Estimation of Genetic Diversity and Number of Unique Genotypes of Cassava Germplasm from Burkina Faso Using Microsatellite Markers.

Genetic diversity is very important in crop improvement. This study was carried out to assess the genetic diversity and the number of unique multilocus genotypes (MLGs) in a cassava collection in Burkina Faso. To achieve this objective, 130 cassava accessions were genotyped using 32 simple sequence repeat (SSR) markers. The results revealed that among these markers, twelve (12) were highly informative, with polymorphic information content (PIC) values greater than 0.50; twelve (12) were moderately informative, with PIC values ranging between 0.25 and 0.50; and eight (8) were not very informative, with PIC values lower than 0.25. A moderate level of genetic diversity was found for the population, indicated by the average expected heterozygosity (0.45) and the observed heterozygosity (0.48). About 83.8% of unique multilocus genotypes were found in the cassava collection, indicating that SSR markers seem to be most appropriate for MLG identification. Population structure analysis based on hierarchical clustering identified two subpopulations and the Bayesian approach suggested five clusters. Additionally, discriminant analysis of principal components (DAPC) separated the cassava accessions into 13 subpopulations. A comparison of these results and those of a previous study using single nucleotide polymorphisms (SNP) suggests that each type of marker can be used to assess the genetic structure of cassava grown in Burkina Faso.

Molecular Tools to Infer Resistance-Breaking Abilities of Rice Yellow Mottle Virus Isolates.

Rice yellow mottle virus (RYMV) is a major biotic constraint to rice cultivation in Africa. RYMV shows a high genetic diversity. Viral lineages were defined according to the coat protein (CP) phylogeny. Varietal selection is considered as the most efficient way to manage RYMV. Sources of high resistance were identified mostly in accessions of the African rice species, Oryza glaberrima. Emergence of resistance-breaking (RB) genotypes was observed in controlled conditions. The RB ability was highly contrasted, depending on the resistance sources and on the RYMV lineages. A molecular marker linked to the adaptation to susceptible and resistant O. glaberrima was identified in the viral protein genome-linked (VPg). By contrast, as no molecular method was available to identify the hypervirulent lineage able to overcome all known resistance sources, plant inoculation assays were still required. Here, we designed specific RT-PCR primers to infer the RB abilities of RYMV isolates without greenhouse experiments or sequencing steps. These primers were tested and validated on 52 isolates, representative of RYMV genetic diversity. The molecular tools described in this study will contribute to optimizing the deployment strategy of resistant lines, considering the RYMV lineages identified in fields and their potential adaptability.

Diversity of Sclerotium rolfsii antagonist fungi isolated from soils of the rhizosphere of tomato crops and identification of some antifungal compounds.

Sclerotium rolfsii Sacc. the causative agent of white rot is one of the destructive pathogens of nightshade crops. In Côte d'Ivoire, this fungal pathogen constitutes a major constraint for the cultivation of tomato (Solanum lycopersicum) with 41.01% crop losses in humid forest areas. Controlling this fungus with synthetic chemicals can be effective, but harmful to human health and the environment. The use of biological control agents could be an alternative approach to control S. rolfsii. In this perspective, the objective of this work was to select fungi from the rhizosphere of tomato crops capable of inhibiting the growth of S. rolfsii. To do this, 153 fungi were isolated from the rhizosphere and from direct confrontation tests 10 fungi whose antagonistic power of S. rolfsii varied between 27 and 60% were selected. Molecular identification (ITS) of these antagonist fungi revealed that the isolates belonged to the genera Talaromyces sp. (n = 4), Trichoderma sp. (n = 3), Penicillium sp. (n = 2) and Clonostachys sp. (n = 1). Among these fungi, Talaromyces purpureogenus and Talaromyces assiutensis were able to diffuse compounds in agar capable of inhibiting the growth of S. rolfsii. The chemical study of these 2 fungi made it possible to identify mitorubrin and mitorubrinol produced by T. purpureogenus and spiculisporic acid produced by T. assiutensis. Mitorubrin and mitorubrinol had inhibitory activities of 100 and 70% at 10 mg/mL, respectively, whereas spiculisporic acid showed moderate inhibition of 38 at 20 mg/mL of the growth of S. rolfsii; however, its abundant production by the fungus could be an advantage in the control of this phytopathogen. Isolated from the same biotope as S. rolfsii, T. purpureogenus and T. assiutensis represent favorable candidates for the biological control against S. rolfsii.

