A diallel crossing approach aimed on selection for ripening time and yield in breeding of new strawberry (Fragaria × ananassa Duch.) cultivars

The extension of the ripening season in open field production is of high economic interest for strawberry growers. Therefore, targeted breeding for extreme early or late ripening cultivars with high yield potential is of particular interest. Thirteen strawberry cultivars were crossed in a reciprocal way without selfing, and the 144 resulting F₁ populations were evaluated in a field trial over a period of two consecutive years. The data were analysed using a mixed‐model approach adapted for diallel crossing designs using SAS 9.3. The variability in the crossing approach is mainly based on the general combining ability (GCA) of the cultivars (additive effects). Specific and reciprocal combining abilities (non‐additive effects) appear less important. The highest GCAs for the trait Marketable Yield were found for the cultivars ‘Polka’ and ‘Yamaska’. The trait Earliness is bilateral with significantly low GCAs for early ripening in ‘Clery’ and ‘Daroyal’ and significantly high GCAs for late ripening in ‘Yamaska’ and ‘Florence’. Crosses with these cultivars are likely to deliver populations with both high yield and an extended ripening period.     

Economic values of supply chain productivity and quality traits calculated for a farmed European whitefish breeding program

Economic values of different fish traits are needed to direct breeding programs to optimize economic benefits for aquaculture industry. The aim of this article is to highlight and calculate how different traits affect the value of farmed fish supply chain. Supply chain approach is needed to calculate economic impact of fish traits because several fish traits affect costs and returns not only in fish farming but also at the processing and retail level. In this article, economic values are calculated for 14 productivity and product quality traits in European whitefish (Coregonus lavaretus). Productivity affecting traits, such as growth, mortality and different yields, are included in the study. In addition, economic values are calculated for several quality traits like fillet gaping, appearance and fat content of flesh.

Productivity traits had the highest economic importance if the traits could be improved. However, quality traits may cause even higher economic losses, if the quality decreases. Thus, the management of the breeding program should pay simultaneous attention to both quality and productivity traits.     

Synthesis and fungicidal activity of tubulin polymerisation promoters. Part 1: pyrido[2,3‐b]pyrazines

BACKGROUND: The excellent fungicidal activity of [1,2,4]triazolo[1,5‐a]pyrimidines suggested the search for further analogues with improved properties. RESULTS: A series of novel trisubstituted pyrido[2,3‐b]pyrazines has been designed and prepared as 6,6‐biheterocyclic analogues of related 5,6‐bicyclic [1,2,4]triazolo[1,5‐a]pyrimidines. Their fungicidal activity was evaluated against the plant pathogens Puccinia recondita Rob. ex Desm. f. sp. tritici (Eriks.) CO Johnston (wheat brown rust), Mycosphaerella graminicola (Fuckel) Schroter (Septoria tritici Rob., leaf spot of wheat) and Magnaporthe grisea (Hebert) Barr (Pyricularia oryzae Cav., rice blast). Structure–activity relationship studies revealed the advantage of a fluoro substituent in position 6 and of a secondary amine in position 8. CONCLUSION: 8‐Amino‐7‐aryl‐6‐halogen‐substituted pyrido[2,3‐b]pyrazines have been prepared as 6,6‐biheterocyclic analogues of similarly substituted triazolopyrimidine fungicides. A concise four‐step synthesis route has been worked out to prepare these novel compounds from commercially available starting materials. [(R)‐(1,2‐Dimethylpropyl)]‐[6‐fluoro‐7‐(2,4,6‐trifluorophenyl)pyrido[2,3‐b]pyrazin‐8‐yl]amine showed excellent activity against three economically important phytopathogens. Copyright © 2009 Society of Chemical Industry     

Evaluation of the discriminatory power of variable number tandem repeat (VNTR) typing of Mycobacterium bovis strains

The discriminatory power of variable number tandem repeat (VNTR) typing based on 16 known loci (12 MIRUs, 3 ETRs and VNTR 3232) was assessed for Mycobacterium bovis strains collected sequentially at the slaughterhouse of N'Djaména, Chad. Of 67 M. bovis strains analyzed, 67% were clustered. In this study, VNTR typing was highly discriminative with an overall allelic diversity (h(oa)) of 0.922. We defined five loci (ETR A, B, C and MIRU 26, 27) as highly (h>0.25), two loci (MIRU 4, and VNTR 3232) as moderately (0.11相似文献   

A survey to detect subclinical polyomavirus infections of captive psittacine birds in Germany

Infections of avian polyomavirus (APV) are known to cause fatal disease in a wide range of psittacine and non-psittacine birds. Here, we present a survey to investigate the existence of subpopulation of persistent or subclinically infected parrots inside the population of captive psittacine birds in Germany. DNA was isolated from feathers of 85 symptom-free birds from 20 different genera (all psittaciformes) taken from 30 different breeders from all over Germany. The presence of APV was analysed by performing polymerase chain reaction assays (PCR). APV was detected in none of the samples, indicating that the existence of a subpopulation of captive psittacine birds having a persistent APV infection in Germany seems to be relatively low.     

