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Vitis vinifera L. germplasm diversity: a genetic and ampelometric study in ancient vineyards in the South of Basilicata region (Italy)
Get PDFThe evaluation of the existing grapevines biodiversity in several areas still unexplored in Basilicata region has been carried out. A four years survey in ancient vineyards of Potenza was performed to investigate grapevine biodiversity. 85 collected accessions were subjected to genetic characterization through nine microsatellite markers. A total of 42 genotypes were obtained. The comparison with national and international databases allowed the identification of 26 accessions corresponded to new autochthonous genotypes and minor/local cultivars, in addition 16 international and national cultivars commonly cultivated in several Italian regions were found (data not shown in this work). Results indicated that minor/local cultivars were mainly cultivated in the near regions. The genetic profile of 9 new autochthonous grapevines was described here for the first time. Comparison of the genotypes, allelic frequencies, allelic sizes and ampelometric traits on mature leaves are highlighted. Conservation of new autochthonous and minor/local cultivars in germoplasm collections has been carried out including them in the germoplasm collection of CREA-VE in Arezzo in order to save grapevine biodiversity and allows further agronomical and enological evaluation
Correlation between the microscopy and qPCR methods (SYBR Green) to detect and quantify Rhizophagus irregularis in grapevine roots
Get PDFFor an easier identification and quantification of R. irregularis in grapevine, a molecular tool was developed so that each DNA concentration calculated would relate to the degree of root system colonization. To correlate the results obtained by qPCR and microscopy, a different approach for the visualization technique was chosen. It combined the detailed standard method of evaluation on microscopic slides with the global magnifying glass evaluation method in the grids. The global assessment sampling was closer to the qPCR sampling that was made on a representative fraction of the whole root system. This fact became the base of successful correlation between microscopy and qPCR. The result of these measures were the attribution of an average qPCR value to each level of colonization defined as five different classes. Around 0.66 ng·µL-1, the DNA concentration corresponded to the first contacts between the fungus and the grapevine roots (class M1), while around 42 ng·µL-1 it accounted for the beginning of the mycorrhizal symbiosis (class M2). A satisfactory mycorrhization level could be concluded from a 258 ng·µL-1 DNA concentration (class M3), while all values above 563 ng·µL-1 (class M4) showed a full mycorrhization level. The development of this qPCR tool allowed the fast and accurate evaluation of the mycorrhization level in the root system without having to realize any microscopic observation
Novel detected entomopathogenic fungus Pandora sp. infects Cacopsylla spp. and other phloem-feeding hemipteran insects
Get PDFHigh throughput reverse genetic tools for knocking out several genes of the phytic acid pathway in Brassica napus
Get PDFTranscriptional regulation of iron homeostasis of the hemibiotrophic phytopathogen Colletotrichum graminicola
Get PDFFire blight resistance of the wild apple species Malus fusca
Get PDFErwinia amylovora is the pathogen responsible for inciting fire blight - the most dreaded bacterial disease of apple (Malus × domestica) and other members of the Rosaceae family. The disease is very destructive as is difficult to control. Even though fire blight was first observed over two centuries ago in America, no sustainable control measure is known till date. Disease management practices such as pruning of affected tissues as well as the application of copper and antibiotics, for example, streptomycin, are to minimize the population of E. amylovora in an orchard. However, the use of streptomycin is not allowed in many European countries as a consequence of its environmental risks and the issue of raising antibiotic resistant E. amylovora populations. Therefore, natural resistance is thought to be the most sustainable approach to manage fire blight. Genetic resistance has been investigated in Malus leading to the detection of several quantitative trait loci (QTLs) in apple cultivars and apple wild species accessions. Nevertheless, only one functionally characterized fire blight resistance gene has been isolated till date. This situation, coupled with the proof that resistance is strain specific, reinforces the need to detect more donors that could be used to establish durable resistance against fire blight. For this reason, the works described in this thesis aimed at investigating fire blight resistance in another apple wild species – Malus fusca. Different accessions of M. fusca were phenotyped in JKI, Dresden, Germany to ascertain the accession with a high resistance level. Accession MAL0045, found as having a very high resistance level was then crossed with the very susceptible apple cultivar ‘Idared’ to establish a segregating F1 population of 134 individuals. To facilitate the development of a genetic map of M. fusca, molecular markers such as DArT (Diversity Arrays Technology), SNPs (Single Nucleotide Polymorphisms) and SSRs (Simple Sequence Repeats) were developed, sourced, tested and polymorphic ones applied to the 134 individuals and then mapped. The phenotypic and genotypic data were employed for QTL analyses which resulted in the identification of a major quantitative trait locus which is located on linkage group 10 (LG10) of the apple genome and could explain about 66 % of the phenotypic variation; the second highest effect of all QTLs previously detected in Malus. Furthermore, this thesis also describes the stability and validation of the M. fusca fire blight resistance locus (Mfu10) after another phenotypic evaluation of the F1 population with a highly virulent E. amylovora isolate Ea3049 originating from Canada. Moreover, the fine mapping of the resistance region was undertaken via chromosome walking approach with the development of closely linked SSR markers suitable for marker assisted selection (MAS). For this purpose, the population was substantially increased to 1,336 individuals from an additional cross of M. fusca × ‘Idared’ and a reciprocal cross of ‘Idared’ × M. fusca. Genotyping of the whole population allowed for the identification of individuals showing recombination events within the interval of the QTL region. Phenotyping of recombinant individuals ensured that the exact position of the QTL was well defined. The first steps towards uncovering the underlying gene(s) responsible for the resistance of fire blight in M. fusca have been achieved with the development and screening of a M. fusca bacterial artificial chromosome (BAC) library with SSR markers closely linked to Mfu10 and the identification of some BAC clones in the QTL interval. This is the first report of a major quantitative trait locus for resistance to fire blight in this wild relative of apple. The implications of the results obtained in these research works in respect to breeding for resistance against the very destructive fire blight disease of Malus are discussed extensively.Erwinia amylovora is the pathogen responsible for inciting fire blight - the most dreaded bacterial disease of apple (Malus × domestica) and other members of the Rosaceae family. The disease is very destructive as is difficult to control. Even though fire blight was first observed over two centuries ago in America, no sustainable control measure is known till date. Disease management practices such as pruning of affected tissues as well as the application of copper and antibiotics, for example, streptomycin, are to minimize the population of E. amylovora in an orchard. However, the use of streptomycin is not allowed in many European countries as a consequence of its environmental risks and the issue of raising antibiotic resistant E. amylovora populations. Therefore, natural resistance is thought to be the most sustainable approach to manage fire blight. Genetic resistance has been investigated in Malus leading to the detection of several quantitative trait loci (QTLs) in apple cultivars and apple wild species accessions. Nevertheless, only one functionally characterized fire blight resistance gene has been isolated till date. This situation, coupled with the proof that resistance is strain specific, reinforces the need to detect more donors that could be used to establish durable resistance against fire blight. For this reason, the works described in this thesis aimed at investigating fire blight resistance in another apple wild species – Malus fusca. Different accessions of M. fusca were phenotyped in JKI, Dresden, Germany to ascertain the accession with a high resistance level. Accession MAL0045, found as having a very high resistance level was then crossed with the very susceptible apple cultivar ‘Idared’ to establish a segregating F1 population of 134 individuals. To facilitate the development of a genetic map of M. fusca, molecular markers such as DArT (Diversity Arrays Technology), SNPs (Single Nucleotide Polymorphisms) and SSRs (Simple Sequence Repeats) were developed, sourced, tested and polymorphic ones applied to the 134 individuals and then mapped. The phenotypic and genotypic data were employed for QTL analyses which resulted in the identification of a major quantitative trait locus which is located on linkage group 10 (LG10) of the apple genome and could explain about 66 % of the phenotypic variation; the second highest effect of all QTLs previously detected in Malus. Furthermore, this thesis also describes the stability and validation of the M. fusca fire blight resistance locus (Mfu10) after another phenotypic evaluation of the F1 population with a highly virulent E. amylovora isolate Ea3049 originating from Canada. Moreover, the fine mapping of the resistance region was undertaken via chromosome walking approach with the development of closely linked SSR markers suitable for marker assisted selection (MAS). For this purpose, the population was substantially increased to 1,336 individuals from an additional cross of M. fusca × ‘Idared’ and a reciprocal cross of ‘Idared’ × M. fusca. Genotyping of the whole population allowed for the identification of individuals showing recombination events within the interval of the QTL region. Phenotyping of recombinant individuals ensured that the exact position of the QTL was well defined. The first steps towards uncovering the underlying gene(s) responsible for the resistance of fire blight in M. fusca have been achieved with the development and screening of a M. fusca bacterial artificial chromosome (BAC) library with SSR markers closely linked to Mfu10 and the identification of some BAC clones in the QTL interval. This is the first report of a major quantitative trait locus for resistance to fire blight in this wild relative of apple. The implications of the results obtained in these research works in respect to breeding for resistance against the very destructive fire blight disease of Malus are discussed extensively
Impact of land-use and land-management on the water infi ltration capacity of soils on a catchment scale
