| 1. |
- Mårtensson, Ulrika, et al.
(författare)
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Deletion of the G protein-coupled receptor 30 impairs glucose tolerance, reduces bone growth, increases blood pressure, and eliminates estradiol-stimulated insulin release in female mice.
- 2009
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Ingår i: Endocrinology. - : The Endocrine Society. - 1945-7170 .- 0013-7227. ; 150:2, s. 687-98
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Tidskriftsartikel (refereegranskat)abstract
- In vitro studies suggest that the G protein-coupled receptor (GPR) 30 is a functional estrogen receptor. However, the physiological role of GPR30 in vivo is unknown, and it remains to be determined whether GPR30 is an estrogen receptor also in vivo. To this end, we studied the effects of disrupting the GPR30 gene in female and male mice. Female GPR30((-/-)) mice had hyperglycemia and impaired glucose tolerance, reduced body growth, increased blood pressure, and reduced serum IGF-I levels. The reduced growth correlated with a proportional decrease in skeletal development. The elevated blood pressure was associated with an increased vascular resistance manifested as an increased media to lumen ratio of the resistance arteries. The hyperglycemia and impaired glucose tolerance in vivo were associated with decreased insulin expression and release in vivo and in vitro in isolated pancreatic islets. GPR30 is expressed in islets, and GPR30 deletion abolished estradiol-stimulated insulin release both in vivo in ovariectomized adult mice and in vitro in isolated islets. Our findings show that GPR30 is important for several metabolic functions in female mice, including estradiol-stimulated insulin release.
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| 2. |
- Larsson, Staffan, 1947-, et al.
(författare)
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Kortutbildade i kunskapsamhället
- 1991
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Ett forskningsprogram om forskning kring kortutbildades situation
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| 3. |
- Agback, Peter, et al.
(författare)
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Root morphology and cluster root formation by seabuckthorn (Hippophae rhamnoides L.) in response to nitrogen, phosphorus and iron deficiency
- 2015
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Ingår i: Plant and Soil. - : Springer Science and Business Media LLC. - 0032-079X .- 1573-5036. ; 397, s. 75-91
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Tidskriftsartikel (refereegranskat)abstract
- The aims were to investigate effects of availability of nitrogen (N), phosphorus (P) and iron (Fe) on root properties of seabuckthorn (HippophaA << rhamnoides) and to test the hypothesis that seabuckthorn is able to form cluster roots (CRs).Two sources of seabuckthorn were used: the seabuckthorn cultivar BHi10726 originating from a breeding programme based on H.r. ssp mongolica and carried out in rich agricultural field soil in the black earth (chernozem) region of Russia and the seabuckthorn accession named Pk originating in a natural population of H.r. ssp turkestanica in the mountainous region of northern Pakistan. Three cultivation systems giving different water availabilities were used at two levels each of N, P and Fe. Root morphology of seedlings and clones was characterized and metabolite content in extracts of young and old CRs of Pk was analyzed by proton nuclear magnetic resonance spectroscopy.Availability of N affected growth and distribution of biomass between shoot and root, while P and Fe deficiency modified root system architecture towards more lateral roots. Densely positioned rootlets with a determinate type of growth consistent with the definition of CR were observed under low P and low Fe. Pk formed on average 12 CRs per plant, which was 3 to 4-fold higher compared to BHi10726 also when normalized per root length. Malate and glycine were most abundant of the organic acids and amino acids, respectively, and decreased in old CRs.Seabuckthorn has the ability to form cluster roots especially in Pk and under deficiency of P and Fe. The two sources of seabuckthorn with different histories showed distinctly different root system architectures. The high contents of malate and glycine and their decrease in old CRs may reflect roles in CR metabolism.
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| 4. |
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| 5. |
- Chapman, Elizabeth A., et al.
