ABSTRACT Neotropical Beta-rhizobia have a particular affinity to the large legume ( Fabaceae ) genus Mimosa and some of its relatives in the tribe Mimosae of the Caesalpinioideae subfamily. However, little is still known about the ecology of this interaction, especially the relationship between the rhizobia of “widespread” pan-tropical Mimosa species like M. pudica and the rhizobia that nodulate endemic Mimosa species that are very restricted in their habitats. The objective of this study was to examine the microsymbionts of Mimosa spp. and some other mimosoids in climates ranging from tropical to subtropical, humid to semi-arid, with varied soil characteristics and altitudes, with the aim of testing the hypothesis that widespread species have more cosmopolitan symbiont preferences than endemic ones. Nodules were sampled from more than 40 Mimosa spp. and related taxa in eleven Brazilian states, many endemics or biome-restricted, but particular attention was paid to sample nodules from the widespread species M. pudica at all locations. The Mimosa symbionts comprised 19 potential 16S rRNA and recA groups at the species level, with 16 belonging to the genus Paraburkholderia , including six lineages that may represent new species. The remaining genotypes consisted of 14 strains in two lineages of Cupriavidus that were mainly isolated from M. pudica growing at low altitudes, plus a single lineage of Rhizobium also from M. pudica . It is concluded that a high diversity of Paraburkholderia strains dominate as symbionts of Mimosa in the acidic soils of its main center of radiation in Central Brazil but that Cupriavidus and Rhizobium comprise a significant minority of symbionts of widespread Mimosa spp., especially M. pudica , in lowland or disturbed areas with less acidic soils. Mimosa symbiont diversity is thus driven either by edapho-climatic characteristics for widespread species and/or by co-evolution of the symbiotic partners for endemic species.

Neotropical Beta-rhizobia have a particular affinity to the large legume (Fabaceae) genus Mimosa and some of its relatives in the tribe Mimosae of the Caesalpinioideae subfamily. However, little is still known about the ecology of this interaction, especially the relationship between the rhizobia of “widespread” pan-tropical Mimosa species like M. pudica and the rhizobia that nodulate endemic Mimosa species that are very restricted in their habitats. The objective of this study was to examine the microsymbionts of Mimosa spp. and other mimosoids in climates ranging from tropical to subtropical, humid to semi-arid, with varied soil characteristics and altitudes, with the aim of testing the hypothesis that widespread species have more cosmopolitan symbiont preferences than endemic ones. Nodules were sampled from >30 Mimosa spp. and related taxa in 13 Brazilian states covering all five national regions; many of the species were endemics or biome-restricted, but particular attention was also paid to sample nodules from the widespread species M. pudica at all locations. The Mimosa symbionts comprised 21 potential 16S rRNA and recA groups at the species level, with 17 belonging to the genus Paraburkholderia, including four lineages that may represent new species. The remaining genotypes consisted of 14 strains in two lineages of Cupriavidus that were mainly isolated from M. pudica growing at low altitudes, and a single lineage of Rhizobium also from M. pudica. In addition, a strain of Trinickia symbiotica was isolated from M. misera. It is concluded that diverse genotypes of Paraburkholderia dominate as symbionts of Mimosa in the acidic soils of its main center of radiation in Central Brazil but that Cupriavidus and Rhizobium comprise a significant minority of symbionts of widespread Mimosa spp., especially M. pudica, in lowland or disturbed areas with less acidic soils. Mimosa symbiont selection is thus driven either by edapho-climatic characteristics for widespread species and/or by co-evolution of the symbiotic partners for endemic species.

Purpose Arbuscular mycorrhizal fungi (AMF) play a key role in medicinal plant species, besides their ecological role in shaping plant communities. Knowledge about the diversity and structure of AMF communities associated with the endangered Prunus a fricana is valuable in the conservation and domestication of the species for its medicinal products. Methods We investigated the diversity and structure of AMF species communities in the rhizosphere soils of P. africana trees occurring in four fragmented Afromontane forests found in Cameroon (Mount Cameroon and Mount Manengouba) and Kenya (Chuka and Malava) using Illumina Miseq sequencing of 18S rRNA gene amplicons. Results A total of 64 virtual taxa (VT) belonging to eight genera were detected, namely Glomus (43 VT), Claroideoglomus (6 VT), Paraglomus (5 VT), Acaulospora (4 VT), Diversispora (3 VT), and Archaeospora , Pacispora , and Scutellospora with 1 VT each. Scutellospora heterogama VTX00286 was the most abundant and common species in all four sites (49.62%). Glomeraceae and Gigasporaceae were the most abundant families found across the sites, while Acaulosporaceae, Pacisporaceae, and Archaeosporaceae were rare, represented by < 1% of all the detected taxa. Conclusion Our data shows a high diversity of AMF species associated with P. africana and variable community structure partially shaped by local edaphic factors.

