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Krzyszczak J.,Polish Academy of Sciences | Baranowski P.,Polish Academy of Sciences | Zubik M.,Polish Academy of Sciences | Hoffmann H.,Institute of Crop Science and Resource Conservation INRES
Agricultural and Forest Meteorology | Year: 2017

Scale issues become very important when applying weather time series. We address problems associated with transferring meteorological data across time scales by comparing multifractal properties of hourly and daily meteorological time series. The multifractal detrended fluctuation approach revealed that temporal aggregation of agro-meteorological time series can impact on their multifractal properties. The most apparent evidence of changing the time scale on multifractal properties was found for precipitation. It was the least noticeable for the wind speed time series. The change from hourly to daily time scale had an effect on the long-range correlations and the broadness of the probability density function. The contribution of these two components to series multifractality was smaller than before data aggregation. Our results confirm the loss of unique multifractal features at daily time scale as compared to hourly time series. © 2017 Elsevier B.V.


Pame A.R.,Institute of Crop Science and Resource Conservation INRES | Kreye C.,Institute of Crop Science and Resource Conservation INRES | Johnson D.,International Rice Research Institute | Heuer S.,University of Adelaide | Becker M.,Institute of Crop Science and Resource Conservation INRES
Experimental Agriculture | Year: 2015

Seedling vigor is important to help ensure good crop establishment. In direct-seeded rice, this is particularly relevant when soil conditions are marginal. In Asia, about one third of the area of rainfed rice is situated on unfavorable soils, many of which are low in plant available P. In such environments, as farmers tend to have few resources, options to overcome poor crop establishment should be low cost and preferably seed-based. The P content of seed depends on genotype and can be augmented by soaking seeds in a P-containing solution prior to seeding (P-priming). In addition, the presence of the Pup1 quantitative trait locus can reportedly confer tolerance to low soil P availability. We tested combinations of seed priming (unprimed control, water priming, P-priming), and inherent seed P concentrations in contrasting rice genotypes (DJ123, Sadri Tor Misri), and two near isogenic sister lines of IR74 with (+Pup1) and without (-Pup1) the Pup1 QTL. Treatment effects on germination were studied in Petri dishes, while seedling growth and P accumulation were assessed using pots with P deficient soil. Germination was less than 75% in seeds with low seed P content. Seed priming with both water and P enhanced germination and seedling growth. In plants growing from high P seeds, water priming outperformed P-priming. In Sadri Tor Misri with low seed P, we observed a tendency for better performance in some parameters when P-primed. While the presence of the Pup1 QTL in IR74 increased shoot biomass and total root length, these effects could be further enhanced by water priming. Combining genetic and seed management approaches may contribute to improved rice establishment in P deficient soils but its effectiveness depends on genotype and seed attributes. © 2015 Cambridge University Press.


Baranowski P.,Polish Academy of Sciences | Krzyszczak J.,Polish Academy of Sciences | Slawinski C.,Polish Academy of Sciences | Hoffmann H.,Institute of Crop Science and Resource Conservation INRES | And 2 more authors.
Climate Research | Year: 2015

Agro-meteorological quantities are often in the form of time series, and knowledge about their temporal scaling properties is fundamental for transferring locally measured fluctuations to larger scales and vice versa. However, the scaling analysis of these quantities is complicated due to the presence of localized trends and nonstationarities. The objective of this study was to characterise scaling properties (i.e. statistical self-similarity) of the chosen agro-meteorological quantities through multifractal detrended fluctuation analysis (MFDFA). For this purpose, MFDFA was performedwith 11 322 measured time series (31 yr) of daily air temperature, wind velocity, relative air humidity, global radiation and precipitation from stations located in Finland, Germany, Poland and Spain. The empirical singularity spectra indicated their multifractal structure. The richness of the studied multifractals was evaluated by the width of their spectrum, indicating considerable differences in dynamics and development. In log-log plots of the cumulative distributions of all meteorological parameters the linear functions prevailed for high values of the response, indicating that these distributions were consistent with power-law asymptotic behaviour. Additionally, we investigated the type of multifractality that underlies the q-dependence of the generalized Hurst exponent by analysing the corresponding shuffled and surrogate time series. For most of the studied meteorological parameters, the multifractality is due to different long-range correlations for small and large fluctuations. Only for precipitation does the multifractality result mainly from broad probability function. This feature may be especially valuable for assessing the effect of change in climate dynamics. © Inter-Research 2015.