(författare)
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Perennials as Future Grain Crops : Opportunities and Challenges
- 2022
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Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Perennial grain crops could make a valuable addition to sustainable agriculture, potentially even as an alternative to their annual counterparts. The ability of perennials to grow year after year significantly reduces the number of agricultural inputs required, in terms of both planting and weed control, while reduced tillage improves soil health and on-farm biodiversity. Presently, perennial grain crops are not grown at large scale, mainly due to their early stages of domestication and current low yields. Narrowing the yield gap between perennial and annual grain crops will depend on characterizing differences in their life cycles, resource allocation, and reproductive strategies and understanding the trade-offs between annualism, perennialism, and yield. The genetic and biochemical pathways controlling plant growth, physiology, and senescence should be analyzed in perennial crop plants. This information could then be used to facilitate tailored genetic improvement of selected perennial grain crops to improve agronomic traits and enhance yield, while maintaining the benefits associated with perennialism.
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| 6. |
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| 7. |
- Ekblad, Alf, 1957-, et al.
(författare)
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Day-to-day variation in nitrogenase activity of alnus-incana explained by weather variables : a multivariate time-series analysis
- 1994
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Ingår i: Plant, Cell and Environment. - : Wiley. - 0140-7791 .- 1365-3040. ; 17:3, s. 319-325
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Tidskriftsartikel (refereegranskat)abstract
- A modelling system is described that indicates the extent to which day-to-day variations in nitrogenase activity in young Alnus incana (L.) Moench, grown in defined conditions in the field, may be affected by weather conditions both during and prior to the day of measurement. Nitrogenase activity (acetylene reduction activity, ARA) was measured weekly on intact field-grown grey alder (A. incana) plants, 0.15–0.42 m tall at planting, nodulated with Frankia. The measurements were done at noon on two groups of plants in 1987 and on two other groups in 1988. Each group was made up of five or six plants. Seven weather variables: daily sunshine hours, daily mean, maximum and minimum air temperature, daily mean and 1300 h relative humidity, and daily rainfall were used. The relation between log(ARA/leaf area) and the weather variables were analysed using a PLS model (partial least squares projection to latent structures). The advantage of PLS is that it can handle x-variables that are correlated. Data from 1987 were chosen as a training set. Multivariate PLS time series analysis was made by adding, in a stepwise manner, the weather data up to 5 d before the day of measurement. This procedure gave six models with n * 7 x-variables (n= 1–6). With the models from the time series analysis of 1987 data, true predictions of ARA per leaf area were made from weather data 1988 (test set 1) and from ‘early-season’ weather data from 1987 and 1988 (test set 2). The variation in ARA/leaf area could be predicted from the weather conditions. The predictions of the two test sets improved when the weather conditions one and two days before the day of measurements were added to the model. The further addition of weather data from 3 to 5 d before the day of measurement did not improve the model. The good predictions of ARA/leaf area show that the alders responded to the variable weather conditions in the same way in 1988 as in 1987, despite the ten-fold difference in size (leaf area) at the end of the growing season. Among the weather variables, air temperature and the daily sunshine hours were positively correlated to ARA, while relative air humidity and rainfall were negatively correlated to ARA. The daily minimum temperature and rainfall appeared to have least impact on ARA. By use of PLS, we could extract information out of a data set containing highly correlated x-variables, information that is non-accessible with conventional statistical tools such as multiple regression. When making measurements of nitrogenase activities under field conditions, we propose that attention should be paid to the weather conditions on the days preceding the day of measurement. The day-to-day variation in nitrogenase activity is discussed with reference to known effects of stress factors under controlled conditions.
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| 8. |
- Eliasson, Lena, et al.
(författare)
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SUR1 Regulates PKA-independent cAMP-induced Granule Priming in Mouse Pancreatic B-cells.
