The effect of land management on carbon and nitrogen status in plants and soils of alpine meadows on the Tibetan plateau

Large‐scale grassland rehabilitation has been carried out on the severely degraded lands of the Tibetan plateau. The grasslands created provide a useful model for evaluating the recovery of ecosystem properties. The purposes of this research were: (1) to examine the relative influence of various rehabilitation practices on carbon and nitrogen in plants and soils in early secondary succession; and (2) to evaluate the degree to which severely degraded grassland altered plant and soil properties relative to the non‐disturbed native community. The results showed: (1) The aboveground tissue C and N content in the control were 105·97 g m⁻² and 3·356 g m⁻², respectively. The aboveground tissue C content in the mixed seed treatment, the single seed treatment, the natural recovery treatment and the severely degraded treatment was 137 per cent, 98 per cent, 49 per cent and 38 per cent, respectively, of that in the control. The corresponding aboveground tissue N content was 109 per cent, 84 per cent, 60 per cent and 47 per cent, respectively, of that in the control. (2) Root C and N content in 0–20 cm depths of the control had an average 1606 g m⁻² and 30·36 g m⁻², respectively. Root C and N content in the rehabilitation treatments were in the range of 26–36 per cent and 35–53 per cent, while those in the severely degraded treatment were only 17 per cent and 26 per cent of that in the control. (3) In the control the average soil C and N content at 0–20 cm was 11 307 g m⁻² and 846 g m⁻², respectively. Soil C content in the uppermost 20 cm in the seeded treatments, the natural recovery treatment and the severely degraded treatment was 67 per cent, 73 per cent and 57 per cent, respectively, while soil N content in the uppermost 20 cm was 72 per cent, 82 per cent and 79 per cent, respectively, of that in the control. The severely degraded land was a major C source. Restoring the severely degraded lands to perennial vegetation was an alternative approach to sequestering C in former degraded systems. N was a limiting factor in seeding grassland. It is necessary for sustainable utilization of seeding grassland to supply extra N fertilizer to the soil or to add legume species into the seed mix. Copyright © 2005 John Wiley & Sons, Ltd.     

河北省主栽小麦品种醇溶蛋白遗传多样性分析

【研究目的】为了解河北省40年来不同小麦品种之间的遗传多样性,以及为小麦育种工作提供理论依据;【方法】采用酸性聚丙烯酰胺凝胶电泳（A-PAGE）对河北省40年来的118个主栽小麦品种进行了醇溶蛋白位点特异性检测,分析了这些品种的遗传多样性及其变化情况;【结果】这些品种具有118种醇溶蛋白带型,共分离出101条迁移率不同的醇溶蛋白谱带。绝大多数品种在α、β、γ、ω 4个区中存在着较大差异,其中α区有15条带,87种带型;β区有24条带,110种带型;1区有21条带,90种带型;（1）区有41条带,111种带型,其中（1）区的多态性最大。供试品种的遗传相似性系数（GS）在0．043-43．86之间,平均值为0．35。用非加权成组算术平均法对GS值进行聚类,供试品种在GS值为0．354的水平下可明显聚为6类;【结论】用非加权成组算术平均法对Gs值进行聚类,供试品种在GS值为0．354的水平下可明显聚为6类。讨论了种子醇溶蛋白在品种遗传多样性评价方面的应用价值。     

Chemotherapeutic efficacy of imidocarb dipropionate on experimentalEperythrozoon ovis infection in sheep

Summary Non-splenectomised Cheviot and Soay sheep experimentally infected with Eperythrozoon ovis were treated subcutaneously with two doses of 4 mg/kg of imidocarb dipropionate 24 hours apart. A rapid reduction in E. ovis parasitaemias following the first injection of imidocarb was observed and E. ovis organisms were not demonstrable 48 hours after the first treatment. However, recrudescences of infection were observed 14 and 28 days after treatment in the Soay and Cheviot sheep respectively. Side-effects associated with treatment were registered in the Cheviot sheep but not in the Soay sheep.

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Resumen Ovejas no esplenectomizadas de las razas Cheviot y Soay infectadas experimentalmente conEperythrozoon ovis, fueron tratadas subcutáneamente con dos dosis de 4 mg/kg de dipropionato de imidocarb, con un intervalo de 24 horas. Se notó una sensible reducción delE. ovis despues de la primera inyección, desapareciendo el organismo a las 48 horas del primer tratamiento. Sin embargo, se observaron recaídas a los 14 y 28 días despues del tratamiento en las ovejas Soay y Cheviot respectivamente. Se notaron efectos colaterales asociados al tratamiento en ovejas Cheviot pero no en las Soay. Intoxicaciones fueron observadas en los animales Cheviot pero no en los Soay.

