Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Foreign investment, organizational innovation and transformation in food supply chains : evidence from the Ethiopian barley sector
    Tefera, Delelegne Abera - \ 2017
    Wageningen University. Promotor(en): S.W.F. Omta, co-promotor(en): W.J.J. Bijman; M.A. Slingerland. - Wageningen : Wageningen University - ISBN 9789463437165 - 217
    foreign investment - organizations - innovations - management science - food supply - supply chain management - farmers - barley - economic sectors - ethiopia - east africa - buitenlandse investering - organisaties - innovaties - bedrijfswetenschap - voedselvoorziening - ketenmanagement - boeren - gerst - economische sectoren - ethiopië - oost-afrika

    Driven by rapid urbanization, economic growth, and changes in consumption patterns, food chains in emerging and developing economies are experiencing a fundamental transformation process. This transformation is usually characterized by increased vertical coordination, growth of modern distribution channels (e.g. supermarkets), consolidation of retail markets, and an increase in export orientation. The rapid growth in demand of modern food with higher quality and safety attracts multinational enterprises to invest in agriculture and food processing in emerging economies. The appearance of multinationals in the food systems of developing countries has been claimed to have a positive impact on economic development and reduction of poverty. The multinationals have adopted modern supply chain management practices for securing a large volume and consistent supply of high quality products. They introduce new technologies that boost productivity and post-harvest management for product upgrading.

    While so far most research on the modernization of food systems has focused on export chains, there is growing interest in the transformation of domestic and staple food chains. Upgrading domestic food chains is needed for a more efficient supply to fast growing urban markets and to sustain access to affordable food for the rapidly growing urban consumers in sub-Saharan Africa. As domestic food value chains are more inclusive than high-value export chains, upgrading these food chains can contribute more to poverty reduction and food security. However, much remains to be understood about the process of modernization in domestic food chains and its implications for rural development. The overarching aim of this dissertation was to deepen our understanding on how organizational innovations facilitate modernization of domestic food chains using case studies from the Ethiopian barley sector. In particular, the thesis examines the effectiveness and impacts of foreign direct investments (FDI), contract farming arrangements (CFAs), producer organizations (POs), and partnerships on the upgrading of malt barley value chains and welfare of local suppliers. To address this objective, we use a combination of qualitative and quantitative research approaches. Data were analyzed using parametric and non-parametric econometric models.

    The findings from the empirical chapters show that: First, our analysis reveals that the appearance of foreign companies in the malt barley chain has brought important changes in the structure and economics of the barley value chain, resulting in the development of a modern chain next to the conventional chain. It is also shown that participation in modern supply chains is determined by a range of factors that include farmer and farm characteristics. Second, the results show that participation in modern supply chains has a positive and significant impact on commercialization, intensification, quality improvement and farm gate prices, ultimately resulting in increased farmer income and spillovers towards productivity of other food crops. Third, we found that POs perform diverse economic functions to enhance rural development , but tighter coordination in food value chains demands alignment of chain activities among actors which leads to changes in the strategies and functions of POs. Fourth, we showed that POs have a positive impact on farm productivity and smallholder income. However, this positive impact of POs come at the expense of inclusiveness, i.e. POs are less inclusive. Thus, there is a tension between business performance and inclusiveness of POs. Moreover, the results show that the motivation to participate in a PO is determined by demographic and economic factors. Lastly, we found that the determinants of quality improvement at farm level are socioeconomic, technological and institutional factors. Specifically, the identified factors are farmers’ level of education, age (as a proxy for farming experience), entrepreneurial attitude, PO membership, CFA participation, and type of improved seed varieties. The thesis concludes that enhancing the modernization of food value chains involving smallholders requires organizational innovation that facilitate coordination and collaborative activities among chain actors.

    Brewing with fractionated barley
    Donkelaar, L.H.G. van - \ 2016
    Wageningen University. Promotor(en): Remko Boom; Atze Jan van der Goot. - Wageningen : Wageningen University - ISBN 9789462577343 - 152
    brewing - brewing quality - barley - fractionation - endosperm - beers - malt - filtration - industrial wastes - process optimization - food process engineering - bierbereiding - brouwkwaliteit - gerst - fractionering - endosperm - bieren - mout - filtratie - industrieel afval - procesoptimalisatie - levensmiddelenproceskunde

    Brewing with fractionated barley

    Beer is a globally consumed beverage, which is produced from malted barley, water, hops and yeast. In recent years, the use of unmalted barley and exogenous enzymes have become more popular because they enable simpler processing and reduced environmental impact. Raw barley, however, contains less endogenous enzymes and more undesired components for the use of beer brewing, compared to malted barley.

    The overall aim of this thesis is to investigate how barley can be fractionated to optimize the use of resources for the beer brewing process, while maintaining the quality of the brewed beer. A resource use efficiency analysis was performed to verify the presumed benefits on the environmental sustainability of the proposed process change. The work was based on the hypothesis that fractionation of the unprocessed barley will reduce the amount of undesired components, which leads to improvements in the brewing process based on partial or no malting. Fractionation can be performed by milling and separation, which requires physical disentanglement of the components. This fractionation can be influenced by properties of the components of the material, such as the glass transition temperature (Stuart et al.). Fractionation by abrasive milling, also known as pearling, is another possibility: here one makes use of the spatial distribution of components in the kernels. In case of barley for brewing this technique is especially promising as most of the undesired components are in the outer layer of the kernel. In addition, the removal of bran from the barley reduces the amount of water needed in the process. It will also reduce the volume of spent grains, hence reducing wastes and energy required for drying the spent grains. A disadvantage of pearling is however that it lowers the ability of the barley kernel to produce enzymes. This leads to the need of the addition of exogenous enzymes, as is the case when the malting step is omitted.

