Juglans regia L. is an edible fruit tree cultivated worldwide for its fruits and wood and as an urban tree. Globally, there is growing concern for preserving the genetic diversity of trees with high economic and ecological value. This study investigates the genetic diversity of J. regia in urban landscapes and assesses the quality of its walnut kernels as a local food product. An inventory of 150 trees from five populations in public green spaces in Lugoj, Caransebeș and Jupa, as well as two semi-natural hilly ecosystems in the Banat Region, was conducted. Molecular analyses showed that Directed Amplification of Minisatellite-region DNA (DAMD) markers were more effective than Start Codon Targeted (SCoT) markers, with a higher average polymorphism of 56.26%, compared to 49.44%. DAMD07 achieved 100% polymorphism and DAMD05 showed a strong balance between P.I.C. (0.35) and polymorphism (54.54%). Chemical analysis revealed the following contents in walnut kernels: protein (12.81% to 16.80%), lipids (60.39% to 69.08%), total polyphenols (5484.66 to 10,788.4 mg GAE/kg), copper (3.655 to 8.532 mg/kg), manganese (14.408 to 28.618 mg/kg), zinc (19.813 to 46.583 mg/kg), lead (1.204 to 2.27 mg/kg) and cadmium (0.03451 to 0.08065 mg/kg). These findings are critical for conservation efforts, urban forestry management and ensuring the quality and safety of walnut products derived from J. regia.

The cultivation of alfalfa is crucial for farmers as it is an excellent forage crop with a high nitrogen-fixing capacity, making it indispensable in crop rotations. Breeding programs face challenges in advancing more rapidly in genetic diversity to achieve a higher heterosis effect and, consequently, greater yield. In this study, we used 30 alfalfa varieties, which were used for molecular analyses by 5 ISSR primers and 13 RAPD primers. The results obtained highlighted the greater efficiency of ISSR primers in identifying genetic diversity. On the other hand, the simultaneous use of ISSR + RAPD allowed for clearer clustering of varieties that enabled more efficiently distinguishing the genetic diversity. The most efficient ISSR primer, A17, generated 31 polymorphic bands, while the most efficient RAPD primer, L-07, generated only 21 bands. Varieties such as “Pastoral” and “F1413-02” exhibited low similarity coefficients (0.39), suggesting their potential for enhancing genetic variability through crossbreeding, thereby increasing the potential of achieving a greater heterosis effect. Conversely, varieties with high similarity coefficients, such as ”Cristal” and “Viking” (0.81) are less suited for this purpose. The correlation between specific markers highlights that using both ISSR and RAPD markers together offers a clear understanding of genetic diversity in alfalfa, aiding in more effective selection for crossbreeding in breeding programs.

Salt stress induces cytotoxicity at the cellular level, influencing the vacuolization process, disrupting mitotic division, and thus inhibiting plant growth. The results for a range of species used in agriculture have shown that high soil salt levels affect germination, chlorophyl content and yield. In this study, an experiment was carried out in the laboratory using NaCl concentration treatments of 0, 100, 125 and 150 mM on sunflower seeds of the inbred line HA-89 obtained from the USDA gene bank. For the experiment, the seeds were germinated in a salt solution and analyzed cytologically by calculating the mitotic index, chromosomal aberration index, provacuolar index and vacuolization index. Following our cytological studies, we observed that the vacuolization phenomenon was caused by salt stress and progressively accentuated by the salt concentration levels and exposure times. The formation of vacuolized cells is due to the fusion of provacuoles, which contributes to a uniform or non-uniform distribution of genetic material around them. According to our results, the vacuolization index showed high values depending on the NaCl concentration and stress exposure time. Similarly, high salt concentrations significantly decreased the mitotic index and increased the chromosomal aberration index. The effect of salt stress causes cell vacuolization, a decrease in the mitotic index and an increase in the number of chromosomal aberrations in meristematic tissues, inhibiting growth and development and consequently leading to a reduction in productivity per unit area.