No full textAgriculture is the largest user of the resource soil. So, even small changes in certain soil properties can lead to huge effects on a regional scale. The infiltration capacity is as such an important soil parameter, and also a good indicator of soil quality and soil fertility. Silent sealing, as a result of a negative change in the infiltration capacity due to unfavourable landuse and management, will results in severe effects like faster runoff production and flooding on regional scale,. The assessment of impacts due to land-use or land-management changes on a regional scale is difficult, because detailed information on soil properties and land-management are rarely available. The awareness of the effects of interference in ecosystems is extremely important to supply landscape planners and politicians with information about the impacts of their proposed plans. The aim of this work is the assessment of the maximum water storage capacity of soils under different land-use and land-management situations in a real river catchment (Schunter). Based on field measurements of infiltration under several land-use and land-management situations, a modelling approach has been developed to determine the maximum potential water storagecapacity (Smax). This maximum water storage capacity is closely related to the saturated hydraulic conductivity (Ks), and also a suitable indicator, which can be used to compare different land-use/land-management scenarios. Smax is a theoretical value describing the maximum potential of a given soil/land-use unit. Although, in reality, the water storage is highly variable due to different soils and land-uses on a catchment scale, Smax allows the direct comparison of different soil/land-use units. Since the required input parameters for detailed process models are often not available at a regional scale, general assumptions and simplifications have to be applied in order to provide meaningful statements. In this special case an integrated measure is needed which takes the soil properties in combination to the land-use and the land-management into account. Such an integrated measure can be found as a part in the Curve Number (CN) from the “Curve Number Model" of the National Resource Conservation Service. The CN is a dimensionless value which has been experimentally identified for a variety of different soil, land-use and land-management situations for small scale catchments in the US. The CN is related to the water retention potential (S), and S was originally used to compute the direct runoff from a precipitation event. Since this work addresses only the agricultural viewpoint of impacts of land-use and land-management, the main focus is on the relation of CN to the water retention potential and the computation of Smax. Final runoff computations were not the aim of this work. Knowing the limitations of the Curve Number Model for hydrological questions, runoff has been computed for the year 2002for demonstration purposes only. The CN-Model has often been criticized for its obscure determination of the CN from precipitation/runoff relations, which have not been properly published, not even in the official handbooks. In this work new methods for the determination of the CN have been developed. Now the CN can be directly measured (CNm) based on field infiltration measurements. Use of the saturated hydraulic conductivity allows the computation of the maximum water storage capacity (Smax) for a given soil, land-use and land-management combination. Since the maximum storage capacity is used, the prevailing wetting status of the soil can also be neglected. On a catchment scale, only a subset of all soil, land-use and land-management situations can be covered by measurements. The remaining situations have to be estimated or be adapted from literature values. The use of pedotransfer functions allow the computation of soil properties (e.g., Ks) based on their textural composition. The performance of the pedotransfer functions in comparison to the field measurements have been tested, resulting in a poor capability of predicting correct values from the pedotransfer functions. The comparison of measured CNm with published values of the CN performed very well. Based on the CNm-Model, scenarios of historic (1950), current (2009) and future (2070) land-uses for the Schunter catchment have been computed, showing the direct impact of different land-use situations to the maximum water storage capacity on a regional scale. Although the scenarios are just snapshots, not taking the temporal dimension of land-use changes into account, this method is useful to detect the impacts of land-use and landmanagement changes. This work examined a new method to derive the CNm by infiltration measurements in the field. The experimental determination of the CNm allows the update of existing curve numbers for special situations not covered in the handbook. Also, the application of the CN concept to German soils is now possible. The computation of the maximum potential storage capacity (Smax) is a useful measure to identify the impacts and to compare land-use and landmanagement scenarios. The impact of land-use and land-management changes on a catchment scale has been clearly demonstrated. Compared to the situation in 1950, in the year 2009 the maximum water storage capacity has decreased by 17 %. Projecting a similar land-use change of the past 60 years into the future will result in a loss of water storage capacity of 19 % compared to 1950. The model approach offers a useful tool for landscape analysis. Due to the manifold different landmanagement practices in agriculture, additional measurements should be performed in the future.
