Nordic Gene Bank Research Articles

The Impact of N.I. Vavilov on the Conservation and Use of Plant Genetic Resources in Scandinavia: A Review

In this review we examine Nikolai Ivanovich Vavilov's relationship to Scandinavia and the impact he and his ideas have had on Scandinavia. We trace the historical connections from Vavilov back to 18th century scientists, such as Carl Von Linneaus (Sweden) and 19th century European scientists such as Alphonse de Candolle (Switzerland), Henry de Vilmorin (France), and William Bateson (England). Vavilov has influenced the conservation work in Scandinavia resulting amongst other in the establishment of the Nordic Gene Bank in 1979 and the Svalbard Global Seed Vault which started operating in 2008. Vavilov travelled to Scandinavia in 1921 and in 1931 to give lectures and exchange ideas, especially with the breeders at the Swedish Seed Association (Svalöf) in Scania, Sweden, but also at the Copenhagen University in Denmark. Vavilov did not recognize Scandinavia as part of a center of origin of cultivated plants. It was only after World War II, when P.M. Zhukovsky, a scholar of N.I Vavilov, developed the concept of mega-centers of diversity of cultivated plants, that Scandinavia became part of what he termed the European-Siberian Region of Diversity. We list species domesticated in Scandinavia or Northern Europe, and we further discuss concepts related to crop evolution and highlight the great impact Vavilov has had by inspiring scientists across disciplines and over many decades.

Diversity and population structure of Nordic potato cultivars and breeding clones

BackgroundThe genetic diversity and population structure of breeding germplasm is central knowledge for crop improvement. To gain insight into the genetic potential of the germplasm used for potato breeding in a Nordic breeding program as well as all available accessions from the Nordic genebank (NordGen), 133 potato genotypes were genotyped using the Infinium Illumina 20 K SNP array. After SNP filtering, 11 610 polymorphic SNPs were included in the analysis. In addition, data from three important breeding traits – percent dry matter and uniformity of tuber shape and eye – were scored to measure the variation potato cultivars and breeding clones.ResultsThe genetic diversity among the genotypes was estimated using principal coordinate analysis based on the genetic distance between individuals, as well as by using the software STRUCTURE. Both methods suggest that the collected breeding material and the germplasm from the gene-bank are closely related, with a low degree of population structure between the groups. The phenotypic distribution among the genotypes revealed significant differences, especially between farmer’s cultivars and released cultivars and breeding clones. The percent heterozygosity was similar between the groups, with a mean average of 58–60%. Overall, the breeding germplasm and the accessions from the Nordic genebank seems to be closely related with similar genetic background.ConclusionThe genetic potential of available Nordic potato breeding germplasm is low, and for genetic hybridization purposes, genotypes from outside the Nordic region should be employed.

Insights Into the Genetic Diversity of Nordic Red Clover (Trifolium pratense) Revealed by SeqSNP-Based Genic Markers.

Red clover (Trifolium pratense) is one of the most important fodder crops worldwide. The knowledge of genetic diversity among red clover populations, however, is under development. This study provides insights into its genetic diversity, using single nucleotide polymorphism (SNP) markers to define population structure in wild and cultivated red clover. Twenty-nine accessions representing the genetic resources available at NordGen (the Nordic gene bank) and Lantmännen (a Swedish agricultural company with a red clover breeding program) were used for this study. Genotyping was performed via SeqSNP, a targeted genotype by sequencing method that offers the capability to target specific SNP loci and enables de novo discovery of new SNPs. The SNPs were identified through a SNP mining approach based on coding sequences of red clover genes known for their involvement in development and stress responses. After filtering the genotypic data using various criteria, 623 bi-allelic SNPs, including 327 originally targeted and 296 de novo discovered SNPs were used for population genetics analyses. Seventy-one of the SNP loci were under selection considering both Hardy-Weinberg equilibrium and pairwise FST distributions. The average observed heterozygosity (HO), within population diversity (HS) and overall diversity (HT) were 0.22, 0.21 and 0.22, respectively. The tetraploids had higher average HO (0.35) than diploids (0.21). The analysis of molecular variance (AMOVA) showed low but significant variation among accessions (5.4%; P < 0.001), and among diploids and tetraploids (1.08%; P = 0.02). This study revealed a low mean inbreeding coefficient (FIS = −0.04) exhibiting the strict outcrossing nature of red clover. As per cluster, principal coordinate and discriminant analyses, most wild populations were grouped together and were clearly differentiated from the cultivated types. The cultivated types of red clover had a similar level of genetic diversity, suggesting that modern red clover breeding programs did not negatively affect genetic diversity or population structure. Hence, the breeding material used by Lantmännen represents the major genetic resources in Scandinavia. This knowledge of how different types of red clover accessions relate to each other and the level of outcrossing and heterozygosity will be useful for future red clover breeding.

