Magnus Göransson

Crop wild relatives (CWR) are wild plant taxa that are closely related to crops and other cultivated species. The importance of conserving CWR genetic diversity as a valuable source of variation for plant breeding has been regularly brought forward, and knowledge about the distribution of genetic diversity within and among natural populations can aid in efficient conservation and increased availability of CWR genetic resources. Within the Nordic countries (Iceland, Norway, Denmark, Sweden and Finland), the European wild strawberry, Fragaria vesca L., has been recognized as a CWR of priority. However, information about the distribution of its within- and among-population genetic diversity in the Nordic countries is limited. In total, 180 individuals from twelve populations covering the majority of the Nordic range of F. vesca were genotyped with 14 microsatellite markers. Overall, populations had high inbreeding coefficient F _IS values, although a large variation was observed across the region. In agreement with expectations, populations from higher latitudes tended to have less genetic diversity and a higher presence of genetically identical individuals, possibly the result of clonal propagation. The analysis of molecular variance (AMOVA) showed that genetic diversity was primarily distributed among populations within countries, supporting a regional conservation approach. Analysis of the geographic distribution of the genetic diversity with STRUCTURE and principal component analyses and calculation of pairwise F _ST values revealed that the studied individuals formed clusters which partially, but not completely, corresponded to the geographical origin of the populations. The inclusion of multiple individuals per populations allowed geographic clustering to be detected on a finer scale than previously described. Ex situ conservation of F. vesca is recommended mainly to improve availability of these genetic resources for research and breeding and based on the within- and among-population distribution of genetic diversity, prioritizations are suggested.

Introduction . Crop wild relatives (CWR) play an important role in combatting threats to global food security and the adverse effects of climate change on food production. At the same time, climate change is predicted to lead to significant challenges for species survival, including Nordic CWR taxa. Aim . The modelling of future climate scenario effects on Nordic priority CWR taxa was undertaken to set priorities for in situ and ex situ conservation for both species and areas. Methods . We modelled the effect of future climate change on suitable habitats for 84 taxa under two CMIP6 Shared Socio-economic Pathways scenarios (SSP 2-4.5, and SSP 5-8.5). The present potential distribution range was compared to the status by year 2100. Results . The results revealed that even modest climate change causes negative effects in many species. There was large variation among the species’ responses to climate change, but over half of the taxa showed a reduction in suitable future habitats under both SSP scenarios. Threatened and mountainous species appear to be more negatively affected than the rest of the priority CWR taxa. Conclusions . We recommend in situ conservation with active management of Nordic CWR, prioritizing ex situ collection for species vulnerable to climate change. In addition, regular monitoring of CWR populations is essential to detect diversity loss and guide management, and a comprehensive Nordic CWR in situ network, integrated with ex situ conservation, is critical for long-term species survival.

The current global crisis of biodiversity loss calls for urgent conservation actions for many species, not the least wild species related to crop plants. These crop wild relatives are considered harbouring genetic diversity of major importance for future crop plant improvement, e.g. adaptation to climate change. Hence, their conservation needs to be a priority. To ensure the long-term conservation and to maximize the utility value of these species, it is important that as much of their genetic diversity as possible is conserved. Thus, the distribution of intraspecific diversity must be taken into consideration when planning conservation efforts. Caraway, Carum carvi L., has been cultivated since medieval times and is today one of the most important spice crops worldwide. In order to identify populations that would be of particular interest for in situ and ex situ conservation and for use in plant breeding we evaluated the geographic distribution of intraspecific diversity in populations of Carum carvi in the Nordic region (Iceland, Denmark, Norway, Sweden and Finland). Using a genotyping by sequencing approach, we genotyped 198 individuals from 16 Nordic populations. The amount of intrapopulation genetic diversity was similar among populations (mean H_e = 0.29), and the diversity was structured in an east–westerly manner, probably reflecting colonisation patterns associated with different glacial refugia. In addition, some populations likely have a history shaped by human interventions. The results have important conservation implications and based on the outcome of this study, populations of conservation priority are suggested.

The causal agent of the barley net blotch disease, Pyrenophora teres, is known for its high level of diversity due to sexual reproduction. Different pathotypes, defined by a virulence combination, even within the same fields are frequently found and virulence between locations can vary considerably. Evaluation of virulence patterns of a pathogen population is essential for breeding resistant cultivars suitable for specific locations. To identify virulence patterns in Icelandic Pyrenophora teres f. teres (Ptt) isolates, twenty single spore isolates of Ptt were collected from seven locations in Iceland and analysed with AFLP markers. Principle Coordinate Analysis (PCoA) revealed Icelandic Ptt isolates clustering away from reference isolates from Austria, Finland, Sweden, Switzerland, UK, and USA. Hierarchical clustering grouped the Icelandic isolates into three distinct groups. Furthermore, the virulence of these twenty isolates was tested on 16 barley differential lines and revealed high variation in their virulence. Twenty-one barley cultivars commonly used in Iceland showed high susceptibility towards inoculation with Icelandic Ptt isolates.

