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.
2016
Abstract
Black currant is a woody plant in which growth and development are intimately controlled by, and synchronised with seasonal changes in photoperiod and temperature. Concern over the potential impact of global warming on plant phenology and yield, led us to initiate relations. An experimental system with single-stemmed potted plants was developed which allowed a research program to address both qualitative and quantitative assessment of climatic responses. Growth cessation and flowering were both induced by short days, with critical photoperiods of approximately 17 and 16 h, respectively, for most cultivars. Both processes were advanced and promoted by increasing autumn temperature with an optimum in the 18-21°C region. An exception was cultivars of high-boreal origin, which had an early growth cessation at low temperature. Unexpectedly, however, not all plants flowered after exposure to 10 h photoperiod, and the number of flowers decreased as the photoperiod was reduced from the near-critical length of 15 h. This was due to premature dormancy induced by an abrupt change to photoperiods well below the critical level. Field experiments revealed that cultivars of varying geographic origin, exhibited a typical latitudinal cline in their photoperiodically controlled timing of growth and flowering responses. Breaking of bud dormancy and promotion of flower bud development required chilling at -5°C for 14 weeks or more for optimal responses. However, while chilling at -10°C for 8 weeks resulted in dormancy release, continued chilling to 16 weeks inhibited bud break completely. We therefore propose that excessive chilling induces secondary bud dormancy in black currant. The observed high chilling requirements of black currants concur with the reported vulnerability of this crop to declining winter chill in the wake of the ongoing global warming. Furthermore, such conditions also induce a particularly deep bud dormancy state that further increases the chilling need.
Authors
Rasmus John Normand Frandsen Silas A. Rasmussen Peter B. Knudsen Silvio Uhlig Dirk Petersen Erik Lysøe Charlotte H. Gotfredsen Henriette Giese Thomas O. LarsenAbstract
Biosynthesis of the black perithecial pigment in the filamentous fungus Fusarium graminearum is dependent on the polyketide synthase PGL1 (oPKS3). A seven-membered PGL1 gene cluster was identified by over-expression of the cluster specific transcription factor pglR. Targeted gene replacement showed that PGL1, pglJ, pglM and pglV were essential for the production of the perithecial pigment. Over-expression of PGL1 resulted in the production of 6-O-demethyl-5-deoxybostrycoidin (1), 5-deoxybostrycoidin (2), and three novel compounds 5-deoxybostrycoidin anthrone (3), 6-O-demethyl-5-deoxybostrycoidin anthrone (4) and purpurfusarin (5). The novel dimeric bostrycoidin purpurfusarin (5) was found to inhibit the growth of Candida albicans with an IC50 of 8.0 +/− 1.9 μM. The results show that Fusarium species with black perithecia have a previously undescribed form of 5-deoxybostrycoidin based melanin in their fruiting bodies.
Editors
Lars T. HavstadAbstract
No abstract has been registered
Authors
Aslaug Helgadottir Liv Østrem Rosemary P. Collins Mike Humphreys Athole Marshall Bernadette Julier F Gastal Philippe Barre G LouarnAbstract
Global climate change and increased pressure for adopting more sustainable agricultural practices call for new approaches in breeding forage crops. In the cool temperate regions of Europe these crops may benefit from a warmer and prolonged growing season, but new stresses may emerge during autumn and winter, whereas further south risk of drought will increase. In addition, future forage crops have to use both nutrients and water more efficiently to maximize production per unit area. This paper presents examples of how perennial forage crops can be adapted to the projected European environmental conditions through breeding. In the Nordic region, the focus is on identifying traits that are important for high yields under changed overwintering conditions and management practices. In temperate maritime Europe, the breeding focus is on forage grass and legume root systems for ecosystem service, nutrient and water use, as well as the advantages and potential for Festulolium, including its role in ruminant nutrition. In temperate and southern Europe, breeders aim to develop varieties that can survive long drought periods and recover rapidly following autumn rains, as well as improving adapted legume species with the following aims: reducing use of synthetic fertilizers, mitigating the environmental impacts of ruminant production systems; and reducing their dependency on external protein-rich feeds. Forage production systems, which are commonly found in areas less suited to grain production, can contribute significantly to future food security but only if forage crops can be successfully adapted to meet future environmental challenges.
Authors
Hong Yang Roger J. Flower Xianjin HuangAbstract
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Authors
Hanna Marika Silvennoinen Teresa Gómez de la Bárcena Christophe Moni Marcin Szychowski Paulina Rajewicz Daniel RasseAbstract
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Authors
Paal KrokeneAbstract
No abstract has been registered