Rhizobium rhizogenes-mediated transformation of Rhodiola rosea leaf explants

ABSTRACT Rhodiola rosea L. is an endangered medicinal plant distributed in mountains and in high latitude regions. For its conservation, sustainable methods for the obtaining of its bioactive compounds must be developed. This work hypothesized that leaf, stem and rhizome explants of R. rosea from different geographical origins respond differently to inoculation with Rhizobium rhizogenes agropine strain ATCC43057. The objective was to generate R. rosea hairy roots (HRs) containing rol-genes. These HRs could be cultivated under axenic conditions for the extraction of the medical compounds rosavinoids and salidroside. Hereby, production of bioactive compounds could be improved per plant biomass. Thirteen R. rosea accessions of Alpine, Scandinavian, Nordic Gene Bank (NGB) and Russian origins were compared for their explant survival and HR formation. Significant differences were observed among plants from different geographical origins, where the NGB leaf explants exhibited up to 70% of HR formation and the Russian accessions did not exhibit HRs at all. Moreover, maintaining explants in light conditions after R. rhizogenes inoculation resulted in higher explant survival and HR formation rate (35%) when compared with explants kept in darkness (9%). Taken together, an efficient HR formation in roseroot by inoculation of R. rhizogenes following culturing in light was reported as a required step. This work represents a stepping-stone to R. rosea HR cultivation in bioreactors as well as regenerating whole plants. Hence, it is initiating a novel route towards high-throughput production of bioactive compounds as well preventing depletion of natural roseroot populations.

Seed Germination after 30 Years Storage in Permafrost.

More than 30 years ago, the Nordic Gene Bank established a long-term experiment on seeds stored under permafrost conditions in an abandoned mine corridor in Svalbard, as a tool to monitor storage life under these conditions. The study included seeds from 16 Nordic agricultural and horticultural crops, each represented by two or three cultivars (altogether 38 accessions). All seeds were ultra-dried to 3–5% moisture before being sealed in glass tubes. Germination tests were performed in accordance with the International Seed Testing Association (ISTA) protocols. At the initiation of the experiment, the samples showed good germination with the median value at 92%. The overall picture remained stable over the first twenty to twenty-five years. However, the variation became larger over time and at 30 years, the median value had dropped to 80%. At the lower end, with a high drop in germination, we found rye, wheat, and English ryegrass. At the upper end, we found Kentucky bluegrass and cucumber. The lowest germination was found in samples with the highest initial seed moisture levels. Pre-storage conditions are likely to be of major importance for longevity.

SCANDINAVIAN TABLE AND STUBBLE TURNIPS: VARIABILITY AND VALUE FOR BREEDING

The climatic conditions of the Nordic countries are similar to the conditions of the North-West region of the Russian Federation, which makes it possible to introduce interesting varieties for Russian breeding. Most of the local varieties of stubble turnips in the USSR were created using Scandinavian material. Local varieties are the source of the genetic diversity of vegetable crops. The work with such material is promising in terms of searching for sources and donors of valuable traits for breeding programs. 16 samples of local table turnips and stubble turnips from the Scandinavian countries were obtained from the Nordic genebank and a comprehensive study was carried out. Samples are described from the point of view of the existing agrobiological classification of turnip (M.A. Shebalina). Most of the local accessions are mixed populations of two or more types. It was found that the local accessions of Denmark, Norway, Finland and Sweden were represented by table turnips of the Karelian and Petrovsky types, a Tankard yellow type prevailed among the stubble turnips. A representative of a very rare variety type of turnip Kostenevskaya (Petrozavodskaya) was found. The fact of changing of the prevailing types of table and stubble turnips Scandinavian countries is probably connected with the introduction of the widespread European varieties of these cultures. Accessions of local Scandinavian stubble turnips have been identified as sources of productivity and valuable biochemical composition, exceeding the standard variety of Osterzundomsky. Gul Finlandsk, Norway (the Petrovskaya type), Ljusnedal, Sweden (May yellow greenhead type), Rana, Denmark, (the Bortfeld type) and Ova Daehnfeldt, Denmark (Tankard yellow) are promising sources for turnip breeding in Russian Federation.