- 2003
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Ingår i: Journal of General Physiology. - : Rockefeller University Press. - 0022-1295 .- 1540-7748. ; 121:3, s. 181-197
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Tidskriftsartikel (refereegranskat)abstract
- Measurements of membrane capacitance were applied to dissect the cellular mechanisms underlying PKA-dependent and -independent stimulation of insulin secretion by cyclic AMP. Whereas the PKA-independent (Rp-cAMPS–insensitive) component correlated with a rapid increase in membrane capacitance of ~80 fF that plateaued within ~200 ms, the PKA-dependent component became prominent during depolarizations >450 ms. The PKA-dependent and -independent components of cAMP-stimulated exocytosis differed with regard to cAMP concentration dependence; the Kd values were 6 and 29 µM for the PKA-dependent and -independent mechanisms, respectively. The ability of cAMP to elicit exocytosis independently of PKA activation was mimicked by the selective cAMP-GEFII agonist 8CPT-2Me-cAMP. Moreover, treatment of B-cells with antisense oligodeoxynucleotides against cAMP-GEFII resulted in partial (50%) suppression of PKA-independent exocytosis. Surprisingly, B-cells in islets isolated from SUR1-deficient mice (SUR1-/- mice) lacked the PKA-independent component of exocytosis. Measurements of insulin release in response to GLP-1 stimulation in isolated islets from SUR1-/- mice confirmed the complete loss of the PKA-independent component. This was not attributable to a reduced capacity of GLP-1 to elevate intracellular cAMP but instead associated with the inability of cAMP to stimulate influx of Cl- into the granules, a step important for granule priming. We conclude that the role of SUR1 in the B cell extends beyond being a subunit of the plasma membrane KATP-channel and that it also plays an unexpected but important role in the cAMP-dependent regulation of Ca2+-induced exocytosis.
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| 9. |
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| 10. |
- Lundquist, Per-Olof, et al.
(författare)
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Discussion: Prioritize perennial grain development for sustainable food production and environmental benefits
- 2023
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Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 895
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Tidskriftsartikel (refereegranskat)abstract
- Perennial grains have potential to contribute to ecological intensification of food production by enabling the direct har-vest of human-edible crops without requiring annual cycles of disturbance and replanting. Studies of prototype peren-nial grains and other herbaceous perennials point to the ability of agroecosystems including these crops to protect water quality, enhance wildlife habitat, build soil quality, and sequester soil carbon. However, genetic improvement of perennial grain candidates has been hindered by limited investment due to uncertainty about whether the approach is viable. As efforts to develop perennial grain crops have expanded in past decades, critiques of the approach have arisen. With a recent report of perennial rice producing yields equivalent to those of annual rice over eight consecutive harvests, many theoretical concerns have been alleviated. Some valid questions remain over the timeline for new crop development, but we argue these may be mitigated by implementation of recent technological advances in crop breed-ing and genetics such as low-cost genotyping, genomic selection, and genome editing. With aggressive research invest-ment in the development of new perennial grain crops, they can be developed and deployed to provide atmospheric greenhouse gas reductions.
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| 11. |
- Lundquist, Per-Olof
(författare)
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Nodule inhabiting non-rhizobial bacteria and their influence on growth of selected leguminous plants of Bangladesh
- 2016
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Ingår i: Bioresearch communications. - 2411-0485 .- 2411-0272. ; 2, s. 134-138
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Tidskriftsartikel (refereegranskat)abstract
- The present study aimed to identify non-rhizobial bacteria present in the root nodules of four legume plants viz. Arachis hypogaea L., Dolichos lablab L., Vigna mungo L., and Sesbania sesban L. grown in Bangladesh. Pure isolates of the bacteria obtained from the surface sterilized root nodules were identified by sequencing of 16S rRNA gene. A total of 13 isolates belonging to 10 genera under 7 families were obtained. Effects of these non-rhizobial bacteria on nodulation, plant height, shoot biomass, and leaf chlorophyll contents were compared in between A. hypogaeae L. and V. mungo L. Of all the isolates identified, Klebsiella sp. and Enterobacter sp. produced nodules in both V. mungo L. and A. hypogaea L. and Bacillus sp. produced nodules only in V. mungo L. Results also demonstrated that most of the isolates enhanced shoot height, shoot biomass and leaf chlorophyll contents in V. mungo L. but not in A. hypogaea L. Results of the present study are thus relevant for enhancing our knowledge about the beneficial use of non-rhizobial bacterial in growth and development of leguminous crops in order to secure sustainable agriculture.
