A framework genetic map for \u3ci\u3eMiscanthus sinensis\u3c/i\u3e from RNAseq-based markers shows recent tetraploidy

Background: Miscanthus (subtribe Saccharinae, tribe Andropogoneae, family Poaceae) is a genus of temperate perennial C4 grasses whose high biomass production makes it, along with its close relatives sugarcane and sorghum, attractive as a biofuel feedstock. The base chromosome number of Miscanthus (x = 19) is different from that of other Saccharinae and approximately twice that of the related Sorghum bicolor (x = 10), suggesting largescale duplications may have occurred in recent ancestors of Miscanthus. Owing to the complexity of the Miscanthus genome and the complications of self-incompatibility, a complete genetic map with a high density of markers has not yet been developed. Results: We used deep transcriptome sequencing (RNAseq) from two M. sinensis accessions to define 1536 single nucleotide variants (SNVs) for a GoldenGate™ genotyping array, and found that simple sequence repeat (SSR) markers defined in sugarcane are often informative in M. sinensis. A total of 658 SNP and 210 SSR markers were validated via segregation in a full sibling F1 mapping population. Using 221 progeny from this mapping population, we constructed a genetic map for M. sinensis that resolves into 19 linkage groups, the haploid chromosome number expected from cytological evidence. Comparative genomic analysis documents a genomewide duplication in Miscanthus relative to Sorghum bicolor, with subsequent insertional fusion of a pair of chromosomes. The utility of the map is confirmed by the identification of two paralogous C4-pyruvate, phosphate dikinase (C4-PPDK) loci in Miscanthus, at positions syntenic to the single orthologous gene in Sorghum. Conclusions: The genus Miscanthus experienced an ancestral tetraploidy and chromosome fusion prior to its diversification, but after its divergence from the closely related sugarcane clade. The recent timing of this tetraploidy complicates discovery and mapping of genetic markers for Miscanthus species, since alleles and fixed differences between paralogs are comparable. These difficulties can be overcome by careful analysis of segregation patterns in a mapping population and genotyping of doubled haploids. The genetic map for Miscanthus will be useful in biological discovery and breeding efforts to improve this emerging biofuel crop, and also provide a valuable resource for understanding genomic responses to tetraploidy and chromosome fusion

A framework genetic map for Miscanthus sinensis from RNAseq-based markers shows recent tetraploidy

Abstract Background Miscanthus (subtribe Saccharinae, tribe Andropogoneae, family Poaceae) is a genus of temperate perennial C4 grasses whose high biomass production makes it, along with its close relatives sugarcane and sorghum, attractive as a biofuel feedstock. The base chromosome number of Miscanthus (x = 19) is different from that of other Saccharinae and approximately twice that of the related Sorghum bicolor (x = 10), suggesting large-scale duplications may have occurred in recent ancestors of Miscanthus. Owing to the complexity of the Miscanthus genome and the complications of self-incompatibility, a complete genetic map with a high density of markers has not yet been developed. Results We used deep transcriptome sequencing (RNAseq) from two M. sinensis accessions to define 1536 single nucleotide variants (SNVs) for a GoldenGate™ genotyping array, and found that simple sequence repeat (SSR) markers defined in sugarcane are often informative in M. sinensis. A total of 658 SNP and 210 SSR markers were validated via segregation in a full sibling F1 mapping population. Using 221 progeny from this mapping population, we constructed a genetic map for M. sinensis that resolves into 19 linkage groups, the haploid chromosome number expected from cytological evidence. Comparative genomic analysis documents a genome-wide duplication in Miscanthus relative to Sorghum bicolor, with subsequent insertional fusion of a pair of chromosomes. The utility of the map is confirmed by the identification of two paralogous C4-pyruvate, phosphate dikinase (C4-PPDK) loci in Miscanthus, at positions syntenic to the single orthologous gene in Sorghum. Conclusions The genus Miscanthus experienced an ancestral tetraploidy and chromosome fusion prior to its diversification, but after its divergence from the closely related sugarcane clade. The recent timing of this tetraploidy complicates discovery and mapping of genetic markers for Miscanthus species, since alleles and fixed differences between paralogs are comparable. These difficulties can be overcome by careful analysis of segregation patterns in a mapping population and genotyping of doubled haploids. The genetic map for Miscanthus will be useful in biological discovery and breeding efforts to improve this emerging biofuel crop, and also provide a valuable resource for understanding genomic responses to tetraploidy and chromosome fusion

Papel dos tricomas glandulares da folha do tomateiro na oviposição de Tuta absoluta

Os tricomas glandulares presentes nas folhas e ramos das plantas do gênero Lycopersicon são responsáveis pela secreção de metabólitos de diferentes naturezas. A presença de alguns desses compostos tem sido associada à resistência do tomate a diferentes insetos. A traça-do-tomateiro, Tuta absoluta (Meyrick), é uma das pragas mais nocivas da América do Sul. O adulto oviposita sobre as folhas do tomate e suas larvas abrem galerias no mesófilo das folhas, ramos, flores e frutos. As espécies silvestres do tomate conservam a capacidade de biossintetizar compostos químicos que lhes conferem resistência a esta praga. No presente trabalho, foi avaliada a preferência para oviposição desse inseto sobre folhas com e sem tricomas glandulares de L. esculentum (Mill.) cv. Uco Plata, suscetível, e de L. hirsutum f. glabratum (Mull.) PI 134417, espécie silvestre afim ao tomate, e resistente à traça. Os resultados sugerem que as fêmeas ovipositam indistintamente sobre as folhas de ambas espécies, independentemente da presença, ou não, dos tricomas glandulares. E a presença destes e de seus exsudatos não têm efeito inibidor na oviposição do inseto

