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.

Loss of seed viability, poor and delayed germination, and inaccessibility to high-quality seeds are key bottlenecks limiting all-year-round production of African traditional leafy vegetables (TLVs). Poor quality seeds are the result of several factors including harvest time, storage, and conservation conditions, and seed dormancy. While other factors can be easily controlled, breaking seed dormancy requires thorough knowledge of the seed intrinsic nature and physiology. Here, we synthesized the scattered knowledge on seed dormancy constraints in TLVs, highlighted seed dormancy regulation factors, and developed a conceptual approach for molecular genetic analysis of seed dormancy in TLVs. Several hormones, proteins, changes in chromatin structures, ribosomes, and quantitative trait loci (QTL) are involved in seed dormancy regulation. However, the bulk of knowledge was based on cereals and Arabidopsis and there is little awareness about seed dormancy facts and mechanisms in TLVs. To successfully decipher seed dormancy in TLVs, we used Gynandropsis gynandra to illustrate possible research avenues and highlighted the potential of this species as a model plant for seed dormancy analysis. This will serve as a guideline to provide prospective producers with high-quality seeds.

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Article 25fa states that the author of a short scientific work funded either wholly or partially by Dutch public funds is entitled to make that work publicly available for no consideration following a reasonable period of time after the work was first published, provided that clear reference is made to the source of the first publication of the work.This publication is distributed under The Association of Universities in the Netherlands (VSNU) 'Article 25fa implementation' project. In this project research outputs of researchers employed by Dutch Universities that comply with the legal requirements of Article 25fa of the Dutch Copyright Act are distributed online and free of cost or other barriers in institutional repositories. Research outputs are distributed six months after their first online publication in the original published version and with proper attribution to the source of the original publication.

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Melothria sphaerocarpa (egusi gourd) is an economically important cucurbit species cultivated only for its seeds in West and Central Africa but also found in South and Central America. The species is thought to originate from America and sister of wild relatives such as Melothria candolleana and Melothria campestris, which thrive in America only. The species is rich in nutrients and is a useful crop to ensure food and nutritional security. It also has several applications in industries for cooking oil, soap, paint and biodiesel production. However, the production of egusi gourd is declining because of its low yield, the requirement of stakes and the long production cycle. These bottlenecks lead to the substitution of egusi gourd by other sister egusi crops and increase the threat on the species. This review documents current knowledge for improving existing cultivars of egusi gourd to promote sustainable utilization. Breeding objectives may include developing early maturing, high yielding, as well as pests and diseases resistant varieties. Current in situ and ex situ conservation strategies need to be strengthened. Further investigations need to be carried out on the phylogeny and phylogeography of the genus Melothria, the genetic diversity among American and African populations, the reproductive biology and nutritional value.

Increased public awareness of healthy foods and healthy living, coupled with escalating medicinal costs and recent advances in research and technology, has sparked a paradigm shift to nutraceuticals, which guarantee human health and disease prevention. Spider plant (Gynandropsis gynandra) contains dietary phytochemicals with high nutritional and medicinal properties that can contribute to healthy living. A study was conducted to identify spider plant (Gynandropsis gynandra (L.) Briq.) accessions with superior levels of dietary phytochemicals and anti-oxidative activity for use in nutraceutical breeding. Thirty-three accessions of spider plant, representing a wide genetic diversity based on geographic areas of origin (Asia, East Africa, Southern Africa, and West Africa), were used. Total phenolic acids, tannins, and anthocyanins were extracted and quantified using the Folin-Ciocalteau colorimetric, spectrophotometric, and pH differential methods, respectively. Antioxidant activity was determined using phosphomolybdenum method. Results showed significant variation in levels of total phenolic compounds, tannins, anthocyanins, and antioxidant activity (P < 0.05) amongst the spider plant accessions and regions of origin; ODS-15-037 (464 mg TAE/g DW), ODS-15-053 (270 mg GAE/g DW), and BC-02A (127 mg cyanidin-3-glucoside/g DW) had the highest levels of total tannins, phenolic compounds, and anthocyanins, respectively. Antioxidant activity was high in ODS-15-053 (492.2 mg AAE/100 g DW), NAM 2232 (445.3 mg AAE/100 g DW), and NAM-6 (432.5 mg AAE/100 g DW). On average, West African accessions had significantly high tannin concentrations (239 mg TAE/g DW), while Southern Africa accessions contained significantly high anthocyanin content (58.9 mg cyanidin-3-glucoside/g DW). The superior accessions are potential candidates for use in nutraceutical breeding, while the regions of origin could be used as gene pools for specific phytochemicals for improving dietary supplements of nutraceuticals. The strong antioxidant activity exhibited by spider plant accessions suggests the presence of compounds responsible for scavenging free oxygen or nitrogen radicals. Further studies are recommended to identify the chromosomal regions that contain genes controlling the dietary nutraceuticals in the genetic materials and to determine their association with foliage yield and other phenotypes, which can be utilized in spider plant improvement.

Vitex doniana is a major but threatened economic plant collected as a leafy vegetable and fruit in West Africa. How the species withstands coppicing as an agricultural management practice was investigated in this research. Three seedling vigor classes (10–25 mm, 25–30 mm, 30–40 mm) and two coppicing heights (20 and 40 cm) were compared to controls in eight replicates using a randomized complete block design. Mixed effect models were used to compare the effects of treatments on sprouting intensity, sprout growth, and biomass yield in the short (12 months) and medium term (three and five years). Results indicated that V. doniana is a fast-growing species, with heights between 2.72–7.73 m and diameter at breast height between 4.46–14.64 cm in five years. Vigorous (basal diameter > 30 mm) and shorter coppices (20 cm high) produced a higher number of sprouts. Although biomass yield was relatively higher on high coppices, the difference was not statistically significant. While a more severe harvesting regime was detrimental to plant growth, V. doniana can be managed to produce both vegetables and fuel wood in the medium term. These findings are significant for further improvement of the species, for food security, and climate resilience.