scholarly journals Gametophytic phase of the Indonesian ferns Amblovenatum immersum (Blume) Mazumdar and Christella subpubescens (Blume) Holttum (Thelypteridaceae)

2021 ◽  
Vol 45 ◽  
pp. e73379
Author(s):  
Sofía Ruano ◽  
Andrea Seral ◽  
Rubén Vázquez ◽  
Sonia Molino ◽  
José María Gabriel y Galán
Keyword(s):  
Spore Germination ◽  
Developmental Pattern ◽  
Morphological Development ◽  
Normal Type ◽  
Reproduction Strategies

The gametophytic generation of Amblovenatum immersum and Christella subpubescens (Thelypteridaceae), including spore germination, morphological development of the gametophytes, major vegetative features and reproduction strategies, was studied. For both species, the spore germination was of the Vittaria type and the developmental pattern was of the Drynaria type. Adult gametophytes were cordate and hairy, with unicellular and secretory hairs located in the margins and both the ventral and dorsal surfaces of the prothalli. C. subpubescens has another type of acicular hairs only in the margin of the prothallus. Gametangia were of the normal type described for leptosporangiate ferns. In A. immersum all the gametophytes were female. In C. subpubescens the gametophytes produced at first instance female gametangia and then became bisexual with time. Antheridiogen activity was observed in both species, suggested by the presence of small young ameristic gametophytes with antheridia surrounding well-developed female ones.

DEVELOPMENTAL MORPHOLOGY OF THE INFLORESCENCE IN HEXAPLOID WHEAT CULTIVARS WITH AND WITHOUT THE CULTIVAR NORIN 10 IN THEIR ANCESTRY

1973 ◽  
Vol 53 (1) ◽  
pp. 7-15 ◽  
Author(s):  
JOHN E. FISHER
Keyword(s):  
Triticum Aestivum ◽  
Apical Dominance ◽  
Triticum Aestivum L ◽  
Leaf Primordia ◽  
Developmental Pattern ◽  
Morphological Development ◽  
Wheat Cultivars ◽  
Developmental Morphology ◽  
Secale Cereale L ◽  
The Individual

The morphological development of the spike in short-statured hexaploid wheats (Triticum aestivum L.) derived from the cultivar Norin 10, and in Norin 10 as well, was markedly different from that in standard hexaploid wheats. In Norin 10 and its derivatives, the single ridges (slowly growing leaf primordia) on the elongating apex were considerably larger and spikelet primordia initiation and expansion were markedly delayed, resulting in a long apex with many single ridges. When spikelet development commenced, it was much more synchronous and hence gave rise to longer heads than in standard wheat in which spikelet development began soon after the start of the elongation of the apex. In most Norin 10 derivatives, more spikelets were initiated than in standard wheat. Apical dominance in the spike appeared to be stronger than in standard wheats. Also, apical dominance within the individual spikelets appeared to be greater, the net result being more fertile florets per spikelet. The developmental pattern of the spike of Norin 10 and its derivatives resembled, to a marked degree, the developmental pattern of rye (Secale cereale L.).

scholarly journals Study of the Gametophytic phase of Diplazium caudatum (Athyriaceae, Polypodiopsida) from Spain

2021 ◽  
Vol 45 ◽  
pp. e73313
Author(s):  
David Martín Alonso ◽  
Sonia Molino de Miguel ◽  
Andrea Seral ◽  
José María Gabriel y Galán
Keyword(s):  
Spore Germination ◽  
Germination Rate ◽  
Reproductive Development ◽  
Sexual Expression ◽  
Morphological Development ◽  
Observational Period ◽  
Reproductive Phase ◽  
La Gomera

The gametophytes of the Athyriaceae are not very well known, such as Diplazium caudatum. The aim of this work is to analyze the gametophytic phase of this species, which includes germination study, morphological development and reproductive phase. Spores belonging to two different sporophytes from La Gomera, Spain, were mixed and sown in multisporic cultures. Plates have been cultured in chambers with nutritive agar at 25ºC and 12 hours photoperiod. The germination was registered every three days, and the main vegetative and reproductive development was checked throughout the observational period. The germination rate reached a maximum of 58%. The spore germination followed a Vittaria pattern meanwhile prothallial development followed an Adiantum type. Regarding sexual expression, all gametophytes developed archegonia and later some of them developed antheridia becoming bisexual.

Scanning Electron Microscopy and x-ray analysis of microparticles and early hydration effects

1995 ◽  
Vol 53 ◽  
pp. 692-693
Author(s):  
Yun Lu ◽  
David C. Joy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Morphological Development ◽  
Early Hydration ◽  
X Ray ◽  
Blended Cements ◽  
Powder Particles ◽  
Chemical Wastes ◽  
Scanning Electron

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.

