Productivity of single-culm and multi-culm plants of winter wheat cultivars in field conditions

Summary The productivity of 1-, 2-, and 3-culm plants of three winter wheat cultivars was studied under field conditions in three spatial arrangements. The treatments with 2- and 3-culm plants produced higher grain yield per unit area than the treatments with 1-culm plants. This was explained as the result of a higher interplant than intraplant competition. It seems that the interplant competition is lower with dwarf than with tall cultivars. The secondary culms may be as productive as the primary ones if there are only a few of them per plant and if they develop before the beginning of winter. If the tillering takes place mainly in spring, the differences in productivity between the primary and secondary culms are considerable. Under conditions of dry autumns and late planting not the tillering must be taken as the main factor which regulates the optimal number of spikes/m², but the high planting rate.     

Quercetin influences response in Nicotiana megalosiphon infected by satellite-associated cucumber mosaic virus

Journal of Plant Diseases and Protection - Quercetin is a prominent flavonoid with a remarkable spectrum of biochemical activities. Its impact on human health, as well as its role in the normal...     

Root distribution of under-planted European beech (<Emphasis Type="Italic">Fagus sylvatica</Emphasis> L.) below the canopy of a mature Norway spruce stand as a function of light

Aboveground and belowground biomass of 15-year-old under-planted European beech seedlings (Fagus sylvatica L.) in Norway spruce stand were studied along a light gradient in three plots, in the northern part of Slovenia. Differences in soil water content, aboveground and fine root biomass distribution were confirmed between studied plots. Light had significant effect on the total biomass, root-shoot ratio (0.388 ± 0.076 under canopy, 0.549 ± 0.042 in the edge, 0.656 ± 0.047 in the open), specific root length (SRL) of fine beech roots (561.9 ± 42.2 under canopy, 664.3 ± 51.2 in the edge, 618.2 ± 72.8 in the open) and specific leaf area in beech, indicating morphological adjustment to shade. However, SRL of beech fine roots indicated no change between plots. The correlation between total aboveground and root biomass and light below the mature stand canopy was higher in the case of diffuse light intensity. Most fine roots of spruce were concentrated in the top (0–20 cm) soil layer. Beech fine roots under canopy and edge conditions were also concentrated in top (0–20 cm) soil layer and exhibited shift downwards to deeper soil horizons in open plot. Root proportion between beech and spruce changed with light toward beech with increasing light intensity for both fine and coarse roots.     

T and B lymphocytes in horses persistently infected with equine infectious anaemia virus

The percentage of T and B lymphocytes in the peripheral blood of horses chronically infected with equine infectious anaemia (EIA) virus was determined and the results were compared with the percentage of these cells in healthy uninfected horses. Cells with membrane receptors for sheep erythrocytes (T and active T lymphocytes) were determined by E and A rosette techniques, while cells with receptors for the C3b component of complement and those with receptors for mouse erythrocytes (B lymphocytes), were determined by the EAC rosette method. The percentage of Fc positive cells was assayed by the EA rosette test.The majority of peripheral blood lymphocytes (PBL) from both uninfected and EIA-infected horses formed rosettes of each kind with only three erythrocytes indicating a low density of the corresponding receptors on the cell membrane under the condition of the assays used. The percentage of T lymphocytes in the peripheral blood of diseased horses (52.4±1.6%), as detected by E rosettes, was significantly (p<0.01) higher than in control animals (42.4±3.5%). In clinically healthy horses 8.9±1.1% of PBL were identified by A rosettes as active T cells, whereas animals with a chronic form of EIA had a much lower (p<0.001) percentage of these cells (4.7±0.7%). In the B lymphocyte subpopulations the percentages of cells bearing Fc and C3b receptors were markedly elevated (p<0.001) in EIA-infected horses (24.7±0.8% and 42.8±2.2% respectively) as compared to uninfected animals (15.1±1.4% and 29.6±1.2% respectively). Receptors for mouse erythrocytes, as yet undescribed on equine PBL, were demonstrated in approximately equal proportions on lymphocytes from EIA-infected (24.8±1.5%) and uninfected horses (24.3±2.1%).     

