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 nonparametric 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.

-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 interspecifi c level. Consequently, seed morphology and anatomy with a few exceptions demonstrated diversity and they had taxonomic importance in terms of distinguishing among species.

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.

Seed morphology and anatomy are taxonomically significant in Brassicaceae. The seed structures of Aethionema from Turkey, which include 12 taxa (Aethionema syriacum, A. froedinii, A. arabicum, A. eunomioides, A. fimbriatum, A. speciosum subsp. speciosum, A. speciosum subsp. compactum, A. saxatile, A. oppositifolium, A. iberideum, A. armenum, A. grandiflorum) were studied for knowing seed morphological and anatomical features with one-way analysis of variance, cluster analysis and principal component analysis. Seed size, shape and color were examined with stereomicroscopy.The surface patterns of seed were observed using Scanning Electron Microscopy (SEM). In addition, structure, and thicknesses of testa and endosperm were investigated anatomically. Thickness of testa and endosperm were of major significance to illustrate interspecific relations among the examined taxa.

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