SEM study of the morphological effects of kinetin and zeatin on the growth and development of the apical meristem in wheat

1995 ◽  
Vol 53 ◽  
pp. 978-979
Author(s):  
G. M. Hutchins ◽  
J. S. Gardner
Keyword(s):  
Growth And Development ◽  
Furfuryl Alcohol ◽  
Apical Meristem ◽  
Plant Cells ◽  
Triticum Aestivum L ◽  
Morphological Development ◽  
Naturally Occurring ◽  
Chinese Spring Wheat ◽  
Sem Study ◽  
Moist Environment

Cytokinins are plant hormones that play a large and incompletely understood role in the life-cycle of plants. The goal of this study was to determine what roles cytokinins play in the morphological development of wheat. To achieve any real success in altering the development and growth of wheat, the cytokinins must be applied directly to the apical meristem, or spike of the plant. It is in this region that the plant cells are actively undergoing mitosis. Kinetin and Zeatin were the two cytokinins chosen for this experiment. Kinetin is an artificial hormone that was originally extracted from old or heated DNA. Kinetin is easily made from the reaction of adenine and furfuryl alcohol. Zeatin is a naturally occurring hormone found in corn, wheat, and many other plants.Chinese Spring Wheat (Triticum aestivum L.) was used for this experiment. Prior to planting, the seeds were germinated in a moist environment for 72 hours.

Ageing: Parental Care and Reproduction Strategies

1995 ◽  
Vol 5 (12) ◽  
pp. 1689-1695 ◽  
Author(s):  
John Thoms ◽  
Peter Donahue ◽  
Doug Hunter ◽  
Naeem Jan
Keyword(s):  
Parental Care ◽  
Reproduction Strategies

Intestinal microbiota balance modulates host susceptibility to infection with enteric pathogenss

2007 ◽  
Vol 30 (4) ◽  
pp. 93
Author(s):  
I Sekirov ◽  
N Tam ◽  
M Robertson ◽  
C Lupp ◽  
B Finlay
Keyword(s):  
Intestinal Microbiota ◽  
Small Animal ◽  
Host Susceptibility ◽  
Morphological Development ◽  
Future Design ◽  
Susceptibility To Infection ◽  
Colonic Microbiota ◽  
Food Borne ◽  
Serovar Typhimurium ◽  
Intestinal Pathogens

Background: During our lifetimes we develop a very complex set of interactions with the multitude of microorganisms colonizing our bodies. In the gastrointestinal system, the microbiota is highly important for morphological development, nutrition, and protection against infectious diseases. The gastrointestinal pathogens, enterohemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC) and Salmonella enterica serovar Typhimurium (ST) are food-borne pathogens that cause much morbidity and mortality worldwide. Citrobacter rodentium (Cr) is a mouse pathogen that is used in small animal models to mimic EHEC and EPEC infections. Methods: We began to characterize the contribution of intestinal microbiota to the progression of these infections. Two main phyla comprise the majority of mouse intestinal microbiota: Bacteroidetes and Firmicutes. Bacteria from a number of additional phyla are also present in smaller numbers; among them γ-Proteobacteria class, belonging to Proteobacteria phylum, is note-worthy as this class harbours many intestinal pathogens, such as ST and Cr. The mouse intestinal microbiota was perturbed using tetracycline (Tet) and streptomycin (Sm) to increase the proportion of Bacteroidetes in the colonic microbiota, and using vancomycin (Vanc) to create a predominance of Firmicutes. The mice with this perturbed microbiota were infected with ST to investigate the resultant pathology and virulence characteristics, and any additional shifts in microbiota as a result of infection. Results: Treatment of mice with Sm and Vanc was found to decrease the resistance of mice to colonization with ST, while Tet-treated mice exhibited unchanged colonization resistance. Treatment of mice with gradually increasing doses of Sm, which gradually augmented the proportion of CFB bacteria in the microbiota, resulted in progressively increasing colonization of mice by ST, as well as a step-wise increase in the ST-induced typhlitis, associated with higher levels of inflammatory markers IL-6 and KC. The increasing levels of ST colonization following both Sm and Vanc treatment were associated with an increase in the proportion of γ-Proteobacteria in the cecal and colonic microbiota, as well as a decrease in the total bacterial numbers in both organs. Conclusions: It is evident that the intestinal microbiota plays a significant role in the host’s response to infection with enteric pathogens, and its composition and numbers are also affected by the offending bacteria. Elucidation of the details regarding the contribution of the microbiota to infectious disease progression will offer novel targets for the future design of superior prevention and treatment methods.

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