An investigation of angle-meristem development in excised stem segments of Selaginella martensii

1969 ◽  
Vol 47 (5) ◽  
pp. 717-722 ◽  
Author(s):  
T. R. Webster
Keyword(s):  
Early Development ◽  
Filter Paper ◽  
Shoot Tip ◽  
Intact Plant ◽  
Developmental Study ◽  
Distilled Water ◽  
Effective Factor ◽  
Meristem Development ◽  
Stem Segments ◽  
Applied Auxin

The development of dorsal and ventral angle-meristems in excised Y-shaped stem segments of Selaginella martensii grown on filter paper moistened with distilled water has been investigated. Based on the position of the branchings relative to the shoot tip on the intact plant, segments were designated as young, intermediate, or old. In most segments, with no auxin treatment, ventral angle-meristems formed shoots. In most young segments the dorsal angle-meristem formed a root, whereas most old segments formed a dorsal shoot. A developmental study suggests that (1) in young segments early development of a ventral shoot, controls development of the dorsal angle-meristem as a root, and (2) in old segments where both angle-meristems develop at approximately the same time, there is no ventral control over dorsal development, and a dorsal shoot results. Experiments with externally applied auxin suggest that auxin is an effective factor in controlling ventral angle-meristem development as a root.

scholarly journals Larvicidal potencial of Sapindus saponaria (Sapindaceae) against Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae)

2007 ◽  
Vol 59 (1) ◽  
pp. 145-149 ◽  
Author(s):  
F.F. Fernandes ◽  
R.N. Leles ◽  
I.G. Silva ◽  
E.P.S. Freitas
Keyword(s):  
Larvicidal Activity ◽  
Filter Paper ◽  
Control Measure ◽  
Larval Mortality ◽  
Rhipicephalus Sanguineus ◽  
Distilled Water ◽  
Alternative Control ◽  
Ethanolic Extracts ◽  
Sapindus Saponaria ◽  
Botanical Acaricide

The larvicidal potential of the crude ethanolic extracts (CEE) of the stem peel of Sapindus saponaria was evaluated against Rhipicephalus sanguineus. Lethal concentrations (LC), were calculated by preparing CEE solutions at different concentrations in distilled water. Larvae fasted for 14-21 days were utilized in the bioassays, after incubation of engorged females collected from infested environments frequented by dogs in several neighborhoods of Goiânia, GO. Bioassays were performed in a specially constructed biological chamber for testing botanical acaricides, acclimatized to 27±1ºC, RH>80%. The larvae were counted on filter paper envelopes impregnated with the solutions or distilled water and larval mortality observed after 48h. S. saponaria showed good larvicidal activity (LC50 and LC99 of 1994 and 3922ppm, respectively) and the results demonstrated its potential as a botanical acaricide and an alternative control measure for R. sanguineus.

scholarly journals Effect of Seed Priming Techniques on Germination Parameters of Safflower (Carthamus tinctorius L.)

2018 ◽  
Vol 67 (2) ◽  
pp. 157-163
Author(s):  
Milan Jocković ◽  
Petar Čanak ◽  
Vladimir Miklič ◽  
Jelena Ovuka ◽  
Velimir Radić ◽  
...  
Keyword(s):  
Filter Paper ◽  
Low Cost ◽  
Seed Priming ◽  
Carthamus Tinctorius ◽  
Distilled Water ◽  
Significant Difference ◽  
Mean Germination Time ◽  
Metabolic Activities ◽  
Germination Parameters ◽  
Priming Technique

Summary A useful approach for improving seed germination and seedling growth is a seed priming technique. Application of the priming technique enhances water absorption, causing activation of metabolic activities in the seed. The objective of this study was to evaluate the effect of seed priming on germination parameters of safflower and to compare different priming techniques: priming by soaking and priming on filter paper. The priming treatments included hydropriming (distilled water) and osmopriming with 0.1% and 0.5% solutions of KNO3 for 8 and 16 hours. The experiment revealed significant difference between the priming treatments and the control. The highest germination (89.50%) was recorded within the priming treatments by soaking in the solution of 0.1% KNO3 and priming on filter paper moistened with 0.5% KNO3 for 8 hours. Considering germination index, mean germination time and time to 50% germination, the best results were obtained within hydropriming on filter paper for 16 hours. This study has shown that the priming techniques significantly improved germination parameters of safflower. Although priming on filter paper showed better results, the soaking technique – due to its simplicity, low cost and easiness of application – can be successfully used to improve germination parameters of safflower and increase the number of plants per unit of area and thus increase the seed yield per acreage.

