R. Vodouhè

Diversity of the Neglected and Underutilized Crop Species of Importance in Benin

Many of the plant species that are cultivated for food across the world are neglected and underutilized. To assess their diversity in Benin and identify the priority species and establish their research needs, a survey was conducted in 50 villages distributed throughout the country. The study revealed 41 neglected and underutilized crop species (NUCS) among which 19 were identified as of priority base on 10 criteria among which included their extent and degree of consumption. Reasons for neglect vary with the producers and the agricultural technicians. Market surveys revealed that NUCS are important source of household incomes and substantially contribute to poverty reduction. Review of the literature available revealed that most of the species are rich in nutrients and have some proven medicinal values and the promotion of their use would help in combating malnutrition and improving the health status of the local populations. The knowledge gaps and research needs are immense on most of the species identified as no concrete scientific data is nationally available. In terms of research, almost all has to be done starting from basic ethnobotanical investigation. The results will help the scientists and students willing to conduct research on NUCS in Benin to better orient their research programs.

Diversity, conservation and related wild species of Fonio millet (Digitaria spp.) in the northwest of Benin

Fonio (Digitaria exilis (Kipp.) Stapf, white fonio; Digitaria iburua Stapf, black fonio), is one of the oldest native, but neglected, cereal crops of cultural, nutritional and economic importance of West Africa. To gather key information that will help to preserve its diversity in Benin and develop modern and well-adapted varieties that could meet both farmers’ and consumers’ needs, a participatory research appraisal survey was conducted in 15 villages randomly selected in the fonio production zone of Benin. Altogether 15 farmer-named landraces were recorded and further grouped into five morphotypes of which four belong to D. exilis and one to D. iburua. The number of landraces inventoried varied from one to five per village (three on average) and from one to three per household. Their distribution and extent are presented and their importance in terms of genetic resources conservation is discussed. Farmers’ preferences for fonio varieties were assessed and eight preference criteria (earliness, culinary characteristics, ease of processing, productivity, facility of harvesting, grains size, storability, and drought tolerance) were identified and prioritised according to the gender. The traditional seed supply system and on-farm seed maintenance were investigated. Two plant species (Digitaria horizontalis Willd. and Digitaria longiflora (Retz.) Pers.) were reported by farmers as putative parents of cultivated fonio. Of these, only Digitaria longiflora has interesting agronomic traits (erect habit; stem long, big, strong and resistant to lodging; panicle long and rich in grains; large sized seeds) that are useful for the improvement of cultivated fonio. In the entire study area, the crop is under threat. Therefore, concerted efforts should be deployed to preserve its diversity and increase its use to combat food insecurity and malnutrition in Benin.

Diversity of cassava (Manihot esculenta Crantz) cultivars and its management in the department of Bouenza in the Republic of Congo

Cassava (Manihot esculenta Crantz) is one of the most produced and consumed food crops in the Republic of Congo. To assess the diversity and understand the traditional management of its cultivars in the department of Bouenza, twenty-one villages randomly selected from nine ethnic zones were surveyed using participatory rural appraisal. Altogether, 86 land races cultivars were recorded and further grouped into 36 types based on their agronomic and culinary characteristics. The number of cultivars accessed varied from 6 to 21 per village (13 on average) and from 1 to 11 (4 on average) per household. Their distribution and extent analysis revealed some worrying rates of cultivar loss in the range of 7.41–66.67% (32.06% on average) per village. The reasons of cultivars abandonment, the folk nomenclature and the traditional cutting supply system and planting techniques were documented and their importance in terms of genetic resources conservation and utilisation are discussed. Twenty farmers’ cultivar preference criteria were identified and prioritised. Their relative importances were examined across ethnic groups. Among them, the most important were yield, taste, cossette quality and root size which account for 72.39% of the total responses. The study revealed that most of the farmers did not consider the importance of the sexual reproduction in the cultivar diversification and the impact of cassava mosaic disease on the productivity of the infested plants. Awareness efforts and extension of the study to other cassava production zones were recommended for food security needs in Congo. To clarify synonym, morphological classification and molecular analysis were also suggested.

