively, with a decrease of 91 % in the dry biomass of E. heterophylla seedlings. The tuberous root extract (boiling), on the other hand, reduced the germination percentages for E. heterophylla and B. pilosa in 18 % and 80 %, respectively. The phytochemical evaluation indicated the presence of flavonoids, coumarins and saponins in the shoot and tuberous root extracts, while tannins were only observed in the shoot extract. Thus, it can be concluded that P. erosus extracts display an allelopathic effect on the weed species evaluated.

Allelopathic effects of weed spp on the root border cells of Fagopyrum tataricum (L.) Gaertn

2021 ◽  
Vol 52 (1) ◽  
pp. 85-102
Author(s):  
Y.Y. Xie ◽  
L.X. Yao ◽  
S. Wei ◽  
S.H. He ◽  
L. Chen ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Mitochondrial Membrane ◽  
Reactive Oxygen ◽  
Aqueous Extracts ◽  
Oxygen Species ◽  
Weed Species ◽  
Fagopyrum Tataricum ◽  
Bidens Pilosa ◽  
Allelopathic Effects

We studied the allelopathic effects of aqueous extracts of Galinsoga parviflora Cav., Chenopodium ambrosioides L., and Bidens pilosa L. weed species on the developmental characteristics of Tartary buckwheat RBCs. The increase in the concentration of aqueous extracts, there was increase in apoptosis rate and mucigel thickness of the RBCs, level of intracellular reactive oxygen species and nitric oxide, but decreased the mitochondrial membrane potential (P <0.05). The allelopathic effects of aqueous extracts of donor weed species on RBCs followed the order: C. ambrosioides > B. pilosa > G. parviflora. The increased levels of reactive oxygen species, nitric oxide and the reduced potential of mitochondrial membrane, further disrupted the homeostasis and normal metabolism of cells, thereby inducing the cell death. Among the three weed species, C. ambrosioides had the most significant impact

scholarly journals Recent Trends in Controlling the Enzymatic Browning of Fruit and Vegetable Products

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2754 ◽  
Author(s):  
Kyoung Mi Moon ◽  
Eun-Bin Kwon ◽  
Bonggi Lee ◽  
Choon Young Kim
Keyword(s):  
Enzymatic Browning ◽  
Fruit And Vegetable ◽  
Food Ingredients ◽  
Polyphenol Oxidases ◽  
Current Trends ◽  
Vegetable Products ◽  
Chemical Inhibitors ◽  
Recent Trends ◽  
Physical And Chemical

Enzymatic browning because of polyphenol oxidases (PPOs) contributes to the color quality of fruit and vegetable (FV) products. Physical and chemical methods have been developed to inhibit the activity of PPOs, and several synthetic chemical compounds are commonly being used as PPO inhibitors in FV products. Recently, there has been an emphasis on consumer-oriented innovations in the food industry. Consumers tend to urge the use of natural and environment-friendly PPO inhibitors. The purpose of this review is to summarize the mechanisms underlying the anti-browning action of chemical PPO inhibitors and current trends in the research on these inhibitors. Based on their mechanisms of action, chemical inhibitors can be categorized as antioxidants, reducing agents, chelating agents, acidulants, and/or mixed-type PPO inhibitors. Here, we focused on the food ingredients, dietary components, food by-products, and waste associated with anti-browning activity.

scholarly journals De Novo Nucleic Acids: A Review of Synthetic Alternatives to DNA and RNA That Could Act as Bio-Information Storage Molecules

Life ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 346
Author(s):  
Kevin G Devine ◽  
Sohan Jheeta
Keyword(s):  
Nucleic Acids ◽  
Genetic Information ◽  
De Novo ◽  
Chemical Properties ◽  
Amino Acid Sequences ◽  
Information Storage ◽  
Heterocyclic Base ◽  
Dna And Rna ◽  
Phosphate Backbone ◽  
Physical And Chemical

Modern terran life uses several essential biopolymers like nucleic acids, proteins and polysaccharides. The nucleic acids, DNA and RNA are arguably life’s most important, acting as the stores and translators of genetic information contained in their base sequences, which ultimately manifest themselves in the amino acid sequences of proteins. But just what is it about their structures; an aromatic heterocyclic base appended to a (five-atom ring) sugar-phosphate backbone that enables them to carry out these functions with such high fidelity? In the past three decades, leading chemists have created in their laboratories synthetic analogues of nucleic acids which differ from their natural counterparts in three key areas as follows: (a) replacement of the phosphate moiety with an uncharged analogue, (b) replacement of the pentose sugars ribose and deoxyribose with alternative acyclic, pentose and hexose derivatives and, finally, (c) replacement of the two heterocyclic base pairs adenine/thymine and guanine/cytosine with non-standard analogues that obey the Watson–Crick pairing rules. This manuscript will examine in detail the physical and chemical properties of these synthetic nucleic acid analogues, in particular on their abilities to serve as conveyors of genetic information. If life exists elsewhere in the universe, will it also use DNA and RNA?