scholarly journals Larvicidal potential of Sapindus saponaria to control the cattle tick Boophilus microplus

2005 ◽  
Vol 40 (12) ◽  
pp. 1243-1245 ◽  
Author(s):  
Fernando de Freitas Fernandes ◽  
Edméia de Paula e Souza Freitas ◽  
Anna Carolina da Costa ◽  
Ionizete Garcia da Silva
Keyword(s):  
Filter Paper ◽  
Test Group ◽  
Ethanol Extract ◽  
Boophilus Microplus ◽  
Lethal Concentration ◽  
Cattle Tick ◽  
Control Group ◽  
Distilled Water ◽  
Sapindus Saponaria

The objective of this study was to evaluate the larvicidal potential of a crude ethanol extract (CEE) of soapberry Sapindus saponaria stem peel on the cattle tick Boophilus microplus. Tick larvae obtained by incubating engorged females, collected from naturally infested cattle, were placed in envelopes of filter paper impregnated with different concentrations of CEE in the test group, and distilled water in the control group. Four repetitions were made with each solution (n>120). Mortality was observed after 48 hours. Lethal concentration values of 1,258 ppm (LC50) and 6,360 ppm (LC99) were obtained.

scholarly journals Tribo-electricity and friction. III.—Solid elements and textiles

1928 ◽  
Vol 118 (779) ◽  
pp. 108-113 ◽  
Keyword(s):  
General Practice ◽  
Filter Paper ◽  
Reliable Method ◽  
Preceding Paper ◽  
Systematic Investigation ◽  
The Other ◽  
Textile Material ◽  
Distilled Water ◽  
Initial Surface

1. No systematic investigation on this subject has yet been attempted. The efforts made to group these materials in a series according to the charges generated when they are rubbed two at a time are of uncertain value because of (1) impurities of substance and surface, (2) indeterminate initial surface strains. Moreover, the general practice has been to rub the solids when held, one in each hand. A more reliable method is to mount the bodies in a mechanism which ensures that the same parts of them come into contact at each fresh stroke. In the present research, the elements, mostly metals, are those specified in the preceding paper. The textiles are made and cleansed as described in an earlier paper. Silk, cotton and linen in our experience behave reliably when fully cleaned. The other great textile material, wool, is more oily and cannot be readily cleansed; so is less trustworthy. We therefore at present confine ourselves to one animal and one vegetable textile, choosing the pure samples of silk and cotton specified in the above paper. Also filter paper, another convenient fabric, is used after being boiled in several lots of distilled water. As the silk and cotton are treated with boiling chloroform, we tried exhausting the filter paper in this solvent to see if such treatment affected the cellulose in any way; but no effect on the properties of the paper could be found.

Cell wall water dilution: an explanation of apparent negative turgor potentials

1981 ◽  
Vol 59 (9) ◽  
pp. 1722-1725 ◽  
Author(s):  
Albert H. Markhart III ◽  
Nasser Sionit ◽  
James N. Siedow
Keyword(s):  
Cell Wall ◽  
Mathematical Simulation ◽  
Filter Paper ◽  
Plant Tissue ◽  
Osmotic Potential ◽  
Sucrose Solution ◽  
Model Systems ◽  
Significant Problem ◽  
Distilled Water ◽  
Water Dilution

Errors in psychrometric determinations of osmotic potential (Ψs) due to dilution of the cytoplasm by cell wall water are investigated. Model systems using filter paper to represent the cell wall and sucrose solution and distilled water to represent protoplasm and cell wall water, respectively, show significant dilution of the sucrose solution at cell wall to protoplast ratios typical of plant tissue. Mathematical simulation of error in Ψs determination as a function of percent cell wall and cell wall hydration indicate that wall water dilution can be a significant problem and could explain reported apparent negative turgor potentials.

