Genetic resources and breeding of maize for Striga resistance: a review

The potential yield of maize (Zea mays L.) and other major crops is curtailed by several biotic, abiotic, and socio-economic constraints. Parasitic weeds, Striga spp., are major constraints to cereal and legume crop production in sub-Saharan Africa (SSA). Yield losses reaching 100% are reported in maize under severe Striga infestation. Breeding for Striga resistance has been shown to be the most economical, feasible, and sustainable approach for resource-poor farmers and for being environmentally friendly. Knowledge of the genetic and genomic resources and components of Striga resistance is vital to guide genetic analysis and precision breeding of maize varieties with desirable product profiles under Striga infestation. This review aims to present the genetic and genomic resources, research progress, and opportunities in the genetic analysis of Striga resistance and yield components in maize for breeding. The paper outlines the vital genetic resources of maize for Striga resistance, including landraces, wild relatives, mutants, and synthetic varieties, followed by breeding technologies and genomic resources. Integrating conventional breeding, mutation breeding, and genomic-assisted breeding [i.e., marker-assisted selection, quantitative trait loci (QTL) analysis, next-generation sequencing, and genome editing] will enhance genetic gains in Striga resistance breeding programs. This review may guide new variety designs for Striga-resistance and desirable product profiles in maize.

Noncommunicable Diseases Prevention Policies and Their Implementation in Africa: A Systematic Review

Objectives: To synthesize the existing evidence on NCD policy equity, policy practices, and policy implementation gaps to prevent NCDs in African countries.

Methods: Following the PRISMA-Extension for equity-focused review guidelines, the authors systematically searched documentary evidence from seven databases (BMC, CINHAL Plus, Cochrane, Google Scholar, PubMed, Web of Science, and Scopus) to identify studies conducted and published on African countries between April 2013 and December 31, 2020.

Results: From identified 213 records, 21 studies were included in the final synthesis. Major results showed inadequate studies on NCD policy, unsatisfactory NCD-related policy development, poor policy implementation, lack of policy equity to combat NCDs, and lack of data recorded on NCDs’ prevalence, morbidity, and mortality.

Conclusion: The rigorous WHO-endorsed NCD policies and prevention strategies on the African continent might debar African policymakers and leaders from developing and implementing indigenous NCD-combating strategies. Continent-wide innovative and indigenous NCD-prevention policies and policy equity to effectively prevent, control, and manage NCDs must be developed by African scientists and policymakers.

Recent Progresses in the Multicomponent Synthesis of Dihydropyridines by Applying Sustainable Catalysts Under Green Conditions

The synthesis of dihydropyridines, valuable molecules with diverse therapeutic properties, using eco-friendly heterogeneous catalysts as a green alternative received significant consideration. By selecting appropriate precursors, these compounds can be readily modified to induce the desired properties in the target product. This review focused on synthesising diverse dihydropyridine derivatives in single-pot reactions using magnetic, silica, and zirconium-based heterogeneous catalytic systems. The monograph describes preparation techniques for various catalyst materials in detail. It covers facile and benign magnetic, silica, zirconium-based, and ionic liquid catalysts, exhibiting significant efficacy and consistently facilitating excellent yields in short reaction times and in a cost-effective way. Most of the designated protocols employ Hantzsch reactions involving substituted aldehydes, active methylene compounds, and ammonium acetate. These reactions presumably follow Knoevenagel condensation followed by Michael addition and intra-molecular cyclisation. The multicomponent one-pot protocols using green catalysts and solvents have admirably increased the product selectivity and yields while minimising the reaction time. These sustainable catalyst materials retain their viability for several cycles reducing the expenditure are eco-friendly.