Loss in macronutrient pools in bilberry and lingonberry in mesic Scots pine forests after Northern red oak introduction

Forest transformation from coniferous monocultures to mixed stands is being promoted worldwide, including the introduction of fast-growing broadleaved tree species within native stands. Here, we studied how enrichment of temperate European Scots pine (Pinus sylvestris) forest by North-American northern red oak Quercus rubra impacted macronutrient concentrations in two long-lived and dominant components of the forest understory: bilberry Vaccinium myrtillus and lingonberry V. vitis-idaea. Study sites were located in forest complexes (central Poland) which occupy continuously reforested lands (hereafter ancient forests) as well as post-agricultural lands (recent forests), all suitable for mesic pine forests. Samples of bilberry and lingonberry leaves, stems, and fruits were collected in pine stands and in adjacent Scots pine-red oak stands, in both ancient and recent forests. Concentrations of macronutrients (C, N, P, K, Ca, S, and Mg) in aboveground biomass components were analysed using standardized chemical procedures. The study revealed intra- and interspecific (bilberry vs. lingonberry) differences in concentrations of all nutrients in leaves, stems, and fruits, except for invariable C concentrations. Macronutrient accumulations in plants were decreased by land-use discontinuity and favoured by enrichment of tree stands by Q. rubra. The estimated macronutrient pools were much higher for V. myrtillus than V. vitis-idaea in all forest types studied. They were lower in forests enriched with Q. rubra, both ancient (up to 25.5% for bilberry and 99.9% for lingonberry) and recent (46.9% and 99.9%, respectively), as well as in recent pine forest (46.6% and 81.1%, respectively) than in ancient pine forest. Higher K and S pools (39.3% and 6.5%, respectively) noted for bilberry in an ancient forest with Q. rubra were exceptions. Despite more effective accumulations of elements at the species level, macronutrient pools of Vaccinium myrtillus and V. vitis-idaea decreased significantly in the presence of introduced Q. rubra due to negative impacts of this broadleaved tree on bilberry and lingonberry cover and biomass. Therefore, the limitation of alien Q. rubra planting in sites of mesic pine forest with the abundant occurrence of V. myrtillus and/or V. vitis-idaea is recommended.

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Modified flotation method with the use of Percoll for the detection of Isospora suis oocysts in suckling piglet faeces

The modification of flotation method for the examination of diarrhoeic piglet faeces for the detection of Isospora suis oocysts was elaborated. The method was based on removing fractions of fat from the sample of faeces by centrifugation with a 25% Percoll solution. The investigations were carried out in comparison to the McMaster method. From five variants of the Percoll flotation method, the best results were obtained when 2ml of flotation liquid per 1g of faeces were used. The limit of detection in the Percoll flotation method was 160 oocysts per 1g, and was better than with the McMaster method. The efficacy of the modified method was confirmed by results obtained in the examination of the I. suis infected piglets. From all faecal samples, positive samples in the Percoll flotation method were double the results than that of the routine method. Oocysts were first detected by the Percoll flotation method on day 4 post-invasion, i.e. one-day earlier than with the McMaster method. During the experiment (except for 3 days), the extensity of I. suis invasion in the litter examined by the Percoll flotation method was higher than that with the McMaster method. The obtained results show that the modified flotation method with the use of Percoll could be applied in the diagnostics of suckling piglet isosporosis.     

Morphological and molecular identification and PCR amplification to determine the toxigenic potential of Fusarium spp. isolated from maize ears in southern Poland

The average amount of precipitation in spring and summer 2010 and 2011 coupled with relatively high temperatures caused massive Fusarium spp. infection of maize and yield losses in southern Poland. In order to examine the cause of this disease outbreak, Fusarium spp. were isolated and fungal strains were identified based on morphological characters and species-specific PCR assays. A total of 200 maize samples were processed, resulting in the obtention of 71 strains, which belonged to five Fusarium species, F. poae being the predominant one (74.56%). Other isolates were identified as F. graminearum, F. oxysporum, F. verticillioides and F. proliferatum. PCR-based detection of mycotoxin-synthesis-pathway genes was also used to determine the potential of the analyzed strains to produce trichothecenes (DON and NIV) and fumonisins (FUM). Only 14 isolates revealed the potential to produce DON (11 strains) and FUM (3 strains). HPLC analyses of grain samples revealed the presence of DON only – other mycotoxins were not detected. Moreover, 57.1% of potentially mycotoxin-producing isolates indicated the toxicity in a biological test.     

