QTL mapping for Mediterranean corn borer resistance in European flint germplasm using recombinant inbred lines

<p>Abstract</p> <p>Background</p> <p><it>Ostrinia nubilalis </it>(ECB) and <it>Sesamia nonagrioides </it>(MCB) are two maize stem borers which cause important losses in temperate maize production, but QTL analyses for corn borer resistance were mostly restricted to ECB resistance and maize materials genetically related (mapping populations derived from B73). Therefore, the objective of this work was to identify and characterize QTLs for MCB resistance and agronomic traits in a RILs population derived from European flint inbreds.</p> <p>Results</p> <p>Three QTLs were detected for stalk tunnel length at bins 1.02, 3.05 and 8.05 which explained 7.5% of the RILs genotypic variance. The QTL at bin 3.05 was co-located to a QTL related to plant height and grain humidity and the QTL at bin 8.05 was located near a QTL related to yield.</p> <p>Conclusions</p> <p>Our results, when compared with results from other authors, suggest the presence of genes involved in cell wall biosynthesis or fortification with effects on resistance to different corn borer species and digestibility for dairy cattle. Particularly, we proposed five candidate genes related to cell wall characteristics which could explain the QTL for stalk tunnelling in the region 3.05. However, the small proportion of genotypic variance explained by the QTLs suggest that there are also many other genes of small effect regulating MCB resistance and we conclude that MAS seems not promising for this trait. Two QTLs detected for stalk tunnelling overlap with QTLs for agronomic traits, indicating the presence of pleitropism or linkage between genes affecting resistance and agronomic traits.</p

ANALYSIS OF DEPOSITIONAL ENVIRONMENT AND PETROLEUM SYSTEM BASED ON INTEGRATION OF SEISMIC AND WELL DATA IN THE COASTAL OF CENTRAL SUMATRA BASIN

As one of the hydrocarbon-producing basins in Indonesia, the Central Sumatra Basin’s development had been hampered due to limited exploration and studies. This study aimed to identify depositional environments and petroleum systems through stratigraphic seismic and well studies. This study used a seismic method with Hampson Russell and Petrel software. Log data helped process seismic data with Interactive Petrophysic (IP) software and Techlog for well data processing. This research zone had five depositional sequences, most of which were formed in the depositional environment of branching channels and estuaries. There were two potential source rocks, namely in the Pematang Formation and shale layers in the upper TST-1. Based on stratigraphic sequence analysis on seismic sections, petroleum systems were identified in the Merak, Melibur, and Garib wells on the coast of the Central Sumatra Basin. Hydrocarbon reservoirs were found in the Bekasi, Bangko, and Menggala Formations and parts of the Pematang Formation; source rock was found in parts of the Menggala and Pematang Formations. The determination of reservoir layers and source rock was strengthened by the results of the analysis of wells located on seismic trajectories. Faults were useful as migration pathways for hydrocarbon fluids from source rock to reservoirs so that a petroleum system was formed in the area. This layer had immature and mature parent rocks. It was concluded that the depositional environment and the petroleum system in the wells in the area could be identified.Cekungan Sumatra Tengah merupakan salah satu cekungan penghasil hidrokarbon di Indonesia, karena keterbatasan ekplorasi dan studi, perkembangan cekungan tersebut mengalami hambatan. Penelitian ini bertujuan untuk mengidentifikasi lingkungan pengendapan dan sistem petroleum melalui studi stratigrafi seismik dan sumur. Penelitian ini menggunakan metode seismik dengan software Hampson Russell dan Petrel. Data log membantu pengolahan data seismik dengan software Interactive Petrophysic (IP) dan Techlog untuk pengolahan data sumur. Zona penelitian ini memiliki lima sekuen pengendapan yang sebagian besar terbentuk di lingkungan pengendapan alur bercabang dan estuari. Terdapat dua batuan induk potensial, yakni pada Formasi Pematang dan lapisan serpih pada TST-1 atas. Hasil analisis sekuen stratigrafi pada penampang seismik, sistem petroleum teridentifikasi pada Sumur Merak, Melibur, dan Garib di pesisir Cekungan Sumatra Tengah. Reservoar hidrokarbon terdapat di Formasi Bekasap, Bangko, Menggala, dan sebagian Formasi Pematang; batuan induk terdapat di sebagian Formasi Menggala dan Pematang. Penentuan lapisan reservoar dan batuan induk diperkuat oleh hasil analisis sumur yang terletak pada lintasan seismik. Patahan berguna sebagai jalur migrasi fluida hidrokarbon dari batuan induk hingga reservoar, sehingga terbentuk sistem petroleum pada daerah tersebut. Lapisan ini memiliki batuan induk yang belum matang dan matang. Karenanya dapat disimpulkan bahwa lingkungan pengendapan dan sistem petroleum pada sumur-sumur di daerah tersebut dapat diketahui

