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Ilias D. Avdikos Nektaria Tsivelika Athanasia Gallidou Metaxia Koutsika-Sotiriou Ekaterini Traka-Mavrona 《Scientia Horticulturae》2011
This paper presents the efficiency of recurrent selection in the segregating generations of recycled lines, obtained via mass selection, in two tomato commercial single-cross hybrids, and the assessment of advanced lines in two farming systems at two different locations. In particular, in the F3 and F4 mass selection lines of the hybrids Iron and Sahara, half-sib (HS) selection was applied by crossing within the F3 and F4 plants. Two experiments were conducted, the first for evaluating the F4 mass lines with the HS lines obtained by crossing in the F3 generation, and the second for evaluating the F5 mass lines with the HS lines obtained by crossing in the F4 generation, and the second generation HS lines, which were selected from the first experiment. F1 and F4 generations were used as controls, respectively. The HS lines of cv. Sahara overyielded 18–56% the F4 mass line, while Iron's HS lines presented greater uniformity in yield components and also outperformed qualitatively. The effectiveness of mass selection showed positive realized heritability only for fruit number of cv. Iron. In this study, where evaluation and selection was practiced in the absence of competition, the expected response in heterosis via HS depended on σ2g. The differences of σ2g of F1 from mass and HS lines were positive for both hybrids, while when the control was the F4 generation, mass lines showed a lower performance and some HS lines showed a higher performance. This means that HS lines have favorable alleles and heterosis. In this sense, Sahara's and Iron's HS lines increased 50.2 and 5.3% the charge of favorable alleles, respectively, compared to the corresponding control. The selected advanced lines were assessed in two farming systems at two different locations; the organic one, where two HS-lines, one from each hybrid, outyielded significantly the control; and the conventional one, where all lines performed equally to the control. The results assume the evidence that stable hybrids incorporate individual buffering into inbred line cultivars. 相似文献
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Recently, it has been demonstrated that subtype 3 strains of European type porcine reproductive and respiratory syndrome virus (PRRSV) are more virulent/pathogenic than subtype 1 strains. This points to differences in the pathogenesis. In the present study, a new polarized nasal mucosa explant system was used to study the invasion of the low virulent subtype 1 PRRSV strain Lelystad (LV) and the highly virulent subtype 3 PRRSV strain Lena at the portal of entry. Different cell types of the monocytic lineage (alveolar macrophages (PAM), cultured blood monocytes and monocyte-derived dendritic cells (moDC)) were enclosed to examine replication kinetics of both strains in their putative target cells. At 0, 12, 24, 48 and 72 hours post inoculation (hpi), virus production was analyzed and the infected cells were quantified and identified. Lena replicated much more efficiently than LV in the nasal mucosa explants and to a lesser extent in PAM. Differences in replication were not found in monocytes and moDC. Confocal microscopy demonstrated that for LV, almost all viral antigen positive cells were CD163+Sialoadhesin (Sn)+, which were mainly located in the lamina propria of the respiratory mucosa. In Lena-infected nasal mucosa, CD163+Sn+, CD163+Sn- and to a lesser extent CD163-Sn- monocytic subtypes were involved in infection. CD163+Sn- cells were mostly located within or in the proximity of the epithelium. Our results show that, whereas LV replicates in a restricted subpopulation of CD163+Sn+ monocytic cells in the upper respiratory tract, Lena hijacks a broader range of subpopulations to spread within the mucosa. Replication in CD163+Sn- cells suggests that an alternative entry receptor may contribute to the wider tropism of Lena. 相似文献
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Dimitrios Bilalis Ioanna Tabaxi George Zervas Eleni Tsiplakou Ilias S. Travlos Ioanna Kakabouki 《Communications in Soil Science and Plant Analysis》2016,47(15):1764-1770
This study was conducted to evaluate the effect of sowing rates and organic fertilization on growth and yield biomass quality of chia crop. The agronomic performance and nutritive value of chia were analyzed in order to define alternatives to local forages for dry-season feeding of ruminants in the Mediterranean region. Two sowing rates were arranged in the main plots and three levels of organic fertilization in the subplot with three replicates in split-plot design. Chia growth was not affected by sowing rates and fertilization. Concerning the dry weight and leaf area index (LAI), there were no significant differences among fertilization treatments while sowing rates influenced both dry and LAI, which were significantly increased as sowing rates increased. Forage quality traits were not significantly influenced by sowing rates. With regard to crude protein content, fertilization treatments had a positive effect. The greatest values were observed under manure treatment. Moreover, significant increases were revealed in the crude protein yield as sowing rates increased. In addition, acid detergent fiber (ADF) as well as neutral detergent fiber (NDF) were not affected by sowing rates but there were significant differences between fertilization treatments. Data suggest that chia could be successfully used as an alternative forage crop. 相似文献