Tree species with high ecological plasticity are recommended for use in urban green infrastructures. This study explores the genetic diversity of Tilia cordata, Tilia platyphyllos, and Tilia argentea, highlighting their contribution to urban landscapes. In this respect, the genetic variability of individuals from four populations of the Tilia genus has been analyzed using Inter Simple Sequence Repeats (ISSR) molecular markers, and some of their phenotypic characters were naked-eyed observed or determined by dendrometric measurements. Significant variability between the populations studied was determined. Cluster analysis identified two main groups: Tilia cordata I and Tilia cordata II populations formed the first cluster, and Tilia platyphyllos and Tilia argentea populations formed the second cluster. The results of the phenotypic analysis confirmed the genetic results separating the two populations of Tilia cordata from the populations of Tilia platyphyllos and Tilia argentea in relation to their visible morphological characters. Results obtained from dendrometric measurements analysis represent the foundation for further investigations on urban ecology. An essential potential practical use of the results: the establishment of more efficient ISSR primers to identify the Tilia species analyzed: UBC864, A12, UBC840, and A7 for Tilia cordata, A13 for Tilia platyphyllos and A7 for Tilia argentea has been demonstrated.

Applications of the Drosophila melanogaster (D.m.) research model have an important means both for genetic investigations and for the study of metal toxicity, because D.m. has physiological mechanisms comparable to those in human organisms. In this research, the toxic effect of lead (Pb²⁺) and copper (Cu²⁺) on four D.m. genotypes—the wild genotype (Oregon-R, used as control) and three mutant genotypes (white, brown, and white-vestigial)—was compared. Five replicates were made to observe the development progress of monitorized genotypes exposed to five different concentrations 0, 0.50, 0.75, 1.00, and 2.00 mM of copper (CuSO₄) and lead Pb(C₂H₃O₂)₂. Proliferation rates of larvae, pupae, and adults depend on genetic factors, metals used (copper or lead), and their concentrations. The white-vestigial mutant genotype showed the greatest sensitivity at IC₅₀ concentration (inhibition of proliferation of more than 50% compared with the control sample) at doses of 1.00 mM for Cu²⁺ and 2.00 mM for Pb²⁺. In contrast, the control genotype (Oregon-R) showed only an inhibition IC₅₀ concentration of 2.00 mM for Cu²⁺. The white-vestigial mutant genotype showed the greatest sensitivity at IC₅₀ concentration (inhibition of proliferation of more than 50% compared with the control sample) at doses of 1.00 mM for Cu²⁺ and 2.00 mM for Pb²⁺. In contrast, the control genotype (Oregon-R) showed an inhibition at the IC₅₀ concentration of 2.00 mM for Cu²⁺. The results conclude that (i) the dose influences the prolificacy rate in a directly proportional way, (ii) the comparative analyses between Cu²⁺ and Pb²⁺ revealed a more acute effect of Cu²⁺, and (iii) differentiated prolificacy values according to genotypes were recorded. Those reflect the importance of using D.m. as a research model in the comparative studies of the interactions between genetic factors and metal toxicity. Also, this study provides significant information on non-toxic maximum doses for organisms.

The Allium test is a cytological method used to monitor the impact of heavy metals. It can be used to evaluate meristematic tissues and highlight abnormalities occurring during mitotic division, with the advantage of being both rapid and economical. Copper and lead are among the most widespread metals in everyday life, mainly due to the worldwide expansion of industrialization, and are present in soil, water, and air. Using Allium sativum as a bioindicator for this study, statistical analysis confirmed significant differences in genotoxicity between the two metals, reflected by the inhibition of mitotic activity (MI) or increased indices of cellular abnormalities (AI). Toxicity was dose- and time-dependent for both metals, with copper exhibiting greater genotoxic effects than lead. Copper caused a significant reduction in MI, even at relatively low concentrations, with the IC₅₀ observed at 0.50 mM after 72 h of exposure. In contrast, for lead, the IC₅₀ was recorded from 0.75 mM after 72 h exposure. The advantages of the Allium test were demonstrated by its simplicity and high sensitivity in detecting abnormalities. In our experiment, chromosome abnormalities such as chromosome bridges, as well as isolated, delayed, or sticky chromosomes, were observed. In addition, at a concentration of 0.25 mM for copper (72 h exposure) and 0.50 mM for lead (72 h exposure), cellular abnormalities, including giant cells and binucleated cells, were identified.