Genetic variation and quantitative trait loci associated with developmental stability and the environmental correlation between traits in maize

11 páginas, 4 figuras, 5 tablas.There is limited experimental information about the genetic basis of micro-environmental variance (VE) (developmental stability) and environmental correlations. This study, by using a population of maize recombinant inbred lines (RIL) and simple sequence repeat (SSR) polymorphic markers, aims at the following: firstly, to quantify the genetic component of the VE or developmental stability for four traits in maize and the environmental correlation between these traits, and secondly, to identify quantitative trait loci (QTLs) that influence these quantities. We found that, when estimating variances and correlations and testing their homogeneity, estimates and tests are needed that are not highly dependent on normality assumptions. There was significant variation among the RILs in VE and in the environmental correlation for some of the traits, implying genetic heterogeneity in the VE and environmental correlations. The genetic coefficient of variation of the environmental variance (GCVVE) was estimated to be 20%, which is lower than estimates obtained for other species. A few genomic regions involved in the stability of one trait or two traits were detected, and these did not have an important influence on the mean of the trait. One region that could be associated with the environmental correlations between traits was also detected.The National Plan for Research and Development of Spain (project code AGL2006-13140) is acknowledged for financial support. B. Ordas acknowledges a contract from the Spanish National Research Council (I3P Program).Peer reviewe

Identification of genes related to germination in aged maize seed by screening natural variability

Ageing reduces vigour and viability in maize inbred lines due to non-heritable degenerative changes. Besides non-heritable genetic changes due to chromosome aberrations and damage in the DNA sequence, heritable changes during maize conservation have been reported. Genetic variability among aged seeds of inbred lines could be used for association studies with seed germination. The objective of this study was to identify genes related to germination in aged seeds. The sweet corn inbred line P39 and the field corn inbred line EP44 were used as plant material. Bulks of living and dead seeds after 20 and 22 years of storage were compared by using simple sequence repeats (SSRs) and, when the bulks differed for a marker, the individual grains were genotyped. Differences between dead and living seeds could be explained by residual variability, spontaneous mutation, or ageing. Variability was larger for chromosome 7 than for other chromosomes, and for distal than for proximal markers, suggesting some relationships between position in the genome and viability in aged seed. Polymorphic SSRs between living and dead seeds were found in six known genes, including pathogenesis-related protein 2, superoxide dismutase 4, catalase 3, opaque endosperm 2, and metallothionein1 that were related to germination, along with golden plant 2. In addition, five novel candidate genes have been identified; three of them could be involved in resistance to diseases, one in detoxification of electrophillic compounds, and another in transcription regulation. Therefore, genetic variability among aged seeds of inbreds was useful for preliminary association analysis to identify candidate genes

Correlation of total phenolic and flavonoid contents on the antioxidant activity of Psychotria gitingensis and Psychotria pilosella

The genus Psychotria (Rubiaceae) possesses various biological properties, ranging from phytochemical and pharmacological properties of their chemical constituents to traditional medical applications. Most Psychotria species remain unstudied despite high diversity and endemism in the Philippines. Hence, this study investigates the total phenolic and flavonoid contents of Psychotria gitingensis and Psychotria pilosella methanolic crude extracts, evaluates their antioxidant properties, and assesses their antibacterial properties. Results revealed that P. gitingensis fruit extract exhibited the highest phenolic content (254.45 ± 6.63 mg GAE/g extract) and flavonoid content (9.85 ± 0.49 mg QE/g). In addition, it also displayed the highest antioxidant activity (0.993 ± 0.041 mg/mg) in the ABTS assay. P. pilosella leaf extract exhibited the highest antioxidant activity in DPPH (70.53% ± 1.50), and P. gitingensis leaf extract showed the highest iron-reducing antioxidant power (86.06% ± 0.73) in FRAP. Paper disk diffusion tests, however, did not exhibit activity against selected nosocomial pathogens. The results of this study contribute to expanding the field of knowledge on alternative treatments and paving the way for the development of new medicinal products

