From traits to typologies: Piloting new approaches to profiling trait preferences along the cassava value chain in Nigeria

Breeding programs are increasing efforts towards demand-led breeding approaches to ensure that cultivars released meet the needs of end users including processors, traders, and consumers, and that they are adopted by farmers. To effectively deploy these approaches, new tools are required to better understand and quantify the degree of preference differences among alternative trait changes competing for measurement and selection effort. The purpose of this study was to present a method of quantifying preferences and developing typologies according to breeding priorities by applying an online trait preference survey approach to cassava (Manihot esculenta Crantz). This paper presents a conjoint analysis based on Potentially All Pairwise RanKings of all possible Alternatives (PAPRIKA) to help guide breeding programs in understanding trait preferences across value chain roles and social contexts and set breeding priorities that represent diverse interests. Trait preferences were assessed using a comprehensive survey and analysis package incorporating a core adaptive conjoint method (1000minds, 2020). Trait selection was based on a trade-off of 11 cassava traits carried out with 792 cassava value chain actors in four geopolitical regions in Nigeria. Principal component and cluster analyses revealed three clusters (typologies) of respondents according to their trait preferences. The results demonstrate the usefulness of this methodology that innovates on previous trait preference approaches to address the expanding needs of plant breeding programs within smallholder contexts. © 2021 The Authors. Crop Science © 2021 Crop Science Society of Americ

Understanding cassava varietal preferences through pairwise ranking of gari-eba and fufu prepared by local farmer-processors

Within communities in Osun and Imo States of Nigeria, farmer‐processors grew and processed a diverse set of improved and landrace cassava varieties into the locally popular foods, gari, eba and fufu. Local and 15 main varieties were grown in a 'mother and baby trials' design in each state. Mother trials with three replications were processed by farmer‐processors renown in their community for their processing skills. Baby trials were managed and processed by other farmer‐processors. The objective was to identify food quality criteria to inform demand‐led breeding to benefit users, especially women, given their key roles in processing. Farmer‐processors evaluated the overall quality of fresh roots and derived food products through pairwise comparisons. Improved varieties had higher fresh and dry root yield. Overall, landraces ranked first for quality of gari and eba, but several improved varieties were also appreciated for good quality. Landraces in Osun had higher gari yield and a higher swelling power compared to improved varieties. Colour (browning), bulk density, swelling power, solubility and water absorption capacity were the criteria most related to food product ranking by farmer‐processors. Evaluation of varieties under farmer‐processors' conditions is crucial for providing guidance to breeders on critical selection criteria

Drivers of consumer acceptability of cassava gari-eba food products across cultural and environmental settings using the Triadic Comparison of Technologies approach (tricot)

BACKGROUND: Nigeria and Cameroon are multi-ethnic countries with diverse preferences for food characteristics. The present study aimed to inform cassava breeders on consumer-prioritized eba quality traits. Consumer testing was carried out using the triadic compar ison of technologies (tricot). Diverse consumers in villages, towns and cities evaluated the overall acceptability of eba made from differ ent cassava genotypes. Data from both countries were combined and linked to laboratory analyses of eba and the gari used to make it. RESULTS: There is a strong preference for eba with higher cohesiveness and eba from gari with higher brightness and especially in Cameroon, with lower redness and yellowness. Relatively higher eba hardness and springiness values are preferred in the Nigerian locations, whereas lower values are preferred in Cameroon. Trends for solubility and swelling power of the gari differ between the two countries. The study also reveals that the older improved cassava genotype TMS30572 is a benchmark geno type with superior eba characteristics across different regions in Nigeria, whereas the recently released variety Game changer performs very well in Cameroon. In both locations, the recently released genotypes Obansanjo-2 and improved variety TM14F1278P0003 have good stability and overall acceptability for eba characteristics. CONCLUSION: The wide acceptance of a single genotype across diverse geographical and cultural conditions in Nigeria, as well as three acceptable new improved varieties in both locations, indicates that consumers' preferences are surprisingly homogeneous for eba. This would enhance breeding efforts to develop varieties with wider acceptability and expand potential target areas for released varieties

FR1.3: Coping with Stressors along the Cassava Value Chain in Nigeria: Evidence to Strengthen Gender-Responsive Breeding and Inform Resilience

