Quantitative trait loci for head-bug resistance in sorghum

QTLs were mapped in F2 progeny derived from a cross between the head-bug resistant sorghum cultivar Malisor 84-7 and susceptible S 34. The phenotypic evaluation was conducted in Mali. The mapped population consisted of 217 F2 plants, with 345 homologous and heterologous RFLP probes and 49 microsatellite markers tested. Eighty-one RFLP markers revealed polymorphism between the two parents, and 14 microsatellite markers gave usable amplification products. A genetic map including 92 loci distributed over 13 linkage groups, and covering a total distance of 1160 cM was built. Three significant and seven putative QTLs were detected and placed on the ma

Quantitative trait loci for head-bug resistance in sorghum

QTLs were mapped in F2 progeny derived from a cross between the head-bug resistant sorghum cultivar Malisor 84-7 and susceptible S 34. The phenotypic evaluation was conducted in Mali. The mapped population consisted of 217 F2 plants, with 345 homologous and heterologous RFLP probes and 49 microsatellite markers tested. Eighty-one RFLP markers revealed polymorphism between the two parents, and 14 microsatellite markers gave usable amplification products. A genetic map including 92 loci distributed over 13 linkage groups, and covering a total distance of 1160 cM was built. Three significant and seven putative QTLs were detected and placed on the ma

Quantitative trait loci for head-bug resistance in sorghum

QTLs were mapped in F2 progeny derived from a cross between the head-bug resistant sorghum cultivar Malisor 84-7 and susceptible S 34. The phenotypic evaluation was conducted in Mali. The mapped population consisted of 217 F2 plants, with 345 homologous and heterologous RFLP probes and 49 microsatellite markers tested. Eighty-one RFLP markers revealed polymorphism between the two parents, and 14 microsatellite markers gave usable amplification products. A genetic map including 92 loci distributed over 13 linkage groups, and covering a total distance of 1160 cM was built. Three significant and seven putative QTLs were detected and placed on the map

Quantitative trait loci for head-bug resistance in sorghum

QTLs were mapped in F2 progeny derived from a cross between the head-bug resistant sorghum cultivar Malisor 84-7 and susceptible S 34. The phenotypic evaluation was conducted in Mali. The mapped population consisted of 217 F2 plants, with 345 homologous and heterologous RFLP probes and 49 microsatellite markers tested. Eighty-one RFLP markers revealed polymorphism between the two parents, and 14 microsatellite markers gave usable amplification products. A genetic map including 92 loci distributed over 13 linkage groups, and covering a total distance of 1160 cM was built. Three significant and seven putative QTLs were detected and placed on the map

Quantitative trait loci for head bug resistance in sorghum

An experiment was conducted during the 1997/99 cropping seasons, in Mali, France, to study the inheritance for resistance to head bug (Eurystylus oldi) of sorghum progenies using quantitative trait loci (QTL) maps. Cultivars Malisor 84-7 (resistant) and S 34 (susceptible) were used as parents. To build the sorghum genetic map, 345 restriction fragment length polymorphism (RFLP) probes in combination with 6 restriction enzymes (BamHI, DraI, EcoRI, EcoRV, HindIII and SstI) were screened for their ability to reveal polymorphism. Thousand kernel weight (TKW) and germination rate at grain maturity were measured. Head bug damage was assessed visually on a 1 to 9 scale on the infested part of the panicle (NOTF2). Among the 345 RFLP probes, 81 revealed polymorphism between the parents. Additionally, 14 microsatellite markers gave amplification products. The genetic map based on Malisor 84-7 × S 34 includes 13 linkage groups (LGs) covering a total distance of 1160 cM. Three significant and 7 putative QTLs were detected. One QTL for TKW reduction that accounted for 13% of the phenotypic variation was detected on LG C2. For this QTL, resistance is conditioned by the Malisor 84-7 allele and is dominant. Two QTLs were detected on LG D and LG E for visual damage score under natural head bug infestation, explaining 16 and 26% of the phenotypic variation for this trait, respectively. Resistance from the QTL on LG D is conditioned by the S 34 allele, whereas resistance from the QTL on LG E is provided by the Malisor 84-7 allele. In both cases, resistance is recessive. No significant QTLs were detected for NOTF2 and germination rate, but co-localization of 2 putative QTLs for these traits was observed on LG G2, and in both cases, resistance is conditioned by the S 34 allele

A reference microsatellite kit to assess for genetic diversity of Sorghum bicolor (Poaceae)