Pariyar S.R.,Institute of Crop Science and Resource Conservation INRES | Dababat A.A.,International Maize and Wheat Improvement Center | Siddique S.,Institute of Crop Science and Resource Conservation INRES | Erginbas-Orakci G.,International Maize and Wheat Improvement Center | And 4 more authors.
Nematology | Year: 2016

The aim of this study was to search for new sources of resistance against the cereal cyst nematode, Heterodera filipjevi, in a collection of 290 wheat accessions. The plants were inoculated with juveniles and assessed for the number of females and cysts. One percent of the wheat accessions were ranked as resistant, 16% as moderately resistant, 41% as moderately susceptible, 26% as susceptible and 15% as highly susceptible. The infection rate and the number of females and cysts per plant were significantly lower in the resistant accession Nudakota and three moderately resistant accessions Ekonomka, Katea and Lantian 12 compared with susceptible cv. Bezostaya 1. Nematode development was reduced in resistant and moderately resistant accessions. The size of females and the total number of eggs and second-stage juveniles were reduced only in Ekonomka. No significant difference in plant height, plant weight, root length, root weight and root volume were recorded for inoculated plants compared to non-inoculated plants. This study has identified four resistant wheat accessions offering new material for breeding the resistance to H. filipjevi. © Koninklijke Brill NV, Leiden, 2016.


Schlummer M.,University of Bonn | Hoffmann T.,University of Bonn | Dikau R.,University of Bonn | Eickmeier M.,University of Cologne | And 14 more authors.
Earth-Science Reviews | Year: 2014

The study of past socio-environmental systems integrates a variety of terrestrial archives. To understand regional or continental socio-environmental interactions proxy data from local archives need to be transferred to larger spatial scales. System properties like spatial heterogeneity, historical and spatial contingency, nonlinearity, scale dependency or emergence make generalizations from local observations to larger scales difficult. As these are common properties of natural and social systems, the development of an interdisciplinary upscaling framework for socio-environmental systems remains a challenge. For example, the integration of social and environmental data is often hindered by divergent methodological, i.e. qualitative and quantitative, approaches and discipline-specific perceptions of spatial scales. Additionally, joint approaches can be hampered by differences in the predictability of natural systems, which are subject to physical laws, and social systems, which depend on humans' decisions and communication.Here we present results from an interdisciplinary discussion of upscaling approaches in socio-environmental research with a special focus on the migration of modern humans in Central Europe during the last 30,000. years. Based on case studies from different disciplines, we develop a classification system for upscaling approaches used in past socio-environmental research. Finally, we present an initial upscaling framework that fosters the development of an interdisciplinary concept of scales and allows for a consideration of system properties like scale dependency, nonlinearity and contingency. The upscaling framework includes the following steps: i) the identification of relevant spatial and temporal scales at which socio-environmental interactions operate; ii) the definition of appropriate parameters to describe scale-specific interactions; iii) a comparison of process and observation scales to evaluate the potential of local archive data for larger scale generalization and for reconstructing scale-specific past socio-environmental interactions; iv) the identification and adaption of appropriate upscaling approaches for the relevant scales; v) the development of scale-specific models of socio-environmental interactions, and vi) the connection of models in a nested hierarchy. Our intention is not to present final results, but rather to stimulate future discussions and to provide a basic reference on scale issues in the emerging field of integrated socio-environmental research. © 2014 Elsevier B.V.