A Biolog (sole carbon source utilisation) user database of tropical and temperature rhizobial strains was created and used in conjunction with the partial 16S rRNA sequencing method to characterise 12 rhizobial isolates from African acacias and other tropical woody legumes. There was close agreement between the two methods but also some significant discrepancies. A high degree of diversity was shown in the relatively small sample of isolates, with 4 out of 5 of the currently proposed rhizobial genera represented. This is the first time Biolog has shown congruence with genotypic fingerprinting using a wide selection of rhizobial reference and test strains.

Prunus africana bark contains phytochemical compounds used in the treatment of benign prostatic hyperplasia and prostate cancer. It has been shown that this plant establishes association with arbuscular mycorrhizal fungi (AMF). AMF are involved in nutrient uptake, which may also affect plant growth and secondary metabolites composition. However, there is no information regarding the role of AMF in the growth and phytochemical content of P. africana. A pot experiment was carried out to assess the response of 8 months old vegetatively propagated P. africana seedlings inoculated with indigenous AMF collected from Mount Cameroon (MC) and Mount Manengumba (MM) in Cameroon, Malava near Kakamega (MK) and Chuka Tharaka-Nithi (CT) in Kenya. Mycorrhizal (frequency, abundance and intensity), growth (height, shoot weight, total weight, number of leaf, leaf surface) and phytochemical (total phenol, tannin and flavonoids) parameters were measured three months after growth of seedlings from two provenances (Muguga and Chuka) with the following inoculation treatments: MK, CT, MC, MM, non-sterilized soil (NS) and sterilized sand as non-inoculated control. Results showed that seedling heights were significantly increased by inoculation and associated with high root colonization (>80%) compared to non-inoculated seedlings. We also found that AMF promoted leaf formation, whereas inoculation did not have any effect on the seedling total weight. AMF inoculum from MM had a higher tannin content, while no significant difference was observed on the total phenol and flavonoid contents due to AMF inoculation. Pearson's correlation was positive between mycorrhizal parameters and the growth parameters, and negative with phytochemical parameters. This study is the first report on the effect of AMF on the growth and phytochemical in P. africana. Further investigations are necessary to determine the effect of single AMF strains to provide better understanding of the role of AMF on the growth performance and physiology of this important medicinal plant species.

ABSTRACT Osyris lanceolata is an evergreen, drought tolerant tropical African tree species belonging to the family Santalaceae. It is endangered, owing to overexploitation for its essential oil used in cosmetics and pharmaceutical industries. The study aimed at determining: (1) the genetic diversity; and (2) the population genetic differentiation in seven key O. lanceolata populations, representing its natural distribution in Kenya. Genotype data for ISSR neutral molecular markers were generated for seven populations of O. lanceolata. The percentage of polymorphic loci (P), ranged from 51% (Wundanyi) to 82% (Gwasii), with a mean of 65%. The mean number of effective alleles (Ne) was 1.430, whereas the Shannon Information Index (I) mean was 0.263. Gwasii population was the most genetically diverse followed by Mt Elgon and least was Wundanyi. The coefficient of differentiation Gst was 0.343. Results of analysis of molecular variance (AMOVA) showed that most of the genetic variation (62%) in O. lanceolata resided within populations. Principal coordinate analysis (PCoA) analysis showed that Baringo population located in the Rift Valley was genetically distinct from the rest of the populations. In conclusion, Gwasii, Mt Elgon and Baringo populations should be delineated for in situ conservation, whereas selection for ex situ conservation should target good trees from all the populations.

Understanding the variation of mating patterns in disturbed habitats provide insight into the evolutionary potential of plant species and how they persist over time. However, this phenomenon is poorly understood in tropical dryland tree species. In the present study, we investigated how Acacia senegal reproduces in two different environmental contexts in Kenya. Open-pollinated progeny arrays of 10 maternal trees from each environmental context were genotyped using 12 nuclear microsatellite markers. Overall, A. senegal displayed a predominantly allogamous mating pattern. However, higher multilocus outcrossing rate (tm) was found in Lake Bogoria (tm = 1.00) than in Kampi ya Moto population (tm = 0.949). Higher biparental inbreeding (t m  − t s  = 0.116) and correlation of outcrossed paternity (rp = 0.329) was found in Kampi ya Moto than in Lake Bogoria population (t m  − t s  = 0.074, rp = 0.055), showing the occurrence of mating among relatives. Coefficient of coancestry (Θ = 0.208) showed that full-sibs constitute about 21% of the offspring in Kampi ya Moto population compared to about 14% (Θ = 0.136) in Lake Bogoria population. The results demonstrate that low adult tree density of A. senegal may be promoting seed production through consanguineous mating and suggest that man-made disturbance can affect mating patterns of the species. Despite these mating differences, trees from both populations can contribute as seed source for conservational plans, and to support effective genetic conservation and artificial regeneration programs of A. senegal. We suggest collection of seeds from at least 42 and 63 trees in Lake Bogoria and Kampi ya Moto populations, respectively, to retain a progeny array with a total effective population size of 150.

