| 1. |
- Ali, Ashfaq, et al.
(författare)
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Paranoid potato : phytophthora-resistant genotype shows constitutively activated defense
- 2012
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Ingår i: Plant Signaling and Behavior. - : Informa UK Limited. - 1559-2316 .- 1559-2324. ; 7:3, s. 400-408
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Tidskriftsartikel (refereegranskat)abstract
- Phytophthora is the most devastating pathogen of dicot plants. There is a need for resistance sources with different modes of action to counteract the fast evolution of this pathogen. In order to better understand mechanisms of defense against P. infestans, we analyzed several clones of potato. Two of the genotypes tested, Sarpo Mira and SW93-1015, exhibited strong resistance against P. infestans in field trials, whole plant assays and detached leaf assays. The resistant genotypes developed different sizes of hypersensitive response (HR)-related lesions. HR lesions in SW93-1015 were restricted to very small areas, whereas those in Sarpo Mira were similar to those in Solanum demissum, the main source of classical resistance genes. SW93-1015 can be characterized as a cpr (constitutive expressor of PR genes) genotype without spontaneous microscopic or macroscopic HR lesions. This is indicated by constitutive hydrogen peroxide (H₂O₂) production and PR1 (pathogenesis-related protein 1) secretion. SW93-1015 is one of the first plants identified as having classical protein-based induced defense expressed constitutively without any obvious metabolic costs or spontaneous cell death lesions.
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| 2. |
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| 3. |
- Carlson-Nilsson, Ulrika
(författare)
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Facilitation of introgressive hybridization of wild polyploid mexican potato species using DNA markers of R genes and of different cytoplasmic types
- 2017
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Ingår i: Agricultural biology. - : Sel'skokhozyaistvennaya Biologiya Editorial Office (SBEO), NPO. - 2412-0324. ; 52, s. 964-975
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Tidskriftsartikel (refereegranskat)abstract
- Nowadays potato breeding is targeting to develop genetically divers high yielding varieties with multiple pathogen resistance traits. Interspecific hybridization jointed with marker-Assistantselection (MAS) can effectively combine the R genes from different resistance sources. Additionally to effective pyramiding the target genes, MAS allows to restrict introgression of genetic factors conferring the undesirable traits, for example, male sterility of interspecific hybrids associated with Solanum stoloniferum-derived W/gamma cytoplasm that complicate the traditional breeding. Current study is targeting to search for the opportunities to improve the efficiency of introgressive hybridization between common potato and Mexican polyploid species Solanum. neoantipoviczii (=S. stoloniferum) and S. guerreroense using MAS with DNA markers for different cytoplasmic types and markers associated with major R-genes to the most harmful potato pathogens. DNA-based markers of genes for late blight resistance (R2 like, R3a, Rpi-blb1, Rpi-sto1), for extreme resistance to Potato virus Y (PVY) (Ryadg, Rysto, Ry-fsto) and for H1 gene for resistance to the root cyst nematode (Globodera rostochiensis, pathotype Ro1) were used in this study. Based on the MAS, hybrid genotypes with different combinations of these markers were selected. Among them, there were the clones with high field resistance to late blight and to PVY. Of 29 hybrid clones from different combinations of crossing with polyploid Mexican species used as the maternal forms, 15 had a W/α cytoplasmic type and were male sterile; both these traits were maternally inherited. The remaining hybrids with W/γ cytoplasm produced fertile pollen and were used in interspecific crosses as pollinators. Selection of resistant clones with W/alpha cytoplasm and elimination of genotypes with sterile W/γ cytoplasm among wild species germplasm could increase the probability of obtaining male fertile introgressive lines. This approach allows to obtain the multi-species hybrid genotypes that combine R genes for resistance to pathogens from different Mexican species and to avoid various types of male sterility in breeding. The joint use of two systems of DNA markers, i.e. nuclear markers associated to R genes, and cytoplasmic markers for male sterility factors, could reduce costs and increase efficiency of target gene pyramiding programs.