Cereal production in important growing regions is negatively influenced by climate change. This can be countered by expanding cereal production northwards in Scandinavia and Iceland, where today, barley (Hordeum vulgare L.) is primarily used as feed, as it rarely reaches malting quality. This study explores genetic factors underlying the ability of barley to mature fully in low temperature and long photoperiod. A panel of 84 spring barley lines were grown in controlled environments with different day lengths and temperatures, partially mimicking the target environment. The panel was screened for accumulated heat sum to heading, maturity, and height, all traits of importance for adaptation to the northern periphery. Subgroups with different stability and heat sum requirements were found, and day‐length‐neutral lines were identified. Height was temperature controlled, with lower temperature resulting in taller plants. The results were coupled to a genome‐wide association study (GWAS). Despite the small panel size, the Mat‐a locus was identified to have the strongest association with heat sum to heading; Ppd‐H1, Mat‐a, FT1, and DHAR2 with heat sum to maturity; and GA20ox1 with height. Early maturing lines with height stability have successfully been developed in Iceland, and this study confirms their performance in controlled environments for the first time. It provides insight to the mechanisms behind early maturity that will increase our ability to further adapt barley and other cereals to the northern climate. This will facilitate breeding work toward combining early maturity and height stability with traits such as quality, further enabling the northward expansion of grain production.

The northwards expansion of barley production requires adaptation to longer days, lower temperatures and stronger winds during the growing season. We have screened 169 lines of the current barley breeding gene pool in the Nordic region with regards to heading, maturity, height, and lodging under different environmental conditions in nineteen field trials over 3 years at eight locations in northern and central Europe. Through a genome-wide association scan we have linked phenotypic differences observed in multi-environment field trials (MET) to single nucleotide polymorphisms (SNP). We have identified an allele combination, only occurring among a few Icelandic lines, that affects heat sum to maturity and requires 214 growing degree days (GDD) less heat sum to maturity than the most common allele combination in the Nordic spring barley gene pool. This allele combination is beneficial in a cold environment, where autumn frost can destroy a late maturing harvest. Despite decades of intense breeding efforts relying heavily on the same germplasm, our results show that there still exists considerable variation within the current breeding gene pool and we identify ideal allele combinations for regional adaptation, which can facilitate the expansion of cereal cultivation even further northwards.

Objectives: Antithymocyte globulin (ATG)‐based immunosuppression remains a cornerstone in aplastic anaemia (AA) treatment. However, most ATG studies are not population‐based and knowledge about real‐world results concerning response and outcome could offer important information for treating physicians.Methods: We have recently performed a nationwide retrospective cohort study on all AA patients diagnosed in Sweden in 2000–2011 and now present treatment and outcome data on patients receiving first‐line ATG.In total, 158 patients showed a 47.0% response rate which was similar in all age groups (range 41.5%‐51.7%) with no difference regarding ATG formulation. The response was significantly associated with severity grade—especially at time of treatment initiation: very severe (VSAA) 22.7%; severe (SAA) 54.5% (P < .001); and non‐severe 88.5% (P < .001). A logistic regression‐based predictive model indicated that VSAA patients with an absolute reticulocyte count 9/L had only a 19% probability of response. In a multivariable analysis, age and VSAA at the time of treatment were the independent factors for inferior survival.Conclusions: Real‐world VSAA patients respond poorly to ATG which indicates the need for a different treatment approach. Our findings suggest that age alone should not be a discriminating factor for administering ATG treatment.

The woodland strawberry, Fragaria vesca, holds great promise as a model organism. It not only represents the important Rosaceae family that includes economically important species such as apples, pears, peaches and roses, but it also complements the well-known model organism Arabidopsis thaliana in key areas such as perennial life cycle and the development of fleshy fruit. Analysis of wild populations of A. thaliana has shed light on several important developmental pathways controlling, for example, flowering time and plant growth, suggesting that a similar approach using F. vesca might add to our understanding on the development of rosaceous species and perennials in general. As a first step, 298 F. vesca plants were analyzed using microsatellite markers with the primary aim of analyzing population structure and distribution of genetic diversity. Of the 68 markers tested, 56 were polymorphic, with an average of 4.46 alleles per locus. Our analysis partly confirms previous classification of F. vesca subspecies in North America and suggests two groups within the subsp. bracteata. In addition, F. vesca subsp. vesca forms a single global population with evidence that the Icelandic group is a separate cluster from the main Eurasian population.