Comparison of migratory tendency in European Quail Coturnix c. coturnix, domestic Japanese Quail Coturnix c. japonica and their hybrids

Since the 1970s, the decline of the occidental populations of European Quail Coturnix c. coturnix , a partial migrant Galliform species, has driven the release of domestic Japanese Quail Coturnix c. japonica into the wild as game birds. Recent experiments suggest that reproductive isolating mechanisms have not developed to prevent hybridization between European and Japanese Quail. To assess the potential impact of hybridization between the subspecies in the wild, this study aims to compare the migratory characteristics of captive European Quail, domestic Japanese Quail, F₁ hybrids and a backcross. In a laboratory experiment, birds hatched in summer and reared under a natural photoperiod were transferred during winter to an artificial photoperiod (light–dark) of 14 : 10 h. Behavioural (migratory restlessness, crowing activity in males) and physiological (sexual development, fat accumulation, body mass) measures were recorded. Domestic Japanese Quail showed no migratory tendency in response to the increased day length. F₁ hybrids showed rapid sexual development and few of them exhibited the typical profile of a migrant bird. Backcrosses showed great variation in their response, comparable with those of the European Quail. Therefore, hybridization could lead to an increased proportion of quail showing sedentary rather than migratory behaviour. Furthermore, hybrids that do show migratory behaviour have the potential to facilitate Japanese gene flow into areas where the release of domestic Quail as game birds is not yet practised.     

Production of Serine Proteases by the Oyster Pathogen Perkinsus marinus (Apicomplexa) In Vitro

ABSTRACT. Analysis of the cell-free supernatants of Perkinsus marinus cultures by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and silver staining revealed the presence of as many as 17 bands ranging in molecular weight from 239 to 32 kDa. These bands were not present in un-inoculated medium. Moreover, P. marinus produces extracellular proteins that possess proteolytic activities; the cell-free supernatants of P. marinus cultures could digest a variety of proteins including gelatin, casein, fibronectin and laminin. Oyster plasma was also digested by cell-free culture supernatants. The proteolytic activity in cell-free culture supernatants was detected 24 h post-inoculation, while no proteolytic activity could be detected in cell lysates. The proteolytic activities were characterized using substrate-impregnated sodium dodecylsulfate-polyacrylamide gels and had approximate molecular weights ranging from 55 to 35 kDa. The proteolytic activity of cell-free culture supernatants was inhibited by the serine protease inhibitors phenylmethylsulphonyl fluoride, 3,4-dichloroisocoumarin and soybean trypsin inhibitor. In contrast, inhibitors (i.e. trans-epoxysuccinyll-leucylamido(4-guanidino)-butane, 1, 10-phenanthroline, captopril, ethylenediaminetetracetic acid, pepstatin A or diazoacetyl-DL-norleucine methyl ester) from the other three classes of proteases had no effect. It was concluded that the P. marinus proteases in cell-free culture supernatants are serine proteases.     

The Effects of Elevated Atmospheric Carbon Dioxide and Water Stress on Ligth Interception, Dry Matter Production and Yield in Stands of Groundnut (Arachis hypogaea L.

Stands of groundnut (Arachis hypogaea L.), a C₃ legume, weregrown in controlled-environment glasshouses at 28 °C (±5°C)under two levels of atmospheric CO₂ (350 ppmv or 700 ppmv) andtwo levels of soil moisture (irrigated weekly or no water from35 d after sowing). Elevated CO₂ increased the maximum rate of net photosynthesisby up to 40%, with an increase in conversion coefficient forintercepted radiation of 30% (from 1–66 to 2–16g MJ^–1) in well-irrigated conditions, and 94% (from 0–64to 1·24 g MJ^–1) on a drying soil profile. In plantswell supplied with water, elevated CO₂ increased dry matteraccumulation by 16% (from 13·79 to 16·03 t ^–1) and pod yield by 25% (from 2·7 to 3·4t ha^–1).However, the harvest index (total poddry weight/above-grounddry weight) was unaffected by CO₂ treatment. The beneficial effects of elevated CO₂ were enhanced under severewater stress, dry matter production increased by 112% (from4·13 to 8·87 t ha^–1) and a pod yield of1·34t ha^–1 was obtained in elevated CO₂, whereascomparable plotsat 350 ppmv CO₂ only yielded 0·22 t ha^-1.There was a corresponding decrease in harvest index from 0·15to 0·05. Following the withholding of irrigation, plants growing on astored soil water profile in elevated CO₂ could maintain significantlyless negative leaf water potentials (P<0·01) for theremainder of the season than comparable plants grown in ambientCO₂, allowing prolonged plant activity during drought. In plants which were well supplied with water, allocation ofdry matter between leaves, stems, roots, and pods was similarin both CO₂ treatments. On a drying soil profile, allocationin plants grown in 350 ppmv CO₂ changed in favour of root developmentfar earlier in the season than plants grown at 700 ppmv CO₂,indicating that severe waterstress was reached earlier at 350ppmv CO₂. The primary effects of elevated CO₂ on growth and yield of groundnutstands weremediated by an increase in the conversion coefficientfor intercepted radiation and the prolonged maintenance of higherleaf water potentials during increasing drought stress. Key words: Arachis hypogaea, elevated CO₂, water stress, dry matter production     

Genotype and phenotype associations with drought tolerance in barley tested in North Africa