J Trevor Williams (1938–2015): IBPGR director and genetic conservation pioneer

John Trevor Williams (always known as Trevor), who was Executive Secretary and first Director of the International Board for Plant Genetic Resources (IBPGR) between 1978 and 1990, passed away at the age of 76 on 30 March 2015 at his home in Cheshire, UK after a long respiratory illness. One legacy of Trevor’s contribution to the conservation of plant genetic resources can be found deep beneath the Arctic permafrost on the island of Spitsbergen, where millions of seeds of crop varieties and wild species—many collected through the efforts of IBPGR in the 1970s and 1980s—are in backup storage in the Svalbard Global Seed Vault (SGSV), popularly known as the ‘Doomsday Vault’. Opened 7 years ago, the SGSV is one major achievement of a plan set in motion three decades earlier by IBPGR to establish an international network of regional and national genebanks. The proposal to store backup samples of international genebank collections under the permafrost was first developed by IBPGR in 1988 (IBPGR 1990, p. 10), building on the experience of the Nordic Genebank that had already used an abandoned coal mine on Svalbard for the same purpose.

Breeding or Assisted Reproduction? Relevance of the Horse Model Applied to the Conservation of Endangered Equids

Many wild equids are at present endangered in the wild. Concurrently, increased mechanization has pushed back the numbers of some old native horse breeds to levels that are no longer compatible with survival of the breed. Strong concerns arose in the last decade to preserve animal biodiversity, including that of rare horse breeds. Genome Resource Banking refers to the cryostorage of genetic material and is an approach for ex situ conservation, which should be applied in combination with in situ conservation programmes. In this review, we propose that, owing to the great reproductive similarity among the different members of the genus Equus, the domestic horse can be used to optimize cryopreservation and embryo production protocols for future application in wild equids. We will give this hypothesis a scientific underpinning by listing successful applications of epididymal sperm freezing, embryo freezing, intracytoplasmic sperm injection, oocyte vitrification and somatic cell nuclear transfer in domestic horses. Some ART fertilization methods may be performed with semen of very low quality or with oocytes obtained after the death of the mare.

Genotypic and phenotypic diversity in Finnish cultivated sour cherry (Prunus cerasus L.)

The Finnish national sour cherry germplasm collection was established in the end of 1980s following collection missions in Southern Finland. The original plantation consisted of 122 trees representing 77 accessions of locally adapted cherry material. Cultivar names of the collected samples were not known, and they were registered according to the collection site. Phenotypical observations according to the Nordic Genebank instructions were recorded in 1992, 1993 and some repetitions were made in 2003. In 2005 leaf samples were collected from the 52 still remaining accessions for a microsatellite (SSR) DNA marker analysis. DNA analysis distinguished 28 genotypes within the studied material. Two large groups of accessions sharing identical genotype, consisting of 18 and 20 accessions, were detected, one in the amarelle and one in the morello–cultivar group, respectively. Several cultivar group specific SSR markers were found. Clustering analysis of the phenotypical characteristics supported the division into two cultivar groups. Replicate trees of one accession, or accessions representing one SSR genotype, clustered together only occasionally indicating some level of plasticity in the observed descriptors. Our findings indicate that only a few sour cherry clones have been successful and commonly distributed in Finland. The results were taken into account when selecting accessions for long term conservation in the national germplasm collection.