Bioconversion of antifungal viridin to phytotoxin viridiol by environmental non-viridin producing microorganisms.

Biotransformation of viridin, an antifungal produced by biocontrol agent, with non-viridin producing microorganisms is studied. The results show that some environmental non-targeted microorganisms are able to reduce it in the known phytotoxin viridiol, and its 3-epimer. Consequently, this reduction, which happens in some cases by detoxification mechanism, could be disastrous for the plant in a biocontrol of plant disease. However, a process fermentation/biotransformation could be an efficient approach for the preparation of this phytotoxin.

Feasibility Study of the "HemoTypeSC" Test for the Rapid Screening of Sickle Cell Disease in Côte D'Ivoire.

Sickle cell disease is a hereditary disease that predominantly affects black people. It is very widespread in sub-Saharan Africa, particularly at the Lehmann "sickle belt" level, where the prevalence of the hemoglobin S involves at least 10% of the population in West Africa and can reach 40% in Central Africa. In Côte d'Ivoire, the prevalence of the hemoglobin S is about 12-14% in the general population and about 11.71% in the child population in Abidjan. On the other hand, its coexistence with other hemoglobin phenotypes such as AC (6.2%) and ß-thalassemia (2.7%) traits may also cause composite heterogeneous sickle cell disease, e.g., SC or S/ß-thalassemia in this study. Since 2009, sickle cell disease has been recognized as a public health problem; however, much still remains to be performed despite the progress achieved. The objective of this study is thus to promote a rapid screening for the struggling against sickle cell disease in Côte d'Ivoire. This study was carried out over 6 months (April-September 2019) and has included 336 children, of which 236 all-comers, recruited in the municipality of Treichville in Abidjan and 100 other children with already known hemoglobin phenotype followed up in the Hematology Department of the University Hospital of Treichville. Two tests were used: the HemoTypeSC™ for rapid screening and the hemoglobin electrophoresis which is the reference method used for confirming the diagnosis in the laboratory. The findings confirmed the reliability of the HemoTypeSC™ with a sensitivity and specificity at 100% for the detection of hemoglobin A, S, and C. On the other hand, this sensitivity and specificity drop to 98.2% and 99.7%, respectively, when we analyze all the 336 children together, including the cases with HbF detected by hemoglobin electrophoresis. Hence, the importance of performing certainty tests following the HemoTypeSC™ screening test in order to determine the accurate phenotypes and proportions of the types of hemoglobin. The prevalence of hemoglobin S in subgroup 1 of 236 children of all-comers was 15%. The HemoTypeSC™ is therefore reliable, inexpensive, and disposable for rapid screening and early detection of sickle cell disease in Côte d'Ivoire. The HemoTypeSC™ provides rapid detection of hemoglobin phenotypes HbAA, HbSS, HbSC, HbCC, HbAS, and HbAC.

Epidemiological assessment of cassava mosaic disease in Burkina Faso.

Surveys were conducted in 2016 and 2017 across the main cassava-growing regions of Burkina Faso to assess the status of cassava mosaic disease (CMD) and to determine the virus strains causing the disease, using field observation and phylogenetic analysis. CMD incidence varied between regions and across years but was lowest in Hauts-Bassins (6.0%, 2016 and 5.4%, 2017) and highest in Centre-Sud (18.5%, 2016) and in Boucle du Mouhoun (51.7%, 2017). The lowest CMD severity was found in Est region (2.0) for both years and the highest in Sud-Ouest region (3.3, 2016) and Centre-Sud region (2.8, 2017). The CMD infection was primarily associated with contaminated cuttings in all regions except in Hauts-Bassins, where whitefly-borne infection was higher than cuttings-borne infection in 2016. PCR screening of 687 samples coupled with sequence analysis revealed the presence of African cassava mosaic-like (ACMV-like) viruses and East African cassava mosaic-like (EACMV-like) viruses as single infections at 79.5% and 1.1%, respectively. Co-infections of ACMV-like and EACMV-like viruses were detected in 19.4% of the tested samples. In addition, 86.7% of the samples positive for EACMV-like virus were found to be positive for East African cassava mosaic Cameroon virus (EACMCMV). Phylogenetic analysis revealed the segregation of cassava mosaic geminiviruses (CMGs) from Burkina Faso into three clades specific to ACMV, African cassava mosaic Burkina Faso virus (ACMBFV), and EACMCMV, confirming the presence of these viruses. The results of this study show that EACMCMV occurrence may be more prevalent in Burkina Faso than previously thought.

