Periodicum Biologorum

Morphological, phenological and reproducitve characteristics of the invasive weed species Abutilon theophrasti Medik as affected by various plant densities

Maja Šćepanović — 2019-09-15

Background and purpose: Abutilon theophrasti Medik (velvetleaf) is an invasive plant well spread in Croatia as noxious weed species. The aim of this study was to provide morphological, phenological and reproductive information of velvetleaf grown under various densities: 2, 5, 10 and 20 plants m^-2.

Material and methods: The field experiment was conducted in 2014 at University of Zagreb Faculty of Agriculture as complete randomized blocks design. Throughout the vegetation morphological (hypocotyl and epicotyls length, number of leaves and branches, plant height, shoot dry weight and diameter), phenological (beginning of flowering end of flowering and first capsule formation; GDD to beginning of flowering end of flowering and first capsule formation) and reproductive (capsules plant^-1, seed capsules ^-1, seeds plant^-1, seeds m^-2, 1000 seeds weight and germinability) characteristics were measured.

Results and conclusion: Mostly all morphological and reproductive characteristics were significantly affected by plant density. Increase of velvetleaf competition from 2 to 20 plants m^-2hasreduced number of capsule and consequently almost five fold decreased seed production per plant. However, plants which have been growing at densities > 5 plants m^-2 produced in average 50% more seeds per land area than plants at the lowest density. Low germinability at harvest (2%) and six month later (15%) indicate on primary dormancy and possibility for longevity in soil if plants are left uncontrolled in the field. In contrast to morphological and reproductive changes, plants in high density did not showed increasing growing degree days requirements.

Estimation of biological parameters for germination of Abutilon theophrasti Medik.

Valentina Šoštarčić — 2019-09-15

Background and Purpose: Velvetleaf seed longevity and prolonged emergence complicate assessing appropriate time for its control. Estimating biological parameters (base temperature and base water potential) is a first step towards development of emergence predictive model for this weed species in summer crops. Since, development of new model is time consuming, the aim of the research was to provide the data set of biological thresholds for Croatian ecotype and then to compare it with Italian velvetleaf thresholds to assess the implementation of AlertInf predictive weed emergence model from Italy to Croatia.

Materials and methods: Laboratory experiments were conducted with 100 seeds per three replicates at seven constant temperatures (4, 8, 12, 16, 20, 24, 28°C) to estimate base temperature (T_b) and at seven water stress levels (0.00, -0.05, -0.10, -0.25, -0.38, -0.50, -0.80, -1.00 MPa) to estimate base water potential (Ψ_b).

Results: The highest germination occurred at temperature > 20°C with 3.6 days and at water stress level >- 0.25 MPa with 4.9 days to complete 50% of germination (t₅₀). The slowest t₅₀ occurred at 4°C (41.9 days) and < -0.38 MPa (10.1 days). Estimated Croatian velvetleaf biological parameters are: 4.5°C (T_b) and – 0.67 MPa (Ψ_b) with no significant difference compared to Italian ecotype, according to 95% confidence intervals overlapping.

Conclusion: The results indicate that it could be possible to implement AlertInf model from Italy to Croatia for this weed species without additional adjustment. Nevertheless, next step of this implementation should include validation of estimated results in the field conditions.

Key words: invasive weed species, velvetleaf, germination modelling, integrated weed management, base temperature, base water potential

Invasive occurrence and abundance changes of Armadillidium vulgare (Latreille, 1804) in Hungarian roadside verges

Diána Vona-Túri — 2019-09-15

Background and purpose: The impact of invasive species in ecosystems is an important problem worldwide and the spreading of invader species are affected exceedingly by linear infrastructure. Primarily the aim of our investigation was to studied how the invasion of the species impacts the isopod diversity of roadside verges. Secondly, we determined what attributes of linear infrastructure affect on mass occurrence by the species.

Materials and methods: Double-glass pitfall traps were established a total of 37 localities along highways and mainroads in Hungary between 2011 and 2015. To studied what attributes of roads affect the abundance of A. vulgare we considered seasons, adjacent areas, road edge proximity, leaf-litter depth, highway age, vegetation and mowing.

Results: We collected a total of 18 isopod species. The A. vulgare was the most abundant and frequently encountered species in both road types, which represented 89% of the total isopod catches. The high abundance of the species negatively correlated with isopod diversity. The invasive nature of this species is promoted by summer conditions, proximity of arable fields, intermediate distance from the road, leaf-litter at a depth of 3 cm and the youthfullness of the sampling sites. On mainroad verges the highest abundance was in the non-mown sections of the arid grassland sites.

Conclusions: Our results suggest that this species is likely to adversely impact ecosystem function of roadside verges in Hungary. Different land use, water supply, surrounding landscapes, habitat structure, vegetation, biogeographical context and human activities along road verges influence the invasiveness of A. vulgare.

Combined zinc and nitrogen applications at panicle initiation for zinc biofortification in rice

Shahid Hussain — 2019-09-15

Background and purpose: Increasing zinc (Zn) concentration in rice grains can help improve Zn nutrition of people. The combinations of Zn and nitrogen (N) applications at panicle initiation were investigated for Zn biofortification in rice.

Materials and methods: Rice (cv. Super Basmati) seedling were grown in pots having a calcareous soil. All possible combinations of four Zn (control, Soil 6 mg Zn kg^–¹, foliar 2 × 0.2% Zn and soil + foliar Zn) and three N (control, soil 20 mg N kg^–¹ and foliar 0.5% N) levels were imposed at panicle initiation. At maturity, grains were analysed for Zn and proteins.

