Differences in seed germination response of two populations of Phelipanche ramosa (L.) Pomel to a set of GR24 concentrations and durations of stimulation

2021 ◽  
pp. 1-6
Author(s):  
Stéphanie Gibot-Leclerc ◽  
Manon Connault ◽  
Rémi Perronne ◽  
Fabrice Dessaint

Abstract Phelipanche ramosa is a major weed holoparasite characterized by a broad host range with a suboptimal development on numerous hosts, suggesting inter- or intra-species specificities. Seeds of P. ramosa germinate after exposure to exogenous chemicals exuded by surrounding host roots such as strigolactones, the concentrations of these germination stimulants varying between hosts. In France, P. ramosa is characterized by genetically differentiated populations presenting varying germination rates and a host specificity. The objective of our study was to investigate the sensitivity of seeds of two P. ramosa populations harvested on tobacco and oilseed rape, to a set of GR24 concentrations, a synthetic strigol analogue. The assessment of the germination rate was based on in vitro experiments. Seeds of P. ramosa were placed in Petri dishes with various concentrations of GR24. The cumulative number of germinated seeds of P. ramosa was counted several times after application of the treatment. Cumulative germination curves were analysed using a three-parameter log-logistic model and a time-to-event approach. The results show that the germination rate of P. ramosa seeds depends on the GR24 concentration and the duration of stimulation, but also that the response to these two factors varies greatly according to the origin of the P. ramosa seeds. The difference in germination speed between P. ramosa populations further shows distinct responses at the intraspecific level, thus suggesting that the specialization of P. ramosa probably occurs at least from the first stage of the holoparasite cycle.

HortScience ◽  
2015 ◽  
Vol 50 (5) ◽  
pp. 738-743 ◽  
Author(s):  
Margaret W. Kirika ◽  
Jane W. Kahia ◽  
Lucien N. Diby ◽  
Eliud M. Njagi ◽  
Colombe Dadjo ◽  
...  

Erythrina abyssinica (E. abyssinica) is a multipurpose tree and a well-known medicinal plant which is conventionally propagated mainly by seeds. This method may produce a high degree of genetic variability and consequently decrease the medicinal value of the plant. Besides, the seeds have low germination rate and propagation is restricted to rainy season. Hence, there is need to develop a propagation protocol which produces a uniform plants and one which is not restricted to seasons. The objective of this study was to establish an in vitro propagation protocol for the multiplication of E. abyssinica. Seeds were sterilized and germinated in vitro to get sterile starting explants. Sterilization of the seeds was evaluated using different concentrations of a commercial bleach (JIK) ranging from 10%, 20% to 30% for 25 minutes. Kinetin (2.25, 4.50, 6.75, and 9.0 mg/L), and benzylaminopurine (BAP; 2.15, 4.30, 6.46, and 8.61 mg/L) were evaluated in separate experiments for their effect to induce microshoots from nodal explants. Rooting of the microshoot was carried out using half strength Murashige and Skoog (MS) media supplemented with indolebutyric acid (IBA) (0.20, 0.51, and 1.02 mg/L). Statistical analysis software (SAS) package was used to perform analysis of variance on the data to test the significance of the difference between treatments. The result of the sterilization experiment indicated that 10% JIK gave the highest percentage (55%) of clean seeds. Benzylaminopurine evaluated at 8.61 mg/L gave the highest mean number of microshoots (6.80 ± 1.24) after 28 days. On the other hand, IBA evaluated at 0.51mg/L gave the highest mean root length (6.00 ± 01.85 cm). The regenerated plants were acclimatized in the greenhouse and 65% survival rate was recorded after one month. With the increasing worldwide demand for medicinal plants as an alternative to prescription drugs, ex situ, in situ conservation programs and true to type mass propagation of E. abyssinica could benefit from the findings of this study. This is the first report on micropropagation of E. abyssinica.


