Transferability, development of simple sequence repeat (SSR) markers and application to the analysis of genetic diversity and population structure of the African fan palm (Borassus aethiopum Mart.) in Benin

Background

In Sub-Saharan Africa, Borassus aethiopum Mart. (African fan palm) is an important non-timber forest product-providing palm that faces multiple anthropogenic threats to its genetic diversity. However, this species is so far under-studied, which prevents its sustainable development as a resource. The present work is a first attempt at characterizing the genetic diversity and population structure of B. aethiopum across nine collection sites spanning the three climatic regions of Benin, West Africa, through the use of microsatellite markers.

Results

During a first phase we relied on the reported transferability of primers developed in other palm species. We find that, in disagreement with previously published results, only 22.5% of the markers tested enable amplification of B. aethiopum DNA and polymorphism detection is very low.

In a second phase, we generated a B. aethiopum-specific genomic dataset through high-throughput sequencing and used it for the de novo detection of microsatellite loci. Among the primer pairs targeting these, 11 detected polymorphisms and were further used for analyzing genetic diversity. Across the nine sites, expected heterozygosity (He) ranges from 0.263 to 0.451 with an overall average of 0.354, showing a low genetic diversity. Analysis of molecular variance (AMOVA) shows that within-site variation accounts for 53% of the genetic variation. Accordingly, the low number of migrants and positive values of the fixation index (F) in sites from both the Central (Sudano-Guinean) and the Southern (Guinean) climatic regions suggest limited gene flow between sites. The global correlation between genetic and geographic distances is weak; however, our clustering analyses indicate that B. aethiopum palms from Savè (Center) are genetically more similar to those from the North than to samples from other Central sites.

Conclusions

In the light of our results, we discuss the use of inter-species transfer vs. de novo development of microsatellite markers in genetic diversity analyses targeting under-studied species, and suggest future applications for our molecular resources. We propose that, while prominent short-range pollen and seed dispersal in Benin explain most of our results, gene flux between the Central and Northern regions, as a result of animal and/or human migrations, might underlie the Savè discrepancy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12863-020-00955-y.

MooSciTIC: Training of trainers in West African research and higher education

The MooSciTIC project is a capacity-building initiative targeting West African research scientists and higher education teachers. The project aimed to improve the self-reliance of researchers and upgrade research practices by providing on-site summer schools on trans-disciplinary topics such as scientific writing, communication, and integrity. Here, we explain how this program was designed and implemented and share the positive responses from our trainees, hoping to inspire similar initiatives.

This Community Page article describes the MooSciTIC project, which aims to allow West African scientists to improve their skills in scientific writing, communication and ethics, while fostering new collaboration opportunities.

Knowledge, Attitudes, and Hygienic Practices of Boiled Hypocotyls (Borassus aethiopum Mart) Vended in the Streets of Cotonou City and Its Outskirts, Benin

In Benin, the boiled hypocotyl (Borassus aethiopum Mart) is one of the most common street foods consumed for its therapeutic properties. However, the knowledge, attitudes, and practices of boiled hypocotyl food sellers are poorly known despite the high contamination potential of these street foods. This study aimed to determine the knowledge, attitudes, and practices of boiled hypocotyls food vendors in the streets of Cotonou and its outskirts. The approach used concerned the process of good hygiene and production. Face-to-face interviews of 300 hypocotyls vendors and producers from Cotonou, Sèmè, Ouidah, and Abomey-Calavi were conducted. Concurrently, 200 samples of boiled hypocotyl were collected among study vendors. Results showed that all of the interviewed population (100%) of this activity are women. They are generally illiterate and 75% of them have never been to school. Additionally, 76.7% of street boiled hypocotyls sellers interviewed were mobile. The microbial profile of the boiled hypocotyls showed the lack of control and poor understanding of hygiene rules. The processes management also revealed two diagrams processes. The conditions in which hypocotyls vendors operate are largely unacceptable from a food safety point of view and an effort should be made to provide them with adequate infrastructure including potable water. In view of the socioeconomic impact of hypocotyl activities in Benin and their role in the unexpected arrival of food-borne diseases, vendors should be regularly trained in order to prevent outbreaks of food-borne illnesses.

NUTRITIONAL VALUE AND PHYSICOCHEMICAL COMPOSITION OF PEARL MILLET (PENNISETUM GLAUCUM) PRODUCED IN BENIN

The high prices of animal foods and limited income earned in developing countries have resulted in their dependency on cereal-based preparations as staple food. Cereals such as maize, sorghum or pearl millet are often used in the production of various traditional foods and beverages in many African countries including Benin. In the republic of Benin, the nutritive value of cereals such as maize and sorghum is well documented. However, the nutritional value of pearl millet varieties produced in Benin remains to be investigated. The aim of this study was to assess the nutritional value of 22 varieties of pearl millet produced in Benin. After samples collection, the pearl millet grains were milled into fine powder and their compositions in six minerals (Na+, K+, Ca2+, Mg2+, Fe2+, Zn2+) and proximate (ash, dry matter, starch, protein, total and reducing sugars) were determined using standard analytical AOAC methods. Next, we assessed the relationship between these variables using the Pearson Correlation Analysis (PCA). We found that protein, total and reducing sugars levels varied widely (ranged from 1.86 to 93.4 mg/g, 178.64 to 652.54 mg/g and 16.62 to 174.22 mg/g, respectively). Additionally, we found a highly significant correlation (P