Evaluation of cassava hybrids performance obtained by controlled pollination of elite accessions from Niari landscape in the Republic of Congo

Open Access Journal; Published online: 03 May 2018Cassava is the main crop in the Congo but its low yield doesn’t meet the needs of Congolese populations. The low yield is due to the use of less effective sensitive varieties to diseases, non-mastering of techniques and biotic constraint of which the African cassava mosaic. This study aims at selecting resistant genotypes to the African cassava mosaic and assessing their agronomic and production performances. Six elite accessions selected based on a villager participative approach have been crossed by controlled pollination with three clones (192/0401, 192/0325 and 197/0162) distributed by the International Institute for Tropical Agriculture (IITA). Growth, agronomic and production parameters of genotypes from the controlled pollination were evaluated at the station. Of the ten tested genotypes, the one resulting from the crossing (Mahabama x I92/0401) did not show any symptom of the cassava mosaic disease 12 months after planting. Apart from the root length, foliar surface and the height of the plant, this genotype differed from the others only by the biomass, the diameter of the stem, the harvest index, the rate of starch, the rate of dry matter and marketable or non-marketable tuberous roots. The genotype (Mahabama x I92/0401) will be included in the cassava improvement section plan in the Republic of Congo

Economic losses experienced by smallscale farmers in Malawi due to cassava brown streak virus disease

Cassava is an important root crop in Malawi. It is the second most important food crop after maize. It is grown throughout the country as a food security crop, sack/cash crop, and as a staple food crop along the Lake Malawi. Is is a staple for over 39 % of the country’s population. Farmers are not benefiting as much as they might from cassava because they are faced with a number of constraints. These include: - inherent low yielding and late maturing local cultivars - pests and diseases prevalent in the country - low promotion of good cultural practices. The major pests and diseases of cassava in Malawi are, cassava mosaic virus disease (CMD), cassava bacterial blight (CBB), cassava brown streak virus disease (CBSD), cassava green mite (CGM), cassava mealy bug (CM) and termites. The objective of this study was to determine the economic impact of CBSD on the farmers in Malawi where the disease is prevalent. The paper makes the following recommendations: - the cassava research organisations should mount urgent awareness campaigns of the disease and its management for both extension agents and farmers - the cassava research organisations should establish effective collaboration with the extension system on matters of proper cassava husbandry to effectively and efficiently control the disease - they should additionally carry out local collection exercises for cultivars that show CBSD disease resistance in the high disease pressure areas - there is an urgent need for cassava research and extension organisations to multiply cultivars and promising clones that have shown multiple disease resistance and that are widely accepted by farmers for distribution in the heavily affected areas - in collaboration with entrepreneurs, these organisations need to develop and strengthen sustainable seed multiplication and distribution systems as a way of assuring the provision of clean planting material

Neuromuscular disease genetics in under-represented populations: increasing data diversity

Neuromuscular diseases (NMDs) affect similar to 15 million people globally. In high income settings DNA-based diagnosis has transformed care pathways and led to gene-specific therapies. However, most affected families are in low-to-middle income countries (LMICs) with limited access to DNA-based diagnosis. Most (86%) published genetic data is derived from European ancestry. This marked genetic data inequality hampers understanding of genetic diversity and hinders accurate genetic diagnosis in all income settings. We developed a cloud-based transcontinental partnership to build diverse, deeply-phenotyped and genetically characterized cohorts to improve genetic architecture knowledge, and potentially advance diagnosis and clinical management.We connected 18 centres in Brazil, India, South Africa, Turkey, Zambia, Netherlands and the UK. We co-developed a cloud-based data solution and trained 17 international neurology fellows in clinical genomic data interpretation. Single gene and whole exome data were analysed via a bespoke bioinformatics pipeline and reviewed alongside clinical and phenotypic data in global webinars to inform genetic outcome decisions.We recruited 6001 participants in the first 43 months. Initial genetic analyses 'solved' or 'possibly solved' similar to 56% probands overall. In-depth genetic data review of the four commonest clinical categories (limb girdle muscular dystrophy, inherited peripheral neuropathies, congenital myopathy/muscular dystrophies and Duchenne/Becker muscular dystrophy) delivered a similar to 59% 'solved' and similar to 13% 'possibly solved' outcome. Almost 29% of disease causing variants were novel, increasing diverse pathogenic variant knowledge. Unsolved participants represent a new discovery cohort. The dataset provides a large resource from under-represented populations for genetic and translational research.In conclusion, we established a remote transcontinental partnership to assess genetic architecture of NMDs across diverse populations. It supported DNA-based diagnosis, potentially enabling genetic counselling, care pathways and eligibility for gene-specific trials. Similar virtual partnerships could be adopted by other areas of global genomic neurological practice to reduce genetic data inequality and benefit patients globally.Wilson et al. present the findings of an international partnership established to study genetic causes of neuromuscular diseases in under-represented diverse populations from 12 low-middle income sites. A genetic cause was identified in similar to 55% of cases and similar to 30% of variants were novel, improving understanding of neuromuscular disease genetics.Functional Genomics of Muscle, Nerve and Brain Disorder