摘要:

We have investigated the morphology and the cytogenetics in cultivated stem cells of pea (Pisum sativum L.J and faba bean (Vicia faba L.) at the initial stages of callus development in liquid nutrient medium containing different concentrations 2, 4-D (2,4-dichlorophenoxyacetic acid) of 0, 2, 4, 8, 16 and 32 mgl−1The earliest stage of callus development in both species was indicated by the formation of specific morphological patterns—the so-called dividing rows (DR). These arose after periclinal divisions of medium-sized parenchyma cells from the superficial layers in the neighbourhood of the vascular bundles. DR consist of small meristematic cells with high mitotic activity. At the end of the second week of treatment, their structure was lost and meristematic regions of cells with varying shape and size remain in the actively proliferating tissue. Callus induction and development were obtained in the presence of 2 mgl−1of 2,4-D only and this process was initiated by the formation of DR. Xylem and cambium were not involved in callus development in both species. That was true for the epidermis tissue in pea too. The faba bean epidermis was integrated in the proliferation process. In cultures lacking 2,4-D no callus was observed. Concentration of 32 mgl−1was found to inhibit the mitosis. The most frequent aberrations in the two species were polyploidy and aneuploidy. Other anomalies were the enlargement of cells and/or nuclei, bi- and multinuclear cells, increased number of nucleoli, unstained nuclei and loosen nuclear structure. The mitotic aberrations included laggard formation, chromatin bridges besides irregular chromatin distribution and chromosomes with decreased integrity in the metaphase. The observed morphological and cytogenetical anomalies have been arisen under the influence of the cultural conditions. Their distribution by the two species suggests different genotype response in vitro. Deep invaginations in the nuclei of dedifferentiated cells and changes in the wall thickness were observed electron microscopically.

ISSN:1310-2818    

DOI:10.1080/13102818.1997.10818922

出版商:Taylor & Francis    

年代:1997

数据来源: Taylor

摘要:

Leaf mesophyll protoplasts of kanamicine resistant, nitrate reductase deficient mutant Nicotiana tabacum (NR−, Km+) were fused with leaf mesophyll protoplasts of wild type Nicotiana sanderae (wt). Somatic hybrid cell colonies were selected for kanamicine resistance and nitrate reductase proficiency. Nineteen independent cell lines, capable of growth in selection medium were obtained. From 14 of them shoots were regenerated and adapted in soil. All regenerants have intermediate plant and leaf morphology. The chromosome number for regenerants from six lines was determinated, as well as analyses of four isoenzymes: peroxidase, esterase, shikimate dehydrogenase and glutamate-oxaloacetate transminase were performed. Results show that all studied plants represent nuclear somatic hybrids, possessing entire genomes of both parents. Local lesion (hypersensitivity)—type resistance to TSWV has been observed in leaves of these somatic hybrid plants after virus inoculation.

ISSN:1310-2818    

DOI:10.1080/13102818.1997.10818909

出版商:Taylor & Francis    

年代:1997

数据来源: Taylor

摘要:

In order to identify the alien chromosome introgressed into the wheat's genome of the aneuploid lines of the cross: Triticum aestivum cv Kiten (AABBDD) x Aegilops kotschyi (UUSS) a protein polymorphism (gliadins and glutenins) as markers for 1−stand 6−thhomoeologous group is used. An SDS-PAGE and a native 1-D-slab PAGE in the case of glutenins and gliagins respectively are performed. Some additional bands specific for Ae.kotschyi as well as a comparison to Ae. umbellulata (UU), Ae. longissima (S1S1), Ae. squrrosa (DD) and Chinese Spring nullitetrasomic lines indicate the introgression of U genome in the investigated disomic addition and substitution lines. The results of this study show that the polymorphism of the storage proteins can be used as a reliable marker system for quick and cheaper screening of the presence of alien chromosomes.

ISSN:1310-2818    

DOI:10.1080/13102818.1997.10818923

出版商:Taylor & Francis    

年代:1997

数据来源: Taylor

摘要:

Transgenic plants of carnation (Dianthus caryophyllus) were obtained by Agrobacterium mediated transformation. A regeneration procedure was based on the leaf and petals as initial explants. Two different phytohormones- BAP and NAA were employed for the production of adventitious shoots. Transformation of the cultivars Lena, Line 84 and Yanita was performed with a plasmid (p2260 1 170) containig marker genes—npt II and hpt genes encoding neomycinephosphotransferase and hygromicinephosphotransferase, respectively. For cvs. Scania, Nasslada and Lena the plasmid vip 104-carring anti-sense CHS-A and nptII was used. Cultivar Regina was transformed with plasmid vip 165- GUS gene under chs-J promoter. Transformation efficiency varied among tested cvs. Presence of the npt II gene in plants was confirmed by PCR and Southern blot analysis. The expression of CHS-A was confirmed by Northern blot.

