Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
enabled [disable] Abstract
Number of results

Results found: 3

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  COLCHICINE
help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
Biotechnologia
|
2001
|
issue 1
134-138
EN
The objective of the present work was to develop a simple and reliable protocol for chromosome doubling in haploid onion plants. Research on gynogenic plants obtained from different genotypes of onion was carried out over two years. In the first year, diploidization was examined in vivo with 2.5 mM colchicine for 24 h. In the next year, in vitro tests using 0.25 mM and 1.25 mM colchicine or 1.00 muM and 5.00 muM trifluralin were carried out. Both antimitotic agents were applied for 72 h at 14?C or 23?C. The obtained results showed that colchicine applied in vivo caused twice as high loss of then plant material than diploidization at in vitro conditions. Antimitotic agents added to culture media decreased the plant capability to regenerate. Colchicine was found to be less toxic than trifluralin. The use of colchicine allowed for producing more diploids than trifluralin.
EN
We followed changes occurring within bone tissue and marrow cells during the process of colchicine-induced ectopic bone development and its resorption inside the marrow cavity of the rat tibia. To stimulate ectopic bone formation male Wistar rats were i.p injected with 0.5 or 1mg/kg b.w. of colchicine orwith a 100 Fg intra-bone injection.Not all subjects responded to colchicine with ectopic bone formation in the marrow cavity, even among individuals belonging to the same strain. The kind of response in a given animal depended on the dose and site of colchicine administration. During 10 days of the experiment an increase in the occurrence of micronuclei in the polychromatic erythrocytes residing in the bone marrow (even 40-fold) was observed, indicating high genotoxicity of colchicine (at a dose of 1 mg/kg b.w. i.p. or 100 Fg intra-bone injection). An increase in the frequency of emperipolesis in megakaryocytes between the 4th and 8th days of the experiment was caused by the toxic action of colchicine and may indicate the labilisation of cell membranes and microtubule depolymerisation.
EN
Meiotic behavior was analyzed in 6 progenies from 3 artificially induced tetraploid (2n = 4x = 36) sexual genotypes (C31, C41, and C48) of the normally apomictic Brachiaria brizantha (Hochst. ex A. Rich.) Stapf., syn. Urochloa brizantha (Hochst. ex A. Rich.) R. Webster. These are key plants to allow intraspecific hybridization of this important forage species, widely used for pastures in the tropics. The percentage of abnormal cells among the plants ranged from 39.8% to 63.2%. In the single plant derived from C48, only the common meiotic abnormalities typical of polyploids were observed, while in plants derived from C31 and C41, a distinct behavior was found. In the majority of cells of those plants, the chromosomes remained scattered in the cytoplasm in the first division, without forming a metaphase plate. This abnormality blocked chromosome movements at anaphase I. Several micronuclei of various sizes were formed and, after the occurrence of an irregular first cytokinesis, the meiocytes progressed normally to the second division, generating polyads with unbalanced microspores. Pollen viability was not correlated with meiotic abnormalities. The importance of these findings to the Brachiaria breeding program is discussed. The sexual progeny of C48 seems most suitable as female parents to be used in intra- and interspecific hybridization.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.