First report of Sugarcane Streak Mosaic Virus (SCSMV) infecting sugarcane in Côte d'Ivoire.

Sugarcane streak mosaic virus (SCSMV; Poaceavirus; Potiviridae) is the causal agent of streak mosaic disease of sugarcane (Saccharum interspecific hybrids), a major industrial crop that is widely cultivated in tropical and subtropical regions for sugar and ethanol production. was first reported by Hall et al. (1998) from quarantined germplasm material exhibiting mosaic symptoms imported from Pakistan into the USA. Subsequently, the virus was also reported to occur in most of the Asian countries like Bangladesh, India, Indonesia, Iran, Sri Lanka, Thailand, Vietnam and China (Chatenet et al. 2005; Hema et al. 2008, Kasemsin et al. 2016, Putra et al. 2014, Xu et al. 2010, Moradi et al. 2015; Moradi et al. 2018, Zhang et al. 2018). Until now, there is no report of SCSMV outside the Asian continent. From February to October 2018, sugarcane plants exhibiting symptoms such as irregular yellow and green mosaic, interveinal chlorotic specks, and streaks were observed in Bafing (Borotou-Koro), Marahoué (Zuénoula) and Tchologo (Ferkéssédougou) regions of Côte d'Ivoire (Fig. 1a). Varieties under large-scale commercial cultivation such as R570, R579, SP711406, Co997, Co449, M1176/77, M2593/92, M2580/95, and M1400/86 were all symptomatic. A total of 94 sugarcane leaf samples were collected from these regions and, among those, 82 showed disease symptoms and 12 were symptomless. Samples were first tested for the presence of sugarcane mosaic virus (SCMV), which causes mosaic a disease that is already present in Africa. Serological tests with infected sap using a Double Antibody Sandwich (DAS)- Enzyme Linked Immuno Sorbent Assay (ELISA) kit (DSMZ, RT-0166, Braunschweig, Germany) were negative for SCMV and no amplification product was obtained by RT-PCR using primers specific to the coat protein (CP) gene of SCMV (Putra et al. 2003). The 82 symptomatic leaves tested positive by DAS-ELISA with SCSMV antiserum (polyclonal antibodies were graciously provided by Prof. Hema M. of the Sri Venkateswara University, Tirupati, AP, India), whereas the 12 symptomless samples tested negative. To confirm these results, virus free greenhouse-grown sugarcane varieties Co997 and M1176/77, were mechanically inoculated with 10 sap extracts from 10 SCSMV-infected sugarcane leaf samples. Sap was also extracted from DAS-ELISA negative sugarcane leaves and used as negative control. For sap preparation, leaves were homogenized with a mortar in 2 mL of phosphate buffer 0.01 M pH 7.2 (ratio 1:10). Fifteen 4-week-old plants per variety were inoculated separately with each sap. All inoculated plants exhibited streak mosaic symptoms 13 days post-inoculation (fig. 1b), and the presence of SCSMV in the inoculated plants was confirmed by DAS-ELISA. Total RNA was extracted from four symptomatic leaf samples, one symptomless and one DAS-ELISA positive sample using TRIzol reagent (Invitrogen, Carlsbad, CA, USA). cDNA was synthesized using M-MLV Reverse Transcriptase (Promega, Cat.No.M1705, Madison, WI, USA) following the manufacturer's instructions. A 690-nucleotide fragment of the CP gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR) with primers SCSMV-F690 and SCSMV-R690 (Viswanathan et al. 2008). All primers were synthesized by Eurogentec (Seraing, Belgium). Aliquots of RT-PCR products (5 µl) were analyzed by electrophoresis on 1.2 % (w/v) agarose gel, stained with ethidium bromide and visualized on a UV transilluminator (Fig. 2). An amplification product of the expected size was obtained for all five symptomatic or DAS ELISA positive but not for the symptomless sample. Two RT-PCR products were sequenced and deposited in GenBank under accession Nos. LR594547 and LR594582. These partial CP gene sequences shared highest nucleotide identity with two isolates of SCSMV from India in GenBank: 91% with JN315855 and 90% with EF655859, thus confirming that SCSMV was occurring in sugarcane in Côte d'Ivoire. To our knowledge, this is the first report of natural infection of sugarcane by SCSMV in Africa. Streak mosaic is a serious threat to the entire sugar industry in West Africa and needs further investigations as it may affect sugarcane yields and impact local economies. Our findings further illustrate the need to develop virus-free germplasm for local, national, and international distribution of sugarcane.