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| 12. |
- Lundquist, Per-Olof, et al.
(författare)
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Root traits of seabuckthorn
- 2016
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Ingår i: RPD Abstracts. - 2255-8624 .- 2500-9788. ; 2, s. 87-87
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 13. |
- Moreno, Silvana, et al.
(författare)
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Response to Waterlogging Stress in Wild and Domesticated Accessions of Timothy (Phleum pratense) and Its Relatives P. alpinum and P. nodosum
- 2023
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Ingår i: Plants. - 2223-7747. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Timothy (Phleum pratense) is a cool-season perennial forage grass widely grown for silage and hay production in northern regions. Climate change scenarios predict an increase in extreme weather events with fluctuating periods of high rainfall, requiring new varieties adapted to waterlogging (WL). Wild accessions could serve as germplasm for breeding, and we evaluated the responses of 11 wild and 8 domesticated accessions of timothy, P. nodosum and P. alpinum from different locations in northern Europe. Young plants at tillering stage were exposed to WL for 21 days in a greenhouse, and responses in growth allocation and root anatomy were studied. All accessions produced adventitious roots and changed allocation of growth between shoot and root as a response to WL, but the magnitude of these responses varied among species and among accessions. P. pratense responded less in these traits in response to WL than the other two species. The ability to form aerenchyma in the root cortex in response to WL was found for all species and also varied among species and among accessions, with the highest induction in P. pratense. Interestingly, some accessions were able to maintain and even increase root growth, producing more leaves and tillers, while others showed a reduction in the root system. Shoot dry weight (SDW) was not significantly affected by WL, but some accessions showed different and significant responses in the rate of production of leaves and tillers. Overall correlations between SDW and aerenchyma and between SDW and adventitious root formation were found. This study identified two wild timothy accessions and one wild P. nodosum accession based on shoot and root system growth, aerenchyma formation and having a root anatomy considered to be favorable for WL tolerance. These accessions are interesting genetic resources and candidates for development of climate-resilient timothy varieties.
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| 14. |
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| 15. |
- Shah, Syed Rehmat Ullah, et al.
(författare)
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Shoot organogenesis from roots of seabuckthorn (Hippophaë rhamnoides L.): structure, initiation and effects of phosphorus and auxin
- 2015
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Ingår i: Trees - Structure and Function. - : Springer Science and Business Media LLC. - 0931-1890 .- 1432-2285. ; 29, s. 1989-2001
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Tidskriftsartikel (refereegranskat)abstract
- Shoots from roots formed on seedlings in vitro in the groove of lateral roots as on plants growing in a natural habitat. The finding has ecological and applied relevance.Shoot organogenesis from roots (root suckers, shoots from roots, SfRs) allows vegetative propagation of the small tree seabuckthorn (HippophaA << rhamnoides L.) in addition to sexual propagation and is an important trait associated with the root system. Using an in vitro system, we studied initiation, localization and development of SfRs and interacting roles of phosphorus (P) and indole-3-acetic acid (IAA). After transfer of seedlings to the W4 medium (WPM medium with added IAA, benzyl adenine and giberellic acid), SfRs protruded after 2 weeks from the primary root initially at the groove of lateral roots (LR) as seen by scanning electron microscopy and light microscopy. This is also the location of SfRs on plants growing in natural conditions, which suggests a similar developmental pathway. To localize SfR initiation, staining by the DNA-binding fluorochrome 4',6-diamidino-2-phenylindole in root cross sections revealed a high density of small cells as in meristems in the pericycle area between endodermis and vascular tissue. During 8-10 weeks, SfRs emerged also in other positions on the primary root, concomitantly with senescence of existing LRs and suppression of new LR formation. Since SfR formed in relation to LRs, we hypothesized that P and IAA play a role in SfR formation. Highest production of SfRs occurred in W4 medium after pre-treatment with high P in the presence of IAA while LR production in WPM was stimulated by IAA in low and middle P. SfRs developed in vitro on seedlings originating from three subspecies of H. rhamnoides showing this trait to be common. This experimental system allowed studies of organogenesis of SfRs and LRs in response to plant growth regulators, P and IAA and may be further implemented in basic studies and in applied clonal propagation of seabuckthorn.