Pariyar S.R.,Institute of Crop Science and Resource Conservation INRES | Dababat A.A.,International Maize and Wheat Improvement Center | Sannemann W.,Institute of Crop Science and Resource Conservation INRES | Sannemann W.,Martin Luther University of Halle Wittenberg | And 7 more authors.
Phytopathology | Year: 2016

The cyst nematode Heterodera filipjevi is a plant parasite causing substantial yield loss in wheat. Resistant cultivars are the preferred method of controlling cyst nematodes. Association mapping is a powerful approach to detect associations between phenotypic variation and genetic polymorphisms; in this way favorable traits such as resistance to pathogens can be located. Therefore, a genome-wide association study of 161 winter wheat accessions was performed with a 90K iSelect single nucleotide polymorphism (SNP) chip. Population structure analysis grouped into two major subgroups and first principal component accounted 6.16% for phenotypic diversity. The genome-wide linkage disequilibrium across wheat was 3 cM. Eleven quantitative trait loci (QTLs) on chromosomes 1AL, 2AS, 2BL, 3AL, 3BL, 4AS, 4AL, 5BL, and 7BL were identified using a mixed linear model false discovery rate of P < 0.01 that explained 43% of total genetic variation. This is the first report of QTLs conferring resistance to H. filipjevi in wheat. Eight QTLs on chromosomes 1AL, 2AS, 2BL, 3AL, 4AL, and 5BL were linked to putative genes known to be involved in plant-pathogen interactions. Two other QTLs on 3BL and one QTL on 7BL linked to putative genes known to be involved in abiotic stress. © 2016 The American Phytopathological Society.


Frei M.,Institute of Crop Science and Resource Conservation INRES | Tetteh R.N.,Institute of Crop Science and Resource Conservation INRES | Razafindrazaka A.L.,Institute of Crop Science and Resource Conservation INRES | Fuh M.A.,Institute of Crop Science and Resource Conservation INRES | And 2 more authors.
Plant and Soil | Year: 2016

Background and aims: Iron (Fe) toxicity is a wide-spread stress in lowland rice production. The aim of this study was to differentiate between responses to acute Fe stress during the vegetative stage and chronic Fe stress throughout the growing period. Methods: Six rice genotypes were tested in a semi-artificial greenhouse setup, in which acute (almost 1500 mg L−1 Fe in soil solution during the vegetative stage) and chronic (200 to 300 mg L−1 Fe throughout the season) Fe toxicity were simulated. Results: Acute Fe stress induced early development of heavy leaf bronzing, whereas moderate symptoms occurred in the chronic treatment throughout the season. Grain yields were only reduced in the chronic stress treatment (−23 %) due to reductions in spikelet fertility, grain number and grain weight. Symptom formation during the early growth stages did not reflect yield responses in all genotypes. Only one genotype showed increases in grain Fe concentrations (24 % in the acute stress and 44 % in the chronic stress) compared to the control. Conclusions: Contrasting genotypes responded differently to acute and chronic Fe toxicity, and one genotype showed consistent tolerance and the ability to translocate excess Fe into grains. These traits can be useful in the adaptive breeding of rice for Fe toxic environments. © 2016 Springer International Publishing Switzerland


PubMed | Institute of Crop Science and Resource Conservation INRES, Justus Liebig University, Leibniz Institute of Plant Genetics and Crop Plant Research, NPZ Innovation GmbH and German Seed Alliance GmbH
Type: Journal Article | Journal: Trends in plant science | Year: 2015

The need to improve hybrid performance, abiotic stress tolerance, and disease resistance without compromising seed quality makes the targeted capture of untapped diversity a major objective for crop breeders. Here we introduce the concept of Heterotic Haplotype Capture (HHC), in which genome sequence imputation is used to trace novel heterozygous chromosome blocks contributing to hybrid performance in large, structured populations of interrelated F1 hybrids containing interesting new diversity for breeding.

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