Process of Attack on Cashew Tree Branches by Diastocera trifasciata (Coleoptera: Cerambycidae) and the Relationship between These Attacks and the Phenological Stages in the Gbêkê Region (Central Côte d'Ivoire).

Cerambycidae Diastocera trifasciata attacks were studied from October 2015 to September 2017 in three cashew tree orchards in the locality of Brobo in central Côte d'Ivoire. One hundred fifty-three (153) cashew trees, arranged on a diagonal from each orchard, were selected for sampling. The attacked plants and the branches cut per tree were counted every 15 days. Biotic parameters, namely phenological stages of trees, and abiotic factors, which are rainfall, relative humidity and average temperature, were recorded throughout the study. Attacks were observed from mid-September to January from the pre-flowering vegetative stage to the flowering stage. Attack period duration was therefore four and a half months per year. The peak of attacks was recorded in November with an attack rate of 88.02% in 2015 and 75.49% in 2016. No attack was recorded from February to mid-September, corresponding to the flowering, fruiting and post-harvest vegetative growth stages. This description of the attack process and the determination of D. trifasciata attack periods provides essential data for the implementation of an effective and sustainable control method of this species.

Knock-out mutation of eukaryotic initiation factor 4E2 (eIF4E2) confers resistance to pepper veinal mottle virus in tomato.

Translation initiation factors 4E (eIF4E) are the main source of resistance to potyvirus. We systematically assessed tomato single and double knock-out (KO) mutants of members of the eIF4E-coding gene family for resistance to Pepper veinal mottle virus (PVMV), a major constraint to tomato production. We show that the KO mutant of eIF4E2 has partial resistance to PVMV isolate IC, with plants harboring weak symptoms and low virus loads at the systemic level. The causal effect of eIF4E2 loss-of-function on resistance was confirmed on a progeny segregating for the KO mutation. The eIF4E2 KO mutant was resistant to six of the eight PVMV isolates tested and no resistance to other potyviruses was observed. This is the first evidence that mutation of eIF4E2 is in itself conferring resistance to a potyvirus and 3D protein modelling suggests that the eIF4E2 gene could be converted into a functional resistance allele.

Phytogeographical and sociolinguistical patterns of the diversity, distribution, and uses of wild mushrooms in Côte d'Ivoire, West Africa.

BACKGROUND: Many fungal species in tropical Africa are useful, with high added value, and play essential roles in the structure and dynamic of ecosystems. However, the diversity, distribution, and uses by local populations of these non-timber forest products (NTFPs) and their respective habitats are still very poorly understood in sub-Saharan Africa in general and more specifically in Côte d'Ivoire. This study aims at (i) inventorying the wild useful mushrooms of Côte d'Ivoire within its major protected areas and their respective surrounding sociolinguistical groups, according to climatic and phytogeographical gradients, and (ii) recording ethnomycological knowledge and considerations of these local people. METHODS: Field and ethnomycological surveys were conducted in the main and highest protected areas of Côte d'Ivoire (Comoé, Marahoué, and Taï national parks) and a set of their respective surrounding villages, along climatic and phytogeographical gradients. Standardized methods (permanent plots and opportunistic searches) were used for field surveys. In addition, a total 748 respondents belonging to 13 ethnic groups were interviewed at a rate of 300 interviewees during the preliminary investigations and 448 persons during the proper ethnomycological surveys. RESULTS: Sixty-eight useful wild fungal species, belonging to 17 families and 23 genera, were listed and collected. Four categories of usage were reported by the rural people (food, medicinal, belief and recreational), with a dominance of food and medicinal uses. Fifty-six species were reported to be used as food and 16 species as medicinal fungi. These uses varied not only from one sociolinguistical group to another but also from a visited village to another. The high number (41) of the reported useful species was found in the Sudano-Guinean savanna zone while 28 species were collected in the forest zone and 22 species in the forest-savanna mosaic zone. These mushrooms were either saprotrophic or symbiotic (ectomycorrhizal or termitophilic). Auricularia sp3, Psathyrella tuberculata, and Termitomyces spp. were found as the most commonly used mushrooms. CONCLUSIONS: These national scale field and ethnomycological surveys give one of the more complete but non-exhaustive list of useful mushrooms of Côte d'Ivoire. Mushrooms are relatively well known and used by the Ivorian people within the main phytogeographical zone of the country. These people also have an interest in all the functional groups with an important phytogeographical zone-fungal-specific used species. However, protected areas of the visited zones seem to represent the last sanctuaries of these organisms due to high rate of loss of natural habitats.

