scholarly journals Effect of NaCl on seed germination in some Centaurium Hill. Species (Gentianaceae)

2007 ◽  
Vol 59 (3) ◽  
pp. 227-231 ◽  
Author(s):  
S. Zivkovic ◽  
M. Devic ◽  
B. Filipovic ◽  
Z. Giba ◽  
D. Grubisic
Keyword(s):  
Life History ◽  
Salt Tolerance ◽  
Seed Germination ◽  
Gibberellic Acid ◽  
White Light ◽  
The Other ◽  
Distilled Water ◽  
Nacl Concentration ◽  
History Of ◽  
Species Specific

The influence of high NaCl concentrations on seed germination in both light and darkness was examined in the species Centaurium pulchellum, C. erythraea, C. littorale, C. spicatum, and C. tenuiflorum. Salt tolerance was found to depend on the life history of the seeds. To be specific, seeds of all five species failed to complete germination when exposed to continuous white light if kept all the time in the presence of 100-200 mM and greater NaCl concentrations. However, when after two weeks NaCl was rinsed from the seeds and the seeds were left in distilled water under white light for an additional two weeks, all species completed germination to a certain extent. The percent of germination not only depended on NaCl concentration in the prior medium, but was also species specific. Thus, seeds of C. pulchellum, C. erythraea, and C. littorale completed germination well almost irrespective of the salt concentration previously experienced. On the other hand, seeds of C. tenuiflorum completed germination poorly if NaCl concentrations in the prior media were greater than 200 mM. When seeds after washing were transferred to darkness for an additional 14 days, they failed to complete germination if previously imbibed on media containing NaCl concentrations greater than 400 mM. However, the seeds of all species, even if previously imbibed at 800 mM NaCl, could be induced to complete germination in darkness by 1 mM gibberellic acid. .

scholarly journals Environmental and Genotypic Regulation of Alstroemeria Seed Germination

HortScience ◽  
1990 ◽  
Vol 25 (12) ◽  
pp. 1607-1609 ◽  
Author(s):  
Joseph J. King ◽  
Mark P. Bridgen
Keyword(s):  
Seed Germination ◽  
Gibberellic Acid ◽  
The Other ◽  
Distilled Water ◽  
Cold Environment ◽  
Environmental Regime ◽  
Environmental Regimes ◽  
Temperature Regimes ◽  
Percent Germination

Presowing treatments and temperature regimes were tested to improve germination of Alstroemeria hybrids 3 to 12 months following harvest. In addition, seeds from 20 intraspecific F1 hybrids of five selections were also tested 3 to 7 or 8 to 12 weeks following harvest. Seeds were pretreated by chipping the seedcoat above the embryo, general abrasion of the entire seedcoat, or soaking 12 hours in distilled water, GA, (0.029, 0.29, 2.9 mm), or KNO3 (0.5 and 1.0 m). Pretreatments were evaluated under three environmental regimes: 8 weeks at a constant 18-25C (warm), 4 weeks at 18-25C followed by 4 weeks at 7C (warm-cold), or 4 weeks at 7C followed by 4 weeks at 18-25C (cold-warm). There was an interaction between pretreatment and environmental regime for percent germination. Germination percentages for the water soak and GA, at 0.29 or 2.9 mm were significantly higher than for the other pretreatments, but were not significantly different from one another. The warm-cold environment yielded higher germination percentages than the other environments. The time to germination was longest for the cold-warm regime. This response depended on the genotype and the age of the seed. Chemical name used: gibberellic acid (GA3).

scholarly journals On Apogamy and the development of Sporangia upon fern prothalli

1898 ◽  
Vol 63 (389-400) ◽  
pp. 56-61
Keyword(s):  
Life History ◽  
Point Of View ◽  
The Other ◽  
Normal Life ◽  
Other Hand ◽  
General Importance ◽  
Two Generations ◽  
History Of ◽  
Alternation Of Generations

The two most important deviations from the normal life-history of ferns, apogamy and apospory, are of interest in themselves, but acquire a more general importance from the possibility that their study may throw light on the nature of alternation of generations in archegoniate plants. They have been considered from this point of view Pringsheim, and by those who, following him, regard the two generations as homologous with one another in the sense that the sporophyte arose by the gradual modification of individuals originally resemblin the sexual plant. Celakovsky and Bower, on the other hand, maintaint the view tha t the sporophyte, as an interpolated stage in the life-history arising by elaboration of the zygote, a few thallophytes.

