A Combination of Metabolomics and Machine Learning Results in the Identification of a New Cyst Nematode Hatching Factor

Potato Cyst Nematodes (PCNs) are an economically important pest for potato growers. A crucial event in the life cycle of the nematode is hatching, after which the juvenile will move toward the host root and infect it. The hatching of PCNs is induced by known and unknown compounds in the root exudates of host plant species, called hatching factors (HFs, induce hatching independently), such as solanoeclepin A (solA), or hatching stimulants (HSs, enhance hatching activity of HFs). Unraveling the identity of unknown HSs and HFs and their natural variation is important for the selection of cultivars that produce low amounts of HFs and HSs, thus contributing to more sustainable agriculture. In this study, we used a new approach aimed at the identification of new HFs and HSs for PCNs in potato. Hereto, root exudates of a series of different potato cultivars were analyzed for their PCN hatch-inducing activity and their solA content. The exudates were also analyzed using untargeted metabolomics, and subsequently the data were integrated using machine learning, specifically random forest feature selection, and Pearson’s correlation testing. As expected, solA highly correlates with hatching. Furthermore, this resulted in the discovery of a number of metabolite features present in the root exudate that correlate with hatching and solA content, and one of these is a compound of m/z 526.18 that predicts hatching even better than solA with both data methods. This compound’s involvement in hatch stimulation was confirmed by the fractionation of three representative root exudates and hatching assays with the resulting fractions. Moreover, the compound shares mass fragmentation similarity with solA, and we therefore assume it has a similar structure. With this work, we show that potato likely produces a solA analogue, and we contribute to unraveling the hatch-inducing cocktail exuded by plant roots

Do floristic composition, plant species abundance and vegetation structure in Sudanian wetlands vary according to conservation status?

In Sahel, wetlands are particularly endangered hence practical knowledge for their sustainable management is needed. The aim of this study was to compare plant community structure between protected and unprotected wetland bank stands in eastern Burkina Faso. Phytosociological and dendrometrical parameters were carrying out in adult trees, seedling individuals and herbaceous species. Discrimination of plant communities and diversity indices were calculated for each group. Weibull distribution was used to compare the diameter structures. The results shows that plant communities located in riverbanks of unprotected wetlands have a greater specificheterogeneity. They are rich inannual speciesand in species with a wide distribution. Finally their woody stands are characterized by lower basal areas than unprotected wetland riverbank stands. Plant community stands in riverbanks of protected wetlands were better preserved but some disturbances were noticed. Furthermore, juvenile plants of the two sites were threatened and this may affect in long term, the relative stability of these trees stands as revealed by Weibull distribution. Further study should focus on wetlands riverbanks seedling status in order to propose restoration strategies

Survival and growth responses of Jatropha curcas L. to three restoration techniques on degraded soils in Burkina Faso

Land degradation is a major problem in the Sahelian countries. Erosion control through establishment of vegetation cover is at important strategy to reverse the trend. Our research objective was to analyse the e-ffects of three restoration techniques on Jatropha curcas L. seedlings growth and survivorship. Were conducted two separate field trials, involving the sowing and planting of J. curcas, in which several different soil restoration techniques were applied. The trial was monitored using a ran-domized block study design over a period of two years. The design included ten different treatments, six in the sowing trial and four in the planting trial, each with three replicates. In the first experiment, growth rate was found to be significantly higher in the Sub-Soiling treatment, that received additional organic matter than other treatments. However, overall survival rate was low (18%). In the second experiment, the Half-moon treatment yielded a significantly higher growth both in height (df = 3, F = 56.74, p < 0.05) and diameter (df = 3, F = 31.76, p < 0.05) and survival rate compared to those of the other treatments (df = 3, F = 50.4, p < 0.05). In conclusion, planting seedlings produced a greater survival rate than sowing seeds. Among tested the soil restoration and water conservation techniques the Half-moon technique was found as the most effective. This is recommended to be used for improving the revegetation of J. curcas in the future

Uses and vulnerability of ligneous species exploited by local population of northern Burkina Faso in their adaptation strategies to changing environments

Background Arid and semi-arid areas of West Africa are highly subject to climate change effects. This is combined to other drivers such as population growth and livestock number increase. To cope with such changing environment, endogenous adaptation strategies of poor local communities rely on the use of natural resources through empirical knowledge. Unfortunately, these knowledge and practices are insufficiently known to policy makers, and this hampers their consideration in the elaboration of adaptation strategies. A household survey was conducted in the Sillia village in northern Burkina Faso using semi-structured interviews. This study identified most used (preferred) species in this changing environment together with their ethnobotanical use value (VUET). Results Overall, 86 ligneous species were listed in seven (7) use categories: human nutrition, fodder, fuel, traditional medicine, handicraft, construction and trade. From the 86 species, 11 appeared the most preferred by local population (VUET ≥ 6). Except Piliostigma reticulatum and Boscia senegalensis, all these species were part of the 21 very vulnerable species as revealed by the study. Tamarindus indica, Balanites aegyptiaca, Lannea microcarpa and Vitellaria paradoxa are the first most preferred species (VUET ≥ 7) and also most vulnerable (IV > 2.5). In this changing environment, Cassia sieberiana, Combretum micranthum, Balanites aegyptica have, for instance, become the main species used in traditional medicine replacing Ximenia americana, Coclospermum tinctorim, Maytenus senegalensis and Securidaca longepedunculata, formerly used for this need. Also, Piliostigma reticulatum is the main species used in farm lands to combat low soil fertility. Pterocarpus lucens and Adansonia digitata are the main fodder species both during dry and rainy seasons. Apart from the household surveys, vegetation survey was conducted on 96 plots in Sillia. The results showed that 25 species cited in the household surveys had locally disappeared, 22 were rare, 5 were abundant and the others were relatively abundant. Certain collection practices of given species in many use categories increase their vulnerability. Conclusion This study documented preferred species in the adaptation strategies to changing environments and also assessed their vulnerability status under human influence; it is therefore of great use for designing sustainable management