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Prakash Chandra Srivastava Uzma Ilias Ansari Satya Pratap Pachauri Arvind Kumar Tyagi 《Journal of plant nutrition》2016,39(3):348-364
Apparent utilization of zinc (Zn) and potassium (K) fertilizers was examined in rice (Oryza sativa L.)-wheat (Triticum aestivum L.) using combinations of no K; soil applied K levels and no Zn; soil and foliar applied Zn. Application of 33.2 kg K ha?1 in rice and 24.9 kg K ha?1 in wheat along with foliar spray of 2 kg Zn ha?1 at 30 and 60 days gave the highest mean grain yields. Foliar application of zinc increased Zn concentration in flag leaves, grain, and straw of rice and wheat and K concentration in flag leaves of rice and straw of wheat significantly. Potassium application increased Zn concentration in rice grain and straw and K concentration in wheat straw significantly. Zinc and K increased the uptake of each other in grain; straw and total uptake by both crops significantly. Zinc fertilizer enhanced the utilization of soil K. Potassium fertilizer enhanced the utilization of applied Zn. 相似文献
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Predicting the impacts of selection for decreased faecal egg count (FEC) (i.e. host resistance) in grazing ruminants is difficult, due to complex interactions between parasite epidemiology, management and host responses. A mathematical model including heritable between lamb variation in host-parasite interactions, Teladorsagia circumcincta epidemiology and anthelmintic drenching, was developed and used to (i) address such interactions and their impact on outcomes including FEC, live weight (LW, kg) and pasture larval contamination (PC, larvae/kg DM), and (ii) investigate how grazing management strategies, aimed at reducing host exposure to infective larvae via pasture moves at 40 day intervals, affect these outcomes. A population of 10,000 lambs was simulated and resultant FEC predictions used to assign the 1,000 lambs with the highest and lowest predicted FEC to 'susceptible' (S) and 'resistant', (R) groups, respectively. The predicted average FEC of the S group was ～8.5-fold higher than the R group across a grazing season. The R and S groups were then simulated to graze separate pastures (R(sep) and S(sep)); and repeated for 3 grazing seasons to allow predictions to diverge and stabilize. Further, different grazing strategies were superimposed on all groups. PC and average FEC were affected by whether lambs of different resistance genotype grazed together or separately, with differences increasing across grazing seasons. By the third grazing season the average PC of the R(sep) group was reduced by ～83%, and the S(sep) group was increased by ～240%, in comparison to the whole population average. Average FEC of the R(sep) group was reduced by ～40%, and the S(sep) group increased by ～46% in comparison to the R and S groups, respectively, whilst drenching had little impact on the proportional differences in FEC between groups. Predicted LW was similar for the R and R(sep) groups irrespective of anthelmintic treatment, whilst LW of the S(sep) group was reduced by ～14% compared to the S group for un-drenched lambs, and by ～4% for drenched lambs. The differing grazing strategies were predicted to have little impact on FEC or LW, with the exception of the S(sep) group which was predicted to have a 2kg increase in LW when drenched and moved to a clean pasture. Together, these results suggest that host genotype has a substantial impact on parasite epidemiology, however the benefits of anthelmintic treatment and grazing management should only be expected for susceptible animals. This supports the use of targeted selective treatment, focussing on susceptible animals. 相似文献
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It is increasingly being recognized that non-chemical parasite control strategies may need to be combined to control more effectively gastrointestinal parasitism, result in resilient production systems and reduce reliance on anthelmintics. Here, we consider if and how metabolizable protein (MP) supplementation and anti-parasitic plant secondary metabolites (PSM) may modulate parasite epidemiology through intervention in pasture contamination, development of infection on pasture and larval challenge as target processes. We then propose that combining two or more non-chemical parasite control strategies may have additive effects on host resistance, especially if the individual strategies target different drivers of parasite epidemiology, different processes in the parasite life cycle or different phases of acquired immunity to parasites. This epidemiological framework is used to review recent findings on combining maternal MP supplementation and grazing the PSM-rich bioactive forage chicory as an example of combining nutritional treatments to manipulate parasite epidemiology in a temperate production system. In the absence of available data for combined nutritional strategies in tropical production systems, we make predictions on the consequences of combining such strategies in these systems. We conclude that currently published studies on combining nutritional strategies under temperate conditions show potential to improve additively host resilience and reduce reliance on anthelmintics; however, effects on epidemiology have to date not shown the additive results hypothesized. The framework developed may assist further in evaluating combined (nutritional) strategies to manipulate parasite epidemiology. 