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Modelling of climate-sensitive pests in plant health
Get PDFKlimasensitive Schadorganismen sind Arten, deren Risiko einen Schaden zu verursachen sich aufgrund der vorhergesagten klimatischen Veränderungen voraussichtlich erheblich verändern wird. Damit stellen sie eine besondere Herausforderung für die Pflanzengesundheit dar. Zur Vorhersage des Etablierungs- und Ausbreitungspotenzials dieser Schadorganismen ist eine Bewertung unter verschiedenen Umwelt- und Managementszenarien unerlässlich. Ein effizientes Werkzeug zur Untersuchung des Risikos klimasensitiver Schadorganismen (SO) sind prozess-orientierte Simulationsmodelle. Im Rahmen des Projektes,,ProgRAMM“ wird ein solches Modell, das auf Grundlage artspezifischer physiologischer Parameter und Verbreitungseigenschaften arbeitet, entwickelt. Mit diesem Modell wird es möglich sein, die o.g. Vorhersagen und Szenarioanalysen zu realisieren und langfristig einen übertragbaren, verallgemeinerten Open-Source-Modellrahmen als Standardverfahren zur Unterstützung von pflanzengesundheitlichen Risikoanalysen klimasensitiver SO zu etablieren. Dabei steht besonders im Vordergrund, dass das Modell leicht erweiterbar ist und sich leicht mit einzelnen Wirtspflanzen, aktuellen Klimadatensätzen sowie neuen An-/Abwesenheitsdaten der SO koppeln lässt. Die Ergebnisse des Modells werden in Form von Verbreitungs- und Risikokarten grafisch dargestellt. Diese Karten dienen der verbesserten Abschätzung und Darstellung der wirtschaftlichen und ökologischen Risiken durch die Schadorganismen in Risikoanalysen. Zusätzlich kann durch die Identifizierung von Hochrisikogebieten für die Ansiedlung von SO, die Planung von Monitoring-Aktivitäten unterstützt werden. Das Modell wird open-source gehalten und um verschiedene Untermodelle sowie artspezifische Funktionen und Parametrisierung erweiterbar sein, damit die Übertragbarkeit auf möglichst viele Schadorganismengruppen (Pilze, Insekten, Milben, Nematoden, Bakterien) sichergestellt ist.Climate-sensitive pests are those whose risk of causing damage is likely to change significantly due to predicted climatic changes. They therefore pose a particular challenge to plant health. In order to predict the establishment and spread potential of these pests, an assessment under various environmental and management scenarios is essential. Process-oriented simulation models are an efficient tool to investigate the occurrence and spread of climate-sensitive pests. In the project ‘ProgRAMM’ (Proactive phytosanitary risk analysis through modelling and monitoring: adaptation to long-term risks caused by climate-sensitive pests) such a model based on species-specific physiological parameters and distribution characteristics is being developed. With this model the above mentioned predictions and scenario analyses can be carried out. A transferable, generalized open-source modelling framework will be established as a standard procedure to support plant health risk analyses (PRA) of climate-sensitive pests. A particular focus is on the fact that the model is easily extensible and that it can be easily coupled with a different set of additional host plants, plant databases, different climate data sets as well as new presence/absence data of pests. The results of the model are presented graphically in the form of distribution and risk maps. The results can be used in PRAs to better assess the economic and ecological risks of a pest. In addition, the high-risk areas for the occurrence of pests will be identified to support the planning of efficient monitoring activities. The open source license along with the modular nature of the model components will ensure transferability to pest groups such as fungi, insects, mites, nematodes and bacteria. This will also enable the extension of the model by different sub-models as well as by species-specific functions and parameterization
Towards a development of novel bioinsecticides for organic control of Planococcus ficus in vineyards
