Cassava (Manihot esculenta Crantz), a highly heterozygous crop, is devastated by cassava mosaic disease (CMD). The discovery of the CMD2 dominant gene is helpful in the genetic analysis of CMD resistance. Molecular markers for CMD2 gene were used to introgress CMD resistance into Latin American cassava genotypes and validated in the field for 4 yr for stability of resistance conferred by CMD2. Field screening identified 64 Latin American genotypes with stable resistance to CMD. Resistance to CMD of two Nigerian cassava cultivars (TMS 97/2205 and TMS 98/0505) was analyzed with markers and in the field. Molecular data indicated that CMD resistance in the two Nigerian cultivars was mediated by the CMD2 gene. Results showed TMS 97/2205 to be highly resistant to CMD in three ecological zones in Nigeria. Further genetic analysis of this genotype as a source of high level of resistance to CMD using a segregating F1 population derived from a TMS 97/2205 × NR 8083 cross was initiated using 530 simple sequence repeat (SSR) markers to identify quantitative trait loci (QTL) for CMD resistance. A marker (NS198) associated with a QTL for CMD resistance, explaining 11% of the phenotypic variance observed, was identified. The combined effect of this QTL and CMD2 may account for the high level of resistance of TMS 97/2205. The resistance profile of the evaluated CMD2 genotypes in growth cycle was not uniform and was affected by genetic background. The discovery of a new QTL (CMD3) for CMD resistance in TMS 97/2205 offers new opportunities for pyramiding CMD genes for enhanced durability of CMD resistance in cassava.

African countries face key challenges in the deployment of GM crops due to incongruities in the processes for effective and efficient commercial release while simultaneously ensuring food and environmental safety. Against the backdrop of the preceding scenario, and for the effective and efficient commercial release of GM crops for cultivation by farmers, while simultaneously ensuring food and environmental safety, there is a need for the close collaboration of and the interplay between the biosafety competent authorities and the variety release authorities. The commercial release of genetically modified (GM) crops for cultivation requires the approval of biosafety regulatory packages. The evaluation and approval of lead events fall under the jurisdiction of competent national authorities for biosafety (which may be ministries, autonomous authorities, or agencies). The evaluation of lead events fundamentally comprises a review of environmental, food, and feed safety data as provided for in the Biosafety Acts, implementing regulations, and, in some cases, the involvement of other relevant legal instruments. Although the lead GM event may be commercially released for farmers to cultivate, it is often introgressed into locally adapted and farmer preferred non-GM cultivars that are already released and grown by the farmers. The introduction of new biotechnology products to farmers is a process that includes comprehensive testing in the laboratory, greenhouse, and field over some time. The process provides answers to questions about the safety of the products before being introduced into the environment and marketplace. This is the first step in regulatory approvals. The output of the research and development phase of the product development cycle is the identification of a safe and best performing event for advancement to regulatory testing, likely commercialization, and general release. The process of the commercial release of new crop varieties in countries with established formal seed systems is guided by well-defined procedures and approval systems and regulated by the Seed Acts and implemented regulations. In countries with seed laws, no crop varieties are approved for commercial cultivation prior to the fulfillment of the national performance trials and the distinctness, uniformity, and stability tests, as well as prior to the approval by the National Variety Release Committee. This review outlines key challenges faced by African countries in the deployment of GM crops and cites lessons learned as well as best practices from countries that have successfully commercialized genetically engineered crops.

