Trait Patterns and Genetic Resources of Dill (Anethum graveolens L.)

Dill (Anethum graveolens L.) is used fresh or processed for food seasoning and preservation. Production is concentrated in temperate regions but can be grown as a cool season crop in India and Thailand. Several secondary metabolites, among them essential oils are present in the plant and with claimed health benefits. Despite the many potential benefits, dill is an underutilized crop. The current study survey global and European genetic resources. Hence, accessions from the Nordic germplasm collection were evaluated, aiming at tracing trait patterns. The survey showed both gaps and overlaps in available genebank holdings. Accessions from outside Europe were highly under-represented in the global collections, as were wild material and crop wild relatives. The evaluation showed that important agro-botanical traits correlated, such as plant height, umbel size and other size characters. Furthermore, essential oil composition was clearly influenced by high temperature stress. A discussion on access and use of genetic resources of minor crops such as dill was included.publishedVersio

The Effects of Growth Regulators and Apical Bud Removal on Growth, Flowering, and Corms Production of Two Gladiolus Varieties

Gladiolus is commonly propagated from corms. The multiplication rate of corms is low and to increase the propagation rate, we examined a combination of apical bud removal and the application of growth regulators. The experiments were conducted in two varieties, ‘Rose Supreme’ and ‘White Prosperity’, and over two seasons. The apical buds on the planting corms were either removed or left intact before the same corms were soaked in a suspension with either 100 ppm of benzyladenine (BA), 100 ppm of gibberellic acid (GA3), or pure water. The results showed that apical bud removal increased the number of corms and shoots. GA3 had limited the effect on corm and shoot production, but instead resulted in increased total leaf area and leaf weight per shoot. BA, on the other hand, increased the number of corms and shoots. Overall, the removal of the apical bud plus application of BA increased the number of corms and shoots but reduced the average corm diameter and leaf weight per shoot. This was clearer in ‘Rose Supreme’ than in ‘White Prosperity’. To maximize flower production for the coming season, farmers need to produce a high number of planting corms, but they also need to balance this with a sufficient corm size and the production of flowers of good quality. The application of growth regulators in combination with apical bud removal should be fine-tuned to avoid a situation that leads to the production of too many small or too few large corms.publishedVersio

Trait Patterns and Genetic Resources of Dill (Anethum graveolens L.)

Dill (Anethum graveolens L.) is used fresh or processed for food seasoning and preservation. Production is concentrated in temperate regions but can be grown as a cool season crop in India and Thailand. Several secondary metabolites, among them essential oils are present in the plant and with claimed health benefits. Despite the many potential benefits, dill is an underutilized crop. The current study survey global and European genetic resources. Hence, accessions from the Nordic germplasm collection were evaluated, aiming at tracing trait patterns. The survey showed both gaps and overlaps in available genebank holdings. Accessions from outside Europe were highly under-represented in the global collections, as were wild material and crop wild relatives. The evaluation showed that important agro-botanical traits correlated, such as plant height, umbel size and other size characters. Furthermore, essential oil composition was clearly influenced by high temperature stress. A discussion on access and use of genetic resources of minor crops such as dill was included

Long-Term Storage and Longevity of Orthodox Seeds: A Systematic Review

As part of conservation of plant genetic resources, long-term storage of seeds is highly relevant for genebanks. Here we present a systematic review and a meta-analysis of studies on seed longevity focusing on half-life (P-50) under different storage conditions. Six studies were selected for the meta-analysis; in addition, a high number of additional references were included in the discussion of the results. The results show that under ambient conditions, half-life is short, from 5 to 10 years, while under more optimal conditions, which for orthodox seeds is at low humidity and low temperature, half-life is more in the 40-60 years range, although with large interspecies variation. Under long-term genebank conditions, with seeds dried to equilibrium and thereafter kept at minus 18-20 degrees C in waterproof bags or jars, half-life can be twice or three times as long. In general, many of the grain legume seeds, as well as corn, common oat, and common barley are long-lived, while cereal rye, onion, garden lettuce, pepper, and some of the forage grasses are more short-lived. Conditions during maturation and harvesting influence longevity, and proper maturation and gentle handling are known to be of importance. Seed longevity models have been developed to predict final germination based on initial viability, temperature, humidity, storage time, and species information. We compared predicted germination to results from the long-term experiments. The predicted values were higher or much higher than the observed values, which demonstrate that something in the seed handling in the genebanks have not been optimal. Long-term studies are now available with data at least up to 60 years of storage. Our review shows that the knowledge and methodology developed for the conservation of plant genetic resources should also work for wild species of orthodox seed nature

