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91.
Resistance to Fusarium head blight and deoxynivalenol accumulation in wheat   总被引:10,自引:0,他引:10  
Fusarium head blight (FHB), caused by Fusarium graminearum Schwabe (telomorph =Gibberella zeae (Schw.)), is an important wheat disease world‐wide. Production of deoxynivalenol (DON) by F. graminearum in infected wheat grain is detrimental to livestock and is also a safety concern in human foods. An international collection of 116 wheat lines was evaluated for FHB resistance and concentration of DON in grain. Plants were inoculated with mixed isolates of F. graminearum in the greenhouse by injecting conidia into a single spikelet of each spike and in the field by scattering F. graminearum‐infected wheat kernels on the soil surface. FHB symptoms were evaluated by visual inspection in both the greenhouse and field, and DON was analysed by HPLC. Significant differences in FHB ratings and DON levels were observed among cultivars. In the greenhouse test, visual symptoms varied from no spread of FHB from the inoculated spikelet to spread throughout the spike, and DON levels ranged from trace levels to 283 mg/kg. In the field test, DON ranged from 2.8 to 52 mg/kg. The greenhouse test identified 16 wheat lines from various origins that accumulated less than 2 mg/kg DON. These lines may be useful as sources for breeding wheat cultivars with lower DON levels. Correlation coefficients were significant between FHB symptom ratings, seed quality traits, and DON levels. Thus, the percentage of scabbed spikelets and kernels can be generally used to predict DON levels in harvested wheat grain. In breeding programmes, selection for plants having few scabbed spikelets and scabbed kernels is most likely to result in low DON levels.  相似文献   
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Keeping of piglets on slatted metal floor, without complementary iron supply, caused anaemia within seven days from parturition. Hb levels in the blood dropped from 7.00 +/- 1.16 to 3.47 +/- 0.74 mmol/l. Iron deficit reduced growth and vitality. The iron levels in blood plasma of the piglets tested varied between 5 and 35 mumol/l, immediately after parturition. Intraperitoneal or oral administration of Fe-dextran (150 mg Fe) on the first day after parturition resulted in physiological iron levels in blood plasma, after seven days. Yet, when 14 days had passed, the levels were similar to those recorded from piglets without additional iron supply. Iron bonding capacity of blood plasma increased in piglets of all groups up to the seventh day from birth. Death occurred, on the second day of age, to many piglets with protein levels below 50 g/l plasma. Copper levels in blood plasma of newborn piglets were below those recordable from sows, but they went up by more than three times of their original values up to the seventh day from birth. In piglets, zinc, levels of blood plasma after parturition were higher than those of sows and went up by some 50 percent, within seven days from birth.  相似文献   
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The properties of fructose-1.6-disphosphatase in supernatant of homogenate of liver, kidneys, and adductor muscles of cattle were tested. EDTA was found to activate the enzyme up to concentrations of 10 mMol. The pH optimum was 7.5 in the presence of EDTA. Even lower concentrations of magnesium ions caused activation of the enzyme, but an activating effect was obtained as well from relatively high Mg concentrations. Fructose-1.6-diphosphatase could by activated also by 0.2 mMol Mn or Co ions or 1 mMol Zn ions. Inhibitive action was obtained from Cu, Cd, Pb, and Hg ions. Microsomal fractions of cattle liver and kidney caused high activity of glucose-6-phosphatase, but only low action was obtained be using microsomal fractions of mesenteric mucous membrane or brain. Mg ions, basically, failed to trigger activation, and higher concentrations even caused inhibition. The relatively high activity of both fructose-1.6-diphosphatase and glucose-6-phosphatase in kidney of cattle appeared to suggest an involvement of those enzymes in gluconeogenesis.  相似文献   
96.
Massive dose injections of butyrate, isobutyrate, and isovalerate (1.25 mmol/kg body weight) as well as of physiological saline solutions were applied to 4 groups of lambs aged 8 to 15, 16 to 22, 23 to 29, and 30 to 45 days. Blood samples were drawn prior to infusion as well as 5, 15, 30, 60, 90, 120, and 180 minutes from mid-infusion. Original glucose and insulin levels in the blood plasma of 87 lambs had been 5.24 +/- 0.85 mmol/l or 191 +/- 106 pmol/l, respectively. Infusion of these solutions led to temporary rise in blood plasma levels of glucose, insulin, and free fatty acids. The highest insulin level increase resulted from isovalerate infusion. Total alpha amino nitrogen in blood plasma went down. It appeared to be obvious that lambs, even before their forestomachs came into action, responded to infusion of volatile fatty acids by increase in insulin secretion.  相似文献   
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