    Chapter 2 describes the glass-to-rubber transition of protein and starch isolated from the barley endosperm, for different moisture levels. The hypothesis for this chapter is that dry fractionation by milling is facilitated by milling conditions in which the protein is in a rubbery state and the starch in a glassy state. Two methods were used to measure the Tg; differential scanning calorimetry (DSC) and thermo-mechanical compression tests (TMCT). The methods gave different results due to the differences in moisture content range, and heating rates, which may lead to conformational changes of the protein. The value of the Tg of partially crystalline materials, such as starch in barley, was not unambiguous when using TMCT because the mechanical effect of expansion of these materials was smaller. For both results, the Tg lines were modelled using the Gordon-Taylor equation. Based on sorption isotherms, it was concluded that moisture does not distribute evenly over the protein and starch in the kernel. Starch absorbs more moisture than protein at given water activities. This required a correction of the Tg lines. After this correction, the glass transition lines of starch and protein were closer together. The expectation is therefore that achieving good separation between the components based on having one glassy component and one rubbery component is challenging.

    For this reason, another dry fractionation technique, pearling, was considered. Chapter 3 describes the chemical composition of the barley and of fractions removed by pearling. Pearling was shown to selectively remove insoluble fibre, ash, protein and polyphenols, while the β-amylase activity and starch content of the remaining kernel was hardly affected. For example, removing the outer 5% of the kernel reduced insoluble arabinoxylans (15%), insoluble fibres (23%), ash (19%), polyphenols (11%) and water holding capacity of the non-starch components (25%), while only lowering starch content by 0.20%. The water holding capacity of the barley fractions was strongly related to the fibre content. This indicates that when the fibre content in the mash was reduced by pearling, the spent grains will take up less water, leading to less wort and sugar losses in this waste stream, and hence better use of the raw materials and less wastes.

    Chapter 4 compares a traditional brewing process to an enzyme-assisted brewing process with respect to their resource use efficiency, which is one aspect of the sustainability of the processes. The use of exogenous enzymes is found to be more efficient than producing enzymes through the malting process. The exergetic efficiency of the conventional malting process was 77%. The main losses stem from the use of natural gas for removal of moisture from the barley in the kilning process, and from the loss of starch in the germination process. In case of the use of exogenous enzymes, it was concluded that the chemical exergy content of the enzymes was not a good measure for the exergy content of the enzymes. Instead, we proposed to use the cumulative exergetic consumption in the enzyme production rather than just the chemical exergy content of the enzymes. This cumulative exergetic consumption in the production of the enzymes was ± 30 times higher than their standard chemical exergy. This shows that the cumulative exergetic costs of minor components should be taken into account if a process uses them in significant quantities. This can be done by extending the system boundaries to include the production process of the purified components. The exergy efficiency of the enzyme formulation production process ranges between 20% and 42% depending on whether the by-product of the fermentation broth was considered as useful as the enzyme product. Even though the cumulative exergy consumption of the process was 30 times the standard chemical exergy of the dry enzyme, the total exergy input (i.e. both wasted and destroyed) for the production of 100 kg of beer was still larger for the conventional malting process (441 MJ) than for the enzyme-assisted process (354 MJ). In addition, beer produced using exogenous enzymes reduces the use of water by 7%, of raw materials by 14%, and of natural gas by 78%. Thus, the exergy loss of the enzyme production process is more than compensated by the prevention of exergy loss in the total beer brewing process.

    Chapter 5 describes brewing tests using malted, unmalted and pearled, unmalted barley kernels. Brewing with unmalted barley saves material, energy and water in the malting stage but may result in complications during processing. Pearling mitigates these problems. Exogenous enzymes were used to compensate for the low enzyme activity in unmalted barley. Lautertun filtration and mash filtration were considered as filtration methods. Principle component analysis was performed on the chemical composition of the wort and the various spent grains, to investigate the effect of the malt-to-barley ratio, the degree of pearling and the filter method. A mash filter is optimal for this type of process, and we identified a window of operation in which optimal use is made of the raw materials while maintaining the end product quality, judged on basis of 4 quality parameters.

    The concluding chapter 6 presents a general discussion of all results described in this thesis. In addition, the benefits of pearling over that of milling and fractionation, and the effect of pearling on milling properties were discussed. Furthermore, it explores the advantages in environmental sustainability that can be achieved by pearling. Pearling as a pre-treatment for malting reduces the enzyme activity of germinating barley, and therefore the mash quality.

    This thesis provides insights in how pre-treatment of barley can make beer brewing more efficient in the use of resources. It stresses the need to optimally use all material streams in a process, to be able to design an environmentally sustainable process, and it shows that efficient resource use is key for achieving this. Additionally the value of enzymes as processing aids was discussed. A clear result is that one needs to include the resource use in the production of enzymes or other processing aids, when analyzing the environmental sustainability of a process, since this can be significant in the overall process.