Characterization of canine microglial cells isolated ex vivo

Microglia are the principal immune effector elements of the brain sharing immunophenotypic and functional characteristics of macrophages as well as of antigen presenting cells (APCs). The purpose of this study was to isolate canine microglial cells and make them available for ex vivo characterizations of their functions and immunophenotype. After isolation, carried out by density gradient centrifugation, microglial cells accumulated on distinct interfaces of 1.077 and 1.066 g/ml of a Percoll gradient. Identification of microglial cells in other species is realized by their specific immunophenotype of CD11b/c+ and CD45low. Our results indicate, that expression of CD45 is very low or even absent in canine microglial cells. In addition, they expressed CD18 and CD11b/c+, as determined by flow cytometry and immunohistochemistry. Fourteen additional monoclonal antibodies (mAbs) were used to characterize and compare canine microglial cells with monocytes. Microglia and monocytes can be clearly distinguished by their differential expression intensity of surface antigens (CD45, CD44, CD14). Functional characterization was assessed by a reactive oxygen species (ROS)-generation test and phagocytosis assay using flow cytometry. In conclusion, ex vivo examination of microglia is possible in dogs and most probably reflects the conditions in vivo. The measurement of tissue culture artifacts can be largely avoided using this method.     

Role of Toxoplasma gondii myosin A in powering parasite gliding and host cell invasion

Obligate intracellular apicomplexan parasites rely on gliding motion powered by their actomyosin system to disperse throughout tissues and to penetrate host cells. Toxoplasma gondii myosin A has been implicated in this process, but direct proof has been lacking. We designed a genetic screen to generate a tetracycline-inducible transactivator system in T. gondii. The MyoA gene was disrupted in the presence of a second regulatable copy of MyoA. Conditional removal of this myosin caused severe impairment in host cell invasion and parasite spreading in cultured cells, and unambiguously established the pathogenic function of this motor in an animal model.     

Ecologically enhanced areas - a key habitat structure for re-introduced grey partridges Perdix perdix

We analysed the spatial distribution of home-ranges and the habitat use of re-introduced grey partridges Perdix perdix in relation to newly established ecologically enhanced areas, i.e. wild-flower strips and hedges, within an intensively cultivated area in Switzerland from which the species had become extinct. All birds settled within the ca. 30% of the study area where the proportion of enhanced areas was highest (5.8%). At the level of the individual family group, we found a significant over-proportional use of enhanced areas throughout the year. Furthermore, when the birds used the agricultural fields, the use densities strongly declined with distance from the nearest enhanced area. Thus, the availability and spatial distribution of ecologically enhanced areas were the main determinants of the partridges’ range use. These results indicate that a framework of ecologically enhanced areas is a key habitat structure for grey partridges, and that these enhancements, even if small in proportion, were the crucial first measure to restore the research area to an appropriate grey partridge habitat and, thus, the basis for successful re-introduction in this intensively cultivated area.     

Einfluß langjähriger Düngung mit verschiedenen Phosphatdüngerformen auf die Phosphatverfügbarkeit in der Rhizosphäre von Raps

Influence of long-term application of different P-fertilizers on phosphate availability in the rhizosphere of rape The residual P effect was investigated in soils from a 10 years' lasting field trial (North of Hessia, Alfisol-Udalf, pH 5.7) in which different P-fertilizer types had been applied with a rate of 111 kg P₂O₅ ha^?1 a^?1. Soil analysis showed that basic slag phosphate had increased the content of CAL-, H₂O- and EUF extractable P in the soil to a higher extent than Novaphos (partially acidulated phosphate rock) or Hyperphos (phosphate rock). In the latter treatment the highest content of DL soluble P was found as compared with the other P-fertilizer types. Pot experiments with rye-grass, rape and maize showed that P recovery was highest from the soil with the basic slag treatment and lowest in the treatment with Hyperphos, Novaphos taking an intermediate position. This finding demonstrates that the DL-method does not provide a reliable information on the P-availability of a soil, if treated with rock phosphate. The level of water soluble P in the rhizosphere of rape was investigated with a particular technique (Kuchenbuch and Jungk, 1982). It could be shown that the P level in the rhizosphere of the Hyperphos treatment was only slightly higher than the P level of the P₀ treatment (without P fertilizer) while in the Novaphos – and particularly in the basic slag treatment much higher levels of soluble P were found. It thus becomes evident that even in the rhizosphere the solubility of Hyperphos was poor. The levels of water soluble P in the rhizosphere followed a depletion curve. The steepest gradient was found for basic slag, followed by the Novaphos-, Hyperphos- and the P₀ treatment.     

Quantitative analysis of RNA levels from single hepatocytes in vivo: combined use of real-time RT-PCR and laser microdissection

AIM: The manner in which a cell responds to and influences its environment is ultimately determined by the genes that are expressed.To better understand cellular functions,the isolation of single cells and subsequent quantification of the expressed genes is essential.METHODS: Normal liver tissue was obtained from operation,snap-frozen in liquid nitrogen and sectioned in crystat.Individual hepatocytes were microdissected.RNA was extracted,then reverse transcribed and amplified using real-time quantitative polymerase chain reaction (PCR).RESULTS: Single hepatocytes were dissected by laser beam and catapulted to the microcentrifuge cap which was put above the slide.In this way,cells were collected,RNA was extracted,reverse transcribed to cDNA and used for analysis of RNA expression by real-time quantitative PCR.The amplification results showed that quantitation of the RNA inside the cell was compatible with the number of cells.CONCLUSION: The expression of RNA in single cells can be quantitated successfully by using laser microdissection and real-time PCR.These techniques provide an opportunity to monitor in vivo gene expression levels in single hepatocytes.