THE USE OF HORSERADISH IN FOOD AND MEDICINE IN THE NORDIC COUNTRIES

Horseradish, Armoracia rusticana P. Gaertn., B. Mey. & Scherb. has a long history as a plant used by man and it was already mentioned in “De material medicia libri quinque” written in 100 A. D. The plant, which has its origin in southeast Europe, was brought to the Nordic countries by monks during the thirteenth century. In the Nordic countries, horseradish was used both as a bitter spice and as a medicinal plant. The plant contains high levels of sulfur-containing glycosides, so called glucosinolates. The most dominant is sinigrin, which causes a pungent taste . Some glucosinolates also possess anti-microbial characters, and horseradish has traditionally been used as a component in preserving. The root also has a high content of vitamin C and was taken to prevent scurvy on long sailing tours. Horseradish was also used as a medicinal plant for headaches, digestive disorders, high blood pressure and gout. Earlier it was also believed that the plant had magical powers and could prevent snakebites if you had rubbed your hands with it. The production of horseradish has decreased in the Nordic countries due to high production costs, changes in traditional cooking manners and a decrease in homemade preserving. NordGen, the Gene Bank for the Nordic countries, has a collection of horseradish consisting of 170 accessions. The roots were collected from old gardens or as refugees from gardens in Denmark, Finland, Norway and Sweden. The accessions have been evaluated for contents of glucosinolates and vitamin C and a large variation in bioactive substances has been found .

Tolerance of Hordeum marinum accessions to O2 deficiency, salinity and these stresses combined

When root-zone O(2) deficiency occurs together with salinity, regulation of shoot ion concentrations is compromised even more than under salinity alone. Tolerance was evaluated amongst 34 accessions of Hordeum marinum, a wild species in the Triticeae, to combined salinity and root-zone O(2) deficiency. Interest in H. marinum arises from the potential to use it as a donor for abiotic stress tolerance into wheat. Two batches of 17 H. marinum accessions, from (1) the Nordic Gene Bank and (2) the wheat belt of Western Australia, were exposed to 0.2 or 200 mol m(-3) NaCl in aerated or stagnant nutrient solution for 28-29 d. Wheat (Triticum aestivum) was included as a sensitive check species. Growth, root porosity, root radial O(2) loss (ROL) and leaf ion (Na(+), K(+), Cl(-)) concentrations were determined. Owing to space constraints, this report is focused mainly on the accessions from the Nordic Gene Bank. The 17 accessions varied in tolerance; relative growth rate was reduced by 2-38 % in stagnant solution, by 8-42 % in saline solution (aerated) and by 39-71 % in stagnant plus saline treatment. When in stagnant solution, porosity of adventitious roots was 24-33 %; salinity decreased the root porosity in some accessions, but had no effect in others. Roots grown in stagnant solution formed a barrier to ROL, but variation existed amongst accessions in apparent barrier 'strength'. Leaf Na(+) concentration was 142-692 micromol g(-1) d. wt for plants in saline solution (aerated), and only increased to 247-748 micromol g(-1) d. wt in the stagnant plus saline treatment. Leaf Cl(-) also showed only small effects of stagnant plus saline treatment, compared with saline alone. In comparison with H. marinum, wheat was more adversely affected by each stress alone, and particularly when combined; growth reductions were greater, adventitious root porosity was 21 %, it lacked a barrier to ROL, leaf K(+) declined to lower levels, and leaf Na(+) and Cl(-) concentrations were 3.1-9-fold and 2.8-6-fold higher, respectively, in wheat. Stagnant treatment plus salinity reduced growth more than salinity alone, or stagnant alone, but some accessions of H. marinum were still relatively tolerant of these combined stresses, maintaining Na(+) and Cl(-) 'exclusion' even in an O(2)-deficient, saline rooting medium.

Assessment of Phenotypic Variation in Winter Barley in Scandinavia

Phenotypic diversity for agronomic characteristics was determined in an experiment without fertilizer in 1998 in 41 two-row and 21 six-row winter barley accessions, provided by the Nordic Gene Bank, at Højbakkegård (Denmark). There were significant differences among these 62 accessions for spring establishment, early flowering, covering, plant height, lodging, tillering, spike length, number of kernels per spike and thousand kernel weight. On average, two-row barley accessions had better establishment, covering and standability (although they were slightly taller) but showed lower tillering than six-row barley accessions. Two-row barley accessions also had larger spikes with fewer kernels, but heavier weight, than six-row barley accessions. There were significant phenotypic correlations among the characteristics scored. However, not all of them were common to two- and six-row barley accessions, which suggests the evolution of distinct genetic systems controlling these associations in the two sets of barley accessions. Average linkage cluster analysis and principal component analysis confirmed number of rows as an important characteristic to discriminate among cultivated barley accessions.