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| 4. |
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| 5. |
- Caspersen, Siri, et al.
(författare)
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Phosphorus efficiency of potato varieties differing in maturity type
- 2013
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The objective of the present work was to investigate the effect of phosphorus fertilization on yield and phosphorus uptake and to compare the phosphorus efficiency for six potato varieties. During 2011 and 2012, field experiments were conducted on soils containing low levels of available phosphorus. Phosphorus fertilizer was added in the amounts of 0, 30 and 60 kg phosphorus per ha. In 2011, soil heterogeneity was large and tuber yield was increased by phosphorus addition only as a mean over all varieties. In 2012, an improved tuber yield by phosphorus fertilization was observed for most varieties. The weight of the larger tuber fractions was generally increased by phosphorus fertilization. Phosphorus efficiency, calculated as tuber dry weight per unit of fertilizer phosphorus added, tended to be higher for late than for early or intermediate varieties. The results indicate that late varieties might be more suitable than earlier varieties for locations were the risk of nutrient losses is high.
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| 6. |
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| 7. |
- De Palma, Adriana, et al.
(författare)
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Predicting bee community responses to land-use changes : effects of geographic and taxonomic biases
- 2016
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 6, s. 1-14
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Tidskriftsartikel (refereegranskat)abstract
- Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises.
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| 8. |
- Dedicova, Beata, et al.
(författare)
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Effect of Cryopreservation on Growth of Different Elite Embryogenic Cell Lines of Norway Spruce (Picea Abies (L.) Karst.)
- 2011
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Ingår i: International Symposium on Cryopreservation in Horticultural Species. - : International Society for Horticultural Science. - 9789066054707 ; 908, s. 203-206
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Konferensbidrag (refereegranskat)abstract
- Callus from seven different elite embryogenic cell lines of Norway spruce originated from the controlled crossing conducted by Skogforsk (Forest Research Institute of Sweden) have been cryopreserved in liquid nitrogen using the slow freezing method with sorbitol (0.2 and 0.4 M) and DMSO (5% v/v) as cryoprotectants. Cooloing of samples was performed in a programmable freezer Cryo Med 7452. The cryovials were inserted at +4 degrees C and frozen at -0.3 degrees C/min to -16 degrees C. After 15 min at -16 degrees C, to avoid rapid cooling and crystal formation in the cells, the cryovials were further cooled to -35 degrees C at -0.3 degrees C/min. At the end of the freezing program the cryovials were transferred and stored in a CBS V1500 liquid nitrogen storage unit at -196 degrees C. After thawing and plating on proliferation medium, the recovered cells showed a short lag phase, after which they continued to grow. Lags in growth were also observed after the transfer to pre-maturation and maturation media. Somatic embryo maturation and plantlet regeneration occurred in all the tested embryogenic lines.
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| 9. |
- Eriksson, Dennis, et al.
(författare)
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Overview and Breeding Strategies of Table Potato Production in Sweden and the Fennoscandian Region
- 2016
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Ingår i: Potato Research. - : Springer Science and Business Media LLC. - 0014-3065 .- 1871-4528. ; 59, s. 279-294
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Tidskriftsartikel (refereegranskat)abstract
- Recent reductions in the public commitment to potato breeding in Sweden, Norway and Finland call for an evaluation of the current situation regarding the commercial basis for, and structure of, potato breeding in these countries. We here review the extent of cultivation, processing and consumption of table potato in Sweden, as well as provide an overview of the potato breeding tools and programmes in the three countries. We then discuss various strategies to provide long-term stability and increase the impact of public potato breeding, based on the similar overall conditions for potato cultivation across the Fennoscandian region. The conclusions are twofold; first, an increased long-term funding of the public potato breeding programmes is necessary to maintain a minimum level of material, and second, a coordination of the breeding activities in the Fennoscandian region would be of great benefit to all involved stakeholders and allow an enhancement of the current national breeding programmes. In addition, we propose a minimum first field year population size for potato breeding.
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| 10. |
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