Declining tuberculosis notification trend associated with strengthened TB and expanded HIV care in Swaziland.

This retrospective observational review documents the efforts of the Swaziland National Tuberculosis (TB) Control Programme between 2004 and 2014. The objective is to describe the disparity between actual declines in case notification and increases in estimated incidence. The review of policies and practices shows the most influential factors associated with the decrease in TB case notification to be an increase in access to antiretroviral therapy for co-infected TB patients, the general success of TB and human immunodeficiency virus service integration in the country and improvements in implementation of all components of directly observed treatment, active case finding, and rapid diagnosis using new technologies.

Cette étude d'observation rétrospective documente les efforts du programme de lutte contre la tuberculose (TB) du Swaziland entre 2004 et 2014. L'objectif est de décrire la disparité entre un réel déclin dans la déclaration des cas et une augmentation de l'incidence estimée. La revue des politiques et des pratiques montre que les facteurs les plus influents associés au déclin de la déclaration des cas de TB sont liés à une augmentation de l'accès aux antirétroviraux pour les patients tuberculeux co-infectés, au succès d'ensemble de l'intégration des services pour la TB et ceux pour le virus de l'immunodéficience humaine dans le pays et aux améliorations dans la mise en œuvre de tous les composants du traitement sous observation directe, de la recherche active des cas et d'un diagnostic rapide grâce aux techniques nouvelles.

Con el presente análisis observacional retrospectivo se documentan las iniciativas emprendidas por el Programa de Control de la Tuberculosis (TB) de Swazilandia del 2004 al 2014. El objetivo del estudio fue describir la discrepancia existente entre la disminución en la notificación de casos de TB y el aumento en las estimaciones de incidencia de la enfermedad. El análisis de las políticas y las prácticas puso de manifiesto que los factores que más influyen sobre la disminución de la notificación de casos de TB es un aumento en el acceso al tratamiento antirretrovírico por parte de los pacientes coinfectados por el virus de la inmunodeficiencia humana y la TB, el éxito general de la integración de los servicios que se ocupan de ambas enfermedades en el país y los progresos en la aplicación de todos los componentes del tratamiento directamente observado, la búsqueda activa de casos y el diagnóstico rápido mediante nuevas tecnologías.

Genetic analysis of in vitro shoot regeneration from cotyledonary petioles of Brassica oleracea.

Diallel analysis was used to investigate the genetic control of in vitro shoot regeneration in Brassica oleracea. Twelve doubled haploid (DH) lines, selected to include a range of genotypes with differing shoot regeneration potentials, were crossed reciprocally to produce 132 F(1) and 12 selfed, DH families. Cotyledonary petioles from 4-day-old seedlings, from all families, were excised and maintained on MS medium supplemented with 2 mg/l BAP. Explants were scored after 44 days for both the presence or absence of shoots and the number of regenerating shoots per explant. Diallel analysis showed both shoot regeneration and the production of multiple shoots to be controlled by additive and dominant gene effects, with additive effects being more important. Additive gene effects accounted for 71% and 77% of the genetic variation observed within the diallel for shoot regeneration and multiple shoot regeneration, respectively. By investigating the shoot regeneration potential of subsequent backcross and F(2) populations, the ability to introduce and increase shoot regeneration potential into otherwise recalcitrant lines was demonstrated.

Genetic analysis of Agrobacterium tumefaciens susceptibility in Brassica oleracea.

The genetic control and heritability of Agrobacterium tumefaciens susceptibility was investigated using a doubled haploid (DH) mapping population of Brassica oleracea and the associated RFLP map. Preliminary studies were carried out by analysis of an 8 x 8 diallel, for which the parental lines were selected to include a range of susceptibilities to A. tumefaciens. The variation observed within the diallel was attributed to both additive and dominant gene effects, with additive gene effects being more important. A broad sense heritability value of 0.95 suggested that 95% of the observed variation was due to genetic effects, with just 5% attributed to non-genetic or environmental effects. A high narrow-sense heritability value of 0.79 suggested that 79% of this trait was controlled by additive gene effects and, therefore, the potential to introduce this trait into breeding material is high. Fifty-nine DH lines from the mapping population were screened for susceptibility towards A. tumefaciens. Variation in susceptibility was observed across the population. The results of the DH screen were entered into the mapping programme MAPQTL and a highly significant quantitative trait loci (QTL) associated with susceptibility to A. tumefaciens was identified on linkage group 09. The use of substitution lines covering this region confirmed the location of this QTL. This work shows that susceptibility to A. tumefaciens is a heritable trait, and the transfer of susceptibility into resistant lines is demonstrated. These findings may help to overcome genotype restrictions to genetic transformation.

