AM symbiotic traits can be selected using conventional breeding methods in durum wheat

Non-Peer ReviewedThe management of the arbuscular mycorrhizal (AM) symbiosis, could improve plant’s efficiency of fertilizer use. The development and function of an AM symbiosis is largely controlled by the genotype of the host plant. Thus, it may be possible to improve crop nutrient use efficiency by the selection of genotypes with improve symbiotic effectiveness. Variability in the AM symbiotic development of durum wheat genotypes must be present in breeder plant material for a breeding program to be effective. We tested in the greenhouse under two levels of fertility, the hypothesis that durum wheat genotypes representative of five mapping populations vary in their ability to form the AM symbiosis. We found variations in the influence of the commercial AM fungus Glomus intraradices on root colonization, nutrition, and yield of durum wheat. This variation indicates that it is possible to select durum genotypes for improved symbiosis formation using conventional breeding methods

An update on the human and animal enteric pathogen Clostridium perfringens

Clostridium perfringens, a rapid-growing pathogen known to secrete an arsenal of >20 virulent toxins, has been associated with intestinal diseases in both animals and humans throughout the past century. Recent advances in genomic analysis and experimental systems make it timely to re-visit this clinically and veterinary important pathogen. This Review will summarise our understanding of the genomics and virulence-linked factors, including antimicrobial potentials and secreted toxins of this gut pathogen, and then its up-to-date clinical epidemiology and biological role in the pathogenesis of several important human and animal-associated intestinal diseases, including pre-term necrotising enterocolitis. Finally, we highlight some of the important unresolved questions in relation to C. perfringens-mediated infections, and implications for future research directions

The effects of aging of scientists on their publication and citation patterns

The average age at which U.S. researchers get their first grant from NIH has increased from 34.3 in 1970, to 41.7 in 2004. These data raise the crucial question of the effects of aging on the scientific creativity and productivity of researchers. Those who worry about the aging of scientists usually believe that the younger they are the more creative and productive they will be. Using a large population of 13,680 university professors in Quebec, we show that, while scientific productivity rises sharply between 28 and 40, it increases at a slower pace between 41 and 50 and stabilizes afterward until retirement for the most active researchers. The average scientific impact per paper decreases linearly until 50-55 years old, but the average number of papers in highly cited journals and among highly cited papers rises continuously until retirement. Our results clearly show for the first time the natural history of the scientific productivity of scientists over their entire career and bring to light the fact that researchers over 55 still contribute significantly to the scientific community by producing high impact papers.Comment: 12 pages, 4 figure