Pesticides and Phytomedicine / Pesticidi i fitomedicina

A novel Wolbachia ftsZ genotype in 'Candidatus Phytoplasma solani' planthopper vector Hyalesthes obsoletus (Hemiptera: Fulgoromorpha: Cixiidae) associated with Convolvulus arvensis

Luka Stojanović — 2024-06-06

Hyalesthes obsoletus (Hemiptera: Fulgoromorpha: Cixiidae) is a pan-European polyphagous
planthopper known as a significant vector of the plant pathogenic bacterium ‘Candidatus Phytoplasma solani’ (stolbur phytoplasma), which poses threats to various agricultural crops. A population of H. obsoletus associated with Convolvulus arvensis in Serbia was studied to investigate the presence and genetic diversity of Wolbachia, an endosymbiotic bacterium known for its promising biological control applications. Both insect-associated microorganisms, ‘Ca. P. solani’ and Wolbachia, were found in the assessed H. obsoletus population. The analyzed vector population had a ‘Ca. P. solani’ infection rate of 50%, while Wolbachia showed a high infection rate of 80%. Wolbachia presence displayed minimal variation across genders and was independent of individuals’ phytoplasma-infection status. Genotyping of the identified ‘Ca. P. solani’ strains revealed four previously described stamp genotypes (Rqg50/St1, Rqg31/St2, STOL/St4 and M5/St28). Notably, a single novel Wolbachia
ftsZ genotype, designated WHo1, was found in the assessed H. obsoletus population, providing a valuable insight into the genetic diversity of Wolbachia endosymbionts within the Cixiidae family. Phylogenetic analysis demonstrated intricate relationships between WHo1 and other Wolbachia strains infecting hosts from diverse hemipteran suborders. Although Wolbachia-based strategies show promise for phytoplasma vector control, further research is needed to elucidate its potential interactions with ‘Ca. P. solani’ and its effects on vector reproduction and fitness.

Evaluation of the viability of old seeds of several important agricultural weeds

Danijela Šikuljak — 2024-06-06

Persistent seed banks are equally important in agriculture and invasion biology. While seed vitality persistence exemplifies an eternal uphill battle for weed control in agriculture, it signals a potential invasiveness of species in invasion biology. Considering yield losses caused by Amaranthus retroflexus, Abutilon theophrasti, Chenopodium album and Datura stramonium in agriculture, and the importance of Ambrosia trifida as an emerging invader in Europe, the objective of this study was to test the viability and longevity of the aged seeds of these economically important weeds. Three seed viability/longevity tests were conducted: the crush test, germination test in Petri dishes, and 3,5-triphenyltetrazolium chloride (TTC) test.
The results revealed a significant variation in germination potential among the tested species. The highest vitality was observed in 7-year-old seeds of A. retroflexus (41.67 %), followed by 16-year-old A. theophrasti seeds (17.78 %), 13-year-old C. album seeds (15.00 %) and 17-yearold D. stramonium seeds (7.5 %). Furthermore, a remarkable seed longevity was documented in the tested species (with the exception of A. trifida), preserving their germination potential for over half a century. Seed germination was recorded in 49-year-old seeds of D. stramonium, 53-year-old seeds of A. retroflexus, 58-year-old seeds of A. theophrasti and 59-year-old seeds of C. album, in strong evidence of the persistence of these weed species’ seeds in the environment.

Assessing sister chromatid exchanges in human peripheral lymphocytes exposed to tetrachlorvinphos during G0 phase

Ebral Akgun — 2024-06-06

While pesticides undeniably contribute to enhancing agricultural productivity, the escalating trend in their usage has given rise to a myriad of environmental and public health challenges over time. Tetrachlorvinphos, an organophosphate pesticide deemed potentially carcinogenic by the International Agency for Research on Cancer, is commonly employed to combat flies, mites, and larvae in animals, safeguarding public health in open spaces, and managing pest issues in domestic animals. We aimed to investigate the genotoxic and cytostatic effects of tetrachlorvinphos on human lymphocytes in the G0 phase of the cell cycle using the sister chromatid exchange (SCE) assay. We found that tetrachlorvinphos increased SCE values at 3 concentrations (5, 25, 50 μM). On the other hand, the increase in SCE values was found to be statistically significant only at the highest concentration (50 μM, p<0.05). We also found that the
SCE value showed a linear dose-dependent increase (p=0.005). We concluded that exposure to tetrachlorvinphos had genotoxic potential on human lymphocytes in the G0 phase of the cell cycle. Additionally, exposure of cells in the G0 phase of cell cycle to tetrachlorvinphos was found to have no discernible impact on cell cycle kinetics.