Mehmet Cengiz Karaismailoglu

Investigation of the potential toxic effects of prometryne herbicide on Allium cepa root tip cells with mitotic activity, chromosome aberration, micronucleus frequency, nuclear DNA amount and comet assay

In the present study the potential toxic effect of prometryne herbicide was examined by investigating mitotic index, mitotic phase, chromosomal abnormalities, micronucleus frequency, 2C DNA content, and comet assay on the root tip cells of Allium cepa. The roots were exposed to 2, 3, 4 and 6 g l−1 concentrations within 12, 24 and 36 h. Mitotic index was markedly reduced by prometryne in each treatment group compared with the controls. The frequencies of mitotic phases have been changed. Prometryne significantly increased the anomaly cell percentage at all concentrations and application periods in comparison to their control. Mitotic abnormalities were recorded as disturbed prophase, c-mitosis, stickiness, laggards and chromatid bridges. The micronucleus was observed at interphase and its frequency was calculated in the test solutions used. Prometryne decreased the 2C DNA amount in onion root tips. Furthermore, the comet assay was applied to analyze the single stand breakages. Nearly all of the applied concentrations of prometryne enhanced DNA damage. In many cases negative correlation was found between 2C DNA amount and DNA damage; however, positive correlation was found between micronucleus formation and DNA damage.

Assessments on the potential genotoxic effects of fipronil insecticide on Allium cepa somatic cells

Abstract The potential genotoxic influences of fipronil insecticide were analyzed by studying mitotic index and phases, chromosomal abnormalities, and micronucleus percentage on the somatic cells of Allium cepa L. The roots were treated with 1, 2.5, 5 and 10 ppm of fipronil insecticide within 6, 12 and 24 h. Mitotic index was clearly diminished by fipronil in each treatment group in comparison with control. The percentages of mitotic stages have been significantly affected. Fipronil markedly enhanced the abnormality cell percentage in almost all of the concentrations and treatment times compared to the control. Chromosomal abnormalities were recorded as disturbed prophase, sticky, chromatid bridges, c-mitosis, and laggards. The micronucleus was found at interphase and its frequency was calculated at each concentration and in the control. Generally, micronucleus formation augmented with increasing concentration of fipronil as compared to control. Consequently, the genotoxic potency of fipronil insecticide with different assessments was evaluated by using the somatic chromosomes of A. cepa, and the use of a defined non-toxic dose was suggested.

Morphological and anatomical features of seeds of Turkish Romulea taxa (Iridaceae) and their taxonomic significance

Abstract This paper reports on the assessment of morphological (macro and micro) and anatomical characters of seeds of Romulea taxa distributed in Turkey with the use of oneway analysis of variance, cluster analysis and principal component analysis. Morphological characteristics such as size, shape, color and surface of seeds were examined with the use of light and scanning electron microscopes. Thicknesses of testa and phytomelan layer, sizes of embryo in seeds were studied anatomically. The outcomes revealed that taxa were similar in some aspects such as color and shape of seeds. However, seed size, thickness of testa and phytomelan layer, shape of the epidermal cells in testa and sizes of embryo were different among taxa, and have taxonomic value in the distinction of these taxa from each other. In addition, the seed surfaces were more or less different for the examined taxa on an interspecific level. Consequently, seed morphology and anatomy with a few exceptions demonstrated diversity and they had taxonomic importance in terms of distinguishing among species.

Evaluation of potential genotoxic effect of trifluralin in Helianthus annuus L. (sunflower)

In this study, the genotoxic effects of the herbicide trifluralin on the root meristem cells of sunflowers (Helianthus annuus L.) were investigated. The roots were treated with 5 10, 20 and 40 parts per thousand concentrations of trifluralin for 24, 36 and 48 h, with a control for each combination. The morphological changes occurring in sunflower roots with the different herbicide concentrations were monitored. The mitotic index and mitotic abnormalities were determined in both control and test groups. Mitotic index decreased with increasing herbicide concentration at each exposure time. The mitotic abnormalities were recorded as disturbed prophase, c-mitosis, stickiness, laggards and chromatid bridges. The micronucleus was observed at interphase and its frequency was calculated in different test solutions. Thus, the genotoxic potency of trifluralin with different tests was assessed by using root tip cells of Helianthus annuus.

