84 research outputs found

    Genome size estimation of three endemic plant taxa from Malta

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    The Maltese archipelago has several endemic species adapted to an arid and hot climate. Due to its limited land area (316 km2) and high human population density most of these endemics are endangered or critically so. Few genomic studies have been carried out on this flora to date. The purpose of the present study was to estimate genome sizes (1C-values) of three of these endemic taxa using flow cytometry. The genome size of Cheirolophus crassifolius, was found to be 0.98 pg. This is the highest recorded value in this genus and does not fit published values and trends. The genome size of the octoploid Sedum album subsp. rupimelitense was found to be 1.05 pg and that of Anthyllis hermanniae subsp. melitensis 0.52 pg.peer-reviewe

    Molecular and cytological characterization of the global Musa germplasm collection provides insights into the treasure of banana diversity

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    © 2016, The Author(s). Bananas (Musa spp.) are one of the main fruit crops grown worldwide. With the annual production reaching 144 million tons, their production represents an important contribution to the economies of many countries in Asia, Africa, Latin-America and Pacific Islands. Most importantly, bananas are a staple food for millions of people living in the tropics. Unfortunately, sustainable banana production is endangered by various diseases and pests, and the breeding for resistant cultivars relies on a far too small base of genetic variation. Greater diversity needs to be incorporated in breeding, especially of wild species. Such work requires a large and thoroughly characterized germplasm collection, which also is a safe depository of genetic diversity. The largest ex situ Musa germplasm collection is kept at the International Transit Centre (ITC) in Leuven (Belgium) and currently comprises over 1500 accessions. This report summarizes the results of systematic cytological and molecular characterization of the Musa ITC collection. By December 2015, 630 accessions have been genotyped. The SSR markers confirmed the previous morphological based classification for 84% of ITC accessions analyzed. The remaining 16% of the genotyped entries may need field verification by taxonomist to decide if the unexpected classification by SSR genotyping was correct. The ploidy level estimation complements the molecular data. The genotyping continues for the entire ITC collection, including newly introduced accessions, to assure that the genotype of each accession is known in the largest global Musa gene bank. Open Access ispartof: Biodiversity and Conservation vol:26 issue:4 pages:801-824 status: publishe

    In Depth Characterization of Repetitive DNA in 23 Plant Genomes Reveals Sources of Genome Size Variation in the Legume Tribe Fabeae

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    The differential accumulation and elimination of repetitive DNA are key drivers of genome size variation in flowering plants, yet there have been few studies which have analysed how different types of repeats in related species contribute to genome size evolution within a phylogenetic context. This question is addressed here by conducting large-scale comparative analysis of repeats in 23 species from four genera of the monophyletic legume tribe Fabeae, representing a 7.6-fold variation in genome size. Phylogenetic analysis and genome size reconstruction revealed that this diversity arose from genome size expansions and contractions in different lineages during the evolution of Fabeae. Employing a combination of low-pass genome sequencing with novel bioinformatic approaches resulted in identification and quantification of repeats making up 55-83% of the investigated genomes. In turn, this enabled an analysis of how each major repeat type contributed to the genome size variation encountered. Differential accumulation of repetitive DNA was found to account for 85% of the genome size differences between the species, and most (57%) of this variation was found to be driven by a single lineage of Ty3/gypsy LTR-retrotransposons, the Ogre elements. Although the amounts of several other lineages of LTR-retrotransposons and the total amount of satellite DNA were also positively correlated with genome size, their contributions to genome size variation were much smaller (up to 6%). Repeat analysis within a phylogenetic framework also revealed profound differences in the extent of sequence conservation between different repeat types across Fabeae. In addition to these findings, the study has provided a proof of concept for the approach combining recent developments in sequencing and bioinformatics to perform comparative analyses of repetitive DNAs in a large number of non-model species without the need to assemble their genomes

    The ITS1-5.8S-ITS2 Sequence Region in the Musaceae: Structure, Diversity and Use in Molecular Phylogeny