Get PDFThe mealybug species, Planococcus ficus Signoret (Hemiptera: Pseudococcidae) is a pest that mainly affects grapevine plantations (Vitis vinifera L.), causing huge economic losses in the world. The numerous problems caused by the use of synthetic pesticides on the environment and human health have motivated the development and implementation of natural pesticides. The objective of this work was to develop effective and efficient contact bioinsecticide formulations for the control of P. ficus in vineyards. Anti-mealybug formulations were developed using (R)-(+)-pulegone as an active principle, TWEEN® 20 and soy lecithin powder as surfactants, and limonene and diatomaceous earth (DE) as insect waxy layer reducers. The insecticidal properties of formulations against vine mealybugs and their grapevine leaf phytotoxicity were evaluated in laboratory conditions. Pulegone+DE+Lecithin and Pulegone+Limonene+DE+Lecithin formulations showed the highest mortality rates of P. ficus (more than 70 % mortality) at 24 h and 48 h of treatment. This high mortality is probably due to an interaction between pulegone, DE and soy lecithin that allows more molecular mobility and increases the efficiency of the active substance, making it enter and act on the insect. In conclusion, the Pulegone+DE+Lecithin and Pulegone+Limonene+DE+Lecithin formulations can be an efficient tool for the organic control of P. ficus in vineyards
Recovering old grapevine varieties
Get PDFIn this work we report new findings related to the recovery of old vines in The Comunitat Valenciana (Spain), where great diversity of grapevines varieties was present prior the phylloxera arrival. New accessions of old varieties previously recovered by our group and in risk of disappearance were located. Accessions with new SSR profiles were also found and, in some cases, could be ascribed to old grapevine ampelonyms; new synonymies were also detected. Chlorotypes were determined in the recovered germplasm. Several actions for the preservation of the recovered accessions have been initiated
Identification of QTL for resistance against two fungal pathogens, Pyrenophora teres f. teres and Bipolaris sorokiniana, in a barley (Hordeum vulgare L.) diversity set
Get PDFBarley is worldwide the fourth most important cereal crop and is cultivated in near desert to sub-arctic conditions. The majority of production, around 70 %, is used for animal feed, 20 % are used for malting and the rest for human consumption, with regional differences.Pests and diseases constantly result in high yield losses. Two worldwide important fungal foliar diseases of barley are Pyrenophora teres f. teres (Ptt) and Bipolaris sorokiniana (Bs), the causal agents of net blotch and spot blotch, respectively. Yield losses are on average around 40 % and can amount to over 70 % in years with epidemics. Both pathogens are highly variable and the occurrence of new pathogenic strains demands for breeding of resistant cultivars.In order to identify new resistance sources, a diverse barley set comprising 449 accessions originating from over 50 different regions all over the world, expressing different levels of resistance against both pathogens, was screened. Seedling resistance was tested under controlled greenhouse conditions with three isolates of each pathogen. Adult plant resistance was tested in field trials at three and two locations for Ptt and Bs, respectively. Phenotypic results showed a wide range of the level of resistance and significant differences between accessions were observed in all trials. The set was genotyped using the Illumina iSelect 50k barley SNP chip. After filtering for quality control parameters, i.e. failure rates < 10%, heterozygous calls < 12.5% and minor allele frequency > 5%, 33,318 polymorphic, mapped SNPs were left for further genome-wide association studies (GWAS). Markers were mapped against the barley reference sequence. GWAS was conducted using a compressed mixed linear model (CMLM) including population structure and kinship matrix. GWAS for Ptt revealed 254 significant marker-trait associations (MTAs) located on chromosomes 3H, 4H, 5H, 6H, and 7H and corresponding to 15 quantitative trait loci (QTL). Four of these loci are putatively new and were not previously described. In nine out of the 15 regions, 63 high-confidence genes that are directly involved in pathogen defence are located and represent putative candidate genes. GWAS for Bs revealed 38 significant MTAs corresponding to two major QTL on chromosomes 1H and 7H and a putative new minor QTL on chromosome 7H. In the major QTL regions, 10 and 14 high-confidence genes were identified, respectively. Based on haplotypes and phenotypic reactions it was possible to identify accessions with enhanced resistance against Ptt and Bs.Barley is worldwide the fourth most important cereal crop and is cultivated in near desert to sub-arctic conditions. The majority of production, around 70 %, is used for animal feed, 20 % are used for malting and the rest for human consumption, with regional differences.Pests and diseases constantly result in high yield losses. Two worldwide important fungal foliar diseases of barley are Pyrenophora teres f. teres (Ptt) and Bipolaris sorokiniana (Bs), the causal agents of net blotch and spot blotch, respectively. Yield losses are on average around 40 % and can amount to over 70 % in years with epidemics. Both pathogens are highly variable and the occurrence of new pathogenic strains demands for breeding of resistant cultivars.In order to identify new resistance sources, a diverse barley set comprising 449 accessions originating from over 50 different regions all over the world, expressing different levels of resistance against both pathogens, was screened. Seedling resistance was tested under controlled greenhouse conditions with three isolates of each pathogen. Adult plant resistance was tested in field trials at three and two locations for Ptt and Bs, respectively. Phenotypic results showed a wide range of the level of resistance and significant differences between accessions were observed in all trials. The set was genotyped using the Illumina iSelect 50k barley SNP chip. After filtering for quality control parameters, i.e. failure rates < 10%, heterozygous calls < 12.5% and minor allele frequency > 5%, 33,318 polymorphic, mapped SNPs were left for further genome-wide association studies (GWAS). Markers were mapped against the barley reference sequence. GWAS was conducted using a compressed mixed linear model (CMLM) including population structure and kinship matrix. GWAS for Ptt revealed 254 significant marker-trait associations (MTAs) located on chromosomes 3H, 4H, 5H, 6H, and 7H and corresponding to 15 quantitative trait loci (QTL). Four of these loci are putatively new and were not previously described. In nine out of the 15 regions, 63 high-confidence genes that are directly involved in pathogen defence are located and represent putative candidate genes. GWAS for Bs revealed 38 significant MTAs corresponding to two major QTL on chromosomes 1H and 7H and a putative new minor QTL on chromosome 7H. In the major QTL regions, 10 and 14 high-confidence genes were identified, respectively. Based on haplotypes and phenotypic reactions it was possible to identify accessions with enhanced resistance against Ptt and Bs
Sugar content and organic acid profiles of local apple cultivars recovered from mountain zones
Get PDFAncient apple cultivars grown in local areas have so far been largely unexplored and may attract a large share of consumers oriented towards natural foods evoking ancient flavors. In this work, 34 traditional apple cultivars of the Pyrenees were analyzed in terms of sugar and acidity profile and their relation, as alternative fruits for a growing demand in society regarding quality and nutritional proper-ties. The results show a wide range between cultivars of analyzed variables, especially in terms of acid, pH and soluble solids, with high standard deviation values. The results were higher than in other similar studies of commercial apple cultivars, as well as higher values related to other local accessions. The large differences between cultivars can be attributed to the origin of the plant material, since all cultivars were grown under the same geographical conditions and with the same applied agronomic practices. The associations found in this study provide information about the nutritional content of the analyzed apples and their organoleptic and physicochemical qualities, and could be useful in targeting specific consumer requirements. In conclusion, this study highlights the suitability of these local accessions recovered in the Pyrenees as key genetic resources to be used in future breeding programs, as well as its potential use for different products which would open the door to new varieties and new consumption alternatives
Crop rotations with and without legumes: a review
Get PDFLeguminosen sind im ökologischen Landbau aufgrund ihrer Fähigkeit zur Luftstickstofffixierung unverzichtbar für die Stickstoffversorgung der Ackerkulturen und die Proteinversorgung der Nutztiere. Im konventionellen Anbau bieten Leguminosen die Möglichkeit, die häufig getreideintensiven Fruchtfolgen aufzulockern. Eine der wichtigsten Wirkungen dieses Break-crop-Effekts ist das Durchbrechen des Lebenszyklus von fruchtartenspezifischen Pathogenen und der damit verbundenen Einsparung von Pflanzenschutzmitteln. Die vorliegende Übersichtsarbeit stellt den derzeitigen Stand des Wissens zu Fruchtfolgen mit und ohne Leguminosen zusammen. Dabei werden ackerbauliche, ökologische und ökonomische Wirkungen des Anbaus groß- und kleinkörnig Leguminosenarten als Haupt- oder Zwischenfrüchte bzw. Untersaaten oder als Komponenten in Gemengen dargestellt und bewertet. Der Schwerpunkt liegt