    Beheersing aarfusarium en bladvlekkenziekte in zomergerst
    Evenhuis, A. ; Schepers, H.T.A.M. - \ 2015
    Wageningen : Praktijkonderzoek Plant & Omgeving (Applied Plant Research), part of Wageningen UR Business Unit AGV - 24
    akkerbouw - graangewassen - hordeum vulgare - gerst - schimmelziekten - fusarium - gibberella zeae - bladvlekkenziekte - bestrijdingsmethoden - proeven - detectie - fungiciden - arable farming - grain crops - hordeum vulgare - barley - fungal diseases - fusarium - gibberella zeae - leaf spotting - control methods - trials - detection - fungicides
    Aarfusarium leidt tot kwaliteitsverlies in graangewassen. Aarfusarium in granen wordt veroorzaakt door verschillende ziekteverwekkers van het geslacht Fusarium: De belangrijkste veroorzaker van aarfusarium is F. graminearum. De schimmel infecteert de aar tijdens de bloeiperiode, onder vochtige omstandigheden. Is het tijdens de bloei droog dan is er weinig kans op Fusarium. Is het tijdens en voor de bloei nat dan vergroot dat de kans op aarfusarium. Als een partij tarwe of gerst te zwaar geïnfecteerd is kan dat leiden tot een lagere bakkwaliteit, respectievelijk een lagere brouwkwaliteit. In opdracht van het Productschap Akkerbouw is onderzoek gedaan naar de bestrijding van Fusarium in de teelt van brouwgerst. Het onderzoek is uitgevoerd in samenwerking met de gewasbeschermingsindustrie.
    Glutenvrij ? Pils onde de loep
    Sleutels, I. ; Meer, I.M. van der; Broeck, H.C. van den - \ 2014
    Voedingsmiddelentechnologie 7 (2014). - ISSN 0042-7934 - p. 10 - 11.
    gluten - coeliakie - glutenvrije diëten - bieren - alcoholische dranken - gerst - lc-ms - analytische methoden - coeliac syndrome - gluten free diets - beers - alcoholic beverages - barley - liquid chromatography-mass spectrometry - analytical methods
    Gluten meten in gehydrolyseerde en gefermenteerde voedingsmiddelen – zoals pils – is lastig. De door de Codex Alimentarius gevalideerde test onderschat het gehalte gluten in deze producten. Een uitgebreide LC-MS/MS-analyse geeft gedetailleerde informatie over de aanwezige coeliakie-stimulerende gluten in pils. Met deze gegevens is een geschikte test te ontwikkelen.
    Towards map-based cloning of partial resistance QTLs of barley to Puccinia hordei
    Yeo, F.K.S. - \ 2014
    Wageningen University. Promotor(en): Richard Visser, co-promotor(en): Rients Niks. - Wageningen : Wageningen University - ISBN 9789462570733 - 185
    hordeum vulgare - gerst - ziekteresistentie - plantenziekteverwekkende schimmels - puccinia hordei - partiële resistentie - loci voor kwantitatief kenmerk - genkartering - plantenveredeling - hordeum vulgare - barley - disease resistance - plant pathogenic fungi - puccinia hordei - partial resistance - quantitative trait loci - gene mapping - plant breeding

    Partial resistance of barley to Puccinia hordei and near-nonhost resistance to non-adapted rust fungi inherit polygenically. The two types of resistance seem to share some genes and have a similar prehaustorial mechanism of resistance, but partial resistance is less strong than near-nonhost resistance of barley. Partial resistance to adapted, “host”, rust fungi seems, therefore, like a weak form of nonhost resistance to non-adapted rust fungi. If partial resistance and nonhost resistance are indeed based on the same principles, one can understand nonhost resistance by studying partial resistance and vice versa. To study partial and nonhost resistance, as well as their association, the candidate gene(s) for resistance must be cloned and characterized for their action.

    Five resistance quantitative trait loci (QTLs) for partial resistance (Rphq2, Rphq3, Rphq4, Rphq11 and Rphq16) and one nonhost resistance QTL (Rnhq) were selected to pursue map-based cloning. First, the effect of the QTLs was verified in near-isogenic lines (NILs). The NILs of Rphq2, Rphq3, Rphq4 and Rnhq (QTL-NILs) were available in L94 genetic background. L94 is extremely susceptible to Puccinia hordei, and, at seedling stage, somewhat susceptible to certain non-adapted rust fungi. The experimental barley line SusPtrit is also susceptible to P. hordei but, at seedling stage, also very susceptible to at least nine species of non-adapted rust fungi. In Chapter 3, we developed NILs in SusPtrit background for Rphq2, Rphq3, Rphq11, Rphq16 and two alleles of Rnhq, viz. L94 and Vada alleles. The effect of each QTL in L94 and SusPtrit genetic backgrounds was tested not only against different isolates of P. hordei but also against different species and isolates of non-adapted rust fungi. The QTL-NILs suggested that the effects of the partial resistance genes depended on rust species and rust isolates. Some introgressions conferred resistance to a broader spectrum of rust species and isolates than others, the broadest being the Rphq11-introgression. The NILs may overestimate the spectrum of effectiveness of the partial resistance genes because some NILs contain inadvertent donor genome in the background and the introgressed QTL region may contain several linked resistance genes, each with a narrow resistance spectrum. The introgression would then confer a resistance spectrum that is the combination of the spectra of several linked resistance genes. Allowing for the possibility of linkage of narrow-spectrum resistance genes, our study suggests that some genes may be involved in partial as well as nonhost resistance. Data also suggest that genetic background may play a role in the resistance conferred by the QTL-introgression.