Irriga ◽  
2010 ◽  
Vol 15 (4) ◽  
pp. 414-421
Author(s):  
Lucas Aragao Hora Almeida ◽  
Luana Santos Sampaio ◽  
Mateus Ribeiro Santana ◽  
Claudio Lucio Fernandes Amaral

A seleção de gametófitos que respondem a determinados tratamentos de forma diferenciada é de grande importância em programas de melhoramento vegetal. Portanto, foi objetivo deste trabalho avaliar o efeito do estresse salino sob a taxa de viabilidade polínica em mamona (R. comunnis L.). Foram coletadas 300 flores de 60 plantas espontâneas, previamente selecionadas com base em seu aspecto fitossanitário, a partir de duas populações obtidas no município de Jequié - BA. Para seleção in vitro foram testados 5 meios de cultura com diferentes concentrações de NaCl, quais sejam: M1 = 0; M2 = 25; M3 = 50; M4= 75 e M5 = 100 (mM). Foram observadas variações na taxa de germinação dos grãos de pólen, tanto para uma, quanto para outra população. Para todas as plantas de cada uma das populações estudadas, a taxa de germinação de pólen foi maior no meio de cultura contendo 0mM de NaCl, o que significa que o sal influência esta característica. UNITERMOS - Polén, Germinação, Fator Estressante, NaCl.  IN VITRO SELECTION OF CASTOR BEAN TO SALT STRESS RESISTANCE: FOCUS ON SPONTANEOUS PLANTS  2 ABSTRACT The gametophytic selection that reacts to certain treatments in a differentiated manner is of great importance in plant breeding programs. The objective of this work was to evaluate the saline stress effect under the viability pollinic rate in castor oil plant (R. comunnis L.). Three hundred flowers of 60 spontaneous plants were collected, previously selected based on their phytosanitary aspect, from two populations obtained in the city of Jequié - BA. For in vitroselection 5 culture medium  were tested with different NaCl concentrations, which were M1 = 0; M2 = 25; M3 = 50; 75 M4= and M5 = 100 (mM). Variations were observed in the pollen grains germination rate, for both populations. All plants of each studied populations hadpollen germination rate higher in the culture medium containing 0mM of NaCl, which means that the salt influences this characteristic. KEY WORDS - Pollen, Germination, Stress Factor, NaCl


Author(s):  
Annie Lang ◽  
Nancy Schwartz ◽  
Sharon Mayell

The study reported here compared how younger and older adults processed the same set of media messages which were selected to vary on two factors, arousing content and valence. Results showed that older and younger adults had similar arousal responses but different patterns of attention and memory. Older adults paid more attention to all messages than did younger adults. However, this attention did not translate into greater memory. Older and younger adults had similar levels of memory for slow-paced messages, but younger adults outperformed older adults significantly as pacing increased, and the difference was larger for arousing compared with calm messages. The differences found are in line with predictions made based on the cognitive-aging literature.


1988 ◽  
Vol 27 (04) ◽  
pp. 151-153
Author(s):  
P. Thouvenot ◽  
F. Brunotte ◽  
J. Robert ◽  
L. J. Anghileri

In vitro uptake of 67Ga-citrate and 59Fe-citrate by DS sarcoma cells in the presence of tumor-bearing animal blood plasma showed a dramatic inhibition of both 67Ga and 59Fe uptakes: about ii/io of 67Ga and 1/5o of the 59Fe are taken up by the cells. Subcellular fractionation appears to indicate no specific binding to cell structures, and the difference of binding seems to be related to the transferrin chelation and transmembrane transport differences


1973 ◽  
Vol 29 (02) ◽  
pp. 490-498 ◽  
Author(s):  
Hiroh Yamazaki ◽  
Itsuro Kobayashi ◽  
Tadahiro Sano ◽  
Takio Shimamoto

SummaryThe authors previously reported a transient decrease in adhesive platelet count and an enhancement of blood coagulability after administration of a small amount of adrenaline (0.1-1 µg per Kg, i. v.) in man and rabbit. In such circumstances, the sensitivity of platelets to aggregation induced by ADP was studied by an optical density method. Five minutes after i. v. injection of 1 µg per Kg of adrenaline in 10 rabbits, intensity of platelet aggregation increased to 115.1 ± 4.9% (mean ± S. E.) by 10∼5 molar, 121.8 ± 7.8% by 3 × 10-6 molar and 129.4 ± 12.8% of the value before the injection by 10”6 molar ADP. The difference was statistically significant (P<0.01-0.05). The above change was not observed in each group of rabbits injected with saline, 1 µg per Kg of 1-noradrenaline or 0.1 and 10 µg per Kg of adrenaline. Also, it was prevented by oral administration of 10 mg per Kg of phenoxybenzamine or propranolol or aspirin or pyridinolcarbamate 3 hours before the challenge. On the other hand, the enhancement of ADP-induced platelet aggregation was not observed in vitro, when 10-5 or 3 × 10-6 molar and 129.4 ± 12.8% of the value before 10∼6 molar ADP was added to citrated platelet rich plasma (CPRP) of rabbit after incubation at 37°C for 30 second with 0.01, 0.1, 1, 10 or 100 µg per ml of adrenaline or noradrenaline. These results suggest an important interaction between endothelial surface and platelets in connection with the enhancement of ADP-induced platelet aggregation by adrenaline in vivo.


