Genome-wide association study reveals a set of genes associated with resistance to the Mediterranean corn borer (Sesamia nonagrioides L.) in a maize diversity panel

[Background] Corn borers are the primary maize pest; their feeding on the pith results in stem damage and yield losses. In this study, we performed a genome-wide association study (GWAS) to identify SNPs associated with resistance to Mediterranean corn borer in a maize diversity panel using a set of more than 240,000 SNPs.[Results] Twenty five SNPs were significantly associated with three resistance traits: 10 were significantly associated with tunnel length, 4 with stem damage, and 11 with kernel resistance. Allelic variation at each significant SNP was associated with from 6 to 9% of the phenotypic variance. A set of genes containing or physically close to these SNPs are proposed as candidate genes for borer resistance, supported by their involvement in plant defense-related mechanisms in previously published evidence. The linkage disequilibrium decayed (r2 < 0.10) rapidly within short distance, suggesting high resolution of GWAS associations.[Conclusions] Most of the candidate genes found in this study are part of signaling pathways, others act as regulator of expression under biotic stress condition, and a few genes are encoding enzymes with antibiotic effect against insects such as the cystatin1 gene and the defensin proteins. These findings contribute to the understanding the complex relationship between plant-insect interactions.This work was supported by the National Plan for Research and Development of Spain (projects AGL2012-33415). L.F. Samayoa acknowledges a contract JAE-Predoc from the Spanish Council for Scientific Research (CSIC).Peer reviewe

Fibrous and composite materials for blast protection of structural elements : a state of the art review

Contemporary world is facing numerous bomb explosion attacks on public and civil buildings causing huge loss of property and human lives. As a consequence, the society needs more safety and protection for the existing structures against blast loads. Among the various strategies, one effective way to enhance the blast resistance of reinforced concrete and masonry structures is through retrofitting using various types and forms of fibrous and composite mater- ials. This work presents an up to date review of available literature and publications on the fibrous and composite materials utilized for blast protection of structural elements and highlights the lacking areas where further research is required

Assessment of the toxicity of ash-loaded runoff from a recently burnt eucalypt plantation

Although wildfires are identified as an important source of polycyclic aromatic hydrocarbons (PAHs) and PAHs are well-known for their pernicious properties, the toxicity of runoff from recently burnt areas has received little research attention. This knowledge gap was addressed here through laboratory assays in which four aquatic species from distinct trophic levels were exposed to different dilutions of ash-loaded runoff. The runoff was collected in a recently burnt eucalypt stand in north-central Portugal on two occasions, immediately after the wildfire and about 1 year later. The total PAH load was about four times higher at the first than second sampling occasion (1194 vs. 352 ng l-1) but even the latter value was considerably higher than those reported by prior studies on burnt areas. In addition, the two runoff samples differed noticeably in PAH composition, with a clear predominance of naphthalene in the second sample. Both runoff samples produced significant inhibitory effects on the three species representing the lower trophic levels, that is, the bacteria Vibrio fischeri, the algae Pseudokirchneriella subcapitata and the macrophyte Lemna minor. The invertebrate Daphnia magna was not significantly affected but chronic tests are needed to discard the probable propagation of toxic effects from the lower trophic levels. Surprisingly, the runoff collected 1 year after the wildfire was the most toxic to V. fischeri, P. subcapitata and L. minor. Possibly, this was due to predominance of naphthalene in this sample. Surely, however, this demonstrated that detrimental off-site effects of wildfires are not necessarily limited to the immediate post-fire situation.publishe