The Odd Man Out in a Pioneer Cemetery at Seccombe Lake Park, San Bernardino, California

2020 ◽  
pp. 90-113
Author(s):  
Patricia M. Lambert
Keyword(s):  
Life History ◽  
Native American ◽  
Morphological Traits ◽  
The Other ◽  
European Ancestry ◽  
Latter Day Saints ◽  
Community Members ◽  
San Bernardino ◽  
History Of ◽  
The 19Th Century

In 1989, a pioneer cemetery associated with the 19th-century Latter-Day Saints colony in San Bernardino, California, was discovered during the construction of a baseball field. Among the remains of 12 individuals recovered from the cemetery were those of a young man of about 22 years, whose burial treatment differed notably from the other intact interments at the site. Unlike these coffin burials, Burial 5 was found in a sprawling position, apparently tossed unceremoniously into the grave pit. Dental morphological traits identified the genetic affinities of this man as Native American, perhaps a member of the local Cahuilla or Serrano tribes, whereas the other individuals appeared to be of European ancestry, an interpretation consistent with records kept by community members. A possible identity for this individual came from a journal account describing the shooting of an “Indian” by the local sheriff, who was then brought to the fort, died, and was buried before his fellow tribesmen arrived to determine what had transpired and perhaps to claim his remains. This chapter explores the identity and life history of this young man in the context of the history of the valley and the pioneer community in which he met his death.

The Biology of the Genus Pissodes. (George Heriot Research Fellowship Thesis.)

1902 ◽  
Vol 23 ◽  
pp. 319-358
Author(s):  
R. Stewart MacDougall
Keyword(s):  
Life History ◽  
Economic Importance ◽  
The Other ◽  
Remedial Measures ◽  
Research Fellowship ◽  
History Of ◽  
The One ◽  
Harmful Insect

In the case of any harmful insect of economic importance, in order to war against it, or apply remedial measures at all intelligently, a knowledge of the life-history of the pest is necessary. This proposition will, I think, meet with such ready acceptance as to render proof unnecessary, but I might in illustration mention two cases which came under my own observation, where in the one case a knowledge of the round of life of the attacking insect saved a whole forest, and in the other proved of great importance.

Biography and (Global) Microhistory

2017 ◽  
Vol 11 (3) ◽  
Author(s):  
Mark Gamsa
Keyword(s):  
Life History ◽  
Northeast China ◽  
The Other ◽  
Historical Writing ◽  
Forthcoming Book ◽  
Recent Developments ◽  
History Of ◽  
German Origin ◽  
The One ◽  
The City

AbstractThis article has two goals. It reflects on the recent developments and agenda of an approach to historical writing that is now becoming known by the name global microhistory, and it analyses the attention which this approach pays to individual lives. It also explores some of the challenges in writing the biography of a city alongside the life history of a person. The city is Harbin, a former Russian-managed railway hub in Manchuria, today a province capital in Northeast China. The person is Baron Roger Budberg (1867–1926), a physician of Baltic German origin who arrived in Harbin during the Russo-Japanese war and remained there until his death, leaving published works and unpublished correspondence in German and Russian. My forthcoming book about Budberg and Harbin challenges the distinction between writing “biography”, on the one hand, and “history”, on the other, while navigating between the “micro” and “macro” layers of historical enquiry.

Epiphyllous Microorganisms as Palaeoclimate Estimators: The Developmental Sequence of Fungal 'Germlings' on their Living Host

1993 ◽  
Vol 6 (5) ◽  
pp. 377 ◽  
Author(s):  
AK Wells ◽  
RS Hill
Keyword(s):  
Life History ◽  
Host Species ◽  
The Other ◽  
Developmental Sequence ◽  
History Of

It is known that epiphyllous microorganisms have the potential to provide important information about palaeoclimates and palaeohabitats. Previous studies have shown one of the major candidates, fungal 'germlings', to be possibly climatically sensitive. In this study we demonstrate that at least two organisms are present as germlings, one an epiphyte and the other a saprophyte. While there is some evidence to support the hypothesis that grades of germlings represent a sequence of developmental steps, most data either refute this hypothesis or neither refute nor support it. We show that grade 1 and 2 germlings are unlikely to be reliable for predictive purposes, since their presence is not consistent among host species, and they may represent saprophytes as well as epiphytes. The ecology and life history of germlings is complex, and more data are required on these factors before they can be used for predictive purposes.

scholarly journals Memory and Alterity in Zar: Religious Contact and Change in the Sudan

2019 ◽  
Vol 8 ◽  
Author(s):  
Susan M Kenyon
Keyword(s):  
Life History ◽  
The Other ◽  
Ethnographic Research ◽  
The Past ◽  
Life History Data ◽  
History Of ◽  
The One ◽  
Ninteenth Century ◽  
Dynamic Interplay

Drawing on long-term ethnographic research in the Blue Nile town of Sennar, supported by archival and historical documentation, this article explores the history of Zar spirit possession in Sudan, and the light this throws on the interplay of religions over the past 150 years. Life history data supports the argument that contemporary Zar is grounded in forms and rituals derived from the ranks of the ninteenth-century Ottoman army, and these remain the basis of ritual events, even as they accommodate ongoing changes in this part of Africa. Many of these changes are linked to the dynamic interplay of Zar with forms of Islam, on the one hand, and Christianity, on the other. In the former colonial periods, political power resided with the British, and Khawaja (European) Christian Zar spirits are remembered as far more important. Today that authority in Zar has shifted to spirits of foreign Muslims and local holy men, on the one hand, and to subaltern Blacks, on the other. These speak to concerns of new generations of adepts even as changes in the larger political and religious landscapes continue to transform the context of Zar.