Evaluation of potential genotoxic and cytotoxic effects of deltamethrin insecticide on somatic chromosomes of Helianthus annuus L.

Abstract In this research, the genotoxic and cytotoxic effects of the insecticide deltamethrin (DEL) on the root meristem cells of sunflowers (Helianthus annuus L.) were investigated. The lethal dose (LD50) value was determined as approximately 1 ppm in the sunflower root growth tests. The roots were treated with 1 (LD50), 0.25 (LD50/4), 0.5 (LD50/2) and 2 ppm (LD50 ×2) concentrations of DEL for 24, 36 and 48 h, with a control for each combination. Occurring morphological changes such as reduction of root elongation and discoloration in sunflower roots were observed with the using DEL concentrations. The mitotic index and mitotic abnormalities were determined in both control and test groups. Mitotic index reduced with increasing the insecticide concentration at each exposure time. The mitotic abnormalities were recorded as disturbed prophase, c-mitosis, stickiness, laggards and chromatid bridges. In addition, micronucleus was observed at interphase and its frequency was calculated in the test solutions.

Pollen morphology of some taxa of Thlaspi L. sensu lato (Brassicaceae) from Turkey, and its taxonomical importance

ABSTRACT In this study, the pollen morphology of 22 Turkish taxa (12 of which are endemic) of the taxonomically complex genus Thlaspi L. sensu lato was studied with light microscopy (LM) and scanning electron microscopy (SEM). We found that the pollen of Thlaspi are usually bilateral symmetric and anisopolar. They are prolate, subprolate, perprolate or spheroidal, with the polar axis ranging from 14.13 to 28.36 µm and equatorial axis from 8.75 to 19.48 µm. Pollen are usually tricolpate, but some of them are 1–2- or 4-colpate. The ornamentation of pollen of the examined taxa is usually micro or macro reticulate, and rarely foveolate. The exine thickness ranges from 1.59 to 2.75 µm, and the intine thickness from 0.54 to 0.94 µm. As a result of this study, some of the pollen characters such as the sizes of pollen and colpus, ornamentation of exine, apocolpidium, and shape and diameter of amb are found to be significant morphological characters for taxonomic use.

Comparison of the karyotype analyses of two Aethionema speciosum subspecies from Turkey

Abstract The karyotypes of two Aethionema speciosum subspecies, A. speciosum subsp. speciosum and A. speciosum subsp. compactum, from various phytogeographical areas in Turkey were analyzed. The chromosome counts of the taxa were determined as 2n = 2x = 24 and 2n = 2x = 36, respectively. Karyotypes have mostly median and submedian centromeres. Chromosomes of the examined taxa were analyzed in accordance with some previous cytogenetic reports from a systematic perspective.

An evaluation for the standardization of the Allium cepa test as cytotoxicity and genotoxicity assay

ABSTRACT A general report on the use of the Allium test as cytotoxicological and genotoxicological assay is proposed, with particular emphasis about the standardization of the test in several common applications. The intraspecific variation in Allium cepa has been overlooked, as in most investigations no mention is made about origin and denomination of the onion cultivar used. A standardization of the used material would allow a better generalization of the results, since we cannot be sure that all cultivars would give the same response. A more frequent use of transmission electron microscopy (TEM) investigation is proposed. Even if relatively time consuming and not available in all laboratories, it may help to better understand the mechanism of cytotoxicity, since many morphological characters may appear similar but be arisen from different processes observable only with TEM. About statistical testing, tests other than chi-squared may be used in case of a lower amount of data. The most commonly used statistical tests are the parametric tests ANOVA and Student’s t, and the non-parametric tests Kruskal–Wallis and Mann–Whitney U, for analysis of variance. Tests should be used also to assess the minimal sample dimension for obtaining significance, since data collection (microscope observation) appears to be one of the main bottle necks of the test. Also the use of the Allium test for testing liposomes and other nanovectors for drug delivery is proposed, in order to assess the cytotoxicity of these types of medium and the possible increase in cytotoxicity of the associated drug.