scholarly journals Breeding technique of Selenothrips rubrocinctus (Giard, 1901) (Thysanoptera: Thripidae) on roses leaflets

2021 ◽  
Vol 3 ◽  
pp. ec03054
Author(s):  
Jailma R. Dos Santos ◽  
Brigida Souza ◽  
Marvin M. Pec Hernandez ◽  
Letícia G. de Souza ◽  
Luis Claudio P. Silveira
Keyword(s):  
Population Density ◽  
Filter Paper ◽  
Abiotic Factors ◽  
Petri Dish ◽  
Entire Period ◽  
Distilled Water ◽  
Breeding Technique ◽  
Microcentrifuge Tube ◽  
Paper Disk ◽  
Filter Paper Disk

The development of adequate methods for maintaining populations of arthropod organisms in the laboratory has been a challenge due to the characteristics of each species. This work has aimed to define a method for breeding Selenothrips rubrocinctus (Giard, 1901) in rose leaflets in order to study this species in the laboratory. A condition which could maintain the leaflets turgor for a longer time was sought, in order to guarantee both the survival and multiplication of the insects, and less influence of abiotic factors. Four types of substrates were tested: a) a filter paper disk moistened with distilled water covering the bottom of a Petri dish and; b) a vegetable sponge moistened with distilled water surrounding the base of the leaflet; c) a potato, dextrose and agar (BDA) in a microcentrifuge tube surrounding the base of the leaflet; and d) hydrogel in a microcentrifuge tube surrounding the base of the leaflet. The filter paper moistened with distilled water allowed 65% of the leaflets to remain turgid over a 10-day period and was the most suitable substrate for thrips breeding. With the results at hand, we described S. rubrocinctus breeding in the laboratory. The adopted methodology provided the population density stability of the bred insects, as well as the obtainment of specimens of S. rubrocinctus in quantity and quality throughout the entire period of development of studies on the biology of the species.

scholarly journals The Influence of Plant Growth Regulators on Budbreak and Shoot Growth from Large Stem Segments of Acer saccharinum L.

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 984C-984
Author(s):  
Katayoun Mansouri ◽  
John E. Preece
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Shoot Tip ◽  
Old Field ◽  
Latex Paint ◽  
Acer Saccharinum ◽  
Shoot Tip Explants ◽  
Stem Segments

A factorial combination of gibberellic acid (GA3) and benzyladenine (BA) was applied in 20% white exterior latex paint to large (40 cm long, >2.5 cm diameter) stem segments of Acer saccharinum L. (silver maple) to determine the effects on forcing new softwood shoots in the greenhouse or laboratory and the subsequent growth of these new shoots in vitro. Stem segments were harvested from 10-year-old field-grown coppice shoots. The GA3/BA-paint mixes were applied to the entire stem segments that were forced in plastic flats filled with 1 perlite: 1 vermiculite (by volume) and watered with care so as not to wet the new softwood shoots. The flats and stem segments were drenched weekly with Zerotol (0.18% H2O2). The softwood shoots were harvested when they were at least 3 cm long. After disinfesting and rinsing, the nodal and shoot tip explants were established aseptically in vitro on DKW medium with no cytokinin or with 10-8M thidiazuron. Coppice shoots were harvested, cut, and painted on 9 Sept., 28 Oct., and 12 Dec. 2005. Although there were no significant differences in shoot production among stem segments painted with various combinations of GA3/BA, stems treated with plant growth regulators produced a mean of 2.7, 1.8, or 0.5 shoots for the three harvest dates compared to 0.5, 0.0, or 0.25 shoots on control stem segments. It is well-known that shoot forcing is poor from September through January; however, use of GA3/BA resulted in growth of dormant epicormic shoots. Shoot tip explants produced the most shoots in vitro after 8 weeks if they were harvested from stem segments treated with 0.03 mM GA3, whereas nodal explants produced the most shoots if harvested from segments that had been treated with 0.01 mM GA3.

