Genetic variability of bioactive compounds and selection for nutraceutical quality in kola [Cola nitida (Vent) Schott. and Endl.]

Heterosis patterns and sources of self-compatibility, cross-compatibility and key nut traits within single and double hybrid crosses of kola [Cola nitida (Vent) Schott and Endl.]

Sexual incompatibility among kola genotypes accounted for over 50% yield loss. Compatible and high yielding varieties are in demand to develop commercial orchards. The objective of this study was to assess self-compatibility and cross-compatibility of kola (C. nitida) genotypes within self, single and double hybrid crosses and to determine heterosis pattern in the resulting hybrids for sexual compatibility and key nut yield and quality traits. Crosses among kola genotypes from three field gene banks (JX1, GX1, MX2) and one advanced germplasm (Bunso progeny) in Ghana were evaluated along their parents for sexual compatibility, nut yield and nut quality. Data were collected on pod set, pseudo-pod set, pod weight, number of nuts per pod, nut weight, brix, potential alcohol and nut firmness. Significant (P < 0.001) differential pod set was observed within Bunso progeny, JX1, GX1 and MX2 crosses; while pseudo-pod set differed only within JX1 and MX2 crosses (P < 0.001). Very large prevalence of mid-parent, heterobeltiosis, and economic heterosis was observed for sexual compatibility, outturn and brix for the single and double hybrid crosses. Heterosis was prominent among the double hybrid crosses as compared to the single hybrid crosses suggesting that recurrent selection of compatible varieties from advanced generations could result in genetic gain in kola improvement. The top five crosses with best heterosis for sexual compatibility and an appreciable positive heterosis for outturn and brix were B1/11 × B1/71 × B1/157 × B1/149, B1/11 × B1/71 × B1/296 × B1/177, GX1/46 × GX1/33 × B1/212 × B1/236, JX1/90 × JX1/51 and JX1/51 × JX1/36. These materials could serve as sources of beneficial alleles for improving Ghanaian kola hybrids and populations for yield and sexual compatibility.

Hibiscus sabdariffa: Genetic variability, seasonality and their impact on nutritional and antioxidant properties

This study consisted of the physicochemical, phytochemical and antioxidant characterisation of two varieties of Hibiscus sabdariffa, to evaluate the influence of genetic and environmental factors on these parameters leading to an objective and rigorous classification of our extracts. To this end, calyxes and seeds of the red and white phenotypes were collected in Bobo-Dioulasso, Dano and Nouna respectively in December 2019 and 2020. Principal component analysis showed that physico-chemical and biochemical parameters could potentially be used to discriminate varieties. The calyxes of the sabdariffa variety showed the best physicochemical profile (total phenolics, flavonoids, ascorbic acid), pigments (anthocyanins, chlorophyll) and antioxidant activity (free radical scavenging and SOD activity) while the seeds showed the best carbohydrate, lipid and peroxidation inhibition content. In view of these results, the red phenotype has an interesting nutritional and therapeutic potential. It could therefore be interesting candidate in the pharmaceutical and food industries.

The Future of Food: Domestication and Commercialization of Indigenous Food Crops in Africa over the Third Decade (2012–2021)

This paper follows the transition from ethnobotany to a deeper scientific understanding of the food and medicinal properties of African agroforestry tree products as inputs into the start of domestication activities. It progresses on to the integration of these indigenous trees as new crops within diversified farming systems for multiple social, economic and environmental benefits. From its advent in the 1990s, the domestication of indigenous food and non-food tree species has become a global programme with a strong African focus. This review of progress in the third decade is restricted to progress in Africa, where multi-disciplinary research on over 59 species has been reported in 759 research papers in 318 science publications by scientists from over 833 research teams in 70 countries around the world (532 in Africa). The review spans 23 research topics presenting the recent research literature for tree species of high priority across the continent, as well as that in each of the four main ecological regions: the humid zone of West and Central Africa; the Sahel and North Africa; the East African highlands and drylands; and the woody savannas of Southern Africa. The main areas of growth have been the nutritional/medicinal value of non-timber forest products; the evaluation of the state of natural resources and their importance to local people; and the characterization of useful traits. However, the testing of putative cultivars; the implementation of participatory principles; the protection of traditional knowledge and intellectual property rights; and the selection of elite trees and ideotypes remain under-researched. To the probable detriment of the upscaling and impact in tropical agriculture, there has been, at the international level, a move away from decentralized, community-based tree domestication towards a laboratory-based, centralized approach. However, the rapid uptake of research by university departments and national agricultural research centres in Africa indicates a recognition of the importance of the indigenous crops for both the livelihoods of rural communities and the revitalization and enhanced outputs from agriculture in Africa, especially in West Africa. Thus, on a continental scale, there has been an uptake of research with policy relevance for the integration of indigenous trees in agroecosystems and their importance for the attainment of the UN Sustainable Development Goals. To progress this in the fourth decade, there will need to be a dedicated Centre in Africa to test and develop cultivars of indigenous crops. Finally, this review underpins a holistic approach to mitigating climate change, as well as other big global issues such as hunger, poverty and loss of wildlife habitat by reaping the benefits, or ‘profits’, from investment in the five forms of Capital, described as ‘land maxing’. However, policy and decision makers are not yet recognizing the potential for holistic and transformational adoption of these new indigenous food crop opportunities for African agriculture. Is ‘political will’ the missing sixth capital for sustainable development?