Diversity, phenology and distribution of Termitomyces species in Côte d'Ivoire.

The mutualistic symbiosis between termites of the Macrotermitinae subfamily (Isoptera: Termitidae) and fungi of the genus Termitomyces (Basidiomycota: Lyophyllaceae) is of great ecological and socio-economic importance. Seasonal fruit bodies of the symbiotic fungi are regularly collected and sold in Côte d'Ivoire. However, there are very few studies on their diversity, phenology, distribution and especially the socio-economic scope of the fruit bodies of these fungi at a national scale. This study aims at (i) assessing the diversity of Termitomyces fruit bodies in Côte d'Ivoire and (ii) mapping their fructification areas through a determination of their spatiotemporal distribution according to a climatic and phytogeographic gradients. Using ethnomycological surveys all over the Ivorian territory, information was collected from rural populations on the fructification of Termitomyces and their socio-economic importance. Based on these surveys, sampling efforts of these fungi were properly structured and oriented. The results revealed a diversity of 16 species of Termitomyces, including 9 species new to Côte d'Ivoire and 2 probably new to science. Five species were found in the forest zone, nine in theGuinean savannah zone and four in the Sudano-Guinean zone. Termitomyces's fructifications were observed throughout the year, with specific period for each species. All listed species are regularly consumed by populations. However, only Termitomyces letestui (Pat.) R. Heim and Termitomyces schimperi (Pat.) R. Heim are marketed on a relatively large scale.

Efficacy and safety of primaquine and methylene blue for prevention of Plasmodium falciparum transmission in Mali: a phase 2, single-blind, randomised controlled trial.

BACKGROUND: Primaquine and methylene blue are gametocytocidal compounds that could prevent Plasmodium falciparum transmission to mosquitoes. We aimed to assess the efficacy and safety of primaquine and methylene blue in preventing human to mosquito transmission of P falciparum among glucose-6-phosphate dehydrogenase (G6PD)-normal, gametocytaemic male participants. METHODS: This was a phase 2, single-blind, randomised controlled trial done at the Clinical Research Centre of the Malaria Research and Training Centre (MRTC) of the University of Bamako (Bamako, Mali). We enrolled male participants aged 5-50 years with asymptomatic P falciparum malaria. G6PD-normal participants with gametocytes detected by blood smear were randomised 1:1:1:1 in block sizes of eight, using a sealed-envelope design, to receive either sulfadoxine-pyrimethamine and amodiaquine, sulfadoxine-pyrimethamine and amodiaquine plus a single dose of 0·25 mg/kg primaquine, dihydroartemisinin-piperaquine, or dihydroartemisinin-piperaquine plus 15 mg/kg per day methylene blue for 3 days. Laboratory staff, investigators, and insectary technicians were masked to the treatment group and gametocyte density of study participants. The study pharmacist and treating physician were not masked. Participants could request unmasking. The primary efficacy endpoint, analysed in all infected patients with at least one infectivity measure before and after treatment, was median within-person percentage change in mosquito infectivity 2 and 7 days after treatment, assessed by membrane feeding. This study is registered with ClinicalTrials.gov, number NCT02831023. FINDINGS: Between June 27, 2016, and Nov 1, 2016, 80 participants were enrolled and assigned to the sulfadoxine-pyrimethamine and amodiaquine (n=20), sulfadoxine-pyrimethamine and amodiaquine plus primaquine (n=20), dihydroartemisinin-piperaquine (n=20), or dihydroartemisinin-piperaquine plus methylene blue (n=20) groups. Among participants infectious at baseline (54 [68%] of 80), those in the sulfadoxine-pyrimethamine and amodiaquine plus primaquine group (n=19) had a median 100% (IQR 100 to 100) within-person reduction in mosquito infectivity on day 2, a larger reduction than was noted with sulfadoxine-pyrimethamine and amodiaquine alone (n=12; -10·2%, IQR -143·9 to 56·6; p<0·0001). The dihydroartemisinin-piperaquine plus methylene blue (n=11) group had a median 100% (IQR 100 to 100) within-person reduction in mosquito infectivity on day 2, a larger reduction than was noted with dihydroartemisinin-piperaquine alone (n=12; -6·0%, IQR -126·1 to 86·9; p<0·0001). Haemoglobin changes were similar between gametocytocidal arms and their respective controls. After exclusion of blue urine, adverse events were similar across all groups (59 [74%] of 80 participants had 162 adverse events overall, 145 [90%] of which were mild). INTERPRETATION: Adding a single dose of 0·25 mg/kg primaquine to sulfadoxine-pyrimethamine and amodiaquine or 3 days of 15 mg/kg per day methylene blue to dihydroartemisinin-piperaquine was highly efficacious for preventing P falciparum transmission. Both primaquine and methylene blue were well tolerated. FUNDING: Bill & Melinda Gates Foundation, European Research Council.

