EVALUATION OF METAL ION TOXICITY ON ROOT TIP CELLS BY THE ALLIUM TEST

1995 ◽  
Vol 43 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Donghua Liu ◽  
Wusheng Jiang ◽  
Wei Wang ◽  
Lin Zhai

The effects of different concentrations of eleven different metals (aluminum chloride, chromium nitrate and potassium dichromate, lead nitrate, copper sulfate, manganous sulfate, cobaltous nitrate, zinc sulfate, magnesium sulfate, nickel sulfate, cadmium chloride, and mercuric chloride) on cell division and nucleoli in root tip cells of Allium cepa were studied. The results showed that the metal ions could, in varying degrees, cause chromosome, nucleus, and nucleolus irregularities, including c-mitosis, chromosome bridges, chromosome stickiness, irregularly shaped nuclei, micronuclei, irregularly shaped nucleoli, some silver-stained material scattered in the nucleus, the weakening of silver-staining reaction at the periphery of the nucleolus, and the release of nucleolar material from the nucleus into the cytoplasm. The Allium test may be useful for the rapid screening of chemicals involved in environmental problems.

1994 ◽  
Vol 42 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Donghua Liu ◽  
Wusheng Jiang ◽  
Lin Guo ◽  
Yuqing Hao ◽  
Cheng Lu ◽  
...  

The effects of different concentrations of nickel sulfate on root growth and nucleoli in root tip cells of Allium cepa were studied. The concentrations of nickel sulfate (NiSO4 · 7H2O) used were in the range of 10−7-10−1M. The results showed that nickel sulfate has a stimulatory effect on root growth at lower concentrations, and an inhibitory effect at higher concentrations. Nickel has toxic effects on nucleoli at higher concentrations. Phenomena we observed were irregularly shaped nucleoli, weaker silver staining reaction at the periphery of the nucleolus, and extrusion of nucleolar material from nuclei into the cytoplasm after treatment with higher concentrations of Ni.


1999 ◽  
Vol 47 (3) ◽  
pp. 153-156 ◽  
Author(s):  
Wusheng Jiang ◽  
Donghua Liu

The effects of different concentrations (10−5-10−2M) of lead nitrate on root growth and nucleoli in root tip cells of Brassica juncea L. were investigated. The results showed that lead nitrate has a stimulatory effect on root growth at lower concentrations, and an inhibitory effect at higher concentrations. Pb has toxic effects on chromosomal morphology, including c-mitosis and anaphase bridges, and on nucleoli, causing some particulate silver-stained material scattered in the nuclei and inducing irregularly shaped nucleoli. Once the nucleolus was affected, the root growth almost or completely stopped.


Author(s):  
L. Hanzely

Nucleoli are generally thought to be organelles lacking a continuity during cell division, i.e., they disperse during late prophase and reform within the daughter nuclei at telophase. Recently, however, nucleoli have been shown to persist during mitosis in several plant and animal species (e.g., references 1-4). In this report, evidence is presented indicating the persistence of nucleolar material throughout mitosis in root tip cells of Allium sativum.


2010 ◽  
Vol 73 (5) ◽  
pp. 949-954 ◽  
Author(s):  
W. Kwankua ◽  
S. Sengsai ◽  
C. Kuleung ◽  
N. Euawong

2007 ◽  
Vol 49 (4) ◽  
pp. 481-486 ◽  
Author(s):  
Jian-You Li ◽  
Ai-Liang Jiang ◽  
Wei Zhang

Genome ◽  
1988 ◽  
Vol 30 (1) ◽  
pp. 36-43 ◽  
Author(s):  
K. Kerby ◽  
J. Kuspira

To help elucidate the origin of the B genome in polyploid wheats, karyotypes of Triticum turgidum, Triticum monoccum, and all six purported B genome donors were compared. The analysis utilized a common cytological procedure that employed the most advanced equipment for the measurement of chromosome lengths at metaphase in root tip cells. A comparison of the karyotypes of T. turgidum and T. monococcum permitted the identification of B genome chromosomes of T. turgidum. These consist of two SAT pairs, one ST pair, three SM pairs, and one M pair of homologues. Comparisons of the chromosomes of the B genome of T. turgidum with the karyotypes of the six putative B genome donors showed that only the karyotype of Aegilops searsii was similar to the one deduced for the donor of the B genome in T. turgidum, suggesting that Ae. searsii is, therefore, the most likely donor of the B genome to the polyploid wheats. Support for this conclusion has been derived from geographic, DNA-hybridization, karyotype, morphological, and protein data reported since 1977. Reasons why the B genome donor has not been unequivocally identified are discussed.Key words: phylogeny, karyotypes, Triticum turgidum, Triticum monococcum, B genome, B genome donors.


Nature ◽  
1949 ◽  
Vol 164 (4178) ◽  
pp. 930-930 ◽  
Author(s):  
J. CHAYEN

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