Results: Grain protein concentration was significantly increased with foliar Zn treatments, and with soil and foliar N. Maximum grain Zn concertation (30 mg kg^–¹) was achieved with application of soil Zn + foliar Zn + foliar N. At each N level, Zn application by either method significantly increased grain Zn concentration over control. This increase in grain Zn concertation at N levels was 36 to 54% with soil Zn + foliar Zn, 27 to 45% with foliar Zn and 9 to 15% with soil Zn over its control level.

Conclusions: Grain Zn concentration was significantly increased with soil N when combined with soil Zn, and with foliar N when combined with foliar Zn treatments. Conclusively, foliar N combined with soil + foliar Zn is the best combination of late Zn and N application for agronomic Zn biofortification in rice.

Fibrinolytic parameters under ischemic stroke with diabetes mellitus combination

Olha Kravchenko — 2019-09-15

Abstract

Background: Fibrinolysis and thrombosis alterations include important parts of stroke pathophysiology. At the same time fibrinolytic system disorders are a common feature of patients with metabolic syndrome and diabetes. So it may increase the possibility of developing atherosclerotic lesions and occlusive intravascular thrombi. The present study investigated the influence of type 2 diabetes mellitus presence on the indicators of fibrinolytic parameters (plasminogen activator inhibitor 1 (PAI-1), tissue-type plasminogen activator (tPA) content, streptokinase-activated plasminogen and α₂-antiplasmin activities, euglobulin clot lysis time (ECLT) and Hageman-factor-dependent fibrinolysis time) under ischemic stroke (IS).

Materials and methods: Participants were 87 subjects with IS, 22 of them had diabetes mellitus. Blood samples besides for aforementioned parameters were analyzed for glucose and glycosylated haemoglobin content.

Results: The research established increase of plasma PAI-1 and tPA levels, ECLT, Hageman-factor-dependent fibrinolysis time in IS and IS with diabetes mellitus patient groups in comparison with the control. PAI-1 concentration in plasma was positively correlated with both lysis time tests but tPA content was negative correlated with glucose level and PAI-1 for only IS patients. But there was a high negative correlation between tPA and ECLT as well as Hageman-factor-dependent fibrinolysis time for both investigated IS forms.

Conclusions: The results showed important differences in the characteristics of the fibrinolytic mechanism in IS patients compared with healthy population. The major differences were elevated PAI-1 and t-PA contents and prolonged ECLT in IS patients but no significant differences in these parameters were observed between the patients with IS and IS with diabetes.

The effect of subminimal inhibitory concentrations of antibiotics on the adherence ability of Pseudomonas aeruginosa to epithelial cells in vitro

Sanja Bekić — 2019-09-15

Background and purpose: The aim of this study was to examine the influence of subminimal inhibitory concentrations (subMICs) of ceftazidime, ciprofloxacin and gentamicin on the adherence ability and morphology of wild-type Pseudomonas aeruginosa strains to the Buffalo green monkey kidney cell line, using indirect immunofluorescence staining.

Materials and methods: Bacterial adherence changes were tested before and after exposure to 1/2, 1/4, 1/8, 1/16 and 1/32 MIC of antibiotics.

Results: A statistical difference in the number of attached bacteria after exposure to all subMICs of ceftazidime and ciprofloxacin was observed (p<0.05), even after only 1/2 MIC of gentamicin.

Conclusion: The results of this study have shown that antibiotics in much lower concentrations than those necessary for inhibition of bacterial multiplications could damage the adherence of Pseudomonas aeruginosa to the epithelial cell line.

Connection between prey composition and the landscape structure in the hunting area of Barn Owl’s (Tyto alba) in Baranja (Croatia)

Dávid Szép — 2019-09-15

Background and purpose: The assumption that the species composition and the relative abundance of small mammals in pellets of Barn Owls reflects the landscape structure of the hunting area is tested, based on habitat preferences of small mammals identified from pellets collected in the hilly and lowland parts of Baranja county (Croatia).

Materials and methods: During 2007 we collected 2395 whole pellets and their fragments in 21 localities, from which 6613 prey remains were identified as belonging to small mammals (99.5%) of 23 species. The correlation between the relative abundance of mammal species and landscape structures (habitat types and landscape features) was tested.

Results: There was a significant correlation between the relative abundance of seven small mammal species and the proportion of particular landscape structure classes. The number of small mammal species showed a negative correlation with the area of inland marshes. The evenness of the small mammal fauna grew with the mosaicity of landscape and the length of the borders in the owl’s hunting area. In the total prey the Common Vole (Microtus arvalis) dominated with more than 62%, which indicates its population outbreak. The diversity and evenness of small mammals in the hilly and lowland regions did not differ.

Conclusions: We found significant correlations between the relative abundance of some small mammal species and the landscape structure classes in the owls’ hunting area. Our results suggested that the diversity of small mammals increases as the mosaic of the landscape increases, while the degree of population outbreak of the Common Vole decreases. These relationships should be taken into consideration when designing landscapes or changing land use.

Contribution to the knowledge on distribution in Hungary and habitat preferences of Gnaphosa modestior Kulczyński, 1897 a little-known spider species

Tünde Szmatona-Túri — 2019-09-15

Background and purpose: The aim of this review is to present current knowledge on the occurrence of a little-known gnaphosid species Gnaphosa modestior Kulczyński, 1897. Early it was mentioned as G. alpica species in Middle Europe. In this study, we reported the new occurrence of this species in Hungary and we examined of the effect of shrub control and mowing on this species abundance.

Materials and methods: Our arachnological research was conducted in the Mátra Mountains, the highest range of volcanic massin northern Hungary, between 2007 and 2016.

Result and conclusion: We recorded 13 specimens from five habitats of the southern part of the Mátra Mountains. This species can be found mainly in untreated shrubby habitats from April to June. In general, it can say that G. modestior is a stenochronous spider species which lives in habitats not influenced by human activities in the Mátra Mountains. However, this attributes of species differ in some European countries.