Safety of Single-Dose Primaquine in G6PD-Deficient and G6PD-Normal Males in Mali Without Malaria: An Open-Label, Phase 1, Dose-Adjustment Trial.

Background: The World Health Organization recommendation on the use of a single low dose of primaquine (SLD-PQ) to reduce Plasmodium falciparum malaria transmission requires more safety data. Methods: We conducted an open-label, nonrandomized, dose-adjustment trial of the safety of 3 single doses of primaquine in glucose-6-phosphate dehydrogenase (G6PD)-deficient adult males in Mali, followed by an assessment of safety in G6PD-deficient boys aged 11-17 years and those aged 5-10 years, including G6PD-normal control groups. The primary outcome was the greatest within-person percentage drop in hemoglobin concentration within 10 days after treatment. Results: Fifty-one participants were included in analysis. G6PD-deficient adult males received 0.40, 0.45, or 0.50 mg/kg of SLD-PQ. G6PD-deficient boys received 0.40 mg/kg of SLD-PQ. There was no evidence of symptomatic hemolysis, and adverse events considered related to study drug (n = 4) were mild. The mean largest within-person percentage change in hemoglobin level between days 0 and 10 was -9.7% (95% confidence interval [CI], -13.5% to -5.90%) in G6PD-deficient adults receiving 0.50 mg/kg of SLD-PQ, -11.5% (95% CI, -16.1% to -6.96%) in G6PD-deficient boys aged 11-17 years, and -9.61% (95% CI, -7.59% to -13.9%) in G6PD-deficient boys aged 5-10 years. The lowest hemoglobin concentration at any point during the study was 92 g/L. Conclusion: SLD-PQ doses between 0.40 and 0.50 mg/kg were well tolerated in G6PD-deficient males in Mali. Clinical Trials Registration: NCT02535767.

Inhibition of Phytophthora species, agents of cocoa black pod disease, by secondary metabolites of Trichoderma species.

Cocoa production is affected by the black pod disease caused by several Phytophthora species that bring, about each year, an estimated loss of 44% of world production. Chemical control remains expensive and poses an enormous risk of poisoning for the users and the environment. Biocontrol by using antagonistic microorganisms has become an alternative to the integrated control strategy against this disease. Trichoderma viride T7, T. harzanium T40, and T. asperellum T54, which showed in vivo and in vitro antagonistic activity against P. palmivora, were cultured and mycelia extracted. Inhibition activity of crude extracts was determined, and then organic compounds were isolated and characterized. The in vitro effect of each compound on the conidia germination and mycelia growth of four P. palmivora, two P. megakaria, and one P. capsici was evaluated. T. viride that displayed best activities produced two active metabolites, viridin and gliovirin, against P. palmivora and P. megakaria strains. However, no activity against P. capsici was observed. Besides being active separately, these two compounds have a synergistic effect for both inhibitions, mycelia growth and conidia germination. These results provide the basis for the development of a low-impact pesticide based on a mixture of viridin and gliovirine.

Measuring the impact of seasonal malaria chemoprevention as part of routine malaria control in Kita, Mali.