scholarly journals Chemical and Physical Characterization of Peanut Powder Extracts

2018 ◽  
Vol 10 (4) ◽  
pp. 323
Author(s):  
Luzia Marcia de Melo Silva ◽  
Francisco de Assis Cardoso Almeida ◽  
Francinalva Cordeiro de Sousa ◽  
Deise Souza de Castro ◽  
Inácia dos Santos Moreira ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Ambient Temperature ◽  
Spherical Shape ◽  
Chemical Compounds ◽  
Growth Potential ◽  
Chemical Characteristics ◽  
Peanut Extract ◽  
Physical And Chemical ◽  
Great Growth

The production of lyophilized foods is a market with great growth potential, for providing important preservation characteristics, such as stability at ambient temperature, versatility of the product and preservation of the chemical compounds. Given the functional effects of peanut powder extracts, this study aimed to quantify the bioactive compounds and determine physical and chemical characteristics, comparing samples with and without skin. After obtaining the aqueous peanut extract the samples were frozen at -18 °C for 24 h. The formulated extracts were dried in a benchtop lyophilizer operating at temperature of -55 °C for a period of 48 hours. The powder extracts were disintegrated in a multiprocessor for 30 seconds and the samples were physically and chemically evaluated. The powder extracts were classified as non-hygroscopic, exhibiting poor fluidity and intermediate cohesiveness in samples with skin, and high cohesiveness in samples without skin. The powders showed agglomerated particles, with irregular and non-uniform shape. Potassium was the mineral found in largest amounts, as well as oleic and linoleic fatty acids. The particles of the powders exhibit a spherical shape, showing the presence of amorphous surfaces, in which there is no repetition of geometric forms. The peanut powder extracts are classified as non-hygroscopic, have poor fluidity, intermediate cohesiveness in samples with skin and high cohesiveness in samples without skin.

Differences in clinicopathological and biological features between central-type and peripheral-type squamous cell carcinoma of the lung

Lung Cancer ◽  
2006 ◽  
Vol 52 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Takamoto Saijo ◽  
Genichiro Ishii ◽  
Kanji Nagai ◽  
Kazuhito Funai ◽  
Junichi Nitadori ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Central Type ◽  
Biological Features ◽  
Peripheral Type

scholarly journals Novel Use of Trinexapac-Ethyl to Study Weed Seed Germination

2014 ◽  
Vol 28 (4) ◽  
pp. 729-733 ◽  
Author(s):  
Héctor Roberto Huarte ◽  
Antonio Jesús Ruiz Carmona ◽  
María Luz Zapiola
Keyword(s):  
Weed Management ◽  
Crop Production ◽  
De Novo ◽  
Weed Species ◽  
Synthesis Inhibitor ◽  
Seed Biology ◽  
Combined Solution ◽  
Artichoke Thistle ◽  
Germination Requirements

Understanding seed biology and onset of germination requirements is a key point for designing effective weed management programs. Gibberellins (GAs) are known to play a role in onset of germination of several species. Onset of germination often requires an increase in de novo GA content or an increase in sensitivity to GAs. Reduced germination of seeds incubated in solutions containing compounds that inhibit GA synthesis provide evidence that GAs are required to trigger germination. Trinexapac-ethyl (TE), a GA synthesis inhibitor, is frequently used as a plant growth regulator in crop production. However, to the best of our knowledge, TE has not been used to study the requirement of GAs in onset of germination. Germination studies were conducted using seeds of artichoke thistle and common teasel under a range of TE concentrations (0 to 500 μM TE), a combined solution of 125 μM TE + 100 μM GA3for artichoke, and 250 μM TE + 100 μM GA3for common teasel. Germination tests were conducted at 20/10 C (12-h thermoperiod) in darkness for artichoke and at constant 15 C with 12 h of light for common teasel. Germination of artichoke in 125 μM TE was reduced to 47% when compared with the check (95%), but the combined TE + GA3solution maintained germination at 84%. Germination of common teasel in 250 μM TE was reduced to 10% when compared with the check (91%), and the combined TE + GA3solution increased germination to 63%. These results demonstrate the utility of TE to study the role of GAs in onset of germination. This novel use of TE is a valuable option to study germination requirements of weed species, and therefore contributes to the design of weed management programs.

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