Yersiniosis in zoo marmosets (Callitrix jacchuss) caused by Yersinia enterocolitica 4/O:3

The aim of this research was to describe two fatal cases of Yersinia enterocolitica bioserotype 4/O:3 infection in non-human primates and to characterise the isolates by PCR and PFGE. In July 2004, two marmosets (Callitrix jacchuss) born in captivity in Zagreb Zoo, died following a few days of intermittent diarrhoea in intervals of 2 weeks. The pathomorphological diagnosis of the female (born in 1997) and the male (born in 1995) marmoset, was disseminated miliary necrosis of the liver. Y. enterocolitica 4/O:3 was isolated from both livers showing that monkeys are susceptible to this bioserotype. The ail gene, which is an essential chromosomal virulence factor in pathogenic Y. enterocolitica isolates, was present in the marmoset isolates. Two different PFGE patterns were obtained from the isolates of the male liver with NotI enzyme. One genotype of the male marmoset isolate was indistinguishable from the genotype of the female marmoset isolate when NotI, ApaI and XhoI enzymes were used indicating a common infection source for the marmosets. The genotypes of the marmoset isolates differed only slightly from one human (of seven Croatian isolates) and from one pig isolate (representing a common genotype found among human and porcine isolates in Germany) suggesting that raw pork fed to the marmoset could have been the infection source.     

Analysis of Possible Influence of Conjugated Linoleic Acid on Growth Performance and Losses of Piglets

The aim of this work was to evaluate the effect of supplementing the feed ration for lactating sows with the conjugated linoleic acid (CLA) on the growth performance and losses of piglets from birth to weaning. The monitoring comprised 20 litters in control and 20 litters in experimental group of Czech Large White × Czech Landrace hybrid combination sows. The control group was given a standard feed mixture for lactating sows, and experimental group was fed with the feed mixture supplemented with 2% of CLA, from the day of farrowing to the weaning of piglets, that is for the time of 28 days. The results of the experiment indicate the significantly better parameters of the numbers of reared piglets in the experimental group and the related lower level of losses of piglets from birth to weaning (p < 0.01). However, the feed mixture for lactating sows enriched in conjugated linoleic acid had no significant effect on the growth performance of piglets from birth to weaning (p > 0.05). Sows in the experimental group showed earlier onset of post‐partal oestrus after weaning of piglets (p < 0.05). These findings demonstrate that the supplementation of diet for lactating sows with CLA can improve survival of piglets from birth to weaning and shortening of weaning‐to‐oestrous interval in sows.     

Effect of finishing treatments on heat resistance of one- and two-layered fabrics

A series of cotton knitted fabrics was produced and finished according to three different recipes in order to compare the changes of their heat resistances. The heat resistance was measured using the sweating guarded hotplate. Measurements were carried out on one layer of produced knitted fabrics, as well as on two layers of fabrics. The results indicated significant influence of all carried finishing treatments to the decrease of heat resistance of knitted fabrics. It was shown that the high influence of finishing treatment to the total heat transfer trough fabric remains if the fabric is worn with additional knitted fabric layer. The presented results and performed statistical analysis indicated significant effect of finishing treatments to the changes of fabric parameters and furthermore to the changes of heat resistance what directly affects the total thermophysiological comfort of knitwear.     

Kinetic study of flavonoid reactions with stable radicals

The antiradical activities of some flavonols (kaempferol, quercetin, robinetin, quercetagetin, and myricetin), flavones (apigenin, baicalein, and luteolin), flavanones (naringenin and dihydroquercetin), and flavanols [(+)-catechin and (-)-epicatechin] were determined by measuring the reaction kinetics with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and alpha,gamma-bisdiphenylene-beta-phenylallyl (BDPA) radicals. The reactions, which follow the mixed second-order rate law, were investigated under pseudo-first-order conditions by use of a large excess of flavonoids, and their stoichiometry was determined by spectrophotometric titration. The results confirm stoichiometric factors of 1, 2, and 3 for flavonoids with one, two, and three hydroxyl groups in the B-ring, respectively, excluding kaempferol, which, despite a single OH group in the B-ring, has a factor of 2, which is explained by the 3-OH group supporting the reaction with free radicals. Structure-activity considerations indicate for the present series of flavonoids the importance of multiple OH substitutions and conjugation. The logarithms of reaction rate constants with the OH, DPPH, and BDPA radicals correlate well with the reduction potential of the flavonoids.