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51.
The effects of defoliation on soybean [Glycine max (L.) Merr.] growth and yield have been well studied, but relatively little is known about its nitrogen (N) accumulation after defoliation. An experiment was conducted to examine soybean recovery and N accumulation following defoliation. The indeterminate cultivar (‘Tousan 69’) was planted in a greenhouse, and two defoliation treatments (no defoliation and 67% defoliation) were imposed at the R2 stage when plants had at least one flower in the two uppermost nodes. At 0, 15, 30 and 45 days after defoliation (DAD), plants were destructively sampled to measure dry mass production, nitrogen accumulation and nitrogen fixation. Seed yield and N concentration also were measured at maturity. Neither the seed yield nor its N concentration was affected by defoliation. Although defoliation temporarily reduced soybean dry weight and N accumulation during 15 DAD, defoliated plants completely recovered their dry weight and N accumulation 30 DAD. There was little difference in N concentration between defoliated and non defoliated plants, indicating that N acquisition was restored during the recovery process. Recovery of N accumulation in defoliated plant was due to complete recovery of N2-fixing ability and maybe related to improvement in N absorption after defoliation.  相似文献   
52.
To investigate the effects of light on the accumulation of assimilate in rice seeds, ears were allowed to grow in darkness 10 d after their formation. The lipid content of rice bran on the 40th day increased by cultivation of ears in darkness whereas the dry weight and starch and sucrose contents of the rice seeds decreased. In the light, the triacylglyceride (TG) content of rice seeds was lowest on the 20th day but then increased continuously for the next 20 d, while the diacylglyceride (DG) content reached a maximum value on the 20th day. In darkness, in contrast, rice seeds showed a higher TG content, with a lower DG content and lower levels of other lipids on the 20th day compared with seeds exposed to light. These results suggest that the biosynthesis of starch and lipids in rice seeds is regulated by light.  相似文献   
53.
This study was conducted to evaluate the effect of dietary vitamin E (VE) on broiler meat quality, especially focused on PSE (pale color, soft and exudative), under chronic heat stress (HS) conditions. Twenty‐eight‐day‐old female Ross broilers were kept in independent cages with a controlled temperature of 24°C (normal temperature: NT) or 30°C (high temperature: HT). The NT chickens were fed basal feed. The HT chickens were fed basal feed (HT) or VE (200 mg/kg) added feed (HT + E). Broilers were weighed and slaughtered at 38 days old. The breast muscle was removed immediately and then the samples were used for determination of meat color, pH, water holding capacity (WHC) and shear force value (SFV). Body weight gain and feed intake were significantly decreased in the HT and HT + E groups compared to the NT group. VE supplementation did not affect the growth performance. Chronic HS at 30°C for 10 days may cause deterioration of meat quality such as PSE. The effects of chronic HS on meat quality were most significant in the toughness of broiler breast meat. Supplementation of VE in broiler feed would be effective to prevent the extent of PSE on broiler meat by chronic HS.  相似文献   
54.
Seeds of Panicum miliaceum, Panicum sumatrense, Setaria glauca, and Setaria italica were raised in polyvinylchloride tubes filled with soil to determine interspecific differences in waterlogging tolerance and the effect of pre- and post-heading waterlogging on growth and grain yield. Four treatments were conducted including control (no-waterlogging stress during growth). Pre-heading waterlogging treatment was initiated 17 days after sowing to heading (TC). Post-heading waterlogging treatment was initiated heading till harvest (CT). Waterlogging treatment was initiated 17 days after sowing to harvesting (TT). The grain yield of P. miliaceum, S. glauca, and S. italica decreased 16, 18, and 4%, while that of P. sumatrense increased 210% under TT treatment and this showed P. sumatrense had most waterlogging tolerance. The grain yield was more affected under TC treatment in S. italica and P. miliaceum. However, there was not significant differences the grain yield between TC and CT treatment in P. sumatrense and S. glauca. Total dry weight, total root dry weight, number of crown root, and the proportion of lysigenous aerenchyma of P. sumatrense were significantly higher than those of other millets at harvesting. Plant growth rate, total root dry weight, number of crown root, and the proportion of lysigenous aerenchyma of P. sumatrense were significantly higher than those of other millets at heading. These results suggest that P. sumatrense exhibits waterlogging tolerance by enhancing root growth characterized by a high proportion of lysigenous aerenchyma in the crown root.  相似文献   
55.
Carnosine (β‐alanyl‐L‐histidine) and anserine (β‐alanyl‐1‐methyl‐L‐histidine) are dipeptides mainly found in skeletal muscle and brain of many vertebrates, and particularly high concentrations are observed in chicken pectoral muscles. It was reported that these peptides have many functions, such as antioxidant activity. In this study, we examined the effect of different levels of dietary histidine on carnosine and anserine contents in broiler muscles. The 14‐days‐old female Chunky strain broilers were given feeds containing three different levels of histidine; 67% (Low‐His), 100% (Control) and 200% (High‐His) of histidine requirement according to the NRC (1994). Chicks were fed experimental diets for 10 days. Both dipeptides in muscle were significantly decreased. In particular, carnosine was not detected at all in the Low‐His group and was significantly increased in the High‐His group. Both dipeptides were not detected in plasma. These results indicated the possibility to produce chicken meat with enhanced amount of these dipeptides by high histidine feeding.  相似文献   
56.
