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1.
Six populations of faba bean (Vicia faba L.) were developed through various selection schemes to examine the influence of selection In improving tolerance to Orobanche crenata (Forsk.) in local faba bean stocks. All populations trace their origin to 209 farmers’ seed lots that were collected from Egypt. The entries of each population were grown during the 1982/1983 season in the Orobanche nursery located at Giza in Egypt. Comparison among means of the selected, populations showed that more progress in improving Orobanche tolerance could be achieved from combined selection between and within lots. Between-lots selection was less efficient than single-plant selection. Results, of this study show that considerable progress could be achieved from selection for Orobanche tolerance in local faba bean germplasm. There was sufficient residual genetic variation in the selected populations to expect substantial progress from further selection for most tolerance traits.  相似文献   
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OBJECTIVE: To measure the production and amount of oxidation of wool grease secreted immediately after shearing. To identify components of wool grease that might act as a carrier to facilitate lateral diffusion of topically applied insecticides. DESIGN: Fine-wool Merino sheep were shorn and residual greasy wool was collected from the sheep's flank. The quantity of grease produced, and the amount of oxidation was measured during 18 days after shearing. Wool grease was fractionated into five component groups based on their polarity and the degree of oxidation in these fractions determined. RESULTS: There was a 24% increase in grease production within 2 days after shearing but secretions returned to pre-shearing amounts after 4 days. During this period wool grease oxidized rapidly. Of the grease fractions examined, sterol and wax esters remained essentially unoxidized whereas free sterols such as cholesterol and lanosterol, fatty acids and polar lipids, aldehydes and alcohols were extensively oxidized within 7 days after shearing. CONCLUSION: The transient increase in grease production after shearing may facilitate diffusion of topically applied synthetic pyrethroid insecticides. Oxidation of grease components may then contain the insecticide and limit further diffusion. Incorporating the insecticide in non-oxidising fractions of wool grease may make insecticide dispersion more efficient.  相似文献   
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The efficacy of copper sulphate (CuSO4) against the early stages of an experimental acute infection of Flavobacterium columnare in channel catfish (Ictalurus punctatus) was evaluated. Fish were challenged, by waterborne exposure to F. columnare in an ultra‐low flow‐through water delivery system, and treated with CuSO4 at 4.2 and 2.1 mg L?1 at 5.5 h post challenge for 4 h. Bacterial challenged non‐treated fish acted as a positive control and non‐challenged non‐treated fish acted as a negative control. Fish challenged with F. columnare and treated with CuSO4 at 4.2 and 2.1 mg L?1 post challenge had mortalities of 6.4% and 18.3%, respectively, compared with the positive control, which had 90.2% mortality. The mortality of challenged fish treated with CuSO4 at 4.2 and 2.1 mg L?1 was significantly different from the positive control. There was no significant difference between the mortalities of the 4.2 and 2.1 mg L?1 treatments. The results suggest that CuSO4 has clear therapeutic value against columnaris infections.  相似文献   
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The present study aimed to evaluate the effect of organic and inorganic selenium (Se) supplementation on semen quality and blood serum profiles of buffalo bulls. Nine mature buffalo bulls were divided into three groups: control (non‐supplemented); organic Se (10 mg Sel‐Plex®/head twice weekly) and inorganic Se (10 mg sodium selenite/head twice weekly). Semen was collected twice a week for 3 months during Se supplementation. Semen properties were evaluated from fresh ejaculate. Moreover, fructose concentration, aspartate and alanine transaminase (AST and ALT) activities, total protein and total cholesterol were assayed in seminal plasma. Additionally AST, ALT, testosterone and Se levels were determined in the blood serum. Results showed that Se supplementation significantly (P < 0.05) influences the semen parameters during 3 months of treatment. Organic Se significantly (P < 0.05) increased the percentage of viable sperms compared to inorganic Se and the control group. Fructose concentration was significantly higher (P < 0.05) in the seminal plasma of organic Se‐treated bulls. Serum testosterone and Se concentrations were significantly (P < 0.05) increased in the Se supplemented groups than the control group. In conclusion, Se supplementation improved the parameters of buffalo bull semen and more precisely, organic Se was more effective for the improvement of semen quality and some blood components than inorganic Se.  相似文献   
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Based on considerations of membrane activity, a DDT analogue containing crown ether moieties has been conceived and prepared. The preparation of the compound represents a novel route for obtaining crown ether derivatives.  相似文献   
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Three pot experiments were earned our to investigate the variation among geographic accessions of Orobanche crenata Forsk. in their ability to attack different stocks of Vicia faba L. Orobanche accessions were quite different in their influence on the performance of genetic lines of the host. However, host parasite relationships appeared to be dependent upon environmental conditions. The usefulness or host genotypes for differentiating between parasite accessions was rather limited. The number of Orobanche shoots per host plant does not appear 10 be a precise indicator of host tolerance although it has been frequently used for this purpose.  相似文献   
10.
The efficacy of potassium permanganate (KMnO4) against the early stages of an experimental acute infection of Flavobacterium columnare in channel catfish, Ictalurus punctatus, was evaluated. Fish were experimentally challenged by waterborne exposure for 2 h to F. columnare after cutaneous abrasion, and treated with KMnO4 at 2.0 mg L?1 above the KMnO4 demand at 0, 1, 2 or 4 h postchallenge for 24 h. Challenged non‐treated fish acted as a positive control and non‐challenged non‐treated fish acted as a negative control. Fish challenged and treated with KMnO4 at 0, 1, 2 or 4 h postchallenge had mortalities of 26%, 63%, 64% and 83% respectively. The mortality of challenged fish treated with KMnO4 at 0 h postchallenge (26%) was significantly less than the positive control (77%). The mortalities of challenged fish treated at 1, 2 or 4 h postchallenge were not significantly different from the positive control fish. The results suggest that KMnO4 has a clear therapeutic value in early stages of columnaris infection but limited therapeutic value once the infection has progressed.  相似文献   
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