ISSN:1310-2818    

DOI:10.1080/13102818.1997.10818924

出版商:Taylor & Francis    

年代:1997

数据来源: Taylor

摘要:

Progress in application of molecular biological and genetic engineering techniques as a new successful approaches for genetic improvement of the existing grapevine varieties and rootstocks are discussed. The regenerative procedure efficiency and the development of a successful transformation system are species dependent. Agrobacterium mediated gene transfer approach is more useful since now to grape. Beneficai genes encoding for proteins that are involved in disease's resistance have been inserted into established grape cultivars and rootstocks. Transgenic plants expressing selectable genes were obtained and integration of foreign genes was verified by hystochemical GUS assay, RCR assay and Southern blot analysis. The propagation of genetically manipulated grape plants is in the way and their places in breeding programs are also considered.

ISSN:1310-2818    

DOI:10.1080/13102818.1997.10818911

出版商:Taylor & Francis    

年代:1997

数据来源: Taylor

摘要:

Three strains of Thiobacillus ferrooxidans have been isolated from copper mine in Bulgaria, and investigated. The levels of their ferrous- and sulfur-oxidizing activities have been tested as well as their tolerance to copper and zinc ions. The effect of both metal ions on ferrous- oxidizing activity and oxygen uptake have been investigated too. A possible mechanisms for the tolerance of these bacteria to Zn2+and Cu2+ions is discussed.

ISSN:1310-2818    

DOI:10.1080/13102818.1997.10818925

出版商:Taylor & Francis    

年代:1997

数据来源: Taylor

摘要:

A fast growing callus obtained after cultivating root sections of 1 sm lenght on Murashige and Skoog (MS) medium with 2 mg/l 1- naphtalene acetic acid (NAA) and 0.25 mg/l 6-benzyl- aminopurine (BAP) (pH 5.6) as the hormonal balance, was used as the source of protoplasts. Suspensions of 107 protoplasts/g of fresh weight with 94% viability were cultivated on the basic MS medium supplemented with 9% (W/v) mannitol and 2 mg/l NAA, 0.5 mg/l BAP, 0.5 mg/l zeatin (pH 5.6) for further cell wall regeneration, cell colonies formation and microcalli growth. One root regenerated after subcultivating the calli in MS medium with various combinations of NAA, BAP and Zeatin. A second root regenerated after further calli subcultures on Lepoivre medium only containing 2 mg/l indole-3-butyric acid. The paper dwells on the determinant factors for the process of rhizogenesis as an intermediate step towrds obtaining shoot buds on a cherry-tree.

ISSN:1310-2818    

DOI:10.1080/13102818.1997.10818912

出版商:Taylor & Francis    

年代:1997

数据来源: Taylor

摘要:

Chitosan is stepwise treated with periodic acid, urea and formaldehyde and then introduced hydroxymethyl groups reacted with tetracycline and carminomycin. The conjugates obtained are fully soluble in dimethylformamide in contrast to the free chitosan. The conjugate of chitosan with tetracycline preserves almost fully the antibacterial activity of the free tetracycline. An enhenced antitumour activity and decreased toxicity of carminomycin are detected after its conjugation with chitosan.

ISSN:1310-2818    

DOI:10.1080/13102818.1997.10818926

出版商:Taylor & Francis    

年代:1997

数据来源: Taylor

摘要:

The sensitivity of eighteen yeast and mould strains to Cu2+was examined in correlation with the Cu2+uptake and the pH changes during their growth. The tested strains were classified into three groups: sensitive, sub-tolerant and tolerant microorganisms. The increase in resistance of acid—producing strains to Cu2+was associated with the decrease in metal uptake by microbial cells.

ISSN:1310-2818    

DOI:10.1080/13102818.1997.10818927

出版商:Taylor & Francis    

年代:1997

数据来源: Taylor

摘要:

Electron paramagnetic resonance spectra of leaves of rice cultivars Red rice, Labelle, Leah and Lemont with different level of resistance to the red toxin cercosporin, isolated from the fungus Cercospora oryzae Miyake, were assayed. The punctured leaves were treated with 20 μl, 100 μM cercosporin in 10% acetone and with 10% acetone alone in the same quantity per 2 cm2leaf area. The controls were punctured leaves only. An increase of the free radical production was recorded by electron paramagnetic resonance measurements after treatment with acetone and with cercosporin. We were found that the relative quantity of the free radicals correlated significantly well with the level of resistance of studied rice cultivars to the toxin.

ISSN:1310-2818    

DOI:10.1080/13102818.1997.10818914

出版商:Taylor & Francis    

年代:1997

数据来源: Taylor