Analysis of introgression of the Tulipa fosteriana genome into Tulipa gesneriana using GISH and FISH

Southern hybridization and genomic in situ hybridization (GISH) have demonstrated that ‘Purissima’ (2n = 2x = 24) is an interspecific hybrid comprised of one genome of Tulipa (T.) gesneriana and one genome of T. fosteriana. Backcrossing T. gesneriana with ‘Purissima’ was partially successful. Simultaneous GISH and fluorescence in situ hybridization (FISH) distinguished chromosomes from both parent genomes, as well as recombinant chromosomes, in interspecific hybrids and their progeny. Chromosome recombination was observed in all cultivars except ‘Purissima’ and ‘Kouki’ (2n = 3x = 36). ‘Kouki’ (2n = 3x = 36) had two genomes of the T. gesneriana and a single genome of the T. fosteriana. The number of nonrecombinant T. fosteriana chromosomes in ‘Judith Leyster’ (2n = 4x = 48) and ‘Purissima’ progeny varied from two in ‘Hatsuzakura’ to six in ‘Kikomachi’ and ‘Momotaro’. The number and type of recombinant chromosomes also differed among cultivars. The total number of translocations ranged from one in ‘Kikomachi’ to six in ‘Hatsuzakura’. Each was a combination of a single T. fosteriana fragment and a single T. gesneriana fragment, indicating that they resulted from a single crossover event. Sequential GISH and FISH analysis with rDNA probes yielded chromosome-specific markers that were used to identify most of the chromosomes in ‘Purissima’ progeny. This is the first report of introgression of T. fosteriana chromatin into the T. gesneriana genome.     

Ploidy manipulation and introgression breeding in Darwin hybrid tulips

Meiotic polyploidisation via crossing with 2n gamete producing genotypes and interploidy crosses are two of the main methods currently used to obtain polyploid tulips. In our study diploid 2n gamete producing F₁ hybrids of Darwin hybrids (Tulipa gesneriana × Tulipa fosteriana) and triploid hybrid resulting from ‘Rhodos’ × ‘Princeps’ cross were used as pollen donor and crossed with cultivars of T. gesneriana in the following combination: 2x × 2x, 3x × 2x, 2x × 3x, and 3x × 3x. The progenies resulting from crosses at diploid level were mostly diploid, whereas a few seedlings were triploid. In 3x × 2x crosses aneuploids with chromosome constitution in between triploid and tetraploid (43–45 chromosomes) were predominant, but also one tetraploid (2n = 4x = 48) and four pentaploids (2n = 5x = 60) were obtained. In 2x × 3x crosses most progenies were triploid with the exception of a few aneuploids (3x + 1 and 3x ? 1), whereas in 3x × 3x cross diploid and aneuploid genotypes were recorded with chromosome number varied from 27 to 34. These results indicate that triploid parents produced aneuploid as well as euploid (x, 2x, 3x) gametes and that success in ploidy manipulation in tulip depends to a large degree on the ploidy level of the parental genotypes used for hybridization. Genome constitution of selected population of F1 and BC1 hybrids was analyzed through genomic in situ hybridization (GISH). GISH analysis of the BC1 showed a considerable amount of intergenomic recombination which is desirable for introgression breeding.     