The association of flowering time quantitative trait loci with duplicated regions and candidate loci in Brassica oleracea.

A population of 150 doubled haploid lines of rapid cycling Brassica oleracea, derived from an F1 from a var. alboglabra x var. italica cross, was scored for flowering time in two trials. Using information on 82 mapped molecular markers, spread evenly across the nine linkage groups, QTL were identified at six locations; one each on linkage groups O2 and O3 and two each on linkage groups O5 and O9. In total, these QTL explained 58 and 93% of the genetical variation in the two trials. Three of these QTL, on linkage groups O2, O3, and O9, were situated in regions showing considerable homology both with each other and with chromosome regions of B. nigra that have been shown to affect flowering time. These same regions are all homologous to a single tract of Arabidopsis chromosome 5, which contains a number of the flowering-related genes, one or more of which may be candidates for the QTL found in Brassica.

The construction of a substitution library of recombinant backcross lines in Brassica oleracea for the precision mapping of quantitative trait loci.

The currently available methods for locating quantitative trait loci (QTLs) and measuring their effects in segregating populations lack precision unless individual QTLs have very high heritabilities. The use of recombinant backcross lines containing short regions of donor chromosome introgressed into a constant recipient background permits QTLs to be located with greater precision. The present paper describes the use of molecular markers to introgress defined short regions of chromosome from a donor doubled haploid calabrese line of Brassica oleracea (var. italica) into a recipient short generation variety (Brassica oleracea var. alboglabra). We demonstrate that in just two or three generations of backcrossing, combined with selection for mapped molecular markers, the generation of a library of recombinant backcross lines is feasible. The possible use and refinement of these lines are discussed. Key words : backcrossing, Brassica oleracea, introgression, molecular markers, near-isogenic lines, QTL mapping, recombinant backcross lines, substitution lines.

The effects of proline, thioproline and methylglyoxal-bis-(guanylhydrazone) on shoot regeneration frequencies from stem explants of B. napus.

Internode segments from aseptic shoot cultures are the most prolific explants for the regeneration of Brassica shoots in vitro. These explants also have the advantage of not being subject to the genotypic variations in regeneration response observed in hypocotyl and cotyledon explants. Despite reports of 80-100% shoot regeneration from stem explants, observed frequencies are typically 50-60%. Three media additives, proline, thioproline and methylglyoxal-bis-(guanylhydrazone) (MGBG), were tested for their efficacy in promoting shoot regeneration from stem explants of two B. napus varieties, Westar and Cobra. The effects of proline and thioproline on both varieties were neutral or deleterious. In Cobra the MGBG treatments caused a uniform reduction in explant regeneration. However, at low concentrations (0.35µM) MGBG resulted in a 50% increase, to 92%, in regeneration from Westar. The potential of MGBG in promoting explant regeneration in B. napus is discussed in the light of its interaction with the explant genotype.

Biometrical analyses of some economically important characters in Antirrhinum majus.

The experiment described in this paper was designed to measure some of the genotype-environment interactions in Antirrhinum majus and the emphasis has been upon characters which are of economic importance. - Seven F1 hybrids were grown in 27 different environmental conditions, consisting of 3 levels of nitrogen and 9 sowing dates. Analysis of variance followed by regression analysis and the partitioning of the variation into its genetic, environmental and interacting components were employed. - The practical applications of these methods by the grower and plant breeder, are discussed.

The use of regression techniques for predicting the response of peas to environment.

Six pea varieties were grown in seven environments over two consecutive years and the results analysed using regression techniques. In both years a degree of linearity of response to environment was established for many of the characters recorded. Comparisons were made between the values observed in the second year and those predicted from the results of the first year, using 't' tests. As a result of these comparisons it appears that, due to poor linearity of response and/or different degrees of response in different years, accurate predictability of genotype behaviour was not possible.

Genotype-environment interactions in peas.

The experiments described in this paper were designed to measure some of the genotype-environment interactions in peas and the emphasis has been upon the characters which are of importance in relation to the time of maturity, uniformity of maturity and to yield.Six pea varieties were grown at four sites in Eastern England, there being an early an d a late sowing at each site The data were analysed by means of regression techniques and by the analysis of variance. Linear responses t. environment were demonstrated for all the characters in the majority of varieties and the relative importance of somo of the components of yield in different environments were determined. The variation could be partitioned into ite genetic, environmental and interacting components and genotype-environment interactions were demonstrated fos every one of the characters investigated.