Genome biology of the paleotetraploid perennial biomass crop Miscanthus

Miscanthus is a perennial wild grass that is of global importance for paper production, roofing, horticultural plantings, and an emerging highly productive temperate biomass crop. We report a chromosome-scale assembly of the paleotetraploid M. sinensis genome, providing a resource for Miscanthus that links its chromosomes to the related diploid Sorghum and complex polyploid sugarcanes. The asymmetric distribution of transposons across the two homoeologous subgenomes proves Miscanthus paleo-allotetraploidy and identifies several balanced reciprocal homoeologous exchanges. Analysis of M. sinensis and M. sacchariflorus populations demonstrates extensive interspecific admixture and hybridization, and documents the origin of the highly productive triploid bioenergy crop M. x giganteus. Transcriptional profiling of leaves, stem, and rhizomes over growing seasons provides insight into rhizome development and nutrient recycling, processes critical for sustainable biomass accumulation in a perennial temperate grass. The Miscanthus genome expands the power of comparative genomics to understand traits of importance to Andropogoneae grasses

The species-area relationship: new challenges for an old pattern

The species-area relationship (i.e., the relationship between area and the number of species found in that area) is one of longest and most frequently studied patterns in nature. Yet there remain some important and interesting questions on the nature of this relationship, its causality, quantification and application for both ecologists and conservation biologists.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Settlements of spread footing foundations on quick clay stabilized with lime and cement

Since the early 70's ground improvement by use of stabilizing agents such as lime and cement has been widely used for solving geotechnical problems; either as a way to improve slope stability, reduce settlements or vibrations, or to reinforce the inside of braced excavations. On a recently constructed motorway project in south of Trondheim, two bridges were founded with spread footings on a medium stiff, quick Norwegian clay stabilized with lime and cement. The post-tensioned concrete bridges are 78 m and 110 m long, with respectively 4 and 5 spans. In this article, evaluation of various foundation solutions is performed based on cost estimates. This showed that the cost of founding the bridges on stabilized ground to be the most viable alternative. Further, the article discusses the calculation methods used to evaluate settlement properties of the foundations. Settlement measurement is performed for about two years after completion of the structures. A comparison of the calculated deformations and measured settlements is conducted in this work. Settlements are measured to be 3-10 mm after one and a half year, except for one abutment that measured 21 mm of vertical displacements. Then the deformations nearly stop for many of the foundations. The measurements show a higher deformation rate in the first six months after casting of the bridge slab, than expected from the calculations. After some time, the measurements coincide well within the upper and lower bounds in the calculations done in the geotechnical design. Possible reasons for these observations are discussed.publishedVersio

Erfaringer fra studietur til Ministry of Transportation (British Columbia) og Canadian Avalanche Center

Denne erfaringsrapporten omhandler erfaringer og inntrykk fra en studietur til British Columbia og Alberta, Canada. Gunne Håland (VD-TMT), Tore Humstad (VD-TMT) og Eivind Juvik (RM-Ressursavdelingen) besøkte i mars 2012 Ministry of Transportation and Infrastructure (MoT) og Canadian Avalanche Center (CAC), hvor sistnevnte besøk var sammen med representanter fra NVE og met.no. Formålet med turen var å utvikle kompetansen innen skredsikring, -varsling og -beredskap og bringe ideer og metoder hjem til våre prosjekter. I tillegg var målet å bidra til det norske skredvarslingsprosjektet og NIFS gjennom erfaringsutveksling med reisefølget fra NVE og met.n

Settlements of spread footing foundations on quick clay stabilized with lime and cement

Since the early 70's ground improvement by use of stabilizing agents such as lime and cement has been widely used for solving geotechnical problems; either as a way to improve slope stability, reduce settlements or vibrations, or to reinforce the inside of braced excavations. On a recently constructed motorway project in south of Trondheim, two bridges were founded with spread footings on a medium stiff, quick Norwegian clay stabilized with lime and cement. The post-tensioned concrete bridges are 78 m and 110 m long, with respectively 4 and 5 spans. In this article, evaluation of various foundation solutions is performed based on cost estimates. This showed that the cost of founding the bridges on stabilized ground to be the most viable alternative. Further, the article discusses the calculation methods used to evaluate settlement properties of the foundations. Settlement measurement is performed for about two years after completion of the structures. A comparison of the calculated deformations and measured settlements is conducted in this work. Settlements are measured to be 3-10 mm after one and a half year, except for one abutment that measured 21 mm of vertical displacements. Then the deformations nearly stop for many of the foundations. The measurements show a higher deformation rate in the first six months after casting of the bridge slab, than expected from the calculations. After some time, the measurements coincide well within the upper and lower bounds in the calculations done in the geotechnical design. Possible reasons for these observations are discussed

Tropical montane cloud forests : proceedings of an international symposium at San Juan, Puerto Rico, 31 May-5 June 1993

For more about the East-West Center, see http://www.eastwestcenter.org/International Institute of Tropical Forestry (Rio Piedras, San Juan, P.R.). Produced by the East-West Center Program on Environment with the collaboration and assistance of International Hydrological Programme, International Institute of Tropical Forestry."--T.p