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    Genes coding for 45S ribosomal RNA are organized in tandem arrays of up to several thousand copies and contain 18S, 5.8S and 26S rRNA units separated by internal transcribed spacers ITS1 and ITS2. While the rRNA units are evolutionary conserved, ITS show high level of interspecific divergence and have been used frequently in genetic diversity and phylogenetic studies. In this work we report on the structure and diversity of the ITS region in 87 representatives of the family Musaceae. We provide the first detailed information on ITS sequence diversity in the genus Musa and describe the presence of more than one type of ITS sequence within individual species. Both Sanger sequencing of amplified ITS regions and whole genome 454 sequencing lead to similar phylogenetic inferences. We show that it is necessary to identify putative pseudogenic ITS sequences, which may have negative effect on phylogenetic reconstruction at lower taxonomic levels. Phylogenetic reconstruction based on ITS sequence showed that the genus Musa is divided into two distinct clades – Callimusa and Australimusa and Eumusa and Rhodochlamys. Most of the intraspecific banana hybrids analyzed contain conserved parental ITS sequences, indicating incomplete concerted evolution of rDNA loci. Independent evolution of parental rDNA in hybrids enables determination of genomic constitution of hybrids using ITS. The observation of only one type of ITS sequence in some of the presumed interspecific hybrid clones warrants further study to confirm their hybrid origin and to unravel processes leading to evolution of their genomes

    Molecular and cytological characterization of the global Musa germplasm collection provides insights into the treasure of banana diversity

    Get PDF
    © 2016, The Author(s). Bananas (Musa spp.) are one of the main fruit crops grown worldwide. With the annual production reaching 144 million tons, their production represents an important contribution to the economies of many countries in Asia, Africa, Latin-America and Pacific Islands. Most importantly, bananas are a staple food for millions of people living in the tropics. Unfortunately, sustainable banana production is endangered by various diseases and pests, and the breeding for resistant cultivars relies on a far too small base of genetic variation. Greater diversity needs to be incorporated in breeding, especially of wild species. Such work requires a large and thoroughly characterized germplasm collection, which also is a safe depository of genetic diversity. The largest ex situ Musa germplasm collection is kept at the International Transit Centre (ITC) in Leuven (Belgium) and currently comprises over 1500 accessions. This report summarizes the results of systematic cytological and molecular characterization of the Musa ITC collection. By December 2015, 630 accessions have been genotyped. The SSR markers confirmed the previous morphological based classification for 84% of ITC accessions analyzed. The remaining 16% of the genotyped entries may need field verification by taxonomist to decide if the unexpected classification by SSR genotyping was correct. The ploidy level estimation complements the molecular data. The genotyping continues for the entire ITC collection, including newly introduced accessions, to assure that the genotype of each accession is known in the largest global Musa gene bank. Open Access ispartof: Biodiversity and Conservation vol:26 issue:4 pages:801-824 status: publishe

    Shifting the limits in wheat research and breeding using a fully annotated reference genome

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    Introduction: Wheat (Triticum aestivum L.) is the most widely cultivated crop on Earth, contributing about a fifth of the total calories consumed by humans. Consequently, wheat yields and production affect the global economy, and failed harvests can lead to social unrest. Breeders continuously strive to develop improved varieties by fine-tuning genetically complex yield and end-use quality parameters while maintaining stable yields and adapting the crop to regionally specific biotic and abiotic stresses. Rationale: Breeding efforts are limited by insufficient knowledge and understanding of wheat biology and the molecular basis of central agronomic traits. To meet the demands of human population growth, there is an urgent need for wheat research and breeding to accelerate genetic gain as well as to increase and protect wheat yield and quality traits. In other plant and animal species, access to a fully annotated and ordered genome sequence, including regulatory sequences and genome-diversity information, has promoted the development of systematic and more time-efficient approaches for the selection and understanding of important traits. Wheat has lagged behind, primarily owing to the challenges of assembling a genome that is more than five times as large as the human genome, polyploid, and complex, containing more than 85% repetitive DNA. To provide a foundation for improvement through molecular breeding, in 2005, the International Wheat Genome Sequencing Consortium set out to deliver a high-quality annotated reference genome sequence of bread wheat. Results: An annotated reference sequence representing the hexaploid bread wheat genome in the form of 21 chromosome-like sequence assemblies has now been delivered, giving access to 107,891 high-confidence genes, including their genomic context of regulatory sequences. This assembly enabled the discovery of tissue- and developmental stage–related gene coexpression networks using a transcriptome atlas representing all stages of wheat development. The dynamics of change in complex gene families involved in environmental adaptation and end-use quality were revealed at subgenome resolution and contextualized to known agronomic single-gene or quantitative trait loci. Aspects of the future value of the annotated assembly for molecular breeding and research were exemplarily illustrated by resolving the genetic basis of a quantitative trait locus conferring resistance to abiotic stress and insect damage as well as by serving as the basis for genome editing of the flowering-time trait. Conclusion: This annotated reference sequence of wheat is a resource that can now drive disruptive innovation in wheat improvement, as this community resource establishes the foundation for accelerating wheat research and application through improved understanding of wheat biology and genomics-assisted breeding. Importantly, the bioinformatics capacity developed for model-organism genomes will facilitate a better understanding of the wheat genome as a result of the high-quality chromosome-based genome assembly. By necessity, breeders work with the genome at the whole chromosome level, as each new cross involves the modification of genome-wide gene networks that control the expression of complex traits such as yield. With the annotated and ordered reference genome sequence in place, researchers and breeders can now easily access sequence-level information to precisely define the necessary changes in the genomes for breeding programs. This will be realized through the implementation of new DNA marker platforms and targeted breeding technologies, including genome editing