1987 ◽  
Vol 57 (02) ◽  
pp. 201-204 ◽  
Author(s):  
P Y Scarabin ◽  
L Strain ◽  
C A Ludlam ◽  
J Jones ◽  
E M Kohner

SummaryDuring the collection of samples for plasma β-thromboglobulin (β-TG) determination, it is well established that artificially high values can be observed due to in-vitro release. To estimate the reliability of a single β-TG measurement, blood samples were collected simultaneously from both arms on two separate occasions in 56 diabetic patients selected for a clinical trial. From each arm, blood was taken into two tubes containing an anticoagulant mixture with (tube A) and without (tube B) PGE!. The overall mean value of B-TG in tube B was 1.14 times higher than in tube A (p <0.01). The markedly large between-arms variation accounted for the most part of within-subject variation in both tubes and was significantly greater in tube B than in tube A. Based on the difference between B-TG values from both arms, the number of subjects with artifically high B-TG values was significantly higher in tube B than in tube A on each occasion (overall rate: 28% and 14% respectively). Estimate of between-occasions variation showed that B-TG levels were relatively stable for each subject between two occasions in each tube. It is concluded that the use of PGEi decreases falsely high B-TG levels, but a single measurement of B-TG does not provide a reliable estimate of the true B-TG value in vivo.


2019 ◽  
Vol 2 (1) ◽  
pp. 9-13
Author(s):  
Zaim Anshari ◽  
Chrismis Novalinda Ginting ◽  
Linda Chiuman ◽  
Yuliani Mardiati Lubis

This study aims to determine whether mangosteen rind extract (in the form of ethanol extract/EE) can be used as an anti-diarrhea drug after compared with other anti-diarrhea substances in three experimental groups. This research is an in vitro experimental study using adult male guinea pigs weighing 400-600 gr through the standard method of Magnus with the Latin square controlled experiment design. The study was conducted at the Pharmacology and Toxicology Laboratory of the Faculty of Pharmacy, University of North Sumatra. The results showed that the contraction of ileum in Ach with Atp + Ach compared the difference in contraction of ileum Ach with EE + Ach showed the difference in difference between the two contractions of the ileum was significant, the contraction of ileum in His with Dip + His compared indifference in contraction of ileum His with EE + His showed a difference indifference. the two ileal contractions are significant, the ileal contraction in the bar with Papa + Bar compared to the difference between the ileum bar contraction with EE + Bar shows no difference in the difference between the two ileum contractions. The conclusion is that the Mangosteen Skin Ethanol Extract works similarly to Papaverine Hydrochloride which is an antidiarrheal drug used to relax smooth muscles so that it can also make blood vessels dilate by relaxing smooth muscles in the walls of blood vessels.


2020 ◽  
Vol 10 (3) ◽  
pp. 237-249
Author(s):  
Shashank Soni ◽  
Veerma Ram ◽  
Anurag Verma