The Ecosystem Services (ES) concept highlights the varied contributions the environment provides to humans and there are a wide range of methods/tools available to assess ES. However, in real-world decision contexts a single tool is rarely sufficient and methods must be combined to meet practitioner needs. Here, results from the OpenNESS project are presented to illustrate the methods selected to meet the needs of 24 real-world case studies and better understand why and how methods are combined to meet practical needs. Results showed that within the cases methods were combined to: i) address a range of ES; ii) assess both supply and demand of ES; iii) assess a range of value types; iv) reach different stake-holder groups v) cover weaknesses in other methods used and vi) to meet specific decision context needs. Methods were linked in a variety of ways: i) as input-output chains of methods; ii) through learning; iii) through method development and iv) through comparison/triangulation of results. The paper synthesises these case study-based experiences to provide insight to others working in practical contexts as to where, and in what contexts, different methods can be combined and how this can add value to case study analyses. (C) 2017 Published by Elsevier B.V.

Moringa oleifera (MO) and M. stenopetala (MS) are two commonly cultivated species of the Moringaceae family. Some households in southern Ethiopia (S. ETH) and Kenya (KEN) plant MS and MO, respectively. The edible parts of these species are rich in amino acids, vitamins and minerals, especially selenium. Despite their nutritional value, Moringa is sometimes considered as a “famine food”. The aim of this study was to determine the extent of dietary utilization of these plants by Moringa Growing Households (MGHs). Moringa growing households were surveyed in 2015. Twenty-four and 56 heads of MGHs from S. ETH and KEN, respectively, were interviewed using semi-structured questionnaires. Subsistence agriculture was the main source of livelihood for all MGHs in S. ETH and 71% of those in KEN. All MGHs in S. ETH cultivated MS while those in KEN cultivated MO. Of the MGH heads in S. ETH, 71% had grown MS as long as they remember; the median cultivation period of MO in KEN was 15 years. All MGHs in S. ETH and 79% in KEN used Moringa leaves as a source of food. Forms of consumption of leaves were boiled fresh leaves, and leaf powder used in tea or mixed with other dishes. Other uses of Moringa include as medicine, fodder, shade, agroforestry, and as a source of income. Although MO and MS have multiple uses, MGHs face several challenges, including a lack of reliable information on nutritional and medicinal values, inadequate access to markets for their products, and pest and disease stresses to their plants. Research and development to address these challenges and to promote the use of these species in the fight against hidden hunger are necessary.

Spatial planning has to deal with trade-offs between various stakeholders' wishes and needs as part of planning and management of landscapes, natural resources and/or biodiversity. To make ecosystem services (ES) trade-off research more relevant for spatial planning, we propose an analytical framework, which puts stakeholders, their land-use/management choices, their impact on ES and responses at the centre. Based on 24 cases from around the world, we used this framing to analyse the appearance and diversity of real-world ES trade-offs. They cover a wide range of trade-offs related to ecosystem use, including: land-use change, management regimes, technical versus nature-based solutions, natural resource use, and management of species. The ES trade-offs studied featured a complexity that was far greater than what is often described in the ES literature. Influential users and context setters are at the core of the trade-off decision-making, but most of the impact is felt by non-influential users. Provisioning and cultural ES were the most targeted in the studied trade-offs, but regulating ES were the most impacted. Stakeholders' characteristics, such as influence, impact faced, and concerns can partially explain their position and response in relation to trade-offs. Based on the research findings, we formulate recommendations for spatial planning. Crown Copyright (C) 2017 Published by Elsevier B.V. All rights reserved.