    Logistics Focused on Distribution Logistics in a Chosen Company

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    Tato diplomová práce se zabývá logistikou se zaměřením na distribuční logistiku u vybraného podniku. V teoretické části práce jsou vymezeny základní pojmy, členění, řízení zásob a metody související s logistickým řetězcem. Hlavním cílem praktické části je analyzovat distribuční logistiku u vybraného podniku s využitím poznatků v teoretické části. Výstupem jsou návrhy a opatření na zlepšení současného stavu distribuční logistiky.This dissertation applies to logistics focusing on distributional logistics at a chosen company. There are defined basic terms, structure, stock management and methods related to the logistics chain in the theoretical part. The main aim of the practical part is to analyze distributional logistics at the chosen company while using findings in the theoretical part. As a conclusion there are suggestions and measures to improve current situation of distributional logistics at the company.Fakulta ekonomicko-správn

    The market analysis in services industry in a small company example

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    The thesis analyses the ability of competiton of a company in the service branch, in the sector of the installation electronic safeguard alarm. One of partial aims of thesis was an analyse of the historical development till the present, and an analyse of the inner and outer environment and preferences for selection theirs future suppliers. For this have been used methods of SWOT analysis and a questionnaire. The main aim was disclose and take advantage of opportunities, eliminate weak intents and limit distress.. One of the results of the thesis is choice of an acceptable agency for seeking new employees, implementation of a system for customers relationship management and institution of first step for management quality

    Change of Logistics within the Relocation of a Production Company

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    Tato bakalářská práce analyzuje změnu logistiky v rámci relokace zvoleného podniku. V její první části jsou vymezeny základní pojmy a metody související s logistickým řetězcem. Hlavním cílem druhé části je zhodnotit logistiku v původním závodu a porovnat s logistikou v novém závodu, představit cílové a dosahované hodnoty klíčových ukazatelů v době relokace. Výstupem jsou návrhy a opatření, které povedou k dalšímu rozvoji společnosti a zlepšení logistiky.This bachelor's thesis is analyzing logistic changes within relocation of one chosen company. In the first part there are defined basic terms and methods connected to the logistic chain. Main target of the second part is to evaluate logistics in the previous establishment and compare it with logistics in the new establishment, then to introduce targets and achieved values of key indicators at the time of relocation. As an output there are proposals and measures which will lead to further development of the company and improvement in logistics.Ústav podnikové ekonomiky a managementuStudentka seznámila komisi s obsahem a cílem své bakalářské práce. Cílem práce bylo vyhodnotit dopady relokace podniku na podnikovou logistiku. Studentka seznámila komisi se závěry práce a odpověděla na otázky položené vedoucím práce: 1. Jaké další KPI pro oblast logistiky by bylo možné podniku navrhnout? 2. Očekáváte, že budou Vaše návrhy realizovány
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