Variation in honey bee gut microbial diversity affected by ontogenetic stage, age and geographic location

Social honey bees, Apis mellifera, host a set of distinct microbiota, which is similar across the continents and various honey bee species. Some of these bacteria, such as lactobacilli, have been linked to immunity and defence against pathogens. Pathogen defence is crucial, particularly in larval stages, as many pathogens affect the brood. However, information on larval microbiota is conflicting. Seven developmental stages and drones were sampled from 3 colonies at each of the 4 geographic locations of A. mellifera carnica, and the samples were maintained separately for analysis. We analysed the variation and abundance of important bacterial groups and taxa in the collected bees. Major bacterial groups were evaluated over the entire life of honey bee individuals, where digestive tracts of same aged bees were sampled in the course of time. The results showed that the microbial tract of 6-day-old 5th instar larvae were nearly equally rich in total microbial counts per total digestive tract weight as foraging bees, showing a high percentage of various lactobacilli (Firmicutes) and Gilliamella apicola (Gammaproteobacteria 1). However, during pupation, microbial counts were significantly reduced but recovered quickly by 6 days post-emergence. Between emergence and day 6, imago reached the highest counts of Firmicutes and Gammaproteobacteria, which then gradually declined with bee age. Redundancy analysis conducted using denaturing gradient gel electrophoresis identified bacterial species that were characteristic of each developmental stage. The results suggest that 3-day 4th instar larvae contain low microbial counts that increase 2-fold by day 6 and then decrease during pupation. Microbial succession of the imago begins soon after emergence. We found that bacterial counts do not show only yearly cycles within a colony, but vary on the individual level. Sampling and pooling adult bees or 6th day larvae may lead to high errors and variability, as both of these stages may be undergoing dynamic succession

Efficacy of Pythium oligandrum on improvement of lucerne yield, root development and disease score under field conditions

IntroductionBiological control of root diseases of lucerne (Medicago sativa L.) has potential benefits for stand performance but this remains unsupported by evidence from practical field studies.MethodsIn field experiments at three sites our objectives were to determine the effect of Pythium oligandrum, as spring, autumn and intensive regime treatments on (i) lucerne plant density and root traits development, and (ii) forage yield and forage traits. Lucerne stands were managed under two or three treatments: non-treated control and P. oligandrum applied at two intensities of application under four-cut utilization.Results and discussionUnder relatively dry conditions (annual mean 10°C and <500 mm precipitation) lucerne dry matter yield was significantly reduced by 6%, which could be related to mechanisms of inappropriate stimulation and disturbance of the balance between auxins and ethylene. Under annual precipitation of >500 mm, positive impacts on stand height or fine root mass were observed for the autumn and intensive treatments where positive root response was visible only in alluvial soil. However, these changes did not result in higher yield and probably more applications per year will be needed for significant forage yield improvement. This study highlights the limits of field-scale biological control in which the potential of P. oligandrum for lucerne productivity improvement was realised only under a humid environment or deep alluvial soils, where higher root disease infestation may also be expected

SCULPTURE-OBJECT TO THE INTERIOR ON THE THEME OF " MY STATUE IS MY EVIDENCE " USING NATURAL MATERALS

Jedná se o soubor betonových figur opilcůObhájenoIt is a set of concrete drunken figures

SCULPTURE-OBJECT TO THE INTERIOR ON THE THEME OF " MY STATUE IS MY EVIDENCE " USING NATURAL MATERALS

Jedná se o soubor betonových figur opilcůObhájenoIt is a set of concrete drunken figures

Cellulose and cutisin decomposition in soil of Alopecuretum meadow

Plant litter decomposition is a fundamental process to ecosystem functioning regulated by both abiotic and biotic factors. The aim of this study was to determine the decomposition of cellulose and protein (cutisin) substrates on permanent Alopecuretum meadow under different methods of management. The treatments were following: 2 × cut, 2 × cut + NPK, 2 × mulch, 1 × cut, 1 × mulch (frequency of mowing per year) and no-treated plots. Cutting or mulching was carried out in October, under the 2 × cut management also in May. In 2007–2009, cellulose and cutisin in mesh bags were placed in the soil and kept from April to October. Total mean ratios of decomposed cellulose and cutisin were 83 % and 40 % of primal substrate weight, respectively. The cellulose decomposition was affected by weather conditions, but not by applied management. The highest mean ratio of decomposed cellulose was found in 2009 (with increased amount of precipitation in May and July), the lowest in 2007. Coefficients of variation within a year and over the years were up to 22 % and 20 %, respectively. The cutisin decomposition was significantly affected by applied management in all three years. Higher rates of decomposition were noted in two times mowed treatments compared to one or not mowed treatments. Significant differences were found between years in 2× cut and 2 × cut + NPK treatments. Coefficients of variation within the year and over the years were both higher by cutisin than by cellulose samples (up to 50 and 42 %, respectively)

