Cereal cultivation from the Iron Age to historical times: evidence from inland and coastal settlements in northernmost Fennoscandia

For several decades researchers have debated when cereal cultivation was introduced to northernmost Europe. Most previous studies have concentrated on sites along the coast or close to major rivers; these are areas well-suited to agriculture and represent routes for people and knowledge transfer, but omit other vast areas suitable for cultivation and sedentary settlement. Here, we present strong evidence of permanent cultivation from ad 480 onwards at a settlement located at the 64th parallel North in northern Sweden, currently situated 30 km inland from the Gulf of Bothnia. This predates the beginning of permanent cultivation at sites along the present coastline mentioned here and in results from previous studies of places at approximately the same latitude. Our results are based on continuous finds of cereal pollen grains at certain sites, selected on the basis of archaeological records, old maps, plus past and present elevations above sea level. We highlight the importance of taking factors into account such as access to waterways, communication routes and coast displacement following land uplift when choosing study sites in order to pinpoint early cultivation and sedentary settlements. We suggest that these results have implications for attempts to resolve the question of the history of early agriculture in other parts of northern Fennoscandia.     

The early history of polyamine research

In 1678 Antonie van Leeuwenhoek identified crystalline substances in human semen. The structure of these crystals, named “spermine”, was not elucidated by Rosenheim until 250 years later. Subsequently a triamine (spermidine) and a diamine (putrescine; 1,4-diaminobutane) were isolated from prokaryotic and eukaryotic systems. Soon it became apparent that polyamines can promote the growth of fastidious bacteria. Subsequently a group in Helsinki studied the accumulation of polyamines in regenerating rat liver, while Caldarera and his group studied polyamine synthesis in the developing chick embryo. These investigations led to metabolic studies. Ornithine decarboxylase was identified as a key enzyme in polyamine biosynthesis, while polyamine and diamine oxidations were studied by Mondovì. α-Diflouromethylornithine (DFMO) was synthesized by Merrell-Dow and became a potent inhibitor of ornithine decarboxylase. The findings of Russell that polyamines are excreted in the urine of cancer patients drew the attention of oncologists, who attempted the use new technologies for the detection of cancer and improving therapy. With the advance of molecular biology the structure of polyamine-biosynthetic enzymes was elaborated. Plants served as another important tool to study the physiological functions of polyamines. Bagni and his group at Bologna were pioneers in that field and for more than forty-six years set the foundation of a most interesting discipline.     

Growing seasons of Nordic mountain birch in northernmost Europe as indicated by long-term field studies and analyses of satellite images

The phenophases first greening (bud burst) and yellowing of Nordic mountain birch (Betula pubescens ssp.tortuosa, also called B. p. ssp. czerepanovii) were observed at three sites on the Kola Peninsula in northernmost Europe during the period 1964–2003, and at two sites in the trans-boundary Pasvik-Enare region during 1994–2003. The field observations were compared with satellite images based on the GIMMS-NDVI dataset covering 1982–2002 at the start and end of the growing season. A trend for a delay of first greening was observed at only one of the sites (Kandalaksha) over the 40 year period. This fits well with the delayed onset of the growing season for that site based on satellite images. No significant changes in time of greening at the other sites were found with either field observations or satellite analyses throughout the study period. These results differ from the earlier spring generally observed in other parts of Europe in recent decades. In the coldest regions of Europe, e.g. in northern high mountains and the northernmost continental areas, increased precipitation associated with the generally positive North Atlantic Oscillation in the last few decades has often fallen as snow. Increased snow may delay the time of onset of the growing season, although increased temperature generally causes earlier spring phenophases. Autumn yellowing of birch leaves tends towards an earlier date at all sites. Due to both later birch greening and earlier yellowing at the Kandalaksha site, the growing season there has also become significantly shorter during the years observed. The sites showing the most advanced yellowing in the field throughout the study period fit well with areas showing an earlier end of the growing season from satellite images covering 1982–2002. The earlier yellowing is highly correlated with a trend at the sites in autumn for earlier decreasing air temperature over the study period, indicating that this environmental factor is important also for autumn phenophases.     