    The NILs also allow fine-mapping of the QTL as was done for Rphq2 in a previous study. In Chapter 4, we target to fine-map another two partial resistance QTLs of our interest, viz. Rphq11 and Rphq16. We, however, did not use the NILs for fine-mapping of Rphq11 and Rphq16. Instead, after validating the effect of Rphq11 and Rphq16 using the early breeding materials for developing NILs of Rphq11 and Rphq16, we developed fixed QTL-recombinants (i.e. homozygous recombinants at the Rphq11/Rphq16 QTL alleles, homozygous susceptible at the non-targeted QTL alleles). The genomic background of fixed QTL-recombinants was still segregating, but expected not to be relevant for the resistance level. Rphq11 was fine-mapped into a 0.2 cM genetic interval and a 1.4 cM genetic interval for Rphq16, before the NILs were ready. The strongest candidate gene for Rphq11 is a phospholipid hydroperoxide glutathione peroxidase (PHGPx). This gene corresponds to the new Rphq11 peak marker – WBE129, located within the refined 0.2 cM genetic intervals and was one of the candidate genes for Rphq11 identified through e-QTL mapping on Steptoe/Morex challenged with the same rust isolate. There was no clear candidate gene identified for Rphq16.

    A QTL has to be fine-mapped into a sufficiently narrow genetic window to make physical mapping feasible. Rphq2 with a genetic window of 0.1 cM is ready for physical mapping. In Chapter 5, we have constructed two non-gridded Bacterial Artificial Chromosome (BAC) libraries of barley from Vada and SusPtrit. Based on the insert sizes of the BAC clones, the estimated genome coverage of the Vada BAC library is 2.6x and of the SusPtrit BAC library 3.7x. The genome coverage of Vada is comparable to the BAC library of Morex, HVVMRXALLhB and SusPtrit to HVVMRXALLeA. The estimation of genome coverage based on microsatellite markers indicates, however, Vada and SusPtrit BAC libraries to have 5.0x and 6.8x genome coverage, respectively. Based on genome insert size, the BAC library of Vada gives at least 93% probability of identifying a clone corresponding to any sequence of Vada and for the BAC library of SusPtrit a probability of 98% is expected. Together, the two BAC libraries give more than 99% probability of recovering any specific sequence from the barley genome. A tiling path of three BAC clones was constructed for Vada, which cover the Rphq2 genetic window. The physical window of Rphq2 in Vada BAC contig is approximately 195 Kbp. For SusPtrit, the three BAC clones forming the contig did not cover the entire genetic window of Rphq2. The physical length bridged by them is approximately 226 Kbp. The TriAnnot pipeline annotated 12 genes in both the Vada and the SusPtrit contig, but only four of the annotated genes are shared between Vada and SusPtrit. The candidate genes for Rphq2 might be a resistance factor in Vada or a susceptibility factor in SusPtrit. The peroxidases and kinases are good candidates to represent Rphq2. It is possible that one of the peroxidase or kinase gene members in the physical window of Rphq2 explains the resistance phenotype observed. Another possibility is that peroxidase or kinase gene members function as a complex QTL. A member of the Seven in absentia protein family (SINA) can be a candidate as well. The gene families to which previously cloned genes for partial resistance belong were not found to be represented in the Rphq2 region.

    We propose to perform functional analysis of candidate genes through Agrobacterium-mediated stable transformation of the resistance allele into a susceptible genotype, such as SusPtrit. Unfortunately, SusPtrit is, as so many barley accessions, not amenable to Agrobacterium-mediated transformation. In Chapter 2, we developed a doubled haploid (DH) mapping population (n=122) by crossing SusPtrit with Golden Promise to develop a ‘Golden SusPtrit’, i.e., a barley line combining SusPtrit’s high susceptibility to non-adapted rust fungi with the high amenability of Golden Promise for transformation. Using the DH population, we identified nine genomic regions occupied by QTLs against four non-adapted rust fungi and P. hordei isolate 1.2.1 (Ph.1.2.1). From 12 DH lines that were most susceptible to the tested non-adapted rust fungi, we selected four DHs for an Agrobacterium-mediated transformation efficiency test. We obtained a DH line (SG062N) with transformation efficiency of 11 to 17 transformants per 100 immature embryos. The level of susceptibility of SG062N to non-adapted rust fungi is either similar to or higher than the level of susceptibility of SusPtrit. Against P. hordei, the latency period conferred by SG062N at seedling stage is as short as that conferred by SusPtrit. SG062N, designated ‘Golden SusPtrit’, will be a valuable experimental line that could replace SusPtrit in future nonhost and partial resistance studies, especially for stable transformation using candidate genes that may determine the differences in resistance levels against adapted and non-adapted rust fungi.