A review is presented of genetic strategies deployed in a 3-yr project on drought tolerance in barley. Data were collected on genetic, physiological and agronomic traits in non-irrigated and irrigated field trials in Egypt, Morocco and Tunisia. A wide range of barley germplasm (developed from African and European cultivars, adapted landraces and wild barleys) was tested, and positive traits were found in each gene pool. The contrasting environments of the three North African countries had major effects on plant/genotype performance. Genetic effects were also detected, as were genotype × environment interactions. A range of strategies were deployed to investigate the physiology and genetics of quantitative traits associated with field performance. Quantitative trait locus (QTL) analysis was performed using backcross lines, recombinant inbred lines and doubled haploid mapping populations. A detailed genetic map was generated in the Tadmor × (ER/Apm) recombinant inbred lines, an important mapping population specifically developed by ICARDA (Centre for Agricultural Research in Dry Areas) and CIMMYT (International Maize and Wheat Improvement Center) to study drought. Quantitative trait loci (QTLs) for grain yield and other important morphological and physiological traits were also identified in a population of doubled haploids derived from F2BCj plants from a cross between a cultivar and a wild barley accession. Significantly, the wild parental line was found to contribute a number of positive alleles for yield. Effects of major developmental genes could explain many of the responses observed. QTLs were found to cluster around major genes controlling flowering time (sghI), plant stature (sdwI and arie.GP) and ear type (vrsl), and it is highly likely that the associations represent pleiotropic effects. Some QTLs were associated with candidate genes such as dehydrins and rubisco activase. One of the most significant results was the identification and generation of material that out performed the best local standards in the three participating North African countries; the selected lines have now entered local breeding programmes. The strategies adopted provided information on physiological traits, genotypes and genetic markers that could be used for marker-assisted selection. Target QTLs and their associated genetic markers may be deployed in marker assisted selection programmes to match crop phenology to the field environment.     

Egg maturation dynamics of the parasitoid Microplitis rufiventris: starvation speeds maturation in early life

The number of mature eggs carried by a female parasitoid at any given moment (egg load) is a fitness‐related parameter affecting reproductive potential and impacting upon host population dynamics. Microplitis rufiventris Kokujev (Hymenoptera: Braconidae) is a solitary koinobiont endoparasitoid wasp of several noctuid pests, including Spodoptera littoralis. The number of mature eggs carried by females at emergence is approximately 50. The rate of egg maturation is strongly affected both by feeding status and access to host larvae. In early adult life, egg maturation rates are lower for 6–72 h in fed wasps compared with food‐deprived wasps. When given access to hosts, honey‐fed wasps live for approximately 9 days with high lifetime fecundity (226 eggs). By contrast to early adult life, the total realized fecundity is positively affected by feeding status, where water‐fed and starved females have 140 and 107 eggs, respectively. Egg resorption is most pronounced in the later life of females. The results suggest, in addition to confirming the effect of honey‐feeding on total fecundity, that fecundity of starved wasps includes rapid egg maturation early in life, which potentially could improve the performance of the parasitoid as a biological control agent.     

CURRICULUM GUIDE FOR RESEARCH ETHICS WORKSHOPS FOR COUNTRIES IN THE MIDDLE EAST

To help ensure the ethical conduct of research, many have recommended educational efforts in research ethics to investigators and members of research ethics committees (RECs). One type of education activity involves multi‐day workshops in research ethics. To be effective, such workshops should contain the appropriate content and teaching techniques geared towards the learning styles of the targeted audiences. To ensure consistency in content and quality, we describe the development of a curriculum guide, core competencies and associated learning objectives and activities to help educators organize research ethics workshops in their respective institutions. The curriculum guide is divided into modular units to enable planners to develop workshops of different lengths and choose content materials that match the needs, abilities, and prior experiences of the target audiences. The content material in the curriculum guide is relevant for audiences in the Middle East, because individuals from the Middle East who participated in a Certificate Program in research ethics selected and developed the training materials (e.g., articles, powerpoint slides, case studies, protocols). Also, many of the activities incorporate active‐learning methods, consisting of group work activities analyzing case studies and reviewing protocols. The development of such a workshop training curriculum guide represents a sustainable educational resource to enhance research ethics capacity in the Middle East.     

Quantitative trait loci and candidate genes underlying genotype by environment interaction in the response of Arabidopsis thaliana to drought

Drought stress was imposed on two sets of Arabidopsis thaliana genotypes grown in sand under short‐day conditions and analysed for several shoot and root growth traits. The response to drought was assessed for quantitative trait locus (QTL) mapping in a genetically diverse set of Arabidopsis accessions using genome‐wide association (GWA) mapping, and conventional linkage analysis of a recombinant inbred line (RIL) population. Results showed significant genotype by environment interaction (G×E) for all traits in response to different watering regimes. For the RIL population, the observed G×E was reflected in 17 QTL by environment interactions (Q×E), while 17 additional QTLs were mapped not showing Q×E. GWA mapping identified 58 single nucleotide polymorphism (SNPs) associated with loci displaying Q×E and an additional 16 SNPs associated with loci not showing Q×E. Many candidate genes potentially underlying these loci were suggested. The genes for RPS3C and YLS7 were found to contain conserved amino acid differences when comparing Arabidopsis accessions with strongly contrasting drought response phenotypes, further supporting their candidacy. One of these candidate genes co‐located with a QTL mapped in the RIL population.     

Development of microsatellite markers for the barley stem gall midge,Mayetiola hordei (Diptera: Cecidomyiidae)

Ten microsatellites were isolated from the barley stem gall midge, Mayetiola hordei. Polymorphism at each locus was tested on 40 individual midges, among which 34 were collected on barley and six on wheat crops in Tunisia. Six loci were polymorphic with the number of alleles ranging from two to seven. The observed heterozygosity varied between 0.025 and 0.2. These microsatellite loci revealed a strong effect of host plant on the population genetic structure of M. hordei.