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Résumé Des moutons non splénectomisés des races Cheviot et Soay, expérimentalement infectés parE. ovis, ont été traités par inoculation sous-cutanée de deux doses de 4 mg/kg de propionate d’Imidocarb à 24 heures d’intervalle. On constate une réduction rapide des parasitémies àE. ovis après la première injection;E. ovis ne pouvait plus être mis en évidence 48 heures après le premier traitement. Cependant, une récurrence de l’infection a été observée 14 jours après le traitement pour la race Soay et 28 jours pour la race Cheviot. Des effets secondaires associés au traitement ont été enregistrés chez les Cheviots mais non sur les Soays.

     

Pulvérisation à volume rédurt et bas volume en grandes cultures. Résultats de trois années d'expérimentation1

Les expérimentations ont été réalisées en France de 1980 à 1982 par l'ACTA (Association de Coordination Technique Agricole), l'ITCF (Institut Technique des Céréales et des Fourrages) et ITTB (Institut Technique de la Betterave Industrielle). Les techniques et volumes comparés ont été les suivants: 450 ou 300 l/ha (reference), 150, 100 et 75 l/ha en pulvérisation à jet projeté et 25 l/ha en pulvérisation centrifuge (Girojet TECNOMA). Les essais ont porté prindpatement sur les céréales et sur les betteraves. L'efficacité des herbicides sur céréales est pratiquement identique à tous les volumes compris entre 450 et 75 l/ha, pourvu que l'on traite en situation favorable (dose, stade, etc.). Elle devient légèrement moins bonne aux volumes les plus faibles dès que l'ons'éloigne des conditions idéales. Les résultats obtenus avec la pulvérisation centrifuge sont beaucoup plus aléatoires, surtout sur graminées. Les essais fongiddes sur céréales en végétation ont donné, contre le piétin-verse, des résultats pratiquement équivalents à tous les volumes, y compris 25 l/ha. Les essais herbicides de postlevée sur betteraves ont montré une efficacité comparable aux volumes entre 60 et 150 l/ha. Par contre, la pulvérisation centrifuge à 25 l/ha a donné une efficacité herbicide nettement inférieure.     

Preliminary Research on Seed Production and Nutrient Content for Certain Quinoa Varieties in a Saline–Sodic Soil

The aim of the present study was to compare the potential seed yield of eight quinoa varieties, to explore their mineral composition of seeds and to identify superior varieties in two locations with different soil properties. Compared with neutral soil conditions, seed yield in the marginal (saline–sodic) soil was decreased by 45 %. Under the latter soil conditions seed yield was negatively correlated with crop density, indicating that a considerable yield loss was due to poor and uneven plant density caused by adverse soil properties. Among the varieties, ‘RU–5–PQCIP–DANIDA–UNA’ produced the highest seed yield (>20 dt ha^?1) when grown under neutral soil conditions. Under marginal conditions, the above‐mentioned variety and ‘N 407’ produced seed yields up to 10 dt ha^?1 whereas the rest reached yields of only about 5 dt ha^?1. The majority of the varieties accumulated significantly more protein (20 %) in the seeds under saline–sodic soil conditions (lower yielding environment). The varieties originated from South America were superior in accumulating protein in the seeds at both locations. Mineral contents of calcium (Ca), magnesium (Mg), zinc (Zn) and manganese (Mn) in the seeds were significantly higher in the neutral soil. No differences were found for phosphorous (P), iron (Fe), copper (Cu) and boron (B) between the two locations. The South American varieties were again superior in mineral composition. Adaptation of certain quinoa varieties even under marginal environments seems promising for seed production and/or protein and mineral content in the seeds. Agronomic data are needed in a due course, over a higher number of locations and/or various climatic conditions.     

Effect of adding crude glycerine to diets with feed additives on the feed intake,ruminal degradability,volatile fatty acid concentrations and in vitro gas production of feedlot Nellore cattle

The effects of adding crude glycerine with sodium monensin or essential oils to beef cattle diets on the intake, degradability of DM and nutrients, rumen concentration of volatile fatty acids (VFA) and in vitro gas production were evaluated. Five ruminally cannulated Nellore steers were randomly assigned to a 5 × 5 Latin square design. The treatments were as follows: CONT, without crude glycerine and additives; EO, with essential oils and without crude glycerine; MON, with sodium monensin and without crude glycerine; EOG, with essential oils and crude glycerine; MONG, with sodium monensin and crude glycerine. Treatments with essential oil and sodium monensin increased the NDF and STC intake and the DM degradability. When crude glycerine was combined with either sodium monensin or essential oil, there was a reduction in DM, NDF and STC intake and an increase in DM and CP degradability of the diets. The adding crude glycerine to essential oil diets reduced the CH₄ production. Sodium monensin treatments reduced DM and NDF intake and the production of total gas, CH₄, total VFA and acetic acid concentration. In conclusion, the adding crude glycerine (200 g/kg DM) with either sodium monensin (0.03 g/kg DM) or essential oil (0.5 g/kg DM) can be utilized in diets for Nellore cattle without causing detrimental effects on feed intake and improving the DM degradability.     