The genus Dasypyrum—part 2. Dasypyrum villosum—a wild species used in wheat improvement

Dasypyrum villosum (L.) P. Candargy is discussed as a species commonly used in wheat improvement. Chromosomal localization of the potentially useful traits and chromosomal position of some morphological and isozyme markes are shown. The investigations using molecular RAPD, AFLP, SSR, RFLP markers and in situ (GISH, FISH) hybridization experiments on D. villosum itself and in wide hybrids with Triticum are summarized. The article also presents the information about designation of D. villosum chromosomes and the current knowledge on the phenomenon of two-coloured D. villosum caryopses.     

Breeding value of selected blackcurrant (<Emphasis Type="Italic">Ribes nigrum</Emphasis> L.) genotypes for early-age fruit yield and its quality

The study was conducted in the years from 2011 to 2013 at the Research Institute of Horticulture in Skierniewice, Poland. The aim of the research was to assess the breeding value, based on the effects of general and specific combining abilities (GCA and SCA), of 15 parental genotypes of blackcurrant in terms of fruit yield and quality. The plant material consisted of F₁ generation seedlings obtained by crossing, in a factorial mating design of twelve maternal (‘Bona’, ‘Big Ben’, ‘Chereshnieva’, Kupoliniai’, ‘Gofert’, ‘Tines’, ‘Sofievskaia’, ‘Tihope’, ‘Ores’, ‘Ruben’, ‘Titania’ and D13B/11) and three paternal cultivars (‘Ceres’, ‘Foxendown’ and ‘Saniuta’). It was found that the cultivars ‘Ruben’, ‘Big Ben’, ‘Gofert’ and D13B/11 had significant positive effects of GCA on fruit yield at least in two consecutive years. ‘Ruben’, ‘Saniuta’ and D13B/11 had positive GCA effects on fruit weight. For ‘Chereshnieva’, ‘Gofert’, ‘Tines’, ‘Sofievskaia’, ‘Tihope’, ‘Titania’, ‘Ceres’ and Saniuta’ positive GCA effects were estimated for soluble solids content, whereas ‘Ruben’, ‘Ceres’, ‘Gofert’ and ‘Ores’ had positive GCA effects on the ascorbic acid content in fruit. This indicated a high breeding value of these parental genotypes in terms of the evaluated traits. The significantly positive values of SCA, estimated for the crossing combinations: ‘Big Ben’?×?‘Saniuta’, ‘Ruben’?×?‘Foxendown’, ‘Titania’?×?‘Ceres’, ‘Kupoliniai’?×?‘Saniuta’, ‘Gofert’?×?‘Foxendown’, ‘Gofert’?×?‘Saniuta’, ‘Tines’?×?‘Ceres’ and ‘Tihope’?×?‘Foxendown’ for at least two traits describing fruit yield and quality, were evidence of the interaction of both these parental genotypes in the creation of new dessert-type cultivars of blackcurrant.     

Soil organic matter composition as a factor affecting the accumulation of polycyclic aromatic hydrocarbons

Journal of Soils and Sediments - The objective of this study was to evaluate the mutual relations between the soil organic matter (SOM) fractions: fulvic acids (FA), humic acids (HA), humins (HN),...     

Mechanistic insights into furan formation in Maillard model systems

Furan has recently received considerable attention as a possibly carcinogenic compound occurring in thermally processed foods. Although several food constituents have been identified as furan precursors, multiple formation pathways remain unclear. Therefore, the mechanisms of furan formation in Maillard model systems were studied by means of the carbon module labeling (CAMOLA) technique. Under both roasting and pressure-cooking conditions, furan was formed from glucose via the intact skeleton, and its formation pathways from glucose alone were not amino acid-dependent. However, some amino acids, especially alanine and serine, did influence the furan production by providing an additional formation pathway. Furthermore, most amino acids enhanced the furan production from glucose. Roasting conditions produced 25-100 times higher amounts of furan as compared to pressure-cooking conditions. Surprisingly, in the alanine/glucose model systems, the relative importance of furan production from glucose alone and from the combination of a glucose-derived and an alanine-derived fragment changed completely over a limited time course of 60 min.