Biologia最新文献

Abstract

Field campaigns were carried out in the North, Center, and South of Tunisia (2017–2022). Through this, three anophthalmous species of Trichorhina from three different localities in the North and Center-East of Tunisia were recognized as new to science, and consequently as the first record of the genus from Tunisia. A detailed morphological description of these three new species is provided. The abiotic factors of their habitat and micro-habitat are provided as well as their associated fauna.

Anopheles species are freshwater mosquitoes found in Turkey, where they have been the most important malaria vectors locally from the past to the present. The implementation of the integrated vector control methods have been difficult for these important malaria vectors as the different species have evolved different levels of resistance to the presently used insecticides. Population genetics research sheds light on gene flow across mosquito populations and, as a result, the likelihood of the spread of insecticide resistance genes across geographical regions. Considering the importance of these vectors, we analyzed the genetic structure and gene flow levels of six An. sacharovi and An. superpictus populations by using eight microsatellite markers. Anopheles samples were collected from different areas of the Aegean region of Turkey. Genotyping was carried out by using eight microsatellite markers on the ABI Prism 310 Genetic Analyzer. Genetic analyses indicated a relatively high level of genetic variation in Anopheles populations. The results revealed low genetic differentiation and moderate amounts of gene flow for both species among distinct populations. Also, significant genetic differentiation between the plurality of the population pairs analyzed was not found to be relevant to the geographic distances between populations. This is the first study to investigate the population genetics of the main malaria vectors, An. sacharovi and An. superpictus. Breeding habits, host feeding of Anopheles species, different collection times or points, climate, and variable effective population sizes may be some factors in the genetic diversity and genetic differentiation that have been observed between the populations.

Cadmium (Cd) stress seriously affects cucumber growth, yield, and quality. Melatonin (MT) can enhance plant resistance to abiotic stresses. However, studies on the mechanism of MT in enhancing plant resistance are limited. To better understand the underlying physiological and molecular mechanisms, the antioxidant defenses, photosynthesis, and transcriptome profiles of cucumber were analyzed under different growth conditions. The results demonstrated that exogenous MT significantly alleviated the Cd-induced damages to cucumber seedlings. Compared with Cd treatment, MT + Cd treatment enhanced antioxidant enzyme activities, suppressed ROS production, and improved photosynthesis in cucumber seedlings. Intriguingly, the scavenging or inhibition of hydrogen peroxide and nitric oxide reversed the positive effects of melatonin described above. RNA-seq identified 1299 differentially expressed genes in MD (MT + Cd) _vs_ D (Cd). Further detailed analyses suggested that MT-regulated genes are mainly related to photosynthesis, membrane lipid peroxidation, and plant hormone metabolism. In addition, some transcription factors and heavy metal transporters were involved in MT-induced Cd tolerance in cucumber seedlings. The results laid the foundation for further elucidation of the mechanism of exogenous MT-mediated Cd tolerance in cucumber and provided a theoretical reference for the future utilization of melatonin to improve Cd tolerance in cucumber.

This paper reviews more than 40 journal articles that describe the traits of phytoplankton functional groups (FGs) and their responses to biotic and abiotic factors in freshwater environments. Scholars have used different approaches with varying assumptions, making it necessary to subject the available information to a modest review. The paper sheds light on the potential responses of phytoplankton assemblages to biotic factors such as allelopathy, vertical migration, prey-predator interactions, macrophytes dominance, zooplankton grazing, and abiotic factors such as nutrient deficiency, turbulence and mixing processes, light, and temperature. It also highlights the status of studies on phytoplankton FGs in Ethiopian water bodies. While FGs have relevant applications in ecosystem assessment and monitoring, the difficulties faced are briefly discussed.

Abstract

To the best of our knowledge, this paper presents the first report on the microbial status of wild bees (A. dorsata and A. florea) honey collected from different northern states of India. In total, 17 bacterial morphotypes (9 from A. dorsata and 8 from A. florea) were recovered. The bacterial load (log CFU/g) was observed to be maximum (4.01) in A. dorsata honey from Sirmour-Puruwala whereas, lowest load (3.49) was recorded in Punjab-Rupnagar honey. Likewise, A. florea honey from Sirmour-Kala Amb and Punjab-Doraha were recorded with maximum and minimum bacterial loads of 4.17 and 3.40, respectively. Observance of lower bacterial load than hazardous limit ensured its safety for human consumption. Three most dominant bacteria viz., AD1, HF7 and AF4 were identified as Micrococcus endophyticus (MT938911), Bacillus subtilis subsp. stercoris (MT764923) and Bacillus pumilus (MT764923), respectively through 16S rRNA ribotyping. Moreover, the inhibitory activity of honey was good to excellent against Salmonella typhi NCTC 786 and fair to good against Bacillus subtilis ATCC 6633, Pseudomonas aeruginosa ATCC 10662 and Klebsiella pneumoniae ATCC 13883. The Escherichia coli ATCC 1041 was the most sensitive bacterium among all. These results justify wild bees honey as a natural remedy for curing and preventing numerous human ailments.