Etude cytologique de l'embryon du Pin d'Alep lors de la germination : influence d'un traitement stimulant par administration successive d'ions mercure et chlore

1978 ◽  
Vol 56 (23) ◽  
pp. 2931-2936 ◽  
Author(s):  
J. C. Pargney ◽  
P. Thalouarn
Keyword(s):  
Water Uptake ◽  
Filter Paper ◽  
Cytological Study ◽  
Distilled Water ◽  
Seeds Germination

Since it is known that successive applications of Hg2+ and Cl− ions accelerates Apel pine seeds germination, a cytological study of the treated embryo was made during the first 6 days of imbibition. In comparison with control seeds germinating on filter paper imbibed with distilled water, treated seeds show precocious mitoses and an acceleration of lipolysis and proteolysis as well as synthesis of organelles. These phenomena are particularly evident in the radicle. Since water uptake occurs especially in the radicular pole of the seed, this result suggests a determining role of imbibition in the process of germination in the Alep pine. No abnormal ultrastructures are observed in treated seeds.not available

scholarly journals Evaluation of activity of the crude ethanolic extract of Magonia pubescens St. Hil (Sapindaceae) against larvae of the cattle tick Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (Acari: Ixodidae)

2008 ◽  
Vol 51 (6) ◽  
pp. 1147-1152 ◽  
Author(s):  
Fernando de Freitas Fernandes ◽  
Priscilla Antunes Diógenes Bessa ◽  
Edméia de Paula e Souza Freitas
Keyword(s):  
Filter Paper ◽  
Ethanolic Extract ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Distilled Water ◽  
Significant Mortality

The acaricidal potential of the crude ethanolic extract (c.e.e.) of the stem peel of Magonia pubescens was evaluated against larvae of Rhipicephalus (Boophilus) microplus. The larvae were placed in filter paper envelopes impregnated with different concentrations of c.e.e., dissolved in dimethylsulfoxide (DMSO) and distilled water for determination of lethal concentrations (LC). The following treatments were used: 1. Envelopes of dry filter paper; 2. Envelopes of filter paper moistened with distilled water; 3. Envelopes of filter paper moistened with a solution of DMSO in distilled water; and 4. Envelopes moistened with 2 mL of each concentration of the c.e.e. to be tested. The bioassays were carried out in quadruplicate at 27°±1° C and RH e"80% and 12h light. Mortality was observed after 48 h, LC50 and LC99 values of 365 and 4,000 ppm being obtained. There was no significant mortality in larvae exposed to the first three treatments (p < 0.05).

scholarly journals Fruit-induced Dormancy in Apple Seeds: Role of Water and Inhibitors

1992 ◽  
Vol 117 (3) ◽  
pp. 463-466
Author(s):  
C.K. Wan ◽  
F.G. Dennis
Keyword(s):  
Water Content ◽  
Filter Paper ◽  
Wire Mesh ◽  
Distilled Water ◽  
Fruit Volatiles ◽  
Seed Water Content ◽  
Apple Seeds

The roles of inhibitors in the seedcoat and locules and of seed water content in fruit-induced dormancy of apple (Malus domestics Borkh.) seeds were investigated. Seeds were after-ripened at 5C for various periods up to 12 weeks: 1) in the locules of intact fruits or half-fruits, 2) on wire mesh over moist filter paper, which simulated the locule in preventing leaching, or 3) on moist filter paper. The seeds were subsequently germinated in the locules of half-fruits, on screen, or on moist paper. In some experiments, the seeds were soaked in distilled water before or after after-ripening, or the embryos were excised before germination. The results indicate that fruit volatiles are unlikely to inhibit germination of seeds after-ripened in the fruit. Although limited water content reduced the ability of the seeds to germinate, it did not prevent after-ripening. An unidentified inhibitor(s) present in the locule and on the surface of the seed appears to be the major factor(s) preventing germination in the fruit, as seeds after-ripened on moist paper germinated well on paper or screen but poorly in the locule. The inhibitor(s) appears to be metabolized or to break down spontaneously when seeds are after-ripened on a screen, suggesting that the locule serves as a reservoir of the inhibitor as long as the seed remains in the fruit.

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