Genetic diversity of rhizobia nodulating Arachis hypogaea L. in diverse land use systems of humid forest zone in Cameroon

Peanut (Arachis hypogaea) is one of the most important legume cultivated in the humid forest zone of Cameroon. However, in this country the diversity of rhizobial strains that can nodulate peanut was poorly understood. Forty-two strains from Arachis hypogaea were examinated by restriction fragment length polymorphism (RFLP) analysis of 16S-23S rDNA genes amplified by polymerase chain reaction (PCR). A considerable level of genetic diversity was determined among those peanut isolates. Eight composite genotypes were obtained from the combined data of the RFLP analysis with four endonucleases. A correlation between land use system and the diversity of peanut isolates was observed in the current study. The highest diversity was found in the cocoa farm and fallow and the lowest one in peanut farm. our results have shown that the genotype richness diversity of peanut isolates depends on the land use system

Ectomycorrhizal diversity enhances growth and nitrogen fixation of Acacia mangium seedlings

Increasing interest has been given so far to the role of mycorrhizal symbiosis on plant diversity and ecosystem productivity. However much remains unknown about the effect of ectomycorrhizal fungal diversity on plant growth and rhizobial symbiosis. The purpose of this study is to investigate the influence of ectomycorrhizal diversity on root nodulation and plant nutrient uptake during plant growth. A gradient of ectomycorrhizal diversity was created (ranged from one to six fungal isolates) on Australian Acacia (Acacia mangium) seedlings grown on a phosphate-deficient soil in controlled conditions. The results dearly show (i) an enhancement of A. mangium growth due to ectomycorrhizal fungal inoculation, (ii) as well as significant effects of increasing ectomycorhizal diversity and soil ectomycorrhizal mycelium density on whole plant biomass and plant nutrient uptake. They also reveal an effect of ectomycorrhizal diversity effect on the functioning of the nitrogen-fixing symbiosis. These results emphasize the need to manage soil ectomycorrhizal potential (abundance and diversity of ectomycorrhizal mycelium) in forest management practices in order to optimize N-2 fixation and seedling growth, leading thus to dramatic improvements in outplanting performances with fast-growing tree legumes on various reafforestation sites, more particularly in tropical and Mediterranean areas

Biological role of fetuin A and its potential importance for prediction of cardiovascular risk in patients with type 2 diabetes mellitus

The authors’ data and those from literature concerning biological role of fetuin A glycoprotein have been generalized in the article. A direct correlation has been established between fetuin A and some adipokines involved in the formation of insulin resistance and atherogenesis (progranu­lin, omentin-1), and osteoprotegerin (the novel cardiovascular risk factor) as well as an increase of circulating levels of fetuin A in patients with type 2 diabetes mellitus with high cardiovascular risk metabolic pattern but without manifestations of macrovascular complications. This substantiates the involvement of fetuin A in the complex of biomarkers of subclinical atherosclerosis