The somatic chromosomes and karyotype traits of three Romanian genotypes (coded as CB-1, S-16, L-4) of Hippophae rhamnoides L. have been studied. Diploid chromosome number is 2n=24. The karyomorphological data show that the complements have small chromosomes (1.33 ± 0.014 -2.80±0.01 µm, for CB-1 genotype; 1.13 ± 0.029 -2.90 ± 0.029 µm, for S-16; 1.15 ± 0.099 -2.88 ± 0.024 µm, for L-4 genotype) and the length of haploid complements is 23.97 µm, for CB-1, 22.20 µm, for S-16, 21.73 µm, for L-4. In CB-1 and S-16 male genotypes, the putative Y-chromosome has larger sizes than X-chromosome and it is of metacentric type (CI = 45.77, r = 1.18, for CB-1; CI = 46.22, r = 1.15, for S-16). The L-4 female karyotype is constituted by twelve pairs of morphologically similar chromosomes. The karyotype formulae are 2n = 24 = 13m + 11sm (putative male: 22 + XY), for CB-1 genotype, 2n = 24 = 18m + 6sm (putative male: 22 + XY), for S-16 genotype, respectively 2n = 24 = 22m + 2sm (L-4 genotype, considered as female: 22 + XX). The small size of chromosomes (< 3µm), the presence of only two morphometric chromosome types and preponderance of metacentrics confer a relatively high degree of symmetry to the studied karyotypes. Our results show a low intraspecifi c karyotype variation.

The study was performed in order to evaluate Roundup-induced genotoxic effects in Hordeum vulgare L. cv. Madalin root meristems and to analyze herbicide impact on length growth of barley seedlings. Caryopses were treated for 3 hours and 6 hours with 0.1%, 0.5%, 1.0% and 2.0% Roundup solutions (v/v), containing 0.36 mg ml-1, 1.8 mg ml-1, 3.6 mg ml-1 and 7.2 mg ml-1 glyphosate active ingredient. Mitotic index decreased in both exposure times with concentration increase. In 3-h treatment, its average values decreased from 4.73 ± 0.31% to 1.51 ± 0.43%, whereas in 6-h treatment this parameter declined from 3.86 ± 0.92% to 0.62 ± 0.15%. The highest ana-telophase aberration rates were noted in 3-h treatments (8.91%, 9.19%, 9.47%, 11.25%, comparatively to control - 5.99%). Roundup enhanced the number of metaphase disturbances proving its noxious effect on normal functioning of mitotic spindle. Seedling growth was negatively influenced at all tested concentrations in both exposure times. The length decreased as concentration increased, so that the average length is 7.5-9 times smaller than in control at the maximum concentration, in both exposures.

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The pollution increase, as a result of the release into environment of genotoxic chemicals, including heavy metals, largely affects the ecosystems and the health of living organisms. Although zinc is not considered highly phytotoxic, its excess becomes noxious. In literature, the reports on zinc genotoxicity are equivocal. Therefore, the objective of this work was to evaluate the amplitude of cytogenetic damage induced in Hordeum vulgare L. cv. 'Madalin' after seed treatment with different concentrations (10, 100, 250, 500 µM) of Zn +2 , provided as zinc sulphate and zinc acetate. The mitostimulatory effect was present at all concentrations of both zinc compounds. The rate of ana-telophase aberrations exceeded by 2 -3 times the control, and the frequency of metaphase disturbances was 5.0-10.0 times higher than the control. The results indicate the clastogenic and aneugenic potential of zinc in barley and constitute a signal about the risks of its increasing presence into the environment, with repercussions on living systems, even on human health, due to the extensive use of zinc compounds including as pesticides.

The description of the karyotype features and idiogram in Grindelia squarrosa (Pursh) Dunal (Asteraceae), an invasive plant in Romania, are reported here for the first time. The diploid chromosome number is 2n=2x=12, in agreement with the data published for the other species of the genus. The karyomorphological data show that the complements of the studied genotypes have small chromosomes (mean chromosome length is X̅±SE=2.56±0.10 μm, and mean length of haploid complements is X̅±SE=15.33±0.69 μm, with a range of variability comprised between 12.87-17.51 μm). The karyotypes are made up of six pairs of metacentric and submetacentric chromosomes, with an identical formula of the diploid complement: KF=2n=12=8m+ 2sm + 2sm-SAT. Satellites are located on the short arms of the chromosomes of pair III. The karyotypes show a relatively high level of intra-specific uniformity as well as similar symmetry patterns (R=1.29-1.53; TF%=38.78-41.57%; AsI%=54.54-57.61%; A1 = 0.24- 0.32; A2=0.08-0.16), belonging to 1A and 2A classes of symmetry. The small size of the chromosomes, the presence of only two chromosome morphometric types, and the preponderance of metacentrics confer a relatively high degree of symmetry to the karyotypes studied.

Sea buckthorn is a dioecious Eurasian shrub or small tree with large morphological, biochemical and physiological variability, evidenced by the great number of studies. Cytogenetically, uncertainties exist on species basic number, ploidy level, and sex chromosomes. In this study, detailed cytogenetic measurements were carried out on six Romanian ecotypes belonging to Hippophaë rhamnoides L. ssp. carpatica Rousi, in order to establish the features and the symmetry degree of karyotypes, to evidence the sex chromosomes, and to construct the idiogram. The ecotypes have 2n = 24 metacentric and submetacentric chromosomes. An intraspecific variation exists concerning the proportion of these two morphotypes. The karyotypes have similar symmetry patterns (R = 2.57-2.89; TF%= 38.54-42.70; AsI%= 57.99-61.41; A1=0.27-0.35; A2 = 0.26-0.36) and belong to 1B and 2B classes, being relatively high symmetric. Based on obtained results, we presume that the male sex chromosomes are heteromorphic, while in female plants are homomorphic. The Y chromosome is larger than X chromosome.

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