The genetics of gliadin and glutenin,the major storage proteins of the wheat endosperm

This paper reviews our present knowledge of the chromosomal location of the genes that control the synthesis of gliadins and glutenins, the two major groups of storage protein in the endosperm of wheat (Triticum aestivum). Allelic relationships and genetic linkage between genes are also discussed. The areas that require futher investigation are identified.     

Prof. Dr. Habil. Dr. H. C. Martin Körschens Zum 65. Geburtstag

Minimierung von Stoffbelastungen und Sicherung der Nachhaltigkeit sind die beiden Seiten, die Kriterienauswahl und Bewertungsprozeß der Kategorie Düngung prägen.

Das Gefährdungspotential der Kategorie wird durch 13 quantifizierbare und kontrollfähige Kriterien beschrieben. Für diese werden ökologische Optima und kritische Belastungen definiert, die die Grundlage für Bewertungsprozesse von Landwirtschaftsbetrieben bilden. Gleichzeitig wird damit ein Rahmen vorgegeben, der standortbezogen den tolerierbaren und damit umweltverträglichen Bereich der Düngung absteckt. Mittels dieses Rahmens können Betriebe umfassend bewertet, Problemfelder identifiziert und Korrekturerfordernisse formuliert werden.     

田间微集雨技术研究及应用

过去30 a,田间微集雨技术逐渐发展成为黄土高原雨养农业区的主要耕作技术。自上世纪八十年代以来,不同田间微集雨及覆盖（地膜、砂石和秸秆）栽培技术在黄土高原不断更新换代,先后经历了垄沟无覆盖技术、平地覆盖技术、垄沟半覆盖技术和垄沟全覆盖技术等发展过程,特别是沟垄地膜全覆盖技术大面积推广和应用,为西北旱区粮食单产大幅度提高提供了强大的支撑作用。本文综述了田间微集雨技术的演变历程及对农田生态系统的影响及机理,归纳了垄沟和覆盖模式及播种方式对作物产量形成、水分利用效率、作物生理生态、土壤质量、土壤微生物、杂草、病虫害、覆盖物残留和作物物候等的影响,并分析了该技术的高产高效和生态风险以及两者的互作关系。文章最后还对该技术的高效性、可持续性和发展潜力进行了讨论,旨在对雨养农业生态系统的可持续管理提供理论指导。     

Can You Ensure that ICT for Development Apps Are Downloaded and Used? A Case Study of the Plantwise Data Collection App for Plant Health in Kenya

This study used a field experiment and the means-end chain approach to examine the effect of providing information on the biofortification process on consumers' acceptance of orange-fleshed sweetpotato (OFSP). Negative, positive, and neutral information about the biofortification were verbally provided. Images were used to reinforce the verbal information. Meaning representation (mental models) of various constructs relating to OFSP was assessed. We found that the structure of mental constructs differed depending on the type of information provided and concluded that the type of information consumers receive about the biofortification process affects OFSP acceptance. Implications of the findings for policy and development practice are discussed.     

Availability of Compost P to Fescue Under Nonlimiting N Conditions

Nutrient management plans require an accurate assessment of P fertilizer additions to soil. The fertilizer equivalents of manures and composts must be estimated in order to comply. A previous study comparing triple superphosphate(TSP) to poultry litter compost (PLC) as a source of P for fescue indicated that overall they were equal, but when N became limiting during the final harvest, PLC supplied more P to fescue than TSP at comparable rates. A subsequent study was initiated to determine if P from PLC was more available to fescue than TSP when N was not limiting. Sassafras soil was amended with PLC and TSP at rates of 0, 50, 100 and 150 kg ha^?1. Nitrogen was supplied to be uniform across all treatments taking into account the N mineralization rate of PLC. Two harvests of fescue were taken and analyzed for yields and P uptake. Nitrogen was added to all treatments at the original application rate of 120 kg ha^?1 and two more harvests plus roots were collected. Yields were affected by harvest date but not by P rate or source of P. P uptake was affected by date and rate but not source of P. The P uptake response to PLC and TSP was curvilinear and linear respectively, but within the range of P application rates used, the source of P was not a significant factor in P uptake by fescue. Based on the current study testing the effect of unlimited N, addition of supplemental N did not affect P supply from either source. Poultry litter compost is considered equal to TSP in supplying P to fescue and N availability did not affect these conclusions.     

Changes in vitamin K status of growing horses

Serum samples from 15 suckling foals, 119 days of age, of Quarter Horse and Thoroughbred breeding, that were weaned at either 140 days of age (EW) or 182 days of age (LW) were used to measure changes in vitamin K status over time and to assess the effect of age at weaning on vitamin K status. Jugular venous blood samples were collected from each foal at the start of the experiment and 21-day intervals thereafter, with the exception of a one-week interval post-weaning in both groups. The study continued for 84 days post-weaning in both groups. Serum was analyzed for total osteocalcin and hydroxyapatite binding capacity of serum osteocalcin (HABOC) which was calculated as follows: HABOC = [(total serum osteocalcin — serum osteocalcin following extraction of serum with hydroxyapatite)/total serum osteocalcin]x100. Osteocalcin's capacity to bind hydroxyapatite is vitamin K-dependant and, therefore, is used as a marker of vitamin K status. Hydroxyapatite binding capacity of serum osteocalcin increased (quadratic; P<0.01) over the experimental period regardless of weaning age, indicating an increase in vitamin K status in both weaning groups. In addition, there was a tendency for an age at weaning by time interaction (P=0.056) on serum HABOC. This tendency was due to significantly higher HABOC at 182 days of age for EW as compared to LW (P<0.05). After 182 days of age, HABOC was not different between EW and LW. Serum osteocalcin decreased (linear; P<0.01) in both weaning groups over the experimental period. In conclusion, vitamin K status increased and serum osteocalcin decreased with age. In addition, vitamin K status tended to increase at a greater rate in foals weaned early as compared to those weaned late.     