A survey was conducted in the agricultural fields of mustard of Haridwar district, Uttarakhand, India, where a heavy population of Zeldia was recovered. The morphological, molecular, and phylogenetic characterization confirmed the nematode as Zeldia punctata. The phylogenetic analysis based on 18 and 28S rDNA placed the studied population of Z. punctata close to other populations of the same species. The principal component analysis (PCA) data revealed the high intraspecific and interspecific variations between the populations of Zeldia punctata from different geographical regions. The result indicated a variation between the Indian populations of Z. punctata. Additionally, the selected ecological factors indicated an impact of EC, temperature, and phosphorus on Z. punctata during the flowering and podding time of mustard crops in India. However, the PCA revealed no effect of ecological factors on the nematode diversity indices. In conclusion, Z. punctata, with its high individual numbers on mustard, may affect crop production due to activating the bacterial community of the soil and less space for plant-parasitic nematodes.

Abstract

Malaise traps and sweep nets are commonly used to study sawfly faunas, seasonality and communities. Here we analyse a large dataset obtained with these methods in Slovakia and Hungary over the last two and a half decades. The dataset included collections from twenty-one sites, each covering the entire growing season, eleven of which were obtained with the Malaise trap and ten with the sweep net. We conclude that both methods are suitable for faunistic studies of sawflies (Hymenoptera, Symphyta), although they may lead to certain biased results for some Symphyta groups. Special attention should be paid to Siricidae, Orussidae, Xiphidriidae and Cimbicidae, which were only weakly recorded with both methods. Argidae, Blennocampinae, Dolerinae and Tenthredininae were underrepresented in the Malaise trap samples and Allantinae in the sweep net samples. Both methods gave equally good results in measuring species richness in an one-year study. Ideally, they should be used together as they complement each other well. The net method has a great advantage in determining the exact population density. In contrast, the Malaise trap collections were often heavily dominated by only a few species, with males being preferentially trapped. Use of Malasie trap should be preferred for the study of seasonal flight activity.

The conservation of endangered and rare mammal populations requires accurate inventorying. Traditional live-trapping methods can be labor-intensive, time-consuming and prone to errors, while camera trapping (CT) offers an effective alternative, enabling conservation efforts to focus on what is needed most. The current study utilized CT to understand the species richness and relative abundance of mammals in Kali Tiger Reserve, India. The sampling period was from March to May 2021, divided into three phases, each lasting 25 days and covering three different regions of the study area. The Rarefaction technique proved that 364 out of 462 camera stations was adequate effort for accurately estimating the composition of 22 mammal species comprising of eight herbivores, two omnivores, and six carnivores. The eastern region had a higher concentration of mammal species with the highest captures occurring at elevation ranging from 400 to 800 m. The study also noted the extensive presence of domestic animals and human activities, including hunting and poaching of wildlife within the reserve. The findings serve as a baseline for future assessments of conservation management interventions in Kali Tiger Reserve.

Changing environment markedly shapes plant diversity and vegetation across all spatial scales. It leads to innumerable local, regional and sometimes global changes in plant communities. Here, we present eleven full-text research articles of the Special Issue “Plant communities in changing environment”, which focuses on the evaluation of plant diversity and vegetation changes in different plant communities. We conclude that the results of all research studies show that plants, habitat and functional diversity are strongly conditioned in space and time by various factors, including climate, water regime, snow conditions, and human activities. These changes are also among most significant potential threats for plant diversity.

Mosses are key components of many ecosystems and particularly related to water cycling. In principle, the importance of mosses for water-related processes is known; however, their influence is rarely quantified in scientific studies. To fill this research gap, this study concentrates on the influence of mosses of different species on surface runoff, the amount of percolated water, soil loss, and the temporal dynamics of soil water content. For this purpose, an experimental approach consisting of an ex situ rainfall simulation (45 mm h^− 1 for 30 min) with infiltration boxes equipped with biocrust wetness probes was applied. On average, mosses significantly reduced surface runoff by 91% and soil loss by almost 100%, while the amount of percolated water was increased by 85% compared with bare soils. These processes were superimposed by desiccation cracks, and partly water repellency, with the result that the respective influences could not be quantified individually. However, by simultaneously measuring the water content in the substrates during rainfall simulations, we were able to achieve a better understanding of the water flows in the substrates. For instance, water content at 3 cm substrate depth was higher under mosses than in bare soils, implying that mosses facilitated infiltration. In this study, we were able to demonstrate that mosses play an important role in soil hydrology and in protecting the soil from erosion, and it is imperative that further experiments will be conducted to elucidate the apparently underestimated effects of mosses and their specific traits on soil water fluxes and sediment transport.