The history of Dryas octopetala L. in eastern Fennoscandia

The information available concerning the Late-Quaternary history of Dryas octopetala L. in eastern Fennoscandia is surveyed. It is evident that Dryas has been an important component of the treeless periglacial vegetation which existed along most of the perimeter of the Weichselian glacier c. 10,000 B.P., marked by the Salpausselkä-Kuittijärvi-Tromsø-Lyngen end moraine arc. Dryas has not been as common in the archipelago of southern Finland, west of about 28°E long. Disjunctive recent localities inside the area still glaciated during the early Flandrian (Pre-boreal period) are relics of an immigration contemporaneous with the advance of light birch forests.     

The history of rye cultivation in Europe

During recent years finds from several prehistoric and medieval periods have thrown new light on the history of the spread of rye. It is now proven that wild rye is indigenous to Anatolia and was already domesticated there by the early Neolithic at the beginning of agriculture. Secale migrated to Central Europe as a weed among other cereals, and single grains of weed rye have been recorded there since the early Neolithic. The number of finds increased during the Bronze Age and Iron Age, and the status of rye changed from weed to crop plant, probably in the course of the early Iron Age. This acculturation of Secale cereale in central and eastern Europe was obviously independent of the earlier one in Anatolia. The first stages towards deliberate cultivation happened unintentionally through harvesting close to the ground, so that the rye was permanently represented in the seed corn. From this point rye was able to take advantage of its competitive strength on poor soils and in areas with unfavourable climate. The start of rye as a crop in its own right during the pre-Roman Iron Age and Roman period presumably took place independently in different areas. The expansion of intensive rye cultivation occurred in the Middle Ages. However, new finds from north-west Germany, which are presented here, show that in this area rye has been cultivated as a main crop on poor soils since the Roman period. In two maps all rye finds up to 1000 A.D. are shown, which after critical consideration can be regarded as cultivated rye.     

Response of Ralstonia eutropha JMP 134 to long-term exposure to toxic substrates in nutristat cultivation as indicated by on-line fluorescence measurements

Ralstonia eutropha JMP 134 was continuously grown on phenol and 2,4-dichlorophenoxyacetate under nutristatic conditions at elevated stationary concentrations of 90-650 mg phenol/l and 25-100 mg 2,4-D/l, respectively, in order to study the response of the bacterial population to long-term exposure to these potentially toxic substrates. The course of the cells' response over time was observed by determining distinctive growth parameters and by the on-line measurement of fluorescence spectra of intracellular and extracellular fluorophores. The latter were monitored using a modified fluorescence spectrophotometer. The results of the nutristat experiments indicate that the adaptation of the culture to long-term exposure to phenol and 2,4-D exhibited dynamic characteristics of the growth pattern determined by the individual substrates and their concentration, including enforced and reduced levels of substrate conversion. This growth pattern is interpreted as an expression of superimposing cellular events in order to withstand unfavorable environmental conditions. Finally, the growth rate attained retarded levels under stationary conditions, slowing down to almost zero for example in the case of about 100 mg 2,4-D/l. The growth rate profile within the various phases of adaptation was well reflected by the fluorescence signals. The NAD(P)H fluorescence was almost exclusively emitted by the cellular pool of NADPH and behaved inversely to the growth rate. A similar relationship was obtained for the cellular fluorescence of a flavin-containing compound. Sharply reduced growth was additionally accompanied by a rapid rise of the background fluorescence. These data indicate that fluorescence-derived signals provide a useful reflection of cellular events in inhibited growth situations.     

The molecular bases of cereal domestication and the history of rice

In this review, we discuss the development of molecular genetics and genomics that has allowed one to identify and characterize some of the key genes involved in cereal domestication. The list is far from being complete, but the first conclusion that can be drawn from the published works is that only a few loci have been the target of human selection in the first stages of the domestication process at the late neolithic. Mutations at these few loci have led to dramatic changes in plant morphology and phenology, transforming a wild into a cultivated plant. We also show that in the case of rice, for which the complete genome sequence is available, the development of new molecular markers based on retrotransposon insertion polymorphisms helped to resolve some of the questions regarding the origin of the domestication of the crop in Asia. To cite this article: O. Panaud, C. R. Biologies 332 (2009).     