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| 16. |
- Sriskandarajah, Sridevy, et al.
(författare)
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Development of a genetic transformation method for seabuckthorn ( Hippophae rhamnoides L.).
- 2014
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Ingår i: American Journal of Plant Sciences. - : Scientific Research Publishing, Inc.. - 2158-2742 .- 2158-2750. ; 5, s. 528-534
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Tidskriftsartikel (refereegranskat)abstract
- Seabuckthorn (Hippophae rhamnoides L.) is a dioecious plant with berries containing highamounts of several bioactive compounds with nutritional and medicinal traits. It is also planted tocontrol soil erosion. A genetic transformation procedure will facilitate studies of the control ofplant development and interactions with symbionts and pathogens, and will provide a tool forplant breeding. Here, we present a particle bombardment method for transforming seabuckthorn.The early stages of induced adventitious shoots from roots were chosen as a novel target tissue forthe transformation procedure. The root system was bombarded with gold particles coated withplasmid pRT99gus containing genes for plant kanamycin resistance and for β-glucuronidase expression,and shoots were regenerated under kanamycin selection. PCR analysis of the regeneratedtransformed lines confirmed the presence of a 603 bp gus (uidA) gene fragment and a 1.5 kbfragment from the 35S promoter in three shoots from independent transformation events.
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| 17. |
- Sriskandarajah, Sridevy, et al.
(författare)
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High frequency shoot organogenesis and somatic embryogenesis in juvenile and adult tissues of seabuckthorn (Hippophae rhamnoides L.)
- 2009
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Ingår i: Plant Cell, Tissue and Organ Culture. - : Springer Science and Business Media LLC. - 0167-6857 .- 1573-5044. ; 99, s. 259–268-
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Tidskriftsartikel (refereegranskat)abstract
- Seabuckthorn (Hippophae rhamnoides) is a multipurpose small tree with unique berries of high nutritional and pharmaceutical values. A clonally propagated plant originating from a 20-year-old tree of H. r. rhamno- ides 9 mongolica hybrid cultivar Julia and seedling offspring of this cultivar were investigated regarding induction of shoot organogenesis in leaf explants and in roots of intact seedlings, and induction of direct somatic embryogenesis in explants from shoot tissue. The highest percentage of leaf explants showing shoot organogenesis was achieved (juvenile explants, 65%; adult explants, 75%) when incubated in Mu- rashige and Skoog (MS) medium supplemented with either 4.5 lM of the phenylurea cytokinin thidiazuron (TDZ) or 2.25 lM TDZ plus 2.2 lM 6-benzyladenine (BA), for juve- nile and adult explants, respectively, both supplemented with 0.53 lM a-naphthaleneacetic acid (NAA). Juvenile explants developed on average 18 shoots per explant in the MS med- ium supplemented with 4.5 lM TDZ, a four fold increase over those incubated on the medium supplemented with 2.25 lM TDZ and 2.2 lM BA. Adult leaf explants grown on medium containing 2.25 lM TDZ and 2.2 lM BA medium produced 12 shoots per explant, while those grown on med- ium containing 4.5 lM TDZ produced 5 shoots per explant. Shoot organogenesis was observed in roots of intact seedlings pre-cultured on plain medium lacking nutrients (PM) or woody plant medium (WPM) salts and then grown on WPM salts supplemented with 4.4 lM BA, 0.29 lM gibberrelic acid (GA3), and 57.0 lM indoleacetic acid (IAA). The number of shoots formed on each seedling root system was ten fold higher when the pre-culture was in WPM medium indi- cating a promoting effect of mineral nutrients in the pre-cul- ture medium. Somatic embryogenesis was induced in both juvenile and adult leaf explants in 65 and 78% of the explants, respectively, in MS-based medium supplemented with 2.0 lM N-(2-Chloro-4-pyridyl)-N1-phenylurea (CPPU), 0.53 lM NAA and varying concentrations of BA. There was an interaction effect between MS salt strength and BA con- centration. The most effective medium for inducing somatic embryogenesis in juvenile explants contained half strength MS salts and 2.2 lM BA and full strength MS salts and 13.2 lM BA for adult explants
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| 18. |
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| 19. |
- Westerbergh, Anna, et al.
