Comportement D’une Variété Précoce De Mil (Pennisetum glaucum (L.) R. Br) En Réponse A Différents Types De Fumures Combinées A Une Sécheresse De Fin De Cycle Au Nord De La Côte d'Ivoire

Cet article analyse l’influence de l’utilisation des fumures organiques et minérales sur la productivité du mil (Pennisetum glaucum (L.) R. Br) face à la baisse de la fertilité des sols dans un contexte de changements climatiques au Nord de la Côte d’Ivoire. Une étude a été menée pour analyser le comportement d’une variété précoce de mil en fonction de trois fumures organiques et une fumure minérale en situation de déficit hydrique post-floral. Le dispositif utilisé a été un bloc de Fisher complètement randomisé comportant quatre répétitions et cinq traitements (T1: témoin, T2: fiente de volaille, T3: déjection de lapin, T4: déjection de boeuf, T5: fumure minérale N-P-K-S-B+Urée). Les observations et mesures ont porté sur les stades de développement et les paramètres de croissance des plants. L’évapotranspiration réelle de la culture, le taux de satisfaction des besoins en eau des plants, le rendement et ses composantes ont été calculés ainsi que l’efficacité des fumures utilisées. Les résultats ont montré un déficit hydrique au cours de la phase reproductive. La variété de mil étudiée a présenté un cycle de développement plus court, une meilleure croissance, des valeurs de composantes du rendement élevées avec l’application de la fiente de volaille. La fumure fiente de volaille a été donc plus efficace que les autres fumures malgré la poche de sécheresse observée en fin de cycle. L’apport de la fiente de volaille peut être recommandé pour les cultures qui ont besoin de fertilisants, comme les variétés précoces de mil, car elle raccourcit la durée du cycle de culture permettant ainsi aux plants d’échapper aux conséquences néfastes du déficit hydrique de fin de cycle. This Article Analyzes The Influence Of Organic And MineralManures On Millet (Pennisetum Glaucum (L.) R. Br.) Productivity In The Context Of Climate Change And Soil Fertility Degradation In Northern Côte d'Ivoire. To Do This, A Study Was Conducted To Analyze The Response Of An Early VarietyOfMillet Based On Three OrganicManures And OneMineralManure In Post-Floral Water Deficit Situations. The Experiment Had A Completely Randomized Block In Four Repetitions And Five Treatments (T1: Control, T2: Chicken Dropping; T3: Rabbit Dropping, T4: Cow Dung; T5: N-P-K-S B+Urea Mineral Fertilizer). Observations And Measurements Focused On The Stages Of Development And Plant Growth Parameters. The Crop Evapotranspiration, The Satisfaction Rate Of Plant's Water Needs, Yield And ComponentsWere Calculated, And The Efficiency Of The Manure Used. The Results Showed A Water Deficit During The Reproductive Phase. The Millet Presented A Shorter Development Cycle, Better Growth And High Yield Component Values With Chicken Dropping Treatment. The Chicken Dropping Was More Effective Than Other Manure, Despite The Drought Observed At The End Of Crop Cycle. Applying Chicken Dropping May Be Recommended For Crops Needs Immediate Fertilizers, Such As Early Millet Varieties, Because It Shortens The Duration Of The Growing Cycle, Thus Allowing Plants To Escape The Harmful Consequences Of The End Of Crop Cycle Water Deficit

Pf7: an open dataset of Plasmodium falciparum genome variation in 20,000 worldwide samples

We describe the MalariaGEN Pf7 data resource, the seventh release of Plasmodium falciparum genome variation data from the MalariaGEN network.  It comprises over 20,000 samples from 82 partner studies in 33 countries, including several malaria endemic regions that were previously underrepresented.  For the first time we include dried blood spot samples that were sequenced after selective whole genome amplification, necessitating new methods to genotype copy number variations.  We identify a large number of newly emerging crt mutations in parts of Southeast Asia, and show examples of heterogeneities in patterns of drug resistance within Africa and within the Indian subcontinent.  We describe the profile of variations in the C-terminal of the csp gene and relate this to the sequence used in the RTS,S and R21 malaria vaccines.  Pf7 provides high-quality data on genotype calls for 6 million SNPs and short indels, analysis of large deletions that cause failure of rapid diagnostic tests, and systematic characterisation of six major drug resistance loci, all of which can be freely downloaded from the MalariaGEN website

Selection of Appropriate Reference Genes for Gene Expression Analysis under Abiotic Stresses in Salix viminalis

