Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2021
Authors
Milica Fotiric Aksic R. Cerović R. Radošević C. Oparnica Mekjell MelandAbstract
The objective of this study was to determine morphological and anatomical leaf characteristics and stomatal traits of three European (Pyrus communis L.) cultivars, three Asian [Pyrus pyrifolia (Burm. f.) Nakai] pear cultivars together with one interspecies hybrid (P. pyrifolia × P. communis ‘Bartlett’) and link them with the resistance to pathogens. Pear trees were grown under the standard practice without irrigation. Fully developed leaves were picked from the middle part of the extension shoots at the beginning of the July. Leaf traits were measured on leaves picked the same day. Anatomy of leaves was determined under light microscopy (LM) while scanning electron microscopy (SEM) was used for the examination of the stomata cells. Asian pear cultivars (‘Kousui’, ‘Nijisseiki’ and ‘Niitaka’) had much higher leaf parameters (width, length, stem length and leaf area) than the European cultivars (‘Conference’, ‘Williams Bartlett’, ‘Abbate Fetel’) and interspecies hybrid (‘Kieffer Seedling’). Midrib parameters (length and width) were the highest in ‘Kosui’ and ‘Nijisseiki’. Leaves of ‘Kieffer Seedling’ and ‘Abbate Fetel’ were the thickest, mainly due to increased palisade and spongy parenchyma thickness. The leaf stomata density significantly varied among the pear cultivars, ranging from 89.53 stomata mm‑2 (‘Nijisseiki’) up to 134.07 stomata mm‑2 (‘Housui’). SEM proved that Asian pear cultivars and ‘Kieffer Seedling’ shared ‘paracytic’ stomata type, while European pear cultivars had ‘anomocytic’ stomata type. Cluster analysis distinguished pear cultivars into two distinct groups, where European cultivars formed first sub-cluster and Asian together with ‘Kieffer Seedling’ second sub-cluster. Midrib traits and stomata type made a clear separation between the clusters. These results might suggest that thickness of midrib could be a huge barrier for Psylla sp. probing in Asian pears, thus representing one of the key factors in the resistance of these cultivars.
Authors
Artur Kowalski Giovanni Agati Maria Grzegorzewska Ryszard Kosson Barbara Kusnierewicz Tomasz Chmiel Agnieszka Bartoszek Lorenza Tuccio Daniele Grifoni Ingunn M. Vågen Stanislaw KaniszewskiAbstract
The biosynthesis of polyphenolic compounds in cabbage waste, outer green leaves of white head cabbage (Brassica oleracea L. var. capitata subvar. alba), was stimulated by postharvest irradiation with UVB lamps or sunlight. Both treatments boosted the content of kaempferol and quercetin glycosides, especially in the basal leaf zone, as determined by the HPLC analysis of leaf extracts and by a non-destructive optical sensor. The destructive analysis of samples irradiated by the sun for 6 days at the end of October 2015 in Skierniewice (Poland) showed an increase of leaf flavonols by 82% with respect to controls. The treatment by a broadband UVB fluorescent lamp, with irradiance of 0.38 W m−2 in the 290–315 nm range (and 0.59 W m−2 in the UVA region) for 12 h per day at 17 °C along with a white light of about 20 μmol m−2 s−1, produced a flavonols increase of 58% with respect to controls. The kinetics of flavonols accumulation in response to the photochemical treatments was monitored with the FLAV non-destructive index. The initial FLAV rate under the sun was proportional to the daily radiation doses with a better correlation for the sun global irradiance (R2 = 0.973), followed by the UVA (R2 = 0.965) and UVB (R2 = 0.899) irradiance. The sunlight turned out to be more efficient than the UVB lamp in increasing the flavonols level of waste leaves, because of a significant role played by UVA and visible solar radiation in the regulation of the flavonoid accumulation in cabbage. The FLAV index increase induced on the adaxial leaf side was accompanied by a lower but still significant FLAV increase on the unirradiated abaxial side, likely due to a systemic signaling by mean of the long-distance movement of macromolecules. Our present investigation provides useful data for the optimization of postharvest photochemical protocols of cabbage waste valorization. It can represent a novel and alternative tool of vegetable waste management for the recovery of beneficial phytochemicals.
Abstract
Process-based grass models (PBGMs) are widely used for predicting grass growth under potential climate change and different management practices. However, accurate predictions using PBGMs heavily rely on field observations for data assimilation. In data-limited areas, performing robust and reliable estimates of grass growth remains a challenge. In this paper, we incorporated satellite-based MODIS data products, including leaf area index, gross primary production and evapotranspiration, as an additional supplement to field observations. Popular data assimilation methods, including Bayesian calibration and the updating method ensemble Kalman filter, were applied to assimilate satellite derived information into the BASic GRAssland model (BASGRA). A range of different combinations of data assimilating methods and data availability were tested across four grassland sites in Norway, Finland and Canada to assess the corresponding accuracy and make recommendations regarding suitable approaches to incorporate MODIS data. The results demonstrated that optimizing the model parameters that are specific for grass species and cultivar should be targeted prior to updating model state variables. The MODIS derived data products were capable of constraining model’s simulations on phenological development and biomass accumulation by parameter optimization with its performance exceeding model outputs driven by default parameters. By integrating even a small number of field measurements into the parameter calibration, the model’s predictive accuracy was further improved - especially at sites with obvious biases in the input MODIS data. Overall, this comparative study has provided flexible solutions with the potential to strengthen the capacity of PBGMs for grass growth estimation in practical applications.
Authors
Ulrika Carlson-Nilsson Karolina Aloisi Ingunn M. Vågen Ari Rajala Jørgen A.B. Mølmann Søren K. Rasmussen Mari Niemi Ewelina Wojciechowska Pertti Pärssinen Gert Poulsen Matti W LeinoAbstract
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Authors
Muhammad Naseer Tomas Persson Isabella Righini Cecilia Stanghellini Michel Verheul Henk MaessenAbstract
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Authors
Michel VerheulAbstract
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Authors
Ivan PaponovAbstract
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