(författare)
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Towards the Development of Perennial Barley for Cold Temperate Climates—Evaluation of Wild Barley Relatives as Genetic Resources
- 2018
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Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Perennial cereal crops could limit the negative impacts of agriculture on the environment and climate change. In cold temperate climates, perennial plants must be adapted to seasonal changes and abiotic stresses, such as frost, to be able to regrow for several years. Wild crop relatives that are perennials and already adapted to cold temperate climates may provide genetic resources for breeding new perennial cereal grain crops. Barley (Hordeum vulgare) is one of the most important cereals in northern agricultural areas, and its related perennial species may be good candidates for the development of perennial cereals. We evaluated a diverse set of 17 wild perennial Hordeum species represented by 67 accessions in field conditions with a cold winter climate and long days during summer in Central Sweden (latitude 60 degrees N). Six species (H. brevisubulatum, H. bulbosum, H. fuegianum, H. jubatum, H. lechleri and H. secalinum) showed regrowth and formation of spikes for four seasons. The most distant perennial relative of barley, H. stenostachys, showed weak regrowth. H. bulbosum, the closest perennial barley relative, had a large number of accessions with wide geographic origins that showed good regrowth. Together with its storage bulbs and its cross-compatibility with barley, this makes H. bulbosum an important genetic resource for the development of perennial Hordeum grains using either the domestication or the wide-hybridization strategy.
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| 20. |
- Zhao, Enid Ming, et al.
(författare)
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Intercropping affects genetic potential for inorganic nitrogen cycling by root-associated microorganisms in Medicago sativa and Dactylis glomerata
- 2017
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Ingår i: Applied Soil Ecology. - : Elsevier BV. - 0929-1393 .- 1873-0272. ; 119, s. 260-266
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Tidskriftsartikel (refereegranskat)abstract
- The effect of intercropping on the genetic potential for N-cycle pathways promoting either retention or loss of N by the microbial communities associated to the roots or present in the bulk soil for two forage crops was studied in a greenhouse experiment. Medicago sativa ('lucerne') and Dactylis glomerata ('cocksfoot') were grown as sole crops or intercropped in soils with or without addition of biogas digestate to also evaluate fertilizer effects. Eight genes involved in inorganic N-cycling were quantified using real-time PCR to determine the genetic potential for different N-cycling pathways. Both plant species and intercropping affected the abundance of root-associated microbial-derived genes involved in N-cycling processes, while there was no effect of amendment with biogas digestate. The genetic potential for the various pathways differed between bulk soil and roots, as well as between the roots of the two plant species, suggesting that organisms involved in different N-cycling processes were favored in different compartments in the soil-root environment. Ammonia oxidizers involved in nitrification, a pathway resulting in N-leaching, dominated in soil whereas those related to N-2 fixation and gaseous N losses (denitrification) were more abundant on roots. We also observed niche differentiation between the two major groups of organisms with the capacity to reduce N2O in the root- and soil compartment. Legume-grass intercropping resulted in a decreasing trend for several root- associated functional communities. More specifically, the legume exerted an effect on the N-cycling communities on the roots of both the legume and grass species, which suggests altered plant-microbial or microbial-microbial interactions during intercropping.
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