A First Generation Microsatellite- and SNP-Based Linkage Map of Jatropha

Jatropha curcas is a potential plant species for biodiesel production. However, its seed yield is too low for profitable production of biodiesel. To improve the productivity, genetic improvement through breeding is essential. A linkage map is an important component in molecular breeding. We established a first-generation linkage map using a mapping panel containing two backcross populations with 93 progeny. We mapped 506 markers (216 microsatellites and 290 SNPs from ESTs) onto 11 linkage groups. The total length of the map was 1440.9 cM with an average marker space of 2.8 cM. Blasting of 222 Jatropha ESTs containing polymorphic SSR or SNP markers against EST-databases revealed that 91.0%, 86.5% and 79.2% of Jatropha ESTs were homologous to counterparts in castor bean, poplar and Arabidopsis respectively. Mapping 192 orthologous markers to the assembled whole genome sequence of Arabidopsis thaliana identified 38 syntenic blocks and revealed that small linkage blocks were well conserved, but often shuffled. The first generation linkage map and the data of comparative mapping could lay a solid foundation for QTL mapping of agronomic traits, marker-assisted breeding and cloning genes responsible for phenotypic variation

Coefficient of restitution of sub-10 nm silver nanoparticles on an adhesive surface under repulsive and sticky conditions

Filtration and separation of airborne nanoparticles remains a challenge due to their unique properties. This paper reports a molecular dynamics study on the size-dependent coefficient of restitution (CoR) of sub-10 nm nanoparticles on a surface with varying stickiness. The results show the collision regime changes from quasi-elastic or viscoelastic to plastic deformation, with increasing the particle impact velocity. For purely repulsive collisions, CoR of these nanoparticles generally exhibits a similar trend, but they become fluctuating for smaller nanoparticles. When the impact velocity reaches the respective yield velocity, plastic deformation takes place and CoR starts to decrease. During the sticky collisions, the nanoparticles around 2 nm acquire an increased impact velocity higher than their yield velocities, resulting in plastic deformation and reduced CoR for all initial velocities. Larger nanoparticles follow the same trend of the CoR curve for purely repulsive collisions, although their CoR values become smaller than the repulsive collision