ODS ferritic steels obtained from gas atomized powders through the STARS processing route: Reactive synthesis as an alternative to mechanical alloying

Oxide Dispersion Strengthened Ferritic Stainless Steels (ODS FS) are candidate materials for structural components in fusion reactors. Their ultrafine microstructure and the presence of a very stable dispersion of Y-Ti-O nanoclusters provide reasonable fracture toughness, high mechanical and creep strength, and resistance to radiation damage at the operation temperature, up to about 750 °C. An innovative route to produce ODS FS with composition Fe-14Cr-2W-0.3Ti-0.3Y2O3 (wt.%), named STARS (Surface Treatment of gas Atomized powder followed by Reactive Synthesis), is presented. This route avoids the mechanical alloying (MA) of the elemental or prealloyed powders with yttria to dissolve the yttrium in the ferritic matrix. In this study, starting powders containing Ti and Y are obtained by gas atomization at laboratory and industrial scale. Then, a metastable Cr- and Fe- rich oxide layer is formed on the surface of the powder particles. During consolidation by HIP the metastable oxide layer at Prior Particle Boundaries (PPBs) dissociates, the oxygen diffuses towards saturated solutions or metallic Ti- and Y-rich particles, and Y-Ti-O nano-oxides (mainly Y2TiO5) precipitate in the ferritic matrix. Detailed Microstructural characterization by X-ray Photoelectron Spectroscopy (XPS), X-ray Absorption Spectroscopy (XAS), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of powders and consolidated materials is presented and correlated with mechanical behaviour

Analysis of RNAseq datasets from a comparative infectious disease zebrafish model using GeneTiles bioinformatics.

Animal science

Mechanistic and quantitative understanding of pharmacokinetics in zebrafish larvae through nanoscale blood sampling and metabolite modelling of paracetamol

Zebrafish larvae are increasingly used for pharmacological research, but internal drug exposure is often not measured. Understanding pharmacokinetics is necessary for reliable translation of pharmacological results to higher vertebrates, including humans. Quantification of drug clearance and distribution requires measurements of blood concentrations. Additionally, measuring drug metabolites is of importance to understand clearance in this model organism mechanistically. We therefore mechanistically study and quantify pharmacokinetics in zebrafish larvae, and compare this to higher vertebrates, using paracetamol (acetaminophen) as paradigm compound. A method was developed to sample blood from zebrafish larvae at five days post fertilization. Blood concentrations of paracetamol and its major metabolites, paracetamol-glucuronide and paracetamol-sulphate, were measured. Blood concentration data were combined with measured amounts in larval homogenates and excreted amounts and simultaneously analysed through non-linear mixed effects modelling, quantifying absolute clearance and distribution volume. Blood sampling from zebrafish larvae was most successful from the posterior cardinal vein with median volume (interquartile range) of 1.12 (0.676-1.66) nL per blood sample. Samples were pooled (n=15-35) to reach measurable levels. Paracetamol blood concentrations at steady state were only 10% of the external paracetamol concentration. Paracetamol-sulphate was the major metabolite and its formation was quantified using a time-dependent metabolic formation rate. Absolute clearance and distribution volume correlated well to reported values in higher vertebrates, including humans. Based on blood concentrations and advanced data analysis, the mechanistic and quantitative understanding of paracetamol pharmacokinetics in zebrafish larvae has been established. This will improve the translational value of this vertebrate model organism in drug discovery and development.Analytical BioSciencesPharmacolog

The mangal flora diversity of Del Carmen Forest on Siargao Island, Philippines

The municipality of Del Carmen, Siargao Island, hosts one of the Philippines&amp;rsquo; most important contiguous mangrove stands. However, there is limited knowledge about the area&amp;rsquo;s floral assemblages and communities. Hence, we provide a comprehensive species list through exhaustive botanical explorations within its 11 barangays. We report 166 species in 145 genera and 73 families, of which 20 are true mangrove species. Twenty species are Philippine endemics, and seven are threatened based on the IUCN listing. The most dominant families in the area in terms of density are Rhizophoraceae and Rubiaceae, and the dominating species include Rhizophora mucronata Lam. and R. apiculata Blume. Our results exhibit a very high diversity for the entire municipality, with barangays Del Carmen and Katipunan demonstrating the highest diversity among the 11 barangays. We emphasize the value of floristic surveys as essential baseline information in formulating effective conservation and management strategies for these vital wetland ecosystems