    Gebruiksnorm brouwgerst hoger
    Timmer, R.D. - \ 2014
    Boerderij 99 (2014)39. - ISSN 0006-5617 - p. 32 - 32.
    akkerbouw - gerst - veldproeven - brouwgranen - bemesting - stikstofmeststoffen - rassen (planten) - eiwitgehalte - normen - opbrengst - proeven op proefstations - arable farming - barley - field tests - brewers' grains - fertilizer application - nitrogen fertilizers - varieties - protein content - standards - outturn - station tests
    80 Kilo stikstof per hectare is eigenlijk te weinig om kwalitatief goede brouwgerst te telen. Ruud Timmer van het PPO te Lelystad en brouwers pleiten voor een hogere gebruiksnorm. Onderzoek naar rassen voor de mouterijen is gewenst.
    Steeds preciezer met de sensor
    Houweling, P. van; PPO Akkerbouw, Groene Ruimte en Vollegrondsgroente, - \ 2014
    Akker magazine 10 (2014)4. - ISSN 1875-9688 - p. 18 - 21.
    akkerbouw - aardappelen - loofvernietiging - sensors - bemesting - stikstofmeststoffen - gerst - spuitapparaten - pleksgewijs spuiten - bladbespuiting - precisielandbouw - arable farming - potatoes - haulm destruction - sensors - fertilizer application - nitrogen fertilizers - barley - sprayers - spot spraying - foliar spraying - precision agriculture
    Maurits Bax uit Luyksgestel werkt met de Yara N-sensor. Zo spuit hij minder dan een derde van de voorgeschreven dosering voor loofdodingsmiddel in aardappelen. Andere toepassingen zijn minder praktijkrijp, zoals aardappelen bijmesten. Daarvoor lijkt een app, ontwikkeld door het PPO, uitkomst te gaan bieden. PPO Lelystad begeleidt het project waar Bax aan mee doet. De teler kreeg de afgelopen twee teeltseizoenen voor zijn aardappelen een adviesgift van PPO op basis van twee systemen: de BemestingsNavigator aardappel van Altic en een systeem dat PPO ontwikkelt. De volgende toepassing was voor het spuiten van halmverstevigers in zomergerst.
    Identification of traits and QTLs contributing to salt tolerance in barley (Hordeum vulgare L.)
    Nguyen Viet Long, L. - \ 2012
    Wageningen University. Promotor(en): Richard Visser, co-promotor(en): Gerard van der Linden; Oene Dolstra. - S.l. : s.n. - ISBN 9789461734099 - 137
    hordeum vulgare - gerst - zouttolerantie - loci voor kwantitatief kenmerk - groei - plantensamenstelling - genotypen - chromosomen - homeostase - plantenveredeling - hordeum vulgare - barley - salt tolerance - quantitative trait loci - growth - plant composition - genotypes - chromosomes - homeostasis - plant breeding

    Salinity is the most severe abiotic stress perceived by plants and affects about 800 million hectares of land worldwide, including 20% of the world’s highly productive irrigated land. Significant crop yield losses are observed due to salinity. Salinization is increasing because of poor irrigation management and climate change. Improving salt tolerance in crops is for these reasons an important target for plant breeding in the near future. However, salinity tolerance in plants is not easy to breed for due to its interaction with many physiological processes controlled by many genes and their interaction with the environment. Barley is a good model crop to study different mechanisms conferring salt tolerance in cereals. A traditional QTL mapping approach in combination with a new association mapping method allowed us to efficiently explore the genetics and genetic diversity of salt tolerance in barley. Improvements of the association mapping technology highly increased detection power and mapping accuracy. The traits and QTLs identified in this thesis point out both osmotic and ionic stress tolerant genes as important targets for salt tolerance breeding. This thesis provides tools to plant breeders for the application of marker-assisted introgression breeding of salt tolerance genes in their breeding programs. Some QTLs were found to be syntenic with the important QTLs/genes for salt tolerance found in wheat and rice such as Na+ and K+ transporter gene families. Other QTLs were new and suggest the presence of novel genes that play an important role in plant ion homeostasis, transportation of Cl- and Ca2+ and osmotic tolerance. We demonstrated that association mapping can be a powerful approach to dissect the complexity of salt tolerance in barley. The newly available high-density SNP map of barley and the barley genome sequence in the near future further increases the accuracy of mapping studieswith the association panel and will greatly facilitate the cloning of the genes underlying salt tolerance in barley. This thesis thus contributes to better a understanding of the physiological and genetic basis of salt tolerance and improved breeding strategies for the development of salt tolerant varieties.

    Cytological, genetic and agronomic characterization of a barley reciprocal translocation
    Farré Martinez, A. - \ 2012
    Wageningen University. Promotor(en): Fred van Eeuwijk, co-promotor(en): I. Romagosa; Hans Jansen. - S.l. : s.n. - ISBN 9789461734112 - 131
    gerst - cytogenetica - reciproke translocatie - agronomische kenmerken - genetische kartering - toegepaste statistiek - biometrie - biostatistiek - barley - cytogenetics - reciprocal translocation - agronomic characteristics - genetic mapping - applied statistics - biometry - biostatistics

    Reciprocal translocations (RT) are one of the most common structural chromosomal rearrangements occurring in plant species. Spontaneous RT are extremely uncommon in cultivated barley. In fact, ‘Albacete’ is the only extensively cultivated barley variety known to carry a RT without any major reduction in fitness. Previous results have shown that 1H and 3H chromosomes are involved in this translocation which may have a potential interest for plant breeding. A depth understanding of this RT could allowed us to know whether this translocation is involved or not in their drought tolerance and find some interesting phenotypic attributes that could be transfer to other barley genotypes to develop specific germoplasm adapted to stress.

    In a first step, a set of 230 doubled haploid lines derived from the cross between ‘Albacete’ and the non-translocation barley variety ‘Barberousse’ was used to develop a statistical-genetic approach for the construction of a linkage maps in populations obtained from RT heterozygotes. A preliminary linkage study revealed six main linkage groups, compared to the seven linkage groups on the barley consensus map. One of the linkage groups contained markers of chromosomes 1H and 3H. This union was due to the presence of a RT between chromosomes 1H and 3H in the variety ‘Albacete’. The results of this study revealed that the position of the translocation breakpoints was placed around the centromeric regions for both chromosomes.