The Fine Structure of Primordial Germ Cells of the Rat

1973 ◽  
Vol 31 ◽  
pp. 634-635
Author(s):  
E. M. Eddy
Keyword(s):  
Endoplasmic Reticulum ◽  
Life History ◽  
Fine Structure ◽  
Rough Endoplasmic Reticulum ◽  
Germ Cells ◽  
Fibrous Material ◽  
Primordial Germ Cells ◽  
The Other ◽  
Large Size ◽  
History Of

Primordial germ cells are readily recognizable in embryos of the rat due to their large size, generally rounded shape and prominent nuclei with uniformly dispersed heterochromatin. They often have blunted pseudopodal processes at one end and small ruffles or trailing processes at the other, characteristics expected from their known ameboid activity- and migratory abilities. Also, the cytoplasm is rich in polyribosomes and contains a modest amount of rough endoplasmic reticulum and the mitochondria are frequently larger and less dense than those of adjacent somatic cells.In addition to these general characteristics, there are features unique to germ cells which allow them to be identified with certainty. These are: 1) small vesicles containing an irregular, dense core and 2) discrete accumulations of fibrous material known as nuage. Both of these features are present in other species and at other times in the life history of germ cells. The dense-cored vesicles have been noted in fetal and early postnatal mouse oogonia and oocytes, and in hamster and rabbit oocytes.

scholarly journals VIII. Observations on coprozoic flagellates: Together with a suggestion as to the significance of the kinetonucleus in the binucleata

1916 ◽  
Vol 207 (335-347) ◽  
pp. 375-412 ◽  
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Alimentary Canal ◽  
The Other ◽  
Considerable Time ◽  
Parasitic Fauna ◽  
History Of ◽  
Active Condition ◽  
Soil Protozoa ◽  
The Subject

Since publishing, with Mr. Lapage, the first account of the life-cycle of Helkesimastix facicola , I have continued to work alone on the biology and life-history of the flagellates occurring in simple dung-cultures. In the course of this investigation, I have made certain observations which I wish here to record, together with one or two suggestions which I have to offer. The work promises to occupy considerable time before it is completed, and in the case of some of the forms studied I am not yet able to describe the life-cycle in its entirety. Little or no attention has been paid hitherto to the protozoa active in dung, and the study of this fauna is probably not without interest and importance in connection with the subject of the soil-protozoa. To distinguish those protozoa which are carried through the alimentary canal in a passive, encysted condition and become active and go through their life-history in the moist dung, Prof. Minchin has suggested, in the course of his lectures, the useful term coprozoic . The coprozoic fauna of goats and sheep is entirely different from their parasitic fauna, which has for its principal habitat the rumen. Neither the various specialised ciliates (of the fam. Ophryoscolecidæ ) nor the flagellates ( Sphæromonas , Trichomastix and Callimastix ), some of which are invariably present in the rumen, ever occur in an active condition in dung-cultures; and, on the other hand, I have never found any of the coprozoic flagellates active in the rumen-contents, when freshly examined. These facts, readily determined because the sets of forms in the two cases are entirely different, afford important confirmation of the view, now generally accepted, that the Entamæbæ —the truly parasitic forms—are quite distinct from the Amoebæ which develop in fæcal cultures, i. e .,coprozoic species.

scholarly journals Phytotoxicity of the extracts of Lonchocarpus muehlbergianus Hassl. (Fabaceae) leaflets and galls on seed germination and early development of lettuce

2008 ◽  
Vol 22 (4) ◽  
pp. 1095-1100 ◽  
Author(s):  
Denis Coelho de Oliveira ◽  
Geraldo Luiz Gonçalves Soares ◽  
Rosy Mary dos Santos Isaias
Keyword(s):  
Seed Germination ◽  
Trophic Levels ◽  
The Other ◽  
Distilled Water ◽  
Aqueous Extracts ◽  
Seedling Height ◽  
Gall Formation ◽  
Allelopathic Effects ◽  
Axis Length ◽  
Tissue Alterations

Galls induced by Euphalerus ostreoides (Hemiptera: Psyllidae) cause structural and chemical alterations on Lonchocarpus muehlbergianus leaflets. Healthy and galled leaflet tissues of this plant species are rich in secondary metabolites with potential allelopathic effects. This research compares the allelopathic effects of the aqueous extracts of L. muehlbergianus leaflets and galls on seeds and seedlings of Lactuta sativa, and evaluates the chemical impact produced by a gall-inducing insect on the other trophic levels associated with it. The extracts were obtained through static maceration in distilled water (5% p/v). The treatments consisted of aqueous crude extracts and those previously filtered in polyvinylpirrolidone (PVP). After seven days, seedling height was measured, and the radicles were fixed in FAA50 for anatomical analyses. Healthy leaflet and gall aqueous extracts, and those filtered in PVP, significantly inhibited seed germination, with no significant differences between the two groups. Treatments with aqueous extracts reduced seed germination speed and vegetative axis length. Plant tissue alterations confirm the phytotoxicity of allelochemical substances present in the extracts. The differences among the treatments indicated that gall formation altered L. muehlbergianus leaflet metabolism, and this could influence the other trophic levels associated with this gall inducing-host plant system.

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