Introduction: Hydrodynamically balanced system (HBS) possesses prolonged and continuous delivery of the drug to the gastrointestinal tract which improves the rate and extent of medications that have a narrow absorption window. The objective of this work was to develop a Hydrodynamically Balanced System (HBS) of Metoprolol Succinate (MS) as a model drug for sustained stomach specific delivery. Materials and Methods: Experimental batches were designed according to 3(2) Taguchi factorial design. A total of 9 batches were prepared for batch size 100 capsules each. Formulations were prepared by physically blending MS with polymers followed by encapsulation into hard gelatin capsule shell of size 0. Polymers used were Low Molecular Weight Chitosan (LMWCH), Crushed Puffed Rice (CPR), and Hydroxypropyl Methylcellulose K15 M (HPMC K15M). Two factors used were buoyancy time (Y1) and time taken for 60% drug release (T60%; Y2). Results: The drug excipient interaction studies were performed by the thermal analysis method which depicts that no drug excipient interaction occurs. In vitro buoyancy studies and drug release studies revealed the efficacy of HBS to remain gastro retentive for a prolonged period and concurrently sustained the release of MS in highly acidic medium. All formulations followed zero-order kinetics. Conclusion: Developed HBS of MS with hydrogel-forming polymers could be an ideal delivery system for sustained stomach specific delivery and would be useful for the cardiac patients where the prolonged therapeutic action is required.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wasan Katip ◽  
Jukapun Yoodee ◽  
Suriyon Uitrakul ◽  
Peninnah Oberdorfer

AbstractColistin provides in vitro activity against numerous ESBL-producing and carbapenem-resistant bacteria. However, clinical information with respect to its utilization in infection caused by ESBL producers is limited. The aim of this study was a comparison of mortality rates of loading dose (LD) colistin and carbapenems as definitive therapies in a cohort of patients with infections caused by ESBL-producing Escherichia coli and Klebsiella pneumoniae. A retrospective cohort study in 396 patients with ESBL-producing E.coli and K.pneumoniae infection at a university-affiliated hospital was conducted between 1 January 2005 and 30 June 2015 to compare outcomes of infected patients who received LD colistin (95 patients) with carbapenems (301 patients). The three primary outcomes were 30-day mortality, clinical response and microbiological response. The most common infection types were urinary tract infection (49.49%), followed by pneumonia (40.66%), bacteremia (13.64%), skin and soft tissue infections (4.80%) and intra-abdominal infection (3.03%). LD colistin group provided higher 30-day mortality when compared with carbapenems group (HR 7.97; 95% CI 3.68 to 17.25; P = 0.001). LD colistin was also independently associated with clinical failure (HR 4.30; 95% CI 1.93 to 9.57; P = 0.001) and bacteriological failure (HR 9.49; 95% CI 3.76 to 23.96; P = 0.001) when compared with those who received carbapenems. LD colistin treatment was associated with poorer outcomes, i.e. mortality rate, clinical response and microbiological response. Moreover, when adjusted confounding factors, LD colistin was still less effective than carbapenems. It should be noted that, however, the use of Vitek-2 to assess colistin susceptibility could provide inaccurate results. Also, the difference in baseline characteristics could still remain in retrospective study although compensation by hazard ratio adjustment was performed. Therefore, clinical utilization of LD colistin should be recommended as an alternative for treatment ESBL-producing Enterobacteriaceae only in the circumstances where carbapenems cannot be utilized, but this recommendation must be considered carefully.


Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1234
Author(s):  
António Sérgio Silva ◽  
Aurora Carvalho ◽  
Pedro Barreiros ◽  
Juliana de Sá ◽  
Carlos Aroso ◽  
...  

Thermal and self-curing acrylic resins are frequently and versatilely used in dental medicine since they are biocompatible, have no flavor or odor, have satisfactory thermal qualities and polishing capacity, and are easy and fast. Thus, given their widespread use, their fracture resistance behavior is especially important. In this research work, we comparatively analyzed the fracture resistance capacity of thermo and self-curing acrylic resins in vitro. Materials and Methods: Five prosthesis bases were created for each of the following acrylic resins: Lucitone®, ProBase®, and Megacryl®, which were submitted to different forces through the use of the CS® Dental Testing Machine, usually mobilized in the context of fatigue tests. To this end, a point was defined in the center of the anterior edge of the aforementioned acrylic resin bases, for which the peak tended until a fracture occurred. Thermosetting resins were, on average, more resistant to fracture than self-curable resins, although the difference was not statistically significant. The thermosetting resins of the Lucitone® and Probase® brands demonstrated behavior that was more resistant to fracture than the self-curing homologues, although the difference was not statistically significant. Thermosetting resins tended to be, on average, more resistant to fracture and exhibited the maximum values for impact strength, compressive strength, tensile strength, hardness, and dimensional accuracy than self-curing resins, regardless of brand.


Sign in / Sign up

Export Citation Format

Share Document