BACKGROUND: Seasonal malaria chemoprevention (SMC) is a new strategy recommended by WHO in areas of highly seasonal transmission in March 2012. Although randomized controlled trials (RCTs) have shown SMC to be highly effective, evidence and experience from routine implementation of SMC are limited. METHODS: A non-randomized pragmatic trial with pre-post design was used, with one intervention district (Kita), where four rounds of SMC with sulfadoxine + amodiaquine (SP + AQ) took place in August-November 2014, and one comparison district (Bafoulabe). The primary aims were to evaluate SMC coverage and reductions in prevalence of malaria and anaemia when SMC is delivered through routine programmes using existing community health workers. Children aged 3-59 months from 15 selected localities per district, sampled with probability proportional to size, were surveyed and blood samples collected for malaria blood smears, haemoglobin (Hb) measurement, and molecular markers of drug resistance in two cross-sectional surveys, one before SMC (July 2014) and one after SMC (December 2014). Difference-in-differences regression models were used to assess and compare changes in malaria and anaemia in the intervention and comparison districts. Adherence and tolerability of SMC were assessed by cross-sectional surveys 4-7 days after each SMC round. Coverage of SMC was assessed in the post-SMC survey. RESULTS: During round 1, 84% of targeted children received at least the first SMC dose, but coverage declined to 67% by round 4. Across the four treatment rounds, 54% of children received four complete SMC courses. Prevalence of parasitaemia was similar in intervention and comparison districts prior to SMC (23.4 vs 29.5%, p = 0.34) as was the prevalence of malaria illness (2.4 vs 1.9%, p = 0.75). After SMC, parasitaemia prevalence fell to 18% in the intervention district and increased to 46% in the comparison district [difference-in-differences (DD) OR = 0.35; 95% CI 0.20-0.60]. Prevalence of malaria illness fell to a greater degree in the intervention district versus the comparison district (DD OR = 0.20; 95% CI 0.04-0.94) and the same for moderate anaemia (Hb < 8 g/dL) (DD OR = 0.26, 95% CI 0.11-0.65). The frequency of the quintuple mutation (dhfr N51I, C59R and S108N + dhps A437G and K540E) remained low (5%) before and after intervention in both districts. CONCLUSIONS: Routine implementation of SMC in Mali substantially reduced malaria and anaemia, with reductions of similar magnitude to those seen in previous RCTs. Improving coverage could further strengthen SMC impact. Trial registration clinical trial registration number NCT02894294.

Virus surveys of Capsicum spp. in the Republic of Benin reveal the prevalence of pepper vein yellows virus and the identification of a previously uncharacterised polerovirus species.

Surveys were conducted in 2014 and 2015 in Southern and Northern Benin, respectively, to identify the viruses infecting peppers (Capsicum spp.). The samples were screened by ELISA for cucumber mosaic virus (CMV), pepper veinal mottle virus (PVMV), potato virus Y (PVY) and tomato yellow leaf curl virus (TYLCV). A generic reverse transcription PCR (RT-PCR) was used to test for the presence of poleroviruses. ELISA tests confirmed the prevalence of all viruses, while the RT-PCR detected pepper vein yellows virus (PeVYV) which is reported for the first time in Benin. A further, divergent polerovirus isolate was detected from a single pepper sample originating from southern Benin. Screening of samples collected from solanaceous plants during virus surveys in Mali (conducted in 2009) also detected this divergent polerovirus isolate in two samples from African eggplants. The complete genome sequence was obtained from the Mali isolate using transcriptome sequencing and by conventional Sanger sequencing of overlapping RT-PCR products. Based on the sequence characteristics of this isolate we propose a new polerovirus species, African eggplant yellowing virus (AeYV).

Development of variable number of tandem repeats typing schemes for Ralstonia solanacearum, the agent of bacterial wilt, banana Moko disease and potato brown rot.

Ralstonia solanacearum is an important soil borne bacterial plant pathogen causing bacterial wilt on many important crops. To better monitor epidemics, efficient tools that can identify and discriminate populations are needed. In this study, we assessed variable number of tandem repeats (VNTR) genotyping as a new tool for epidemiological surveillance of R. solanacearum phylotypes, and more specifically for the monitoring of the monomorphic ecotypes "Moko" (banana-pathogenic) and "brown rot" (potato-pathogenic under cool conditions). Screening of six R. solanacearum genome sequences lead to select 36 VNTR loci that were preliminarily amplified on 24 strains. From this step, 26 single-locus primer pairs were multiplexed, and applied to a worldwide collection of 337 strains encompassing the whole phylogenetic diversity, with revelation on a capillary-electrophoresis genotype. Four loci were monomorphic within all phylotypes and were not retained; the other loci were highly polymorphic but displayed a clear phylotype-specificity. Phylotype-specific MLVA schemes were thus defined, based on 13 loci for phylotype I, 12 loci for phylotype II, 11 loci for phylotype III and 6 for phylotype IV. MLVA typing was significantly more discriminative than egl-based sequevar typing, particularly on monomorphic "brown rot" ecotype (phylotype IIB/sequevar 1) and "Moko disease" clade 4 (Phylotype IIB/sequevar 4). Our results raise promising prospects for studies of population genetic structures and epidemiological monitoring.

Soil amendments with Brassica cover crops for management of Phytophthora blight on squash.

