Developing improvement strategies for management of the Sisrè berry plant [Synsepalum dulcificum (Schumach & Thonn.) Daniell] based on end-users’ preferences in Southern Nigeria

Synsepalum dulcificum is a valuable horticultural and lesser-known crop, famous for the uniqueness of its taste modifying properties, which is candidate for genetic improvement in West Africa. Semi-structured interviews were conducted with 100 respondents purposively selected to analyze the current production systems and constraints as well as to document the farmers’ and consumers’ preferences for breeding traits in Southern Nigeria. The results showed that none of the investigated farmers applied all required crop management practices to produce the species (land cleaning before establishment, pegging and lining, holing, base manure application, crop irrigation, weeding, pruning, fertilizers application, and pests and diseases control). Farmers were grouped into three clusters based on crop management practices. There was a strong and highly significant agreement among farmers (Kendall’s W = 0.8, p < 0.001) that bush fire, poor plant growth, drought, pests, and parasitic weed were the five most important constraints in Southwest Nigeria. In Southeast Nigeria, damage by insects and birds, poor seed germinability and poor knowledge of cultivation technics were the most important constraints challenging production. Farmers’ agreement around these constraints was moderate but highly significant (Kendall’s W = 0.6, p < 0.001). Overall, the top three desired breeding traits by farmers included: high growth rate, extended fruit shelf-life, and high fruits yield while the top three consumer’s preferences included: high miraculin potency (long lasting action of the miraculin), fruit glossiness, and high metabolites content. However, cultural specificities were detected in these preferences with a higher agreement in Yoruba farmers’ preferences compared with their counterparts Igbo. The Igbo consumers showed a higher concordance in their traits’ preferences than the Yoruba consumers. These findings pave the way for an informed cultivar development for the Sisrè berry plant in Nigeria and expand knowledge on end-users’ preferences for the species in West Africa

Exploring phenotypic variation of diverse bambara groundnut (Vigna subterranea L) origin and development of mini‐core collection for future breeding

Abstract Understanding the phenotypic variation and designing a mini‐core collection is an efficient method to accelerate the genetic gain of bambara groundnut. A collection of 300 bambara groundnut landraces from 25 different countries of origin sourced from gene banks were used to analyze phenotypic variability among the landraces and develop a mini‐core collection for future breeding. The landraces were evaluated in alpha lattice design with two replications for 2 years (2019 and 2020). The results showed highly significant differences (p < 0.001) among the bambara groundnut landraces for all the studied traits implying the selection of landraces with better agronomic traits could be achieved from the crop genetic pool. In addition, landrace x year interactions were significant for studied traits, except for shelling percentage and number of seeds per pod. The genotypic coefficient of variation values were high for most yield component traits, with the highest (65.39%) value obtained on seed dry weight. Furthermore, high heritability in conjunction with high genetic advance obtained in seed dry weight, pod dry weight, petiole length and plant height implies that these traits are majorly controlled by additive genetic action and could be improved through selection. Highly significant and positive correlations of yield were found with seed dry weight, pod dry weight, number of pod per plant, number of leaves, petiole length and plant height. A mini‐core collection of 60 landraces (20%) was developed that represents the entire collection using Core Hunter algorithm. In general, the study provides insight into bambara groundnut germplasm that would enhance cultivar development and sustains the utilization of the crop. In addition, the mini‐core collection established in the present study could be exploited for future bambara groundnut improvement efforts

Role of Non-Structural Sugar Metabolism in Regulating Tuber Dormancy in White Yam (<i>Dioscorea rotundata</i>)

Changes in sugar composition occur continuously in plant tissues at different developmental stages. Tuber dormancy induction, stability, and breaking are very critical developmental transitions in yam crop production. Prolonged tuber dormancy after physiological maturity has constituted a great challenge in yam genetic improvement and productivity. In the present study, biochemical profiling of non-structural sugar in yam tubers during dormancy was performed to determine the role of non-structural sugar in yam tuber dormancy regulation. Two genotypes of the white yam species, one local genotype (Obiaoturugo) and one improved genotype (TDr1100873), were used for this study. Tubers were sampled at 42, 56, 87, 101, 115, and 143 days after physiological maturity (DAPM). Obiaoturugo exhibited a short dormant phenotype and sprouted at 101-DAPM, whereas TDr1100873 exhibited a long dormant phenotype and sprouted at 143-DAPM. Significant metabolic changes were observed in non-structural sugar parameters, dry matter, and moisture content in Obiaoturugo from 56-DAPM, whereas in TDr1100873, significant metabolic changes were observed from 101-DAPM. It was observed that the onset of these metabolic changes occurred at a point when the tubers of both genotypes exhibited a dry matter content of 60%, indicating that a dry matter content of 60% might be a critical threshold for white yam tuber sprouting. Non-reducing sugars increased by 9–10-fold during sprouting in both genotypes, which indicates their key role in tuber dormancy regulation in white yam. This result implicates that some key sugar metabolites can be targeted for dormancy manipulation of the yam crop

Towards conservation and sustainable use of an indigenous crop: A large partnership network enabled the genetic diversity assessment of 1539 fonio (Digitaria exilis) accessions

International audienceThe use of neglected and underutilized species (NUS) in agrosystems is a potential solution to the challenges arising from global change. These species could contribute to the equitable diversification of agricultural systems. Providing knowledge on their genetic diversity and fostering access to data and results is essential for the development of strong collaborative future research. The study addressed these issues by assessing the diversity of the largest fonio (Digitaria exilis) collection existing to date. Associated with a user-friendly Shiny application (https://shinyapps.southgreen.fr/ app/foniodiv), our results reinforce research efficiency and broaden the prospects for all actors involved in enhancing fonio and indigenous crops as valuable resources for the future