The Nordic Gene Bank’s Prunus clone archive in Finland: II Local races of plum

The morphological variation in 104 local races of plum (Prunus domestica subsp. domestica L.) in the Nordic Gene Bank’s Prunus clone archive in Pälkäne, Southwest Finland was examined. Each tree was described using 37 characteristics. On the basis of fruit characteristics the local races were classified into three main groups. The largest one was the red plum group, the yellow plum group being the second largest. Victoria-type plums, which have not been reported to occur in Finland before and which resemble the English cultivar ‘Victoria’, make up the third group. Victoria-type plums proved to be fully and red plums partly self-compatible, whilst the yellow plums were selfincompatible. All the local races of plum were evaluated for their possible further use. Two of them were selected for commercial propagation.

The Nordic Gene Bank’s Prunus clone archive in Finland: I Local races of sour cherry

Morphological variation among 78 local races of sour cherry (Prunus cerasus L.) in the Nordic Gene Bank’s Prunus clone archive in Pälkäne in Southwestern Finland was examined. Each tree was described using 42 characteristics. On the basis of fruit characteristics, 32 samples were classified as morellos, 40 samples as amarelles, and 5 samples distinct from the other amarelles are proposed to be called Rymättylä-type cherries. One sample was found to be Prunus avium. Amarelle type cherries proved to be more self compatible than morello type cherries. In order to find hardy sour cherry cultivars with fruits of good flavour and fit for cultivation in Nordic conditions, the most promising local races from each group were selected for a comparative trial. Additionally, some local races were selected for further use in plant breeding. In 1994-1996, an increasing amount of severe bacterial canker symptoms was observed in the clone achive.

6. Regional gene banks: cooperative programmes

A description is given of the Nordic Gene Bank for Agricultural and Horticultural Plants (NGB), its origins, its mandate, its organization, the scientific concepts it has adopted as a base for its activities and some of the work done during the first ten years. The new project in the South African Development Coordination Conference (SADCC) countries to establish a regional gene bank is also outlined. In both cases the aims are the improvement of crop varieties through the use of local and international genetic resources materials. The mandate of the NGB covers preservation and documentation of the genetic variation of Nordic agricultural and horticultural plants as a service institution for plant breeding and other plant research. NGB is located at Alnarp, Sweden, and is governed by a Board consisting of two members from each of the five Nordic countries, Denmark, Finland, Iceland, Norway and Sweden. The SADCC Regional Gene Bank (SRGB) is a project of the governments of the SADCC member states: Angola, Botswana, Lesotho, Malawi, Mozambique, Namibia, Swaziland, Tanzania, Zambia and Zimbabwe. The primary objective is to establish, over a 20-year period, a Regional Plant Genetic Resources Centre to preserve, evaluate and utilize through breeding the indigenous plant genetic resources material and natural crop heritage of the region. The project is a crucial component in implementing the broader 20-year regional programme of agricultural research, already agreed by the SADCC countries, to increase per capita agricultural output; this programme is expected to lead to a rapid improvement in cultivated plant varieties throughout the region. An essential element of the project is the training and education of plant genetic resources personnel.

Old and New Problems in the Field of Plant Quarantine1

International cooperation in the field of plant quarantine is based on the FAO Convention, Rome 1951, and the accompanying phytosanitary certificate. In the year 1951 the regional organization EPPO was also founded. The recent publication of lists of quarantine pests and diseases, in cooperation between the member countries of this last‐mentioned organization, is of great importance. The importation of exotic consignments, and especially those with vegetative propagation material and seeds, often gives rise to great risks for new pests and diseases. In recent years, the transfer of germplasm material for gene banks in different parts of the world has brought new problems. International cooperation is required within a chain of post‐entry quarantine stations, especially equipped to facilitate safe exchange between gene banks. The author proposes a regional quarantine station of this sort to serve the Nordic gene bank at Lund.