Development of Methods for Improving Flowering and Seed Set of Diverse Germplasm in Cassava Breeding.

Cassava breeding faces obstacles due to late flowering and poor flower and seed set. The acceleration of breeding processes and the reduction in each cycle's duration hinge upon efficiently conducting crosses to yield ample progeny for subsequent cycles. Our primary objective was to identify methods that provide tools for cassava breeding programs, enabling them to consistently and rapidly generate offspring from a wide array of genotypes. In greenhouse trials, we examined the effects of the anti-ethylene silver thiosulfate (STS) and the cytokinin benzyladenine (BA). STS, administered via petiole infusion, and BA, applied as an apical spray, combined with the pruning of young branches, significantly augmented the number of flowers. Controls produced no flowers, whereas treatments with pruning plus either BA or STS alone produced an average maximum of 86 flowers per plant, and the combination of pruning, BA and STS yielded 168 flowers per plant. While STS had its primary effect on flower numbers, BA increased the fraction of female flowers from less than 20% to ≥87%, thus increasing the number of progeny from desired parents. Through field studies, we devised an optimal protocol that maintained acceptable levels of phytodamage ratings while substantially increasing seed production per plant compared to untreated plants. This protocol involves adjusting the dosage and timing of treatments to accommodate genotypic variations. As a result, cassava breeding programs can effectively leverage a diverse range of germplasm to develop cultivars with the desired traits.

Genetic and environmental effects on processing productivity and food product yield: drudgery of women's work.

BACKGROUND: Cassava processing is a crucial source of livelihood for rural farmers and processors in Nigeria and Cameroon. This study investigated the varietal effect on the processing productivity of women farmer processors within their working environment and compared this with the food product quality as evaluated by the processors and the field yield. Field trials were established in Nigeria (Benue and Osun state) and Cameroon (Littoral region). Eight cassava genotypes were evaluated. These eight varieties included newly bred genotypes, commercial checks and varieties provided and preferred by the processors. The roots of these genotypes were harvested and processed into gari and eba by processors. The time of each processing step was recorded. Processors assessed the quality of the roots and food products using pairwise ranking. RESULTS: In the field trials in Cameroon and Nigeria (Benue state), the newly bred genotypes showed superior performance in terms of dry matter content and fresh and dry yield. During processing, genotypes showed significant variation for most assessed parameters in both countries. Some newly bred varieties exhibited lower productivity that can make them more prone to drudgery than the local commercial checks and the varieties provided and preferred by the processors. Newly bred varieties were mostly ranked higher or equal to processors' preferred varieties concerning fresh root and food product quality. In the Cameroon location there were significant varietal differences in processing productivity and drudgery index which suggest that the particular processing methods there - such as pressing methods and fermentation time - cause these varietal differences to matter more. CONCLUSIONS: The varieties that were tested were observed to differ in yield, product quality, processing productivity, and potential drudgery levels. Some breeders' germplasms displayed a combination of increased yields and good product quality and good processor productivity. Those varieties that showed low processor productivity should be avoided during selection to avoid increased labour burden and associated drudgery of women processors. Further research is recommended to enhance food product color, latent culinary qualities, and processing productivity of newly bred varieties to improve acceptability and reduce processing drudgery for women. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Genetic characterization of cassava (Manihot esculenta Crantz) genotypes using agro-morphological and single nucleotide polymorphism markers.

Dearth of information on extent of genetic variability in cassava limits the genetic improvement of cassava genotypes in Sierra Leone. The aim of this study was to assess the genetic diversity and relationships within 102 cassava genotypes using agro-morphological and single nucleotide polymorphism markers. Morphological classification based on qualitative traits categorized the germplasm into five different groups, whereas the quantitative trait set had four groups. The SNP markers classified the germplasm into three main cluster groups. A total of seven principal components (PCs) in the qualitative and four PCs in the quantitative trait sets accounted for 79.03% and 72.30% of the total genetic variation, respectively. Significant and positive correlations were observed between average yield per plant and harvest index (r = 0.76***), number of storage roots per plant and harvest index (r = 0.33*), height at first branching and harvest index (0.26*), number of storage roots per plant and average yield per plant (r = 0.58*), height at first branching and average yield per plant (r = 0.24*), length of leaf lobe and petiole length (r = 0.38*), number of leaf lobe and petiole length (r = 0.31*), width of leaf lobe and length of leaf lobe (r = 0.36*), number of leaf lobe and length of leaf lobe (r = 0.43*), starch content and dry matter content (r = 0.99***), number of leaf lobe and root dry matter (r = 0.30*), number of leaf lobe and starch content (r = 0.28*), and height at first branching and plant height (r = 0.45**). Findings are useful for conservation, management, short term recommendation for release and genetic improvement of the crop.

Gender-based constraints affecting biofortified cassava production, processing and marketing among men and women adopters in Oyo and Benue States, Nigeria.

This study identified gender-based constraints affecting the production, processing and marketing of biofortified cassava in two states in Nigeria, using a mixed methods approach. The study identified major differences between the two study sites (Benue and Oyo). The scale of production of biofortified cassava is higher in Oyo state among adult men because of their active involvement and collaboration with research institutes within the state and the ease of transporting products to Lagos State for designated diverse markets. However, in Benue state more adult and young women are engaged in cultivation, processing and marketing business to meet up with the increased demand due to higher consumer acceptance in this region. Gender analysis revealed that lack of access to hired-labour restricted the scale of production among women in especially Oyo state. Low product price and high price of processing equipment, poor market infrastructure and middle men exploitation were constraints significantly more mentioned by women in general. Majorly, the men identified limited processing facilities/equipment as the most important constraint affecting the demand of biofortified cassava roots, while generally women were more constrained by the shortage of basic amenities and trainings that hindered their processing efficiency. The study proposes integration of gender-responsive strategies to further enhance the delivery of biofortified cassava products in Nigeria.