An integrated agro-ecosystem and livelihood systems approach for the poor and vulnerable in dry areas

More than 400 million people in the developing world depend on dryland agriculture for their livelihoods. Dryland agriculture involves a complex combination of productive components: staple crops, vegetables, livestock, trees and fish interacting principally with rangeland, cultivated areas and watercourses. Managing risk and enhancing productivity through diversification and sustainable intensification is critical to securing and improving rural livelihoods. The main biophysical constraints are natural resource limitations and degradation, particularly water scarcity and encroaching desertification. Social and economic limitations, such as poor access to markets and inputs, weak governance and lack of information about alternative production technologies also limit the options available to farmers. Past efforts to address these constraints by focusing on individual components have either not been successful or are now facing a declining rate of impact, indicating the need for new integrated approaches to research for development of dryland systems. This article outlines the characteristics of such an approach, integrating agro-ecosystem and livelihoods approaches and presents a range of empirical examples of its application in dryland contexts. The authors draw attention to new insights about the design of research required to accelerate impact by integrating across disciplines and scales.

Modelling socioeconomic determinants for cultivation and in-situ conservation of Vitex doniana Sweet (Black plum), a wild harvested economic plant in Benin

BackgroundCultivation is the most appropriate management option when both demand and harvesting of wild plant species increase beyond natural production levels. In the current study we made the assumption that, besides the intrinsic biological and ecological characteristics of the species, the decision to cultivate and/or to conserve an overharvested wild plant species is triggered by the socioeconomic factors such as land tenure and size, origin of respondents, gender, and users’ knowledge of the plant phenology.MethodsWe carried out semi-structured interviews with 178 informants involved in V. doniana exploitation. The data collected were related to socio-demographic characteristics of informants’ household situation, knowledge of the biology and propagation of the species, willingness to cultivate the species, in-situ maintenance of populations, and costs associated with management of the species. According to data types we used Student’s t, Spearman correlation, Kruskal-Wallis, Fisher’s exact and χ2 tests to test the effects of land tenure, origin of respondents, gender and users’ knowledge of plant phenology on the decision making process. Conditional inference tree models and generalized additive models were also used to identify variables which were significantly determinant in the decision to cultivate and/or to conserve the species in-situ.ResultsWe found that men were more willing to cultivate the species than women and this is conditioned by land area available. The willingness to conserve the species in-situ depends mainly on the total land area available, the number of trees within the landscape, accessibility of the trees, land tenure, gender, location, seedling cost, and trade-off cost for conservation. People who offered more than one US dollar to acquire a seedling of V. doniana, landowners, and those who own a total land area in excess of 6.5 ha were most willing to conserve the species in-situ.ConclusionsFrom our findings we conclude that future management and conservation initiatives for V. doniana should first target specific user groups for sustainable exploitation of the species. Also, the Cultivation Opportunity Ratio is an important indicator for quick determination of the likelihood of farmers to engage into cultivation and conservation of the species.

Phenetic characterization of Citrullus spp. (Cucurbitaceae) and differentiation of egusi-type (C. mucosospermus)

Abstract Breeding of Citrullus spp. for various benefits has continuously raised interest particularly for economically important crops. However, the interspecific variations within the genus have remained obscure in many regards and the multitude of names for taxa and subtaxa eludes Citrullus breeders. In the absence of clear taxonomic differentiation, molecular analysis of phenotypes did not help understand the complexity of this genus until recently. In this study we carried out a phenetic characterization of a world collection of 213 accessions using 22 agro-morphological descriptors in field trials conducted in two locations and during two consecutive years. Multivariate analyses confirmed high morphological variation in Citrullus spp. and highlight C. mucosospermus as a homogenous group separated from other Citrullus species. This differentiation of egusi-type melon will help leverage breeding and conservation purposes as C. lanatus represent very important economic crops in the world. Based on our findings we conclude that our knowledge of the relationships between genetic variations and phenotypic traits and the determinism of morphological variations among and within Citrullus need to be further deepened.

Current knowledge and breeding perspectives for the miracle plant Synsepalum dulcificum (Schum. et Thonn.) Daniell

Synsepalum dulcificum, an African native shrub, is a valuable species. All plant parts are of medicinal importance whereas the fruit known as magic berry, miracle berry, or sweet berry is consumed fresh. Surprisingly, very little is known on the species in terms of genotypes utilization and breeding. In this review we recalled the uses and importance of the species and suggested research avenues for an accelerated growth and fruit production. Synsepalum dulcificum is rich in glycoprotein and is an excellent natural sweetener and also a good candidate for the synthesis of drugs against diabetes. Furthermore, S. dulcificum has high content in phytochemical substances (e.g. (+)-epi-syringaresinol, vanillic acid, cyanidin-3-monogalactoside, and quercetin-3-monogalactoside) with various health and food benefits. Data on the nutrient content are limited. Likewise, knowledge on the reproductive biology and mating system is still narrow, combined with poorly developed horticultural practices. To fully exploit the potential of S. dulcificum prospective actions include: (1) improving the propagation and growth abilities of the species, (2) improving knowledge of floral biology and genetic diversity, (3) understanding the phenological phases of the species, gene expressions and how this contributes to metabolites accumulation and (4) improving genotypes for beverages, cosmetics and pharmaceutical industries and other value chains.