    In a second step, a combination of cytological and molecular genetic approaches was used in order to know how large the segments are that are involved in the interchange between the two chromosomes. The results obtained in this study indicate that the translocation is quite large with breakpoints located on the long arms of chromosomes 1H and 3H resulting in the RT 1HS.1HL-3HL and 3HS.3HL-1HL. The gene content around the translocation breakpoints was estimated at approximately 1,100 and 710 gene models for 1H and 3H, respectively.

    A large number of doubled haploid lines derived from four crosses involving ‘Albacete’ as one of the parents were used to phenotypically characterize the effects of the RT on some interesting agronomic traits.The results suggested that the RT alone is not causing the drought tolerance of ‘Albacete’; thousand kernel weight is the only trait which is clearly enhanced in the lines carrying the RT. Further work combining the results from this study with QTL analysis was carried out to phenotypically characterize the effects of the reciprocal translocation and QTL simultaneously. For that, an integrated map was constructed making used of a modified version of an algorithm developed by Jansen (2005). Finally, specific QTL methodology for the simultaneous analysis of these interconnected populations was developed; two traits: days to heading (independent of the RT) and thousand kernel weight (affected by the RT) were used as an example.

    Rassenbulletin zomergerst
    Timmer, R.D. - \ 2011 2010 (2011)10 dec.
    rassenproeven - opbrengsten - gerst - ziekteresistentie - akkerbouw - zomerteelt - variety trials - yields - barley - disease resistance - arable farming - summer cultivation
    Dit rassenbulletin geeft een overzicht van de opbrengsten en eigenschappen van zomergerstrassen.
    Coping with drought for food security in Tigray, Ethiopia
    Berhe, A.A. - \ 2011
    Wageningen University. Promotor(en): Leo Stroosnijder, co-promotor(en): Saskia Keesstra. - [S.l.] : S.n. - ISBN 9789085859253 - 173
    landbouwklimatologie - droogte - waterstress - irrigatie - regen - gewassen - hordeum vulgare - gerst - eragrostis tef - mulches - opbrengsten - ethiopië - agroclimatology - drought - water stress - irrigation - rain - crops - hordeum vulgare - barley - eragrostis tef - mulches - yields - ethiopia

    Agricultural production in drylands suffers from drought and in sub-Saharan Africa, only about 15% of the terrestrial rainwater is used by plants for food, fodder and fiber. Drought was the major cause of crop failure and food insecurity for the last three decades in the semi-arid northern Ethiopia. Information from field experiments, farmers and FAO’s AquaCrop model were used to understand and evaluate characteristics of the local climate in relation to drought and its mitigation. Farmers often have a different perception of drought than scientists. This gap was solved with an improved analysis of rainfall data that focuses on drought. Drought in semi-arid north Ethiopia can be due to (1) a too short growing season due to late start and/or early cessation of rains, (2) a too long dry spell at critical growth stage or (3) due to total failure of rain. Different types of drought have different coping strategies. Coping strategies for drought are adaption of sowing date, in-situ water conservation and water harvesting for deficient irrigation. Physical water conservation structures need to account for extreme variations in rainfall typical for most drylands. Ridging is most promising while mulching is no longer promoted. Agronomic measures such as the use of quick maturing and drought resistant crops are often more attainable than adoption of water conservation practices. Crop failure is often more due to water scarcity than to lack of fertility. However, when agricultural production increases, water and nutrients often alternate as production limiting factors. The strong water-nutrient synergy in drylands requires precision fertilization and plant density adjustment. Farmers also have a different opinion about climate change; farmers’ climate change has more to do with desertification. Experimental results showed that drought alleviation strategies have the potential to reduce the risk of crop failure and drought in the semi-arid northern Ethiopia.

