Micropropagation of marula, Sclerocarya birrea subsp. caffra (Anarcadiaceae) by axillary bud proliferation and random amplified polymorphic DNA (RAPD) analysis of plantlets

The availability of a rapid vegetative amplification procedure of mass-selected superior trees greatly accelerates the development of a new tree species as a crop. This study outlined the protocol for in vitro propagation of marula nodal explants from marula seedlings. Surface sterilized explants were cultured on Murashige and Skoog media (MS) supplemented with 26 combinations of N6-benzyladenine (BA) and kinetin (KN). Shoots were elongated on MS media supplemented with low BA and KN or BA and Gibberellin A3 (GA3) concentrations. Elongated shoots were rooted on half strength MS media supplemented with indolebutyric acid (IBA) at differing concentrations. MS media supplemented with 4.8 µM BA and 2.4 ìM KN resulted in average 2.5 shoots per responding explant. Moderate shoot elongation was achieved on MS media supplemented with 1.2 µM BA plus 1.0 µM KN. Maximum rooting was observed on half- strength MS media supplemented with 10 µM IBA. Marula plants were acclimatized and established in soil in the growth room at an average micropropagation rate of 0.56 per responding nodal explant. The developed protocol has potential for routine micropropagation of elite Sclerocarya birrea subsp. caffra. Randomly amplified polymorphic DNA (RAPD) analysis scoring 1845 markers showed intraclonal genetic stability between explant parent and micropropagated plants.Key words: Anacardiaceae, axillary bud proliferation, marula, randomly amplified polymorphic DNA (RAPD), somaclonal variation

Enhancing access to genetic resources for climate change adaptation in Kenya, Uganda and Tanzania: Seed catalogues of best perfoming varieties of sorghum in Dodoma and Singida Tanzania

Climate change poses an increasing threat to food and nutrition security of resource-poor farmers globally. In Tanzania, homogenization of agriculture to single crops or varieties coupled with the associated loss of biodiversity has further decreased the resilience of resource-poor farmers. The loss of genetic diversity in farmers’ custody has greatly narrowed the gene pool from which they depend on. In order to help them adapt to climate change, the project “Promoting Open Source Seed Systems for Beans, Millet and Sorghum for Climate Change Adaptation” funded by the Benefit-sharing Fund (BSF) of the International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA) was implemented in Kenya, Uganda and Tanzania. Through this project, farmers in Dodoma and Singida in Tanzania tested and evaluated the performance of 24 varieties of sorghum for drought tolerance, yield, early maturity, pest and diseases and taste and selected 10 best performing. This catalogue presents these top selected varieties including their agronomic attributes and nutritional benefits

Social Seed Networks and Climate Change Adaptation in Central Tanzania: Results from a study to better understand farmers’ primary sources of seed information in Dodoma and Singida Districts, Tanzania

Tanzanian smallholder farmers are vulnerable to the effects of climate change, especially the resultant rainfall variability. One strategy for adapting to the changing climate is to utilise genetic seed sources to resist abiotic and biotic stressors. Another strategy is to access and exchange genetic resources, seed, and the information needed to use those resources effectively. In Tanzania, ‘farmer managed’ seed networks are believed to supply about 80-90 percent of seeds to farmers (Below et al., 2015). Farmer seed networks are an important element of seed access because they are resilient and work to maintain and conserve crop genetic diversity. Research in East Africa has suggested that community-generated information sharing might support more effective farmer response to the changing seasonal and weather patterns associated with climate change (Balama et al., 2013)

The role of gender and institutional dynamics in adapting seed systems to climate change: case studies from Kenya, Tanzania and Uganda