Genetic characterization of two traditional leafy vegetables (Sesamum radiatum Thonn. ex Hornem and Ceratotheca sesamoides Endl.) of Benin, using flow cytometry and amplified fragment length polymorphism (AFLP) markers

Amplified fragment length polymorphism (AFLP) markers and flow cytometry were applied for the genetic characterization of wild and cultivated accessions of Sesamum radiatum and Cerathoteca sesamoides ; two neglected and underutilized species of traditional leafy vegetable consumed in Benin. The average 2C nuclear DNA content per nucleus was found to be 1.99 ± 0.06 and 1.05 ± 0.06 pg for S. radiatum and C. sesamoides , respectively which correspond to estimated genome size of 1946,22 Mpb for S. radiatum and 1026,9 Mpb for C. sesamoides. No variation in DNA content could be detected within accessions from each analysed species. Also, no relation was found between nuclear DNA content, ecogeographical origin and the status (cultivated or wild) of the analyzed accessions. AFLP markers revealed low diversity within the accessions analyzed. Results from the study contributed to a better characterization of S. radiatum and C. sesamoides accessions and will help in defining both genetic resources conservation and breeding strategies. Key words : Amplified fragment length polymorphism (AFLP) markers, Ceratotheca sesamoides, flow cytometry, genetic diversity, ploidy, Sesamum radiatum, leafy vegetables.

Black benniseed (Sesamum radiatum Schum. et Thonn.) cultivated as leafy vegetable in Benin

Sesamum radiatum is a nutraceutical traditional leafy vegetable highly consumed in Benin. In spite of its importance for food security, nutrition and income generation, very little is known about in the scientific community and it falls into the group of so-called neglected and underutilised species. In order to document the diversity and the various traditional cultural practices associated with the production of this species and assess its “bringing into cultivation” levels across zones, a survey was conducted in 10 villages randomly selected from different agroecological and ethnic zones of both northern and central Benin. Data were collected in the different sites through application of Participatory Research Appraisal tools and techniques and analysed using both simple descriptive statistics and multivariate analysis. The study revealed a rich folk nomenclature essentially centred on the slimy texture of the sauce. No apparent intraspecific diversity was reported within S. radiatum at village level but the agromorphological characterisation of 18 accessions collected from different regions of the country revealed the existence of clear and well-structured intraspecific diversity exploitable in breeding for the development of new varieties with the potential to attract premium prices in local markets. In most of the households surveyed S. radiatum was found at the steps 1–4 in the “bringing into cultivation process”. The production of S. radiatum is still traditional and biologic (no fertilisers, no pesticides). The cultural practices used vary with the producers and are grouped into four categories. Further agricultural experiments are needed to identify appropriate cultural practices for the large production of this species for food, nutrition and income generation. Strengthening the existing germplasm of this species with additional collection from more agroecological zones is proposed for thorough genetic characterisation.

Managed woodlot revealed a trade-off between edible leaves and timber production in Vitex doniana Sweet (Lamiaceae)

Vitex doniana Sweet is a major wild-harvested tree resource for food in Benin. However, the species is under threats characterised by increasing human pressure on remnant populations. This study represents the first to explore species’ response to biotic stress. We tested the response of V. doniana to coppicing and fertilization. Two stump heights (20 and 40 cm) in combination with three organic manure rates (0.5; 1 and 1.5 kg per seedling), with eight replicates were tested in a randomised complete block design. We used mixed effect models with pseudoreplication, and the maximum likelihood method to compare effects of fixed factors on sprouting vigour, sprout growth and biomass yield in the short (12 months) and medium (5 years) terms. Results indicated that stump height significantly affected sprouting and all growth parameters, in the short and medium terms. However, there seemed a delayed effect of manure. We found initial seedling growth also an important factor. The hidden effect of stump height on biomass yield is discussed. Findings clearly indicate a trade-off between edible leaves and timber production by managed woodlot. Implications of findings for further investigation of above and below ground biomass dynamics and resources allocation in treated trees are discussed. Highlights A clear trade-off between edible leaves and timber production is observed in managed Vitex doniana Sweet woodlot. Coppicing as a biotic stress induced important physiological changes that merit further investigations.