    Opname van gras- en mengkuil door dragende biologische zeugen
    Bikker, P. ; Peet-Schwering, C.M.C. van der; Binnendijk, G.P. - \ 2011
    Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 439) - 33
    biologische landbouw - zeugen - zwangerschap - voersamenstelling - graskuilvoer - kuilvoer - gerst - maïs - voeropname - organic farming - sows - pregnancy - feed formulation - grass silage - silage - barley - maize - feed intake
    In this study it was determined whether the concentrate allowance of pregnant sows can be partly replaced by the supply of grass silage of grass silage mixed with barley or CCM.
    Aanvullend onderzoek mineralenconcentraten 2009-2010 op bouwland en grasland : rapportage van de resultaten van de veldproeven in wintertarwe (klei), zomergerst (zand) en zetmeelaardappelen (dalgrond) in NO-Nederland in 2010
    Wijnholds, K.H. - \ 2011
    Wageningen : Praktijkonderzoek Plant & Omgeving B.V. - 34
    solanum tuberosum - aardappelen - zetmeelgewassen - hordeum vulgare - gerst - triticum aestivum - tarwe - mineralen - concentraten - stikstofrespons - solanum tuberosum - potatoes - starch crops - hordeum vulgare - barley - triticum aestivum - wheat - minerals - concentrates - nitrogen response
    Het in 2009 gestarte onderzoek met MC (Mineralenconcentraat) is in 2010 op vergelijkbare wijze voortgezet. In de verschillende proeven met zetmeelaardappelen op dalgrond, zomergerst op zandgrond en wintertarwe op zware klei was gedurende het groeiseizoen een duidelijke stikstofwerking zichtbaar. In de proeven was de stikstofwerking van MC praktisch 100 % en waren de resultaten van de verschillende beoordelingen en de opbrengst en kwaliteit vergelijkbaar met de vergelijkbare stikstofhoeveelheden op basis van KAS. Oppervlakkige toediening, uitgevoerd bij de proeven in zomergerst en wintertarwe, had een negatieve invloed op de stikstofwerking. Op basis van de verschillende proeven van 2009 en 2010 zal de werkingscoëfficiënt op uniforme worden berekend. Het veldonderzoek wordt in 2011 op vergelijkbare wijze voortgezet
    Beheersing trichodoriden : eindrapport van onderzoek naar beheersing van het aaltje P. pachydermus in Valthermond vanaf 2006 tot en met 2009
    Hoek, H. ; Molendijk, L.P.G. - \ 2010
    Lelystad : Praktijkonderzoek Plant en Omgeving, Sector Akkerbouw, Groene ruimte en Vollegrondsgroenten - 53
    paratrichodorus pachydermus - plantenparasitaire nematoden - nematodenbestrijding - ziektebestrijdende teeltmaatregelen - aardappelen - suikerbieten - gerst - akkerbouw - veldproeven - proeven op proefstations - paratrichodorus pachydermus - plant parasitic nematodes - nematode control - cultural control - potatoes - sugarbeet - barley - arable farming - field tests - station tests
    Het PPO heeft vanaf 2006 tot 2010 onderzoek gedaan naar een beheersingsstrategie voor het aaltje Paratrichodorus pachydermus. Dit onderzoek is uitgevoerd op een perceel van het PPO te Valthermond, met een bouwplan wat in die streek gebruikelijk is. Daarbij is tweemaal in vier jaar aardappelen geteeld. In de andere twee jaar zijn suikerbieten en zomergerst geteeld.
    Comparison of interconnections between barley breeding material traits under organic and conventional growing conditions
    Legzdina, L. ; Kokare, A. ; Beinarovica, I. ; Lammerts Van Bueren, E. - \ 2010
    In: Breeding for resilience: a strategy for organic and low-input farming systems, Paris, France, 1 - 3 December, 2010. - Parijs : Eucarpia - p. 114 - 114.
    biologische plantenveredeling - biologische landbouw - gerst - selectiecriteria - correlatie - milieufactoren - organic plant breeding - organic farming - barley - selection criteria - correlation - environmental factors
    While breeding for organic farming it is necessary to identify the most appropriate growing conditions in which to perform the selection process. Soil fertility, crop management, yield level and other factors may vary very much between each organic farm, and between organic farms and research institutions where the selection is usually performed. Since plant breeding requires considerable input of resources and the market for organic varieties is limited, it is essential to find the most appropriate selection conditions that will provide acceptable varieties for organic farms.
    Basal resistance of barley to adapted and non-adapted forms of Blumeria graminis
    Aghnoum, R. - \ 2009
    Wageningen University. Promotor(en): Richard Visser, co-promotor(en): Rients Niks. - [S.l. : S.n. - ISBN 9789085854197 - 132
    hordeum vulgare - gerst - blumeria - blumeria graminis - ziekteresistentie - verdedigingsmechanismen - genetische analyse - loci voor kwantitatief kenmerk - puccinia hordei - kruisingen - plantenveredeling - resistentieveredeling - hordeum vulgare - barley - blumeria - blumeria graminis - disease resistance - defence mechanisms - genetic analysis - quantitative trait loci - puccinia hordei - crosses - plant breeding - resistance breeding
    In the barley-Blumeria interaction, resistance at penetration stage in association with papilla formation is a commonly occurring mechanism. This mechanism of defense reduces the infection severity by adapted powdery mildew pathogen (basal resistance to Blumeria graminis f.sp. hordei, Bgh) and fully protects the plant against non-adapted powdery mildew pathogens (non-host resistance to non-adapted forms of B. graminis). In this thesis we followed an integrated approach based on QTL mapping and candidate gene analysis. It was our objective to determine which of the known candidate genes have a map position that coincides with one of the QTLs detected in our mapping study. Such candidate genes might determine the natural variation of basal resistance against powdery mildew in barley. We also investigated whether the genotypic variation in level of resistance of barley to the non-adapted wheat powdery mildew, B. graminis f.sp. tritici (Bgt) could be used to develop an experimental line to determine the inheritance of non-host resistance of barley to this pathogen. Finally we aimed to determine whether the basal resistance of barley to powdery mildew is being suppressed by prior attack by a different pathogenic haustorium forming fungus, Puccinia hordei.
    Chapter 1 presents an introduction about basal resistance of barley to powdery mildew and briefly lists evidence on molecular associations between basal, mlo-mediated and non-host resistance. In Chapter 2, we performed QTL analysis for powdery mildew resistance at seedling and at adult plant stage in six mapping populations of barley. In that analysis quantitative resistance of barley to powdery mildew was found to be based on a large number of genes, with only few detected in more than one mapping population. These QTLs for powdery mildew resistance in barley are mainly plant growth stage dependent. From gene-expression, gene silencing and transient transformation assays 39 genes emerged that increased or decreased basal resistance of barley to the powdery mildew fungus. They are considered candidate genes that might be responsible for natural variation in level of basal resistance. By looking for polymorphism in those genes, we could determine the map position of 23 of these candidate genes. Mapping positions of three more genes, mlo, Ror1 and Ror2, were already available, and these were also considered as candidate genes in our study.To compare the map position of QTLs in different mapping populations with the map positions of the 26 candidate genes, we constructed an improved high-density integrated linkage map of barley. This improved map was based on the marker data of seven mapping populations of barley. More than 43% of the markers on our improved integrated map target ESTs or gene sequences (gene-targeted markers, GTM) and can be used for candidate gene identification. Six out of the 26 candidate genes co-localized with QTLs for basal powdery mildew resistance. They are interesting targets for further studies, since their allelic forms may be responsible for part of the differences in basal resistance between the parents in our mapping study. Chapter 3 reports the development of two experimental barley lines with extremely high and low level of basal resistance to barley powdery mildew. These lines were obtained by convergent crossing between the most resistant and the most susceptible lines, respectively, from four mapping populations of barley studied in Chapter 2. We consider the extremely susceptible and resistant lines developed here as valuable material to be used in further experiments to characterize the molecular basis of basal resistance to powdery mildew. The results suggest that phenotypic selection is sufficiently efficient to achieve high levels of basal resistance. We report some difficulties in the application of marker assisted selection that might make that approach unnecessary and less efficient to achieve a similar high level of basal resistance. In Chapter 4 the development of two more experimental lines is described. These lines have, at the seedling stage an unprecedented level of susceptibility to the non-adapted wheat powdery mildew. A large collection of barley germplasm was screened and some rare barley accessions were identified with rudimentary susceptibility to the wheat powdery mildew, Bgt. Those accessions were intercrossed in two cycles, and resulted in the two exceptional research lines, called SusBgt SC and SusBgt DC. The quantitative variation among barley accessions and in the progenies after convergent crossing suggest a polygenic basis of this non-host resistance. Component analysis of the infection process suggested that non-host resistance factors are Blumeria-form specific. The developed lines will serve to elucidate the genetic basis of non-host resistance in barley to wheat powdery mildew, and are useful tools in gene expression and complementation studies on non-host resistance. In Chapter 5 we reported that a compatible interaction of barley-Puccinia hordei induces increased papilla based resistance to a challenge infection by a compatible powdery mildew isolate. These pathogens differ in strategies to suppress plant cell defense. We showed that the level of rust-induced mildew resistance varies among barley accessions and is not determined by the virulent/avirulent spectra of the challenger isolate. Macroarray gene expression analysis showed that several genes involved in metabolism and photosynthesis were highly down-regulated and a few genes involved in plant defense including a pathogenesis related protein (PR-1) and cysteine synthase were highly up-regulated in the double inoculated treatment. Our histological and gene expression analyses are compatible with the hypothesis that the rust “primes” the basal mildew resistance genes prior to the challenge mildew infection. In Chapter 6, the results obtained in the previous Chapters are being discussed. The perspectives of the experimental barley lines that were developed in this study for the identification of genes that determine basal resistance of barley to adapted and non-adapted Blumeria graminis forms are highlighted.