Auf Wunsch des Autors / der Autorin ist diese Dissertation nur als Druckausgabe verfügbar.Agriculture is the largest user of the resource soil. So, even small changes in certain soil properties can lead to huge effects on a regional scale. The infiltration capacity is as such an important soil parameter, and also a good indicator of soil quality and soil fertility. Silent sealing, as a result of a negative change in the infiltration capacity due to unfavourable landuse and management, will results in severe effects like faster runoff production and flooding on regional scale,. The assessment of impacts due to land-use or land-management changes on a regional scale is difficult, because detailed information on soil properties and land-management are rarely available. The awareness of the effects of interference in ecosystems is extremely important to supply landscape planners and politicians with information about the impacts of their proposed plans. The aim of this work is the assessment of the maximum water storage capacity of soils under different land-use and land-management situations in a real river catchment (Schunter). Based on field measurements of infiltration under several land-use and land-management situations, a modelling approach has been developed to determine the maximum potential water storagecapacity (Smax). This maximum water storage capacity is closely related to the saturated hydraulic conductivity (Ks), and also a suitable indicator, which can be used to compare different land-use/land-management scenarios. Smax is a theoretical value describing the maximum potential of a given soil/land-use unit. Although, in reality, the water storage is highly variable due to different soils and land-uses on a catchment scale, Smax allows the direct comparison of different soil/land-use units. Since the required input parameters for detailed process models are often not available at a regional scale, general assumptions and simplifications have to be applied in order to provide meaningful statements. In this special case an integrated measure is needed which takes the soil properties in combination to the land-use and the land-management into account. Such an integrated measure can be found as a part in the Curve Number (CN) from the “Curve Number Model" of the National Resource Conservation Service. The CN is a dimensionless value which has been experimentally identified for a variety of different soil, land-use and land-management situations for small scale catchments in the US. The CN is related to the water retention potential (S), and S was originally used to compute the direct runoff from a precipitation event. Since this work addresses only the agricultural viewpoint of impacts of land-use and land-management, the main focus is on the relation of CN to the water retention potential and the computation of Smax. Final runoff computations were not the aim of this work. Knowing the limitations of the Curve Number Model for hydrological questions, runoff has been computed for the year 2002for demonstration purposes only. The CN-Model has often been criticized for its obscure determination of the CN from precipitation/runoff relations, which have not been properly published, not even in the official handbooks. In this work new methods for the determination of the CN have been developed. Now the CN can be directly measured (CNm) based on field infiltration measurements. Use of the saturated hydraulic conductivity allows the computation of the maximum water storage capacity (Smax) for a given soil, land-use and land-management combination. Since the maximum storage capacity is used, the prevailing wetting status of the soil can also be neglected. On a catchment scale, only a subset of all soil, land-use and land-management situations can be covered by measurements. The remaining situations have to be estimated or be adapted from literature values. The use of pedotransfer functions allow the computation of soil properties (e.g., Ks) based on their textural composition. The performance of the pedotransfer functions in comparison to the field measurements have been tested, resulting in a poor capability of predicting correct values from the pedotransfer functions. The comparison of measured CNm with published values of the CN performed very well. Based on the CNm-Model, scenarios of historic (1950), current (2009) and future (2070) land-uses for the Schunter catchment have been computed, showing the direct impact of different land-use situations to the maximum water storage capacity on a regional scale. Although the scenarios are just snapshots, not taking the temporal dimension of land-use changes into account, this method is useful to detect the impacts of land-use and landmanagement changes. This work examined a new method to derive the CNm by infiltration measurements in the field. The experimental determination of the CNm allows the update of existing curve numbers for special situations not covered in the handbook. Also, the application of the CN concept to German soils is now possible. The computation of the maximum potential storage capacity (Smax) is a useful measure to identify the impacts and to compare land-use and landmanagement scenarios. The impact of land-use and land-management changes on a catchment scale has been clearly demonstrated. Compared to the situation in 1950, in the year 2009 the maximum water storage capacity has decreased by 17 %. Projecting a similar land-use change of the past 60 years into the future will result in a loss of water storage capacity of 19 % compared to 1950. The model approach offers a useful tool for landscape analysis. Due to the manifold different landmanagement practices in agriculture, additional measurements should be performed in the future.
Upon author request this thesis is available as printed version only
24-Epibrassinolide enhanced the quality parameters and phytochemical contents of table grape
Get PDFEnhancing the nutritional quality of fruits using safe and environmental friendly methods has become of the most important targets in modern fruit production systems. Brassinosteroids, a new group of phytohormones with positive roles on human health, have been shown to modulate a wide range of plant activities and enhance fruit quality in some crops. This study was conducted to examine the effect of 24-Epibrassinolide (EBL), a synthetic brassinosteroid, on quality attributes and some active bio-compounds of “Thompson seedless” table grapes. Grape vines and bunches were sprayed with EBL (at 0, 3 and/or 6 µmol L-1) at three different stages (4 weeks after fool bloom, veraison stage and 1 day before harvest). As a novel finding in seedless grapes, exogenous EBL substantially enhanced soluble solids content, total organic acids, antioxidants, phenolics and ascorbic acid levels in treated berries. Also the activity of catalase and polyphenol oxidase enzymes was increased. There was no significant difference between the two brassinosteroid levels in most cases. EBL showed a good potential for enhancing table grape phytonutrients, nutritional quality and phytochemical contents and is introduced as a safe compound to be used in table grape production programs. 