Impact of Long-Term Manure and Mineral Fertilization on Accumulation of Non-Structural Carbohydrates in Lucerne Forage

Fertilization management affects both productivity and nutritive value of forage legumes. However, there are few studies about changes in lucerne non-structural carbohydrates under long-term fertilization. The aims of this study were to compare the effects of mineral fertilization and organic manure on lucerne plant parts (leaf, stem) starch and water-soluble carbohydrate (WSC) accumulation in association with canopy structure following 60 years of different fertilization management approaches. Treatments investigated were: two contrasting levels of mineral N, P2O5 and K2O application (0:0:0 and 91:71:175), each with and without farmyard manure. Changes were mainly reflected in WSC content where intensive mineral fertilization consistently reduced the stem and forage WSC in contrast to unfertilized control or manure alone. These changes could be associated with a dilution effect presented by the highest increase of maximal stem length at these treatments. Manure improved leaf and forage WSC despite the associated increase in maximal stem length and leaf weight ratio, probably as a result of improved soil environment together with the potentially increased presence of arbuscular mycorrhizal fungi. Results showed that manure fertilization has potential for improvement of lucerne WSC, despite some negative relationships between lucerne canopy traits and sugar content

Seed Treatment Potential for the Improvement of Lucerne Seed Performance and Early Field Growth

Seed treatments have a potential to improve seed performance traits and consequently optimize crop establishment. However, there is a lack of systematic research for these techniques in lucerne, especially under field conditions. The goal of this study was to investigate the potential of various seed treatments on the improvement of lucerne germination and emergence under lab conditions and early seedling growth in the field. Compared treatments were heat treatment; seed priming with water, potassium permanganate, chitosan, vermitea, or bokashi juice; and seed coating with cinnamon, gypsum, wood ash, tannin quebracho, and cocoa powder. Among the seed priming methods, potassium permanganate and chitosan provided the best results in the improvement of seedling length or emergence dynamics, whilst coating with bentonite and gypsum could be recommended for having a positive impact on root development. Cinnamon powder significantly improved the emergence dynamics, seedling, and shoot length. The combination of priming and coating methods seems to be the most effective when assessed under the field conditions, where some positive response in root traits can be evaluated

Development of root morphology traits of the Czech lucerne varieties in chernozem over a three year period

The root system of plants is generally in relation to important agronomic and ecological characteristics. The aim of this study was to investigate differences in root morphology development of Czech lucerne varieties under chernozem soil conditions. In spring 2007, a field experiment with ten Czech lucerne varieties was established with a regular space of 125 mm between the rows. During the 2008–2010 period, the plants were sampled every autumn after the last cut in five blocks per each variety; the size of the sampling area was 50 × 50 cm and average depth of sampling was 0.25 m. All varieties provided similar trend in root morphology development but some differences could be detected in the rate of this development. From all evaluated root traits, these differences were connected mainly with tap-root diameter, intensity of root branching and lateral root number. Advisable varieties should provide higher density of plant together with higher root diameter and branching which is resulted to higher root weight per m2 and consequently to higher stand productivity. The root-branched plants achieved a significantly higher tap-root diameter of 10.7 mm in comparison with unbranched-root plants with 7.1 mm. Except of plant age, the stand density and tap-root diameter could be considered as a parameter to drive lucerne root morphology development. Within a year, the increase of tap-root diameter was connected with increase of root branching at root-branched plants whilst decrease of plant density caused the beginning of the process of root branching at tap-rooted plants. The range of root traits influenced themselves so their joint presentation is advisable. It must be remembered that soil conditions are a factor which strongly modified the root morphology traits; therefore, these results must be completed with other experiments under various soil conditions. The knowledge of root morphology traits could contribute to the assessment of lucerne varieties specific features

Effect of Row Spacing and Plant Density on Silage Maize Growth, Dry Matter Distribution and Yield

Maize growth in narrow rows provides a more uniform spatial arrangement, but it does not always lead to increasing yield. A four-year study was conducted to investigate the effect of row spacing on silage maize growth and yield during the growing season and at harvest time. A field experiment with conventional (0.70 m) and narrow rows (0.35 m) at a plant density of 92,000 plants ha−1 was evaluated in the years 2011–2014, and the interaction of row spacing × plant density (92,000 and 110,000 plants ha−1) was tested in 2013–2014. The narrow rows clearly demonstrated potential to support plant height and weight development, together with a higher stalk proportion, at around two months after seeding. However, these contrasts were lost in the later stages and at harvest time. Some potential for non-significantly higher dry matter yield (4.6–10.8%) was shown in the narrow rows in three years of the experiment, in association with lower losses in plant numbers, when compared to conventional row spacing. The potential of yield improvement in the narrow rows showed relationships with weather conditions during the second half of the growing season. In summary, under the growing conditions of the study region, narrow row spacing significantly promoted early plant development, but these effects did not persist until harvest, thus resulting in only limited success in yield improvement