We explore how seed systems enhance access to seeds, and information for climate-change adaptation in farming communities in Kenya, Tanzania and Uganda, as well as how gender-driven roles and institutional dynamics influence the process. Men and women farmers equally experience climate-change related effects, including drought, short rainy seasons and increased pest and disease incidence. Our study relies on exploratory data analysis of 1001 households surveyed in four sites in 2016. Farmers surveyed preferred early-maturing, heat-tolerant, high-yielding, and pest- and disease-resistant varieties, all important climate-adaptive traits. Seed systems of the focus crops studied are largely informal—overall, 68% women and 62% men use their own seed, indicating women’s higher reliance on ‘informal’ seed and information sources. Only 21% of respondents reported interacting with seed experts who are affiliated with formal organizations. Both formal and informal organizations play a key role in providing access to climate-adapted seed/information, with access for men and women varying across the countries studied. There is a need to support further development of those connections, building on existing social networks. We conclude that inclusive and gender-responsive context- and country-specific seed interventions will ensure equitable outcomes, increase women’s empowerment and strengthen both formal and informal seed systems for more effective climate-change adaptation

FIRST EXPERIENCES WITH A NOVEL FARMER CITIZEN SCIENCE APPROACH: CROWDSOURCING PARTICIPATORY VARIETY SELECTION THROUGH ON-FARM TRIADIC COMPARISONS OF TECHNOLOGIES (TRICOT)

SUMMARYRapid climatic and socio-economic changes challenge current agricultural R&D capacity. The necessary quantum leap in knowledge generation should build on the innovation capacity of farmers themselves. A novel citizen science methodology, triadic comparisons of technologies or tricot, was implemented in pilot studies in India, East Africa, and Central America. The methodology involves distributing a pool of agricultural technologies in different combinations of three to individual farmers who observe these technologies under farm conditions and compare their performance. Since the combinations of three technologies overlap, statistical methods can piece together the overall performance ranking of the complete pool of technologies. The tricot approach affords wide scaling, as the distribution of trial packages and instruction sessions is relatively easy to execute, farmers do not need to be organized in collaborative groups, and feedback is easy to collect, even by phone. The tricot approach provides interpretable, meaningful results and was widely accepted by farmers. The methodology underwent improvement in data input formats. A number of methodological issues remain: integrating environmental analysis, capturing gender-specific differences, stimulating farmers' motivation, and supporting implementation with an integrated digital platform. Future studies should apply the tricot approach to a wider range of technologies, quantify its potential contribution to climate adaptation, and embed the approach in appropriate institutions and business models, empowering participants and democratizing science

Mobilizing crop diversity for climate change adaptation and resilience: Field experiences from Africa

In recent years, a number of international initiatives have piloted various forms of support for novel configurations of actors to work together to conserve and use agrobiodiversity in sustainable agricultural production systems and to equitably share benefits derived from those activities. These configurations operate at farm, community, national and international levels. Among these initiatives, Bioversity International (now the Alliance of Bioversity International and CIAT) and partners have researched the effectiveness of using agrobiodiversity, in particular in the form of crop and crop variety diversity, as an adaptive practice. The hypothesis informing this research is that crop diversification can result in positive livelihood outcomes, such as food and nutritional security, income generation and good health. These outcomes, in turn, could lead to (increased) resilience of rural households and communities to environmental, socio- economic and climatic shocks. In this working paper, we present a number of case studies that to a certain extent have “delivered” on this impact pathway. The case studies were compiled during the year 2020, the year that COVID-19 spread across the globe with devastating consequences for countries, communities and households everywhere

Crop diversity, climate change adaptation and resilience: good practice cases from Africa

As part of the Integrated Seed Sector Development in Africa (ISSD Africa) program’s activities for 2020, the Agrobiodiversity, seeds and climate change action learning group (Theme 3) documented and analyzed a series of good crop diversification practice cases from Africa, which were published in an ISSD Africa working paper [https:// hdl.handle.net/10568/115012]. This brief presents a synthesis of the working paper