Measurement of ammonia concentrations in horse stalls

The effect of treating stall floors with an ammonia-absorbingcompound (AAC) on aerial ammonia levels was tested during two 14-day periods in a four-stall barn. In the first period, two stalls were treated with the AAC and the other two stalls remained as the non-treated controls. In the second period, the stalls were switched. Four geldings were used in each period and were randomly assigned to the stalls. The horses remained in the stalls at all times except for 30 min of turn-out per day at which time the stalls were cleaned. Ammonia levels at the stall floor were measured by a Bruel and Kjacr 1302 gas monitor on day 0 before the horses were admitted to the barn and on days 1, 3, 5, 7, 10 and 14. Ammonia diffusion tubes were attached to the horses' halters on days 1, 7, 11 and 13 for 8 hours to determine the level of ammonia exposed to the horse. On day 14, ammonia concentrations near the stall floor were 25% lower in treated stalls than in control stalls (P<0.1). Ammonia concentrations measured at the halter were much lower than those at the floor, but horses in treated stalls had lower ammonia exposure than horses in control stalls (P<0.1).     

A blind test of the serological response of dogs to infection with Taenia ovis

Fifty six dogs of mixed age and sex were acquired from farms in the Otago/Southland region, and maintained at the Hydatid Research Unit, Taieri, where 43 were each fed two Taenia ovis cysts. All were bled fortnightly for six or 12 weeks. Coded sera were sent to Wallaceville Animal Research Centre for testing using ELISA, with antigen from T. ovis scoleces. Dog treatments were identified after all tests were complete. A discriminant level was derived from the mean absorbance value plus three standard deviations of 56 sera taken at time zero and 78 sera from serially bled uninfected dogs. None of these 134 sera registered as a false positive using this discriminant level. The data showed no significant deviation from normality, and the expected frequency of the occurrence of false positives is therefore less than 0.14%. Four weeks after infection 63% of dogs proved to be infected were serologically positive, rising to 78% after 6 weeks. When worms were removed by anthelmintic treatment, ELISA absorbance levels decreased. Four weeks after removal 70% of previously infected dogs remained positive, decreasing to 30% after 6 weeks.

Six weeks after infection the sensitivity of the test was 78%, and the specificity 63%. However, if dogs with positive ELISA absorbance levels, but which did not purge worms, were regarded as having had worms, the respective figures would be 82% and 100%. The latter figures are similar to our previously published laboratory results. The test is of comparable efficiency to arecoline purgation for surveillance, and has the additional advantage of detecting infection in the majority of those dogs that have been infected for three weeks or more but fail to pass worms on purgation, and a substantial proportion of those infected dogs that were treated by their owners prior to presenting them for purgation in order to avoid detection of infection.     

Prevalence and significant geospatial clusters of bovine tuberculosis infection at livestock–wildlife interface ecosystem in Eastern Tanzania

Bovine tuberculosis (BTB) is an important neglected zoonosis that affects livestock, wildlife and human. A study to determine prevalence and geospatial clusters for BTB was conducted from June 2010 to March 2012 at livestock–wildlife interface areas (LWIA). A total of 1,288 cattle located in vicinity of Mikumi-Selous ecosystem Tanzania were tested. Single Intradermal Comparative Tuberculin Test and spatial scan statistic analysis were applied to establish the status of the disease and identify significant spatial BTB clusters. Overall individual prevalence was 3.7 % (n?=?1,288) (95 % CI?=?2.8–4.9) and 7.8 % (95 % CI?=?6.4–9.4) with cut-off of >4 and >2 mm, respectively. Villages with at least one reactor were 55.8 % (n?=?43). Reactivity was significantly higher in Mvomero and Kilosa districts compared with Kilombero and Ulanga districts (χ ²?=?15.9; P?<?0.001). Significant spatial BTB clusters were revealed at 11 villages. BTB clustering was significant in Kilosa and Mvomero districts compared with Kilombero and Ulanga districts. There was overlap and aggregation of BTB clusters covering south and south-east of Kilosa district bordering Mikumi National Park (MNP) and Mvomero. Generally, clustering occurred around major rivers. The current study provides useful information on the dynamics and epidemiological status of BTB around the wildlife–livestock–human interface, it reveals that the wildlife are at risk of BTB from infected livestock. The study revealed hotspots for BTB that can be applied to guide implementation of participatory intervention at LWIA and control strategies in marginalised pastoralist communities. This study calls for similar studies in other Tanzania’s LWIA for efficient intervention of BTB countrywide.