Stratification, scarification and gibberellic acid treatments of garden angelica (Angelica archangelica) seeds

A study was made to examine methods to break seed dormancy in long-term stored garden seed lots of angelica (Angelica archangelica), including cold stratification at 4ᵒC for 60 or 85 days, scarification and gibberellic acid treatments. The results showed that stratification was needed but was not enough alone as 60 days gave almost no germination and 85 days 10%. Addition of gibberellic acid improved germination to up to 27% for the seeds stratified for 60 days and 41% for seeds stratified for 85 days, but with large variation among seed samples. Scarification + stratification gave a somewhat similar result, up to 12 and 22% germination, while the combined stratification + scarification + gibberellic acid treatment resulted in more than 60% germination. The results are useful for genebank managers and others involved in conservation and cultivation of garden angelica

Seed Longevity and Survival of Seed Borne Diseases after 30 Years Conservation in Permafrost : Report from the 100 Year Storage experiment

The Nordic Gene bank established the 100 year seed storage experiment in Coal mine no. 3 outside Longyearbyen in 1986. Security duplicate samples of the Nordic seed collection had been deposited in permafrost in the coal mine since 1984.  The experiment was established with the aim to monitor the longevity of seeds in this Nordic back-up seed collection and to gain general knowledge about the longevity of seed stored under permafrost conditions, as well as studying the survival of seed borne plant pathogens. The experimental set up included in total 41 seed lots of 17 agricultural and horticultural crop species commonly grown in the Nordic countries. The seed germination experiment included two or three varieties of each crop. The experimental part dedicated to studies of pathogen survival included seeds from 11 crops naturally contaminated by pathogens. The test program comprises germination and pathogen survival tests every 2.5 years during the first 20 years and then every 5 years for the last 80 years. In total 25 identical sets of test seeds placed in sealed glass tubes were packed in wooden boxes, one box for each planned test year. The tests have been carried out according to schedule and this report sums up the results from the first 30 years of the experiment. All tests have been carried out in accordance with the same ISTA-protocols

Who lives in poverty?

The Nordic Gene bank established the 100 year seed storage experiment in Coal mine no. 3 outside Longyearbyen in 1986. Security duplicate samples of the Nordic seed collection had been deposited in permafrost in the coal mine since 1984. The experiment was established with the aim to monitor the longevity of seeds in this Nordic back-up seed collection and to gain general knowledge about the longevity of seed stored under permafrost conditions, as well as studying the survival of seed borne plant pathogens. The experimental set up included in total 41 seed lots of 17 agricultural and horticultural crop species commonly grown in the Nordic countries. The seed germination experiment included two or three varieties of each crop. The experimental part dedicated to studies of pathogen survival included seeds from 11 crops naturally contaminated by pathogens. The test program comprises germination and pathogen survival tests every 2.5 years during the first 20 years and then every 5 years for the last 80 years. In total 25 identical sets of test seeds placed in sealed glass tubes were packed in wooden boxes, one box for each planned test year. The tests have been carried out according to schedule and this report sums up the results from the first 30 years of the experiment. All tests have been carried out in accordance with the same ISTA-protocols. The results show that 9 of the 17 species after 30 years had retained more than 90 percent of their initial germination percentage. Beet (Beta vulgaris),Onions (Allium cepa), Cucumber (Cucumis sativus) and Kentucky bluegrass (Poa pratensis) had retained between 97 and 99 percent. At the lower end of the scale, rye (Secale cereale) had lost 51 percent of the initial germination percentage. Among the other cereals, barley (Hordeum vulgare)showed the highest viability as it had kept 89 percent viability, whilst wheat (Triticum aestivum) had kept 79 percent of the initial germination percentage. Mean germination of all test samples showed a drop from 87.2% at year0 to 76.9% at year 30. The pathogen tests showed that all pathogens had survived over the 30 years, more or less at the same contamination levels as were detected at the start of the project. To expand the knowledge about seed longevity under long-term seed storage it is recommended to establish a new more comprehensive experiment with seed materials from a wider selection of crops, and to include more replicates and seeds produced over more years, allowing more indepth statistical studies of the longevity development. A new experiment should be placed in the Svalbard Global Seed Vault, in order to provide results relevant for optimal gene bank conservation methods at -18°C and giving direct data on the longevity of seeds stored in the Seed Vault.publishedVersio