This study investigates gender perspectives on climate change (CC) and conflict stressors surrounding the cassava value-chain (VC) in Nigeria. Research Question(s): A State of Knowledge review identified the need to inquire into coping strategies and the preferred stressor-related cassava traits by specifically asking, "In what ways do gender roles and norms influence these". Methodology: Data elicited from 187 cassava farmers, 15 Key Informants and 63 VC Focus Group participants were analysed using descriptive and inferential statistics. Key findings: The study validates CC as a key factor in increased conflicts. Farmer-herder clashes, communal clashes and land disputes exacerbate the emergence of farm burning, theft and influence the kind of cassava food product made. This shapes stressor-related trait preferences like ‘early re-emergence of leaves after grazing', ‘short stem', ‘ratooning potential', and ‘stem-longevity' among men and women farmers and ‘multi-purpose suitability of roots' among processors/marketers mainly women. Coping mechanisms include relocating farms, migration and fragmented farming among men, and choice of food with less processing steps, backyard farming, forcing daughter's premature marriage and dependence on remittances from husbands among women. Resilience capacity is generally low, but men have a higher overall resilience capacity (t = 5.45) and level of access to assets (t = 6.698) which facilitate coping strategies like ‘relocating farms', migration and ‘fragmented farming'. Relevance and Implication of findings: Results present gendered coping strategies, corresponding stressor-related traits, as additional aspects important when evaluating the gender impact of breeding strategies concerning the positive benefits for, and possible harm to cassava users and especially women engaged in the cassava VC activities

From cassava to gari: Mapping of quality characteristics and end-user preferences in Cameroon and Nigeria

User's preferences of cassava and cassava products along the value chain are supported by specific root quality characteristics that can be linked to root traits. Therefore, providing an evidence base of user preferred characteristics along the value chain, can help in the functional choice of cassava varieties. In this respect, the present paper presents the results from focus group discussions and individual interviews on user preferred quality characteristics of raw cassava roots and the derived product, gari, ‐ one of the major cassava products in Sub Saharan Africa ‐ in major production and consumption areas of Cameroon and Nigeria. Choice of cassava varieties for farming is mainly determined by the multiple end‐uses of the roots, their agricultural yield and the processing determinants of roots that support their major high‐quality characteristics: size, density, low water content, maturity, colour and safety. Processing of cassava roots into gari goes through different technological variants leading to a gari whose high‐quality characteristics are: dryness, colour, shiny/attractive appearance, uniform granules and taste. Eba, the major consumption form of gari in Cameroon and Nigeria is mainly characterized by its textural properties: smoothness, firmness, stickiness, elasticity, mouldability. Recommendations are made, suggesting that breeding will have to start evaluating cassava clones for brightness/shininess, as well as textural properties such as mouldability and elasticity of cassava food products, for the purpose of supporting decision‐making by breeders and the development of high‐throughput selection methods of cassava varieties. Women are identified as important beneficiaries of such initiatives giving their disadvantaged position and their prominent role in cassava processing and marketing of gari

Construction of a Quantitative Acetylomic Tissue Atlas in Rice (<i>Oryza sativa</i> L.)

PKA (protein lysine acetylation) is a key post-translational modification involved in the regulation of various biological processes in rice. So far, rice acetylome data is very limited due to the highly-dynamic pattern of protein expression and PKA modification. In this study, we performed a comprehensive quantitative acetylome profile on four typical rice tissues, i.e., the callus, root, leaf, and panicle, by using a mass spectrometry (MS)-based, label-free approach. The identification of 1536 acetylsites on 1454 acetylpeptides from 890 acetylproteins represented one of the largest acetylome datasets on rice. A total of 1445 peptides on 887 proteins were differentially acetylated, and are extensively involved in protein translation, chloroplast development, and photosynthesis, flowering and pollen fertility, and root meristem activity, indicating the important roles of PKA in rice tissue development and functions. The current study provides an overall view of the acetylation events in rice tissues, as well as clues to reveal the function of PKA proteins in physiologically-relevant tissues

Five Rice Seed-Specific NF-YC Genes Redundantly Regulate Grain Quality and Seed Germination via Interfering Gibberellin Pathway

NF-YCs are important transcription factors with diverse functions in the plant kingdoms including seed development. NF-YC8, 9, 10, 11 and 12 are close homologs with similar seed-specific expression patterns. Despite the fact that some of the NF-YCs are functionally known; their biological roles have not been systematically explored yet, given the potential functional redundancy. In this study, we generated pentuple mutant pnfyc of NF-YC8-12 and revealed their functions in the regulation of grain quality and seed germination. pnfyc grains displayed significantly more chalkiness with abnormal starch granule packaging. pnfyc seed germination and post-germination growth are much slower than the wild-type NIP, largely owing to the GA-deficiency as exogenous GA was able to fully recover the germination phenotype. The RNA-seq experiment identified a total of 469 differentially expressed genes, and several GA-, ABA- and grain quality control-related genes might be transcriptionally regulated by the five NF-YCs, as revealed by qRT-PCR analysis. The results demonstrated the redundant functions of NF-YC8-12 in regulating GA pathways that underpin rice grain quality and seed germination, and shed a novel light on the functions of the seed-specific NF-YCs