Environmental effects on pollen performance:potential consequences on gene flow

This thesis illustrates the effects of environmental factors on pollen performance and its importance on gene flow. Pollen competitive ability between the wild and cultivated species of four genera belonging to Cucurbitaceae family was compared to evaluate the evolutionary potential for selection on pollen tube growth rate. A possibility of hybrids formation between these species was also determined through hand pollination. Effects of herbivory and nutrients on pollen performance and female selection were determined in Cucumis sativus and N. alata. In addition, a study on flower colour inheritance on Nicotiana alata was carried out with the aim of obtaining a possible genetic marker for future gene flow studies. Hybrids between wild and cultivated species were formed in some species of Cucurbitaceae indicating a higher possibility of gene flow. Differences in individual variations on pollen tube growth rate within and between species suggest that there is an evolutionary potential for selection on this trait. Herbivory and nutrient factors were found to have effects on pollen performance on Cucumis sativus and N. alata. The interaction of the two factors was also found to be significant. Nutrient was found to influence herbivory effect on pollen performance. Effects of genotype-by-environment interaction in cultivars of the studied species were observed. The study on the flower colour inheritance suggested that in some cultivars of N. alata, flower colour could be used as a morphological marker on gene flow studies. Because pollen performance influences gene flow, an understanding of the factors affecting pollen performance is fundamental when conducting risk assessment studies. Since plants function the same way whether they are the result of natural selection, human selection, or gene modified, findings from cultivated plants or wild relatives will aid in assessing the environmental effects of all future introductions of GM crops

Development of a practical framework for sustainable surveillance and control of ticks and tick-borne diseases in Africa

A workshop on ticks and tick-borne diseases (T&TBDs) was held on June 25 and 26, 2019, at the Tropical Pesticides Research Institute, Division of Livestock and Human Diseases Vector Control, Arusha, Tanzania. The objectives of the workshop were to discuss the current situation and to formulate actionable strategies to improve surveillance and control of T&TBDs in Africa. The workshop was funded by the National Research Foundation and the Cape Peninsula University of Technology and attended by livestock health providers, farmers, and researchers from East, West, and Southern African countries. During the workshop, experts presented recent surveillance data focused on T&TBDs; participants discussed research opportunities and community engagement. The primary outcome of the workshop was the creation of a new research consortium known as The African Consortium for T&TBDs. The consortium is intended to function as a community for researchers, students, farmers, policymakers, extension workers, and community members who are interested in the advancement of T&TBD control. The consortium will engage in research activities that focus on comprehensive surveillance of T&TBDs, developing tick acaricide resistance, alternative tick control programs, and policy development and education. These areas were identified as top priorities to be developed to improve T&TBD control on the continent

FIRST EXPERIENCES WITH A NOVEL FARMER CITIZEN SCIENCE APPROACH: CROWDSOURCING PARTICIPATORY VARIETY SELECTION THROUGH ON-FARM TRIADIC COMPARISONS OF TECHNOLOGIES (TRICOT)

SUMMARYRapid climatic and socio-economic changes challenge current agricultural R&D capacity. The necessary quantum leap in knowledge generation should build on the innovation capacity of farmers themselves. A novel citizen science methodology, triadic comparisons of technologies or tricot, was implemented in pilot studies in India, East Africa, and Central America. The methodology involves distributing a pool of agricultural technologies in different combinations of three to individual farmers who observe these technologies under farm conditions and compare their performance. Since the combinations of three technologies overlap, statistical methods can piece together the overall performance ranking of the complete pool of technologies. The tricot approach affords wide scaling, as the distribution of trial packages and instruction sessions is relatively easy to execute, farmers do not need to be organized in collaborative groups, and feedback is easy to collect, even by phone. The tricot approach provides interpretable, meaningful results and was widely accepted by farmers. The methodology underwent improvement in data input formats. A number of methodological issues remain: integrating environmental analysis, capturing gender-specific differences, stimulating farmers' motivation, and supporting implementation with an integrated digital platform. Future studies should apply the tricot approach to a wider range of technologies, quantify its potential contribution to climate adaptation, and embed the approach in appropriate institutions and business models, empowering participants and democratizing science