scholarly journals Nuclear differentiation in the filamentous caulonema of the moss Funaria hygrometrica

1995 ◽  
Vol 131 (4) ◽  
pp. 543-556 ◽  
Author(s):  
KEITH I. KINGHAM ◽  
JEFFREY G. DUCKETT ◽  
MATTHEW C. P. GLYN ◽  
ANDREW R. LEITCH
2012 ◽  
pp. 66-69
Author(s):  
Nhan Duc Nguyen ◽  
Cong Nho Luong ◽  
Hoang Vu Nguyen

Background: The erosion of mosses on the surface of Hue imperial citadel has caused a lot of harm and is currently an urgent problem to be solved. Objectives:1. Identifying some moss species growing on Hue relics. 2. Determining the cause of slipperiness and the living environment mosses. 3. Finding a solution to limit the intrusion of the mosses. Methods: The methods are: identifying scientific name by comparing patterns, identify mucus, pH measurement and evaluation of the effects of certain chemicals on the growth of mosses in the laboratory. Result: The moss species that develop popularly in Hue relics is Funaria hygrometrica, Bryum apiculatum, Trichostomum orthodontum, Fissidens lycopodioides. Funaria hygrometrica is the most popular moss. The cause of the slipperiness is mucus in moss cells released outside the moss after death. Mosses grow well in moist environments, clear and slightly acidic surface. After two days assessing the effect of citric acid 18%, 15%, 10% and 7% NaHCO3, 5%, 3% on the growth of moss, the mosses all died completely. Since then identified two types of chemicals have been found to completely dead moss, inexpensive, environmentally friendly and does not affect the surface of architectures are citric acid 10% solution and NaHCO3 3% solution. Keywords: The moss erosion, Funaria hygrometrica, mucus, citric acid, NaHCO3 Key words: The moss erosion, Funaria hygrometrica, mucus, citric acid, NaHCO 3


Genetics ◽  
1997 ◽  
Vol 147 (2) ◽  
pp. 643-655 ◽  
Author(s):  
Kenneth G Ross ◽  
Michael J B Krieger ◽  
D DeWayne Shoemaker ◽  
Edward L Vargo ◽  
Laurent Keller

We describe genetic structure at various scales in native populations of the fire ant Solenopsis invicta using two classes of nuclear markers, allozymes and microsatellites, and markers of the mitochondrial genome. Strong structure was found at the nest level in both the monogyne (single queen) and polygyne (multiple queen) social forms using allozymes. Weak but significant microgeographic structure was detected above the nest level in polygyne populations but not in monogyne populations using both classes of nuclear markers. Pronounced mitochondrial DNA (mtDNA) differentiation was evident also at this level in the polygyne form only. These microgeographic patterns are expected because polygyny in ants is associated with restricted local gene flow due mainly to limited vagility of queens. Weak but significant nuclear differentiation was detected between sympatric social forms, and strong mtDNA differentiation also was found at this level. Thus, queens of each form seem unable to establish themselves in nests of the alternate type, and some degree of assortative mating by form may exist as well. Strong differentiation was found between the two study regions usinga all three sets of markers. Phylogeographic analyses of the mtDNA suggest that recent limitations on gene flow rather than longstanding barriers to dispersal are responsible for this large-scale structure.


1909 ◽  
Vol 12 (3) ◽  
pp. 48
Author(s):  
H. N. Dixon
Keyword(s):  

Planta ◽  
1980 ◽  
Vol 147 (5) ◽  
pp. 405-413 ◽  
Author(s):  
G. Schmiedel ◽  
E. Schnepf

1990 ◽  
Vol 93 (1) ◽  
pp. 44 ◽  
Author(s):  
Redha H. Al-Hasan ◽  
Wagieh E. El-Saadawi ◽  
Ali M. Ali ◽  
Samir S. Radwan

1988 ◽  
Vol 91 (1) ◽  
pp. 127-137
Author(s):  
C. H. BUSBY ◽  
B.E. S. GUNNING

Evidence presented in the accompanying paper that plastids function as microtubule (MT)-organizing centres for development of the quadripolar cytoskeleton of pre-meiotic spore mother cells (SMCs) in the moss Funaria hygrometrica is complemented here by observations on the MT system in these cells. Early in meiotic prophase numerous MTs align progressively along the two plastids as they elongate. Concomitant with (and perhaps causal for) plastid rotation, new MT arrays grow from each tip of each plastid to both tips of the other plastid. The ‘along-plastid’ and ‘between-plastid’ arrays ultimately form the edges of a tetrahedron, enclosing the prophase nucleus. MT breakdown at the centre of each edge leaves four cones of MTs, one emanating from each vertex, located at the plastid tips. These partially fuse in between-plastid pairs to give a twisted spindle with broad knife-edge poles oriented at right angles to one another, i.e. a condensed form of the quadripolar precursor. The twist causes the metaphase plate and the subsequent phragmoplast and organelle band to be saddle-shaped, and the daughter nuclei to be elongated perpendicular to one another along the two knife edges. The tetrahedral array returns during interkinesis and again breaks down into four cones of MTs centred on the plastid tips; these, however, now become individual half spindles for the two perpendicularly arranged second division spindles. When meiosis is completed the four haploid nuclei thus come to lie at the vertices of a tetrahedron that was established by MT-mediated plastid positioning during meiotic prophase. The tetrahedral cage of MTs precedes meiosis yet predicts the planes of division, and in these two respects it is the meiotic counterpart of the preprophase band of MTs, which develops before mitosis in most higher plant cells.


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