The trophic state of Lake Ladoga as indicated by late summer phytoplankton

As a part of the joint Russian-Finnish evaluation of human impact on Lake Ladoga, we studied the phytoplankton of the lake in order to find biological indicators for eutrophication. A second aim of the investigation was intercalibration of sampling and phytoplankton counting techniques between the Russian and Finnish laboratories. Phytoplankton samples were collected from 27 sampling stations in the lake and from the rivers Volkhov and Neva in 9–13 August 1993. In surface water samples the phytoplankton fresh weight biomass varied in the range 218–3575 mg m^–33. Highest biomass values were encountered in Sortavala Bay, and lowest ones in the western central part of the lake. Phytoplankton species composition varied considerably in the lake; blue-green and green algae predominated near-shore areas and Cryptophyceae in the offshore stations. Canonical correspondance analysis revealed close grouping of eutrophy indicating communities, dominated mainly by greens and blue-greens, in the most nutrient-rich parts of Lake Ladoga, the Volkhov and Svir Bays. Samples from the vicinity of the inflows of Vuoksi and Burnaya Rivers and off Pitkaranta formed a separate group, dominated by diatoms, most of which were typical to mesotrophic or eutrophy lakes. As judged by phytoplankton biomass values and chlorophyll a concentrations, Lake Ladoga may generally be classified as mesotrophic. Eutrophicated areas are found in the northern archipelago of the lake and in the areas influenced by large rivers.     

The phylogeny of the hominoid primates,as indicated by DNA-DNA hybridization

Summary The living hominoid primates are Man, the chimpanzees, the Gorilla, the Orangutan, and the gibbons. The cercopithecoids (Old World monkeys) are the sister group of the hominoids. The composition of the Hominoidea is not in dispute, but a consensus has not yet been reached concerning the phylogenetic branching pattern and the dating of divergence nodes. We have compared the single-copy nuclear DNA sequences of the hominoid genera using DNA-DNA hybridization to produce a complete matrix of delta T₅₀H values. The data show that the branching sequence of the lineages, from oldest to most recent, was: Old World monkeys, gibbons, Orangutan, Gorilla, chimpanzees, and Man. The calibration of the delta T₅₀H scale in absolute time needs further refinement, but the ranges of our estimates of the datings of the divergence nodes are: Cercopithecoidea, 27–33 million years ago (MYA); gibbons, 18–22 MYA; Orangutan, 13–16 MYA; Gorilla, 8–10 MYA; and chimpanzees-Man, 6.3–7.7 MYA.     

The early history of estriol

The early history of estriol is reviewed with special emphasis on its isolation, identification, quantitation in tissues and body fluids and its unique biogenesis in the human feto-placental unit. The relationship to epimeric estriols and acidic estrogens and the pharmacokinetic and pharmacodynamic properties which led to a widespread therapeutic use of this compound are also discussed.     

Plant species richness in Fennoscandia: evaluating the relative importance of climate and history

In Fennoscandia, the species richness of vascular plants in 75 × 75 km squares is highly correlated with geographical (latitude and longitude) and climatic variables (accumulated respiration sum, mean January temperature, and mean July temperature). When generalised additive models (GAM) are used, over 80% of the variation in richness can be statistically explained by geography and climate. Even though climate has such a high explanatory power we present several arguments for interpreting these results with care. Climate has no ecologically sound explanatory power when the variation due to latitude and longitude is accounted for, and the strongest latitudinal gradient in summer temperature is in an area where the latitudinal gradient in species richness is absent. We discuss the role that Holocene history might have on the variation in species richness, and argue that history and climate should be considered simultaneously when explaining the observed patterns in the geographical variation of species richness.     

禾谷类作物淀粉合酶

淀粉合酶是禾谷类作物淀粉合成所必需的一类酶.根据淀粉合酶家族成员的氨基酸序列的相似性,分别介绍了一个颗粒性淀粉合酶亚家族和四个可溶淀粉合酶亚家族的组成、基因结构和表达特点,并从转录、转录后和翻译后水平上对这些基因的表达调控做了概述.     

Genetic variation in Drechslera teres populations as indicated by RAPD markers

Random amplified polymorphic DNA (RAPD) was used to assess genetic variation among 48 isolates of Drechslera teres originating from different sites in Finland. RAPD profiles were generated with five arbitrary 10-mer primers and revealed polymorphisms suitable for screening differentiation in this fungal population. Using UPGMA clustering analysis, a similarity coefficient of approximately 63% was observed between all D. teres isolates studied. The variation was, however, distributed on a small scale as different genotypes were found from the same plant. The isolates could not be grouped according to geographic origin, aggressiveness, growth rate or morphological features, indicating that the primers used in this study were neutral markers for these characters. The primers were, however, able to differentiate between isolates of Helminthosporium species (D. teres, Drechslera graminea and Bipolaris sorokiniana).