dabei auf relevanten Publikationen in wissenschaftlichen Journalen sowie Praxis- und Forschungsberichten der Jahre 2010 – 2020 die in Deutschland oder vergleichbaren klimatischen Bedingungen durchgeführt wurden. Abschließend wird daraus der notwendige Forschungsbedarf für die Themenbereiche Pflanzenbau (konventionell und ökologisch), Pflanzenschutz, Ökonomie, Ökologie und Klimaschutz abgeleitet.In organic farming, legumes are indispensable for the nitrogen supply of arable crops and the protein supply of livestock due to their ability to fix atmospheric nitrogen. In conventional farming, legumes offer the potential to break the often cereal-intensive crop rotations. One of the most important consequences of the break-crop effect is the interruption of the life cycle of crop-specific pathogens and the associated savings of pesticides. This review summarizes the current state of knowledge on crop rotations with and without legumes. It presents and evaluates the agronomic, ecological and economic effects of the cultivation of large- and small-seeded legume species as main or catch crops, when undersown in other crops, or used as components in mixtures. The focus is on relevant publications in scientific journals as well as practice and research reports published between 2010 and 2020 which were carried out in Germany or under comparable climatic conditions. Finally, essential research needs in the areas of crop production (conventional and organic), crop protection, economics, ecology, and climate protection are identified
The biochemistry of cocoa flavor - A holistic analysis of its development along the processing chain
Get PDFThe seeds of the cacao tree Theobroma cacao L. are the key ingredient of chocolate (Codex Alimentarius, 1981). They have a unique and complex flavor profile. Up to 87 descriptors can be distinguished (Januszewska et al., 2018). Beside the typical chocolate aroma, floral, fruity and nutty aroma notes may occur. Regarding taste attributes, typical cocoa bitterness and acidity are of key importance. A pleasant, mouth-filling astringency does complete the typical flavor characteristics. These attributes can be more or less intense, or even absent as in the case of floral, fruity and nutty notes, resulting in a great diversity in the flavor profile between countries, regions and even plantations (sukha et al., 2007). This diversity depends on a network of multiple interacting factors along the processing chain, from the genetic background of the cacao trees, seed physiology and climatic conditions over fermentation, drying and roasting up to chocolate ingredients such as sugar (Andersson et al., 2006; Afoakwa et al., 2008; muñoz et al., 2019). The purpose of this review is to analyze the current knowledge about the impact of these factors and their interaction on the composition of taste- and aroma-active substances as well as respective precursors and how specific flavor profiles can be explained through them. Gaps in research as well as potential applications in cocoa processing and chocolate manufacturing are discussed
Besides variety, also season and ripening stage have a major influence on fruit pulp aroma of cacao (Theobroma cacao L.)
Get PDFMore than 1000 different cacao varieties are described. Only few are considered as fine or flavour cocoas, meaning they have the potential to develop special flavour characteristics after appropriate fermenta-tion and drying. It is assumed that aroma compounds located in the fruit pulp migrate into the seed during fermentation. We studied the fine aroma potential of five cacao varieties selected at CATIE, Costa Rica, by analysing aroma compounds in their fresh fruit pulps using Headspace SPME-GCMS. Pulps of unripe, ripe and overripe fruits harvested in the dry and rainy season, respectively, were compared to the control genotypes EET 62 and SCA-6, both known for high amounts of fine aromas described as e.g. “fruity”, “floral” or “spicy”. All genotypes contained a basic content of the two dominating esters 2-pentanol acetate and 2-heptanol acetate, combined with a mixture of aroma-active compounds with small peak areas that form the variety-specific aroma character. Total aroma diversity and intensity increased during ripening. Aroma profiles were more diverse when fruits ripened during the dry season, whereas aroma intensity was higher in the rainy season. Thus, the fruit and environmental condi-tions prior to harvest can already play a decisive role for the aroma potential of the cacao pulp. Due to their aroma profiles, the varieties from CATIE can be classified as fine or flavour cocoas