Interactions between erythromycin,flunixin meglumine,levamisole and plant secondary metabolites towards bovine gastrointestinal motility—in vitro study

Continued ingestion of plant secondary metabolites by ruminants can provoke pharmacological interactions with pharmaceutical agents used in animals. As some drugs and phytocompounds affect smooth muscle activity, the aim of this study was to verify the possible interaction between selected pharmaceutical agents and plant secondary metabolites towards bovine gastrointestinal motility. The interactions between phytocompounds—apigenin, quercetin, hederagenin, medicagenic acid—and medicines—erythromycin, flunixin meglumine and levamisole—were evaluated on bovine isolated abomasal and duodenal specimens obtained from routinely slaughtered cows. The obtained results confirmed the contractile effect of all three drugs used solely. Hederagenin and medicagenic acid (0.001 μM) enhanced the contractile effect of levamisole. Hederagenin additionally increased the impact of erythromycin. Both saponins (100 μM) showed synergistic effects with all tested pharmaceuticals. Apigenin and quercetin (0.001 μM) intensified the contractile response induced by erythromycin and levamisole. Moreover, both flavonoids (100 μM) showed an antagonistic interaction with all tested drugs which in that situation were devoid of the prokinetic effect. To conclude, plant metabolic metabolites such as saponins and flavonoids are potent modifiers of the effect of drugs towards gut motility. The synergy observed between phytocompounds and selected medicines can be beneficial in the treatment of cows with hypomotility disorders.     

Computed tomography is a feasible method for quantifying bone density in Macaca mulatta

Osteopathologies are a result of advanced age and decreased bone density and represent a global health problem. It is therefore important to generate models for longitudinal studies of the pathophysiology in order to improve early diagnosis and develop preventive therapies. For this kind of research, the use of computed tomography (CT) to evaluate bone health offers advantages over other techniques since it provides more complete information. The aim of this prospective, pilot study was to obtain measurements of the left femur from a population in captivity of 32 rhesus monkeys (Macaca mulatta) in order to standardize the model for future research. Healthy subjects from 5 to 28 years old were chosen. Three groups with different ages were formed as follows: (1) 5–9 years, (2) 10–19 years, and (3) 20–28 years. Semi‐automatic segmentation by threshold defined the regions of interest, which were subdivided in the range of 300–700 Hounsfield units (HU) for trabecular bone and >700 HU for cortical bone. Then, the proportional ratios of the volumes of trabecular bone and cortical bone were obtained. Significant differences (analysis of variance test) in the averages of Hounsfield units, cortical, and trabecular bone proportions from each age group proved that a decrease in bone density begins at approximately 20 years of age. The values presented here, as well as the method to obtain them from CT scans, can be used as a baseline in a primate model for long‐term research in bone pathology diagnosis and treatment.     

Kombinierter Einsatz von synthetischen Insektiziden und Bacillus thuringiensis sowie Trichogramma evanescens gegen ausgewa¨hlte Scha¨dlinge an Vigna sesquipedalis unter tropischen Tieflandbedingungen

Field experiments with the synthetic insecticides, Methomyl and Carbaryl, alone and in combination with the biological control agents, Bacillus thuringiensis (Bt) and Trichogramma evanescens, were conducted to control pests in yardlong beans, Vigna sesquipedalis, during the dry season 1998/1999. The experimental area was located at the Central Luzon State University in the province of Nueva Ecija on the Philippine main island Luzon. Carbaryl was applied against bean flies 5 days after plant emergence. Methomyl was sprayed against pod sucking insects and the bean podborer, Maruca vitrata, 45 days after plant emergence. The biological control agents were applied with the beginning of the flowering stage of V. sesquipedalis, when plants were first attacked by M. vitrata. Major insect pests on V. sesquipedalis were cowpea aphid (Aphis craccivora), leafminer (Liriomyza sp.), and bean podborer (M. vitrata). Both, Bt and T. evanescens had no significant impact on yield. M. vitrata eggs, exposed for 48 hours in the fields to augmented T. evanescens, were used to measure field efficacy of the parasitoid. Highest parasitism rate was 13.3?%, thus, generally low. Highest yield was obtained from plots treated with both synthetic insecticides. No significant difference in fresh pod yield was observed when, in addition to the synthetic insecticides, Bt and/or T. evanescens was applied. However, all treatments significantly out-yielded the untreated control.