相似文献
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Athanasios C Kimbaris Elias Kioulos George Koliopoulos Moschos G Polissiou Antonios Michaelakis 《Pest management science》2009,65(3):249-254
BACKGROUND: The activity of several garlic oil ingredients against Culex pipiens L. larvae was studied. In addition to diallyl sulfide (DS) and diallyl disulfide (DDS), the garlic oils used included one essential oil (EO) and two semi‐synthetic garlic essential oils (SSGEO1 and SSGEO2), which resulted from the enrichment of EO with DS and DDS standards respectively. The oils were compared with respect to their toxicity. RESULTS: The chemical composition of the tested oils was evaluated by means of gas chromatography–mass spectrometry. Experimental data from the tested samples revealed high toxicity. In detail, DDS (6.09 mg L?1) was the most active, followed by SSGEO2 (7.05 mg L?1) and EO (8.01 mg L?1), while SSGEO1 and DS were relatively inactive. CONCLUSION: The addition of DDS to EO did not change the toxic effect of the essential oil, whereas the presence of DS in excess produced an enriched essential oil with low toxicity. Furthermore, the antagonistic effect of DS and DDS against the other components of EO was shown by the application of two equations obtained from the literature. Their larvicidal performances were correlated, for the first time, with their detailed chemical composition. Data analysis strongly indicated the toxicity of the other EO sulfur ingredients. Copyright © 2008 Society of Chemical Industry 相似文献
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The annual distribution of aquatic and coastal macrophytes in five selected sites along the Aliakmon River was studied from January 2005 to December 2005 in Northern Greece. Soil and water chemical parameters in these sites were also evaluated. A total of 75 taxa were recorded belonging to 37 families and 53 genera. The majority of the macrophytes belonged to coastal plants (76%), whereas the rest of the macrophytes belonged to aquatic plants (24%). Species of the family Asteraceae were dominant among coastal plants, whereas species of the family Potamogetonaceae were dominant among aquatic plants. Soil samples from the site of Dam of Veria had higher pH and electric conductivity (80-100 cm depth), whereas CaCO3 contents were significantly higher in soil samples from the area of P. Prodromos (60-80 cm depth). Most physicochemical water parameters as well as selected soil nutrients and major ionic components showed an increase during the low charge period (fall) compared to with the high charge period (spring), especially in parameters associated with agricultural activity. Furthermore, there was an increase in most examined values moving towards the delta of the river. 相似文献
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Akmoutsou P Mademtzoglou D Nakou I Onoufriadis A Papadopoulou X Kounatidis I Frantzios G Papadakis G Vasiliadis K Papadopoulos NT Mavragani-Tsipidou P 《Pest management science》2011,67(12):1534-1540
BACKGROUND: The insecticides spinosad and deltamethrin are being increasingly used in pest management programmes. In order to assess further their toxic effects to target and non‐target insect species, an evaluation was made of their insecticidal profile on Bactrocera oleae (Rossi) and Drosophila melanogaster (Meig.). Moreover, possible genotoxic effects of the two pesticides were investigated using the somatic mutation and recombination test (SMART) in D. melanogaster. RESULTS: Both insecticides were highly effective against B. oleae, exhibiting similar LC50 values. Moreover, they were found to be more effective against Bactrocera than against Drosophila adults. However, spinosad was significantly more toxic than deltamethrin to D. melanogaster. The results showed a lack of genotoxic activity of both insecticides under the in vivo experimental procedure employed, at least at applied doses. CONCLUSION: The present study provides information for lethal and sublethal effects of spinosad and deltamethrin against a target and a non‐target species. Both insecticides can exert high toxicity to B. oleae when adults are exposed even to very low doses for long periods of time. The results contribute to the database on the genotoxic potential of spinosad and deltamethrin, suggesting a safety profile for both insecticides. Copyright © 2011 Society of Chemical Industry 相似文献