BACKGROUND: Phytophthora blight induced by Phytophthora capsici is responsible for serious yield loss in vegetable production in the United States and other countries. This study was conducted to evaluate the efficacy of Brassica cover crops used as soil amendments for managing Phytophthora blight of squash. RESULTS: In greenhouse studies, disease incidence on squash plants was significantly reduced by soil amendment with mustard shoots or roots used at 1 and 2.5% (plant tissue/soil, w/w). The shoots of canola used at 1 or 2.5% also suppressed disease, while the roots of canola or other crops did not reduce disease significantly. In field studies, soil amendments with mustard and canola provided the greatest disease reduction and increased squash yield significantly compared with the non-treated control. Mustard and canola did not appear to be susceptible to P. capsici. CONCLUSION: The results indicated that some Brassica crops, particularly mustard and canola, had the potential to significantly reduce Phytophthora blight on squash when used as soil amendments. As P. capsici has a remarkable ability to develop resistance to chemical fungicides, use of effective Brassica cover crops could be a biorational alternative to fungicides and a valuable component in developing integrated disease management programs.

[In vitro activity of different fungicides on the growth in Mycosphaerella fijiensis var. difformis Stover and Dickson, Cladosporium musae Morelet and Deightoniella torulosa (Syd.) Ellis, isolated parasites of the banana phyllosphere in the Ivory Coast]. / Activités in vitro de différents fongicides sur la croissance chez Mycosphaerella fijiensis var. difformis Stover et Dickson, Cladosporium musae Morelet et Deightoniella torulosa (Syd.) Ellis, parasites isolés de la phyllosphère des bananiers en Côte-d'Ivoire.

In Côte-d'Ivoire, banana leaf surfaces are attacked by Mycosphaerella fijiensis var. difformis, Cladosporium musae, and Deigthonielle torulosa. Control is based on fungicides recommanded for Mycosphaerella fijiensis. Fungicides belonging to triazoles and strobilurines types were added, at different concentrations, to the PDA medium, using this PDA medium containing no fungicide as the control. Mycelium disc and spores of Cladosporium musae, Mycosphaerella fijiensis and Deightoniella torulosa were put on the different media. Total inhibition of mycelium growth of every fungus on the PDA amended with propiconazole was observed. The fungicides used show different activities according to their concentration and their mode of action. The application of a fungicide should talke into account the pathogenic fungus involved in the leaf attacked. Against Mycosphaerella fijiensis var. difformis, the Ci(50) are different according to the concentrations (0.44 to 1.06 ppm). Correlations ranked from 0.71 to 0.91 are also different according to fungicide used. The Ci(50) of Cladosporium musae (0.10 to 2.44 ppm) and Deightoniella torulosa (0.26 to 0.52 ppm) are different and their correlations are respectively 0.78 to 0.99 and 0.86 to 0.95. An assessment of the sensitivity of parasitic fungi of banana can be made by mycelium growth measurement of fungi isolated from resistance zones.

Evaluation of an antibiotic-producing strain of Pseudomonas fluorescens for suppression of plant-parasitic nematodes.

The antibiotic 2,4-diacetylphloroglucinol (DAPG), produced by some strains of Pseudomonas spp., is involved in suppression of several fungal root pathogens as well as plant-parasitic nematodes. The primary objective of this study was to determine whether Wood1R, a D-genotype strain of DAPG-producing P. fluorescens, suppresses numbers of both sedentary and migratory plant-parasitic nematodes. An experiment was conducted in steam-heated soil and included two seed treatments (with Wood1R and a control without the bacterium) and six plant-nematode combinations which were Meloidogyne incognita on cotton, corn, and soybean; M. arenaria on peanut; Heterodera glycines on soybean; and Paratrichodorus minor on corn. Wood 1R had no effect on final numbers of M. arenaria, P. minor, or H. glycines; however, final numbers of M. incognita were lower when seeds were treated with Wood1R than left untreated, and this reduction was consistent among host plants. Population densities of Wood1R were greater on the roots of corn than on the other crops, and the bacterium was most effective in suppressing M. incognita on corn, with an average reduction of 41%. Despite high population densities of Wood1R on corn, the bacterium was not able to suppress numbers of P. minor. When comparing the suppression of M. incognita on corn in natural and steam-heated soil, egg production by the nematode was suppressed in natural compared to steamed soil, but the presence of Wood1R did not result in additional suppression of the nematodes in the natural soil. These data indicate that P. fluorescens strain Wood1R has the capacity to inhibit some populations of plant-parasitic nematodes. However, consistent suppression of nematodes in natural soils seems unlikely.