Despite the ecological and economic importance of Acacia senegal , little is known about the effects of anthropogenic disturbances on its natural regeneration patterns and population structure. We investigated the effects of these factors within the Lake Baringo woodland ecosystem. Data was collected from 60 plots of 20 m × 20 m systematically distributed in four A. senegal -dominated populations within the Lake Baringo woodland. Sample populations spanned a degradation gradient measured by a population disturbance index (PDI). Trees were measured for diameter at breast height (DBH) and categorized by growth stages: seedling, sapling and adult tree. Higher seedling and sapling densities were recorded in lightly than heavily disturbed populations, but only sapling density was significantly different between the two disturbance levels ( P = 0.02). Lightly disturbed populations revealed a reversed J-shape size-class distribution (SCD) indicative of stable structure unlike the heavily disturbed populations. The quotient and permutation indices indicated unstable populations with episodic recruitment and mortality. Our study reveals that natural regeneration and population structure of A. senegal were affected majorly by selective harvesting and heavy browsing. Suitable management strategies to control livestock grazing and illegal tree harvesting within the woodland is required to promote conservation of the species genetic resources

Background Moringa oleifera (MO) and M. stenopetala (MS) (family Moringaceae; order Brassicales) are multipurpose tree/shrub species. They thrive under marginal environmental conditions and produce nutritious edible parts. The aim of this study was to determine the mineral composition of different parts of MO and MS growing in their natural environments and their potential role in alleviating human mineral micronutrient deficiencies (MND) in sub-Saharan Africa. Methods Edible parts of MO (n = 146) and MS (n = 50), co-occurring cereals/vegetables and soils (n = 95) underneath their canopy were sampled from localities in southern Ethiopia and Kenya. The concentrations of seven mineral elements, namely, calcium (Ca), copper (Cu), iodine (I), iron (Fe), magnesium (Mg), selenium (Se), and zinc (Zn) in edible parts and soils were determined using inductively coupled plasma-mass spectrometry. Results In Ethiopian crops, MS leaves contained the highest median concentrations of all elements except Cu and Zn, which were greater in Enset (a.k.a., false banana). In Kenya, Mo flowers and MS leaves had the highest median Se concentration of 1.56 mg kg-1 and 3.96 mg kg-1, respectively. The median concentration of Se in MS leaves was 7-fold, 10-fold, 23-fold, 117-fold and 147-fold more than that in brassica leaves, amaranth leaves, baobab fruits, sorghum grain and maize grain, respectively. The median Se concentration was 78-fold and 98-fold greater in MO seeds than in sorghum and maize grain, respectively. There was a strong relationship between soil total Se and potassium dihydrogen phosphate (KH2PO4)-extractable Se, and Se concentration in the leaves of MO and MS. Conclusion This study confirms previous studies that Moringa is a good source of several of the measured mineral nutrients, and it includes the first wide assessment of Se and I concentrations in edible parts of MO and MS grown in various localities. Increasing the consumption of MO and MS, especially the leaves as a fresh vegetable or in powdered form, could reduce the prevalence of MNDs, most notably Se deficiency.

A total of 150 bacterial strains were isolated from the root nodules of Prosopis juliflora growing in soils collected from Marigat area of Kenya.Soil samples from representative colonized zones of Tortilis, Grass and Prosopis were used in trapping the microsymbionts.A physiological plate screening allowed the selection of 60 strains which were characterized based on morphological, cultural and biochemical characteristics.Tolerance to salinity, acid and alkaline pH and resistance to antibiotics were studied as phenotypic markers.Morphological characteristics allowed the description of a wide physiological diversity among tested isolates.Establishing mutualistic interactions in novel environments is important for the successful establishment of some non-native plant species.The associations may have negative impact on the interaction networks of the native species whereby non-native species becoming dominant.Our study suggests that P. juliflora may have led to the diversity of N-fixing microsymbionts observed in the study area.The study provides basis for further research on the phylogeny of rhozobial strains nodulating P. juliflora, as well as their use as inoculants to improve growth and nitrogen fixation in arid lands of Kenya.The data obtained in this study can be used for strain improvement and cross-inoculation experiments with different species when searching for well adapted and compatible partners.

Leafing, flowering, and fruiting patterns of Senegalia senegal were studied over a period of 24 months from January 2014 to December 2015. The phenological events of the species are bimodal and follow the rainfall patterns. The leafing phase starts during the onset of rains and lasts for 18 weeks. New leaves continued to appear on the new shoots while old leaves persisted to the leaf fall period. Flowering event takes 12 weeks and is concentrated in the months of high relative humidity (April and October) with one-month peak flowering period. Fruiting phase starts at the peak of the rainy seasons (May and November) and peaks in June and December. This phase lasted for 14 weeks. The fruits mature towards the end of the rainy season (January/February and July/August). The fruits open for dispersal mainly in February/March and September during the peak dry season. High synchrony index (SI) was found in leafing (SI: 0.87), flowering (SI: 0.75), and fruiting (SI: 0.85) events among the populations. Temperature, precipitation, and soil moisture content were significantly correlated with the phenological events. Significant variations in floral morphology and fruits traits were also evident. Seed collections should be undertaken in the months of January/February and July/August.