Salix viminalis is a fast growing willow species with potential as a plant used for biomass feedstock or for phytoremediation. However, few reference genes (RGs) for quantitative real-time polymerase chain reaction (qPCR) are available in S. viminalis, thereby limiting gene expression studies. Here, we investigated the expression stability of 14 candidate reference genes (RGs) across various organs exposed to five abiotic stresses (cold, heat, drought, salt, and poly-metals). Four RGs ranking algorithms, namely geNormPLUS, BestKeeper, NormFinder, and GrayNorm were applied to analyze the qPCR data and the outputs were merged into consensus lists with RankAggreg, a rank aggregation algorithm. In addition, the optimal RG combinations were determined with geNormPLUS and GrayNorm. The genes that were the most stable in the roots were TIP41 and CDC2. In the leaves, TIP41 was the most stable, followed by EF1b and ARI8, depending on the condition tested. Conversely, GAPDH and β-TUB, two genes commonly used for qPCR data normalization were the least stable across all organs. Nevertheless, both geNormPLUS and GrayNorm recommended the use of a combination of genes rather than a single one. These results are valuable for research of transcriptomic responses in different S. viminalis organs

Can phenotypic selection on floral traits explain the presence of enigmatic intermediate individuals in sympatric populations of Platanthera bifolia and P. chlorantha (Orchidaceae) ?

Pollinators represent one of the main agents of selection on floral traits. Here, we estimated phenotypic selection on floral morphology and phenology in a sympatric population of two orchid species, Platanthera bifolia and P. chlorantha, including enigmatic individuals with intermediate column morphology (as reflected by the distance between viscidia and caudicle length, two traits involved in assortative mating and reproductive isolation among Platanthera species), but genetically indistinguishable from P. bifolia. Our aim was to clarify whether the occurrence of intermediate phenotypes could be explained by the presence of selective pressures exerted by pollinators. Simple linear and quadratic regressions together with univariate and multivariate analyses were used to evaluate the strength of directional, disruptive and stabilizing selection. We found that selection on phenotypic traits varied between groups and sex functions. Contrary to our hypothesis, selection on the viscidia distance and caudicle length appeared to be consistent in the two P. bifolia groups. Interestingly, the viscidia distance was under significant stabilizing selection through female reproductive success in intermediate individuals. Based on these results, we conclude that, despite a significant selective pressure on some phenotypic traits, the presence of individuals with intermediate phenotype is not due to selection. Stabilizing selection on distance between viscidia in intermediate individuals may suggest that assortative mating play a role in the maintenance of this phenotypic polymorphism

Uncontrolled deforestation and population growth threaten a tropical island’s water and land resources in only 10 years

International audienceRapid demographic growth in tropical islands can exacerbate conflicts and pressures on natural resources, as illustrated by the French island of Mayotte where resources are limited. In only 10 years, uncontrolled migration and population growth (+80% of population between 2002 and 2021) have led to a pronounced 3600% increase in deforestation rates (2010–2014) and an intensification of agricultural practices, escalating conflicts over limited land, water, and biodiversity resources. Implementing an original multi-proxy approach to sediment cores, our study reveals a staggering 300% acceleration in erosion during the first wave of migration (2011–2015), followed by a further 190% increase (2019–2021) under sustained migratory and demographic pressures. Sedimentary DNA analysis provided insights into increased connectivity and community changes. By 2050, the population of this region will increase by 74 and 103%, in Comoros and Madagascar islands, respectively. Urgent conservation measures are needed to avoid major socio-environmental crises and to protect resources for future generations

GJB2 and GJB6 Mutations in Hereditary Recessive Non-Syndromic Hearing Impairment in Cameroon

This study aimed to investigate GJB2 (connexin 26) and GJB6 (connexin 30) mutations associated with familial non-syndromic childhood hearing impairment (HI) in Cameroon. We selected only families segregating HI, with at least two affected individuals and with strong evidence of non-environmental causes. DNA was extracted from peripheral blood, and the entire coding region of GJB2 was interrogated using Sanger sequencing. Multiplex PCR and Sanger sequencing were used to analyze the prevalence of the GJB6-D3S1830 deletion. A total of 93 patients, belonging to 41 families, were included in the analysis. Hearing impairment was sensorineural in 51 out of 54 (94.4%) patients. Pedigree analysis suggested autosomal recessive inheritance in 85.4% (35/41) of families. Hearing impairment was inherited in an autosomal dominant and mitochondrial mode in 12.2% (5/41) and 2.4% (1/41) of families, respectively. Most HI participants were non-syndromic (92.5%; 86/93). Four patients from two families presented with type 2 Waardenburg syndrome, and three cases of type 2 Usher syndrome were identified in one family. No GJB2 mutations were found in any of the 29 families with non-syndromic HI. Additionally, the GJB6-D3S1830 deletion was not identified in any of the HI patients. This study confirms that mutations in the GJB2 gene and the del(GJB6-D13S1830) mutation do not contribute to familial HI in Cameroon