Premise of the study: Discrepancies in terms of genotyping data are frequently observed when comparing simple sequence repeat (SSR) data sets across genotyping technologies and laboratories. This technical concern introduces biases that hamper any synthetic studies or comparison of genetic diversity between collections. To prevent this for Sorghum bicolor, we developed a control kit of 48 SSR markers. • Methods and Results: One hundred seventeen markers were selected along the genome to provide coverage across the length of all 10 sorghum linkage groups. They were tested for polymorphism and reproducibility across two laboratories (Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement [CIRAD], France, and International Crops Research Institute for the Semi-Arid Tropics [ICRISAT], India) using two commonly used genotyping technologies (polyacrylamide gel–based technology with LI-COR sequencing machines and capillary systems with ABI sequencing apparatus) with DNA samples from a diverse set of 48 S. bicolor accessions. • Conclusions: A kit for diversity analysis (http://sat.cirad.fr/sat/sorghum_SSR_kit/) was developed. It contains information on 48 technically robust sorghum microsatellite markers and 10 DNA controls. It can further be used to calibrate sorghum SSR genotyping data acquired with different technologies and compare those to genetic diversity reference

Massive Sorghum Collection Genotyped with SSR Markers to Enhance Use of Global Genetic Resources

Large ex situ collections require approaches for sampling manageable amounts of germplasm for in-depth characterization and use. We present here a large diversity survey in sorghum with 3367 accessions and 41 reference nuclear SSR markers. Of 19 alleles on average per locus, the largest numbers of alleles were concentrated in central and eastern Africa. Cultivated sorghum appeared structured according to geographic regions and race within region. A total of 13 groups of variable size were distinguished. The peripheral groups in western Africa, southern Africa and eastern Asia were the most homogeneous and clearly differentiated. Except for Kafir, there was little correspondence between races and marker-based groups. Bicolor, Caudatum, Durra and Guinea types were each dispersed in three groups or more. Races should therefore better be referred to as morphotypes. Wild and weedy accessions were very diverse and scattered among cultivated samples, reinforcing the idea that large gene-flow exists between the different compartments. Our study provides an entry to global sorghum germplasm collections. Our reference marker kit can serve to aggregate additional studies and enhance international collaboration. We propose a core reference set in order to facilitate integrated phenotyping experiments towards refined functional understanding of sorghum diversity

Cleveland: “Where rock began to roll”?

Focused on Cleveland, Ohio, this chapter asks how ‘music cities’ make their claims-to-fame. What underscores Cleveland’s assertion as the “birthplace” of rock ‘n’ roll, and since 1995, the site of the Rock and Roll Hall of Fame? Drawing from archival research, the chapter explores a micro-historical case study of the city’s popular music heritage. Cleveland claims several notable “firsts”, including the “first” rock ‘n’ roll concert—the Moondog Coronation Ball on 21 March 1952. The chapter also recounts the story of local record store, Record Rendezvous, where legend has it that the phrase “rock ‘n’ roll” was invented. Finally, the chapter recounts how these legacies were mobilized and mythologized, especially during the 1980s when Cleveland successfully positioned itself as a “city of origin” and a serious contender in the campaign to become the future site of the Rock and Roll Hall of Fame

Insights into the Musa genome: Syntenic relationships to rice and between Musa species

<p>Abstract</p> <p>Background</p> <p><it>Musa </it>species (Zingiberaceae, Zingiberales) including bananas and plantains are collectively the fourth most important crop in developing countries. Knowledge concerning <it>Musa </it>genome structure and the origin of distinct cultivars has greatly increased over the last few years. Until now, however, no large-scale analyses of <it>Musa </it>genomic sequence have been conducted. This study compares genomic sequence in two <it>Musa </it>species with orthologous regions in the rice genome.</p> <p>Results</p> <p>We produced 1.4 Mb of <it>Musa </it>sequence from 13 BAC clones, annotated and analyzed them along with 4 previously sequenced BACs. The 443 predicted genes revealed that Zingiberales genes share GC content and distribution characteristics with eudicot and Poaceae genomes. Comparison with rice revealed microsynteny regions that have persisted since the divergence of the Commelinid orders Poales and Zingiberales at least 117 Mya. The previously hypothesized large-scale duplication event in the common ancestor of major cereal lineages within the Poaceae was verified. The divergence time distributions for <it>Musa</it>-Zingiber (Zingiberaceae, Zingiberales) orthologs and paralogs provide strong evidence for a large-scale duplication event in the <it>Musa </it>lineage after its divergence from the Zingiberaceae approximately 61 Mya. Comparisons of genomic regions from <it>M. acuminata </it>and <it>M. balbisiana </it>revealed highly conserved genome structure, and indicated that these genomes diverged circa 4.6 Mya.</p> <p>Conclusion</p> <p>These results point to the utility of comparative analyses between distantly-related monocot species such as rice and <it>Musa </it>for improving our understanding of monocot genome evolution. Sequencing the genome of <it>M. acuminata </it>would provide a strong foundation for comparative genomics in the monocots. In addition a genome sequence would aid genomic and genetic analyses of cultivated <it>Musa </it>polyploid genotypes in research aimed at localizing and cloning genes controlling important agronomic traits for breeding purposes.</p