The focus of the study was to determine the symbiotic and growth response of three Senegalia Senegal (Syn. Acacia Senegal, gum arabic tree) provenances, namely Dahra (Senegal), Tera (Niger) and Makueni (Kenya) to inoculation with selected S. Senegal-nodulating rhizobia in soils from Dahra and Goudiry regions of Senegal, representing typical soil and enviromental conditions for establishing gum arabic production plantations.A greenhouse experiment was performed to evaluate the effect of 11 rhizobial strains on nodulation and growth of three S. Senegal provenances in two field soils, differing in nutrient status and indigenous rhizobia. After 4 months, plants were harvested for determination of nodulation, shoot and root dryweight.Nodulation and growth of S. Senegal varied in relation to rhizobial strain, provenance, soil type, and their interactions. Generally, nodulation was higher in Dahra than Goudiry soils, while Makueni provenance was the most compatible host. Inoculation had a significant effect on all parameters measured in Dahra field soil. By contrast, inoculation had a significant effect on height (shoot length), and shoot, root and total dry matter but not on nodulation. In the two field soils, seed provenance effect was significant for all parameters measured. The interaction between inoculation and provenance showed a significant effect on all parameters measured except nodule number in Dahra field soil while in Goudiry, the interaction had a significant effect on seedling height and shoot, root, and total dry matter but this effect was not significant with nodulation parameters.S. Senegal is variable in its response to inoculation, it is therefore advantageous to select and match effective rhizobia-provenance symbionts for each site.

Acacia senegal is endemic to dry forest and woodland ecosystems of Sub-Saharan Africa and provides both ecological and socio-economic benefits. However, these ecosystems are threatened by escalating human disturbances and fragmentation. To investigate the human impacts on genetic diversity and structure of A. senegal, we studied genetic variability and differentiation of 330 individual trees from 11 natural A. senegal populations, grouped into lightly and heavily disturbed, using 12 polymorphic nuclear microsatellite markers. Gene diversity (H (E) ) ranged from H (E) = 0.570 to H (E) = 0.632. Significant differences (P < 0.05) between the levels of disturbances are reported for mean gene diversity, number of alleles and allelic richness with lightly disturbed populations showing higher values. Overall, the indirect estimates of average outcrossing rates ranged from 0.794 (Kiserian) to 0.999 (Kampi ya Moto) with a mean of 0.997 suggesting a predominantly outcrossing species. There was no significant relationship (P > 0.05) detected between genetic and geographic distances, showing lack of isolation by distance. Analysis of population structure using unweighted pair group method with arithmetic mean and Bayesian model suggests presence of three gene pools as most probable, although most individuals showed mixed ancestry. The diversity and genetic structure reported in this study revealed negative impacts of human disturbance on A. senegal within this ecosystem. We recommend in-situ conservation strategies to safeguard the woodland ecosystem from further deforestation.

Knowledge of rangewide variation in DNA content and ploidy level may be valuable in understanding the evolutionary history of a species. Recent studies of Acacia senegal report diploids and occasional tetraploids in the Sudano-Sahelian region of sub-Saharan Africa, but nothing is known about the overall extent of DNA ploidy variation within the species. In this study, we determine the DNA content and ploidy level of A. senegal across its native range, and explore whether the variation is related to its evolutionary and colonization history. We used propidium iodide flow cytometry (FCM) to estimate DNA content (2C value) and infer ploidy in 157 individuals from 54 populations on various tissues, using seeds, fresh leaves, dried leaves and twigs and herbarium specimens. The mean 2C DNA (pg ± s.d.) contents detected were 1.47 ± 0.09, 2.12 ± 0.02, 2.89 ± 0.12, and a single individual with 4.51 pg, corresponding to a polyploid series of diploid, triploid, tetraploid and hexaploid individuals. Diploids were confirmed by chromosome counts (2n = 2x = 26). Most populations (90.7 %) were of single ploidy level, while mixed ploidy populations (9.3 %) comprising mostly diploids (2x+3x, 2x+4x and 2x+6x) were restricted to the Sudano-Sahelian and Indian subcontinent regions, its northern range. The species is predominantly diploid, and no mixed ploidy populations were detected in east and southern Africa, its southern range. The geographic pattern of ploidy variation in conjunction with existing phylogeographic and phylogenetic data of the species suggests that polyploids have occurred multiple times in its evolutionary and recent colonization history, including contemporary ecological timescales. The successful use of external tissues of dried twigs in FCM is new, and presents the opportunity to study numerous other dryland woody species.