Cerebrospinal fluids (CSFs) from 9 Pug dogs with necrotizing meningoencephalitis (NME: Pug dog encephalitis) were examined to identify the antigens for anti-astrocyte autoantibodies. Each CSF exhibited a positive reaction to the cytoplasm of cultured canine astrocytes by an indirect fluorescent antibody test. In an immunoblotting analysis on normal canine brain proteins, eight of 9 CSFs showed a common band of 52 kDa, corresponding to glial fibrillary acidic protein (GFAP), and all of 9 CSFs reacted with purified bovine GFAP. From these results, GFAP is one of the common autoantigens in Pug dogs with NME. On the other hand, the reactivity of CSFs to chymotrypsin-digested bovine GFAP fragments were variable among dogs, indicating that the antibodies in the CSFs recognized different epitopes on GFAP.  相似文献   
57.
不同基因型小麦麦茬对杂草的化感抑制作用   总被引:1,自引:1,他引:0  
采用改进的田间抑制圈生物测定方法,分析了10种不同基因型小麦材料麦茬对杂草生长的影响.结果表明,不同基因型之间以及同一基因型的不同材料之间对杂草的影响均呈现显著差异,说明化感作用基因在稳定遗传的同时存在一定的变异.以现代品种"丰产3号"麦茬地杂草的生物量为对照,其他小麦品种麦茬对杂草均有一定的抑制作用;对10个小麦品种麦茬地杂草的生物量与残茬滞留时间(天)逐步回归分析发现,杂草生长与时间存在明显的正相关关系,其中小麦残茬抑制杂草生长的化感作用有效天数为3~29天,而后杂草生物量逐渐增大,最后达到稳定;染色体组型为AA、AABB及AABBDD的麦茬化感抑制作用均随残留时间的变化而逐渐减弱,抑制杂草的平均有效期分别为21、24和25天,说明小麦在从二倍体到四倍体到六倍体的染色体组变异与倍体变化的长期进化过程中,小麦的遗传可塑性可能有助于化感作用的增强.  相似文献   
58.
To test whether glycosphingolipids (GSLs) on the intestinal mucosa of rainbow trout (Oncorhynchus mykiss) serve as a binding receptor for Vibrio anguillarum, we analyzed neutral GSLs from rainbow trout intestinal mucosa and investigated the binding of bacteria to neutral GSLs. Two kinds of neutral GSLs, designated N-1 and N-2, were identified on high-performance thin-layer chromatography (TLC) plates. In TLC immunostaining tests, V. anguillarum bound only to galactosylceramide (GalCer), lactosylceramide and N-1 having the same TLC mobility as GalCer, but neither to glucosylceramide nor to N-2. These results suggest that N-1 is GalCer (Gal beta 1-1Cer) and also that N-1 (GalCer) on rainbow trout intestinal mucosa act as a receptor for V. anguillarum.  相似文献   
59.
The effect of antibody against ganglioside antigen on Trypanosoma brucei parasites was examined in vitro and in vivo using anti-ganglioside GM1 (AGM-1) monoclonal antibody. The antibody showed complement-dependent cytotoxicity against T. brucei with mouse complement. Furthermore, mice given AGM-1 were challenged intraperitoneally with T. brucei. Although all non-treated control mice died within six days after infection, all of AGM-1-injected mice had survived by six days post-infection. These data suggest that antibody against ganglioside antigen on T. brucei has potential in protection against T. brucei infection.  相似文献   
60.
OBJECTIVE: To determine whether continuous infusion of a low dose of lipopolysaccharide (LPS) to induce a condition mimicking septic shock in dogs would affect systemic and hepatosplanchnic circulation and oxygenation. ANIMALS: 12 healthy adult Beagles. PROCEDURE: Dogs received a low dose of LPS (Escherichia coli O55:B5) by continuous IV infusion at a rate of 1 microg/kg/h for 8 hours. Systemic hemodynamics; systemic oxygenation; blood flow in the cranial mesenteric artery, common hepatic artery, and portal vein; intestinal and hepatic tissue blood flow; mesenteric oxygenation; and intramucosal Pco2 were examined before and at selected time points after onset of the LPS infusion. RESULTS: After onset of the LPS infusion, cardiac index increased and mean arterial pressure (MAP) and systemic vascular resistance decreased, which is characteristic of the hyperdynamic state in septic patients. Hepatosplanchnic blood flow increased during the hyperdynamic state. Intestinal Pco2 was increased even when blood flows increased. During the latter half of the experimental period, MAP was maintained but hepatosplanchnic blood flows decreased and intestinal Pco2 increased further. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of the results suggested that hepatosplanchnic blood flow enters the hyperdynamic state during the early stages of sepsis and that intestinal tissue oxygenation is threatened even when hepatosplanchnic blood flow is increased or maintained. Hence, improvement of hepatosplanchnic circulation and intestinal tissue oxygenation is important in dogs with clinical evidence of a septic condition.  相似文献   
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