The New Partnership for Africa’s Development (NEPAD) Agency recognizes that Africa is in a period of transition and that this demands exploring and harnessing safe advances made in science-based innovations including modern biotechnology. To advance the science of biotechnology in Africa effectively, while at the same time safeguarding human health and the environment, the African Union (AU) adopted a High-Level Panel report on modern biotechnology entitled, Freedom to Innovate, which advocated for a coevolutionary approach where technology development goes hand in hand with regulation. Furthermore, most AU member states are Parties to the Cartagena Protocol on Biosafety (CPB), a legally binding international agreement negotiated, concluded and adopted within the framework of the Convention on Biological Diversity. This seeks to guide Parties in developing systems for the environmentally sound management of modern biotechnology applications. Currently, 49 AU Member States have signed and ratified the CPB, of which 12 have passed biosafety laws.African Union (AU) member states are at different stages in the development of regulatory frameworks for applications of modern biotechnology, which include genetically modified (GM) products and other emerging technologies. Biosafety regulatory frameworks comprise: biotechnology and/or biosafety policy; laws, regulations and guidelines; administrative systems; decision-making systems; and mechanisms for public engagement. To assist Member States to implement functional regulatory frameworks for both agriculture and health applications, the NEPAD Agency established the African Biosafety Network of Expertise (ABNE) and the African Medicines Regulatory Harmonization (AMRH).Currently, transgenic insects and GM crops are regulated by Competent National Authorities whose mandate derives from national biosafety laws. For GM crops, a lot of research has been conducted up to the confined field trial (CFT) and multi-location trials stages in a number of African countries. Burkina Faso has fully functional containment facilities for transgenic mosquitoes while Mali and Uganda are developing theirs. The Burkina Faso regulatory agency has granted permits and has already received sets of sterile mosquito eggs for trials in the contained facility. It is instructive to note that both ABNE and AMRH have worked with national and regional regulatory bodies in Africa to enhance their technical capacities for informed decision making, adoption of best practices, and compliance with international standards. It is against the backdrop of a rich blend of on-the-ground knowledge, experience, expertise, and insight into the context and political sensitivities of member states that the NEPAD Agency seeks to expand existing support. This would include capacity strengthening in the regulation of emerging technologies, such as the application of gene drives in the development of transgenic mosquito for the control of malaria transmission.

Cassava is an important food security crop in the developing world, as it is adapted to a wide range of climatic conditions including marginal semiarid agro-ecologies. Cassava is a starchy staple and the storage roots of commercial cassava cultivar are very low in protein content (0.5-2%, dry weight basis). A diet predominantly based on cassava, as is the case in several sub-Saharan countries, could lead to malnutrition, especially in young children over time. A wild progenitor of cassava, Manihot esculenta ssp. flabellifolia have been found to have high root protein content, up to 18% (dry weight basis) and is excellent source of genetic variability for this important trait. Accessions of M. esculenta ssp. flabellifolia with high storage root protein content were crossed with commercial cassava cultivars. High content of storage root protein ranged from 2.87 to 11.25% could be recovered in the F 1 progenies. The F 1 families had an average dry matter content of 29.6%. These F 1 interspecific hybrids would be an entry point for improvement of cassava storage root protein content. A brief discussion of the strategy to be followed is presented.

The most widespread disease of economic importance of cassava is caused by whitefly vector, both as a single strain or combination of strains. A B 1 P 2 family was generated from the crosses of an inter-specific F 1 hybrid (CW 198-11) as a female parent with a commercial cassava cultivar (MTAI-8) as male parent at CIAT headquarters and evaluated in a high-pressure zone for whiteflies in Colombia. 227 genotypes were scored using a scale ranging from 1 (no leaf damage) to 6 (considerable leaf necrosis and defoliation, sooty mould on mid and lower leaves and young stems). The rest were considered promising. The most promising resistance was for damage ratings below 2 for 17.8% of the genotypes. The availability of the pest resistance genotypes, will serve as a means to combat the problem of CMD in Africa provided that resistance to A. socialis is also effective against B. tabaci with different virus strains that is capable of been introduced.

A new set of breeding techniques, referred to as New Breeding Techniques developed in the last two decades have potential for enhancing improved productivity in crop and animal breeding globally. These include site directed nucleases based genomic editing procedures-CRISPR and Cas associated proteins, Zinc Finger Nucleases, Meganucleases/Homing Endonucleases and Transcription- Activator Like-Effector Nucleases for genome editing and other technologies including- Oligonucleotide-Directed Mutagenesis, Cisgenesis and intragenesis, RNA-Dependent DNA methylation; Transgrafting, Agroinfiltration, Reverse breeding. There are ongoing global debates on whether the processes of and products emerging from these technologies should be regulated as genetically modified organisms or approved as conventional products. Decisions on whether to regulate as GMOs are based both on understanding of the molecular basis of their development and if the GMO intermediate step was used. For example- cisgenesis, can be developed using Agrobacterium tumefaciens methods of transformation, a process used by GMO but if the selection is properly conducted the intermediate GMO elements will be eliminated and the final product will be identical to the conventionally developed crops. Others like Site Directed Nuclease 3 are regulated as GMOs in countries such as United State of America, Canada, European Union, Argentina, Australia. Progress in genome editing research, testing of genome edited bacterial blight resistant rice, development of Guidelines for regulating new breeding techniques or genome editing in Africa is also covered with special reference to South Africa, Kenya and Nigeria. Science- and evidence-based approach to regulation of new breeding techniques among regulators and policy makers should be strongly supported.

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