    Ook groeiregulator voorkomt legering niet
    Timmer, R.D. - \ 2009
    Boerderij/Akkerbouw 94 (2009)31. - ISSN 0169-0116 - p. E26 - E27.
    gerst - legering - groeiregulatoren - klimaatverandering - windeffecten - regenschade - barley - lodging - growth regulators - climatic change - wind effects - rain damage
    Door de klimaatverandering, meer regen en wind, neemt de kans op legering toe. Vooral brouwgerst is gevoelig. Alleen het middel Modus heeft in gerst enige werking
    Checklist zomergerst
    Schans, D.A. van der; Jukema, J.N. - \ 2008
    precisielandbouw - gerst - hordeum vulgare - precision agriculture - barley - hordeum vulgare
    Perceel Centraal is een samenwerkingsverband tussen Agrifirm, HLB, IRS, PPO en 30 telers en wordt medegefinancierd door het Samenwerkingsverband Noord Nederland, E/Z KOMPAS, Ministerie van LNV en het SIO.
    Boer en bier in Limburg : samenwerking tussen gerstteler en brouwer
    Stobbelaar, D.J. ; Duivenvoorden, C. - \ 2008
    Ekoland 28 (2008)10. - ISSN 0926-9142 - p. 28 - 30.
    biologische landbouw - akkerbouw - gerst - bieren - brouwerij-industrie - biologische voedingsmiddelen - samenwerking - limburg - organic farming - arable farming - barley - beers - brewing industry - organic foods - cooperation - limburg
    Bioboer Norbert Huijts werkt samen met Gulpener Bierbrouwerij. Huijts teelt op dit moment 6 hectare brouwgerst dat bij Gulpener verwerkt wordt tot een biologische pilsner. De vraag naar dit bier is groeiende en daarom gaat volgend jaar een tweede teler biologische gerst leveren
    Resultaten precisieketen zomergerst
    Jukema, J.N. ; Vogelzang, K. - \ 2008 2008 (2008)11 sept.
    gerst - graansoorten - rassen (planten) - gewasopbrengst - variatie - gewasteelt - precisielandbouw - landbouwkundig onderzoek - akkerbouw - barley - cereals - varieties - crop yield - variation - crop management - precision agriculture - agricultural research - arable farming
    Dit rapport beschrijft een deel van de resultaten vanuit het project “De precisieketen”. “De precisieketen” is een project welke een looptijd had van 2003 – 2006. Het project speelde zich af op de Veenkoloniën, op bedrijven van ongeveer 18 telers. Het betreft hier in alle gevallen bedrijven op de zand- en dalgronden. De doelstelling van het project was het verbeteren van het ketenrendement van de brouwgerst teelt. Daarnaast werd het ketenrendement van brouwgerst gebruikt als toets voor opbrengstverbeteringen van de volgteelten.
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