Arja Santanen

• PhD
• University of Helsinki

Phosphorus (P) is an essential element for plant growth and development. Finding new P sources and ways to improve crop P utilization are necessary due to the depletion of phosphate reserves. Five crop species, buckwheat (Fagopyrum esculentum L.), maize (Zea mays L.), oilseed rape (Brassica napus L. ssp. oleifera (Moench) Metzg.), spelt wheat (Trit...

Plant tissue cultures are an efficient system to study cell wall biosynthesis in living cells in vivo. Tissue cultures also provide cells and culture medium from which enzymes and cell wall polymers can easily be separated for further studies. Tissue cultures with tracheary element differentiation or extracellular lignin formation have provided use...

Background Digested sludge is a good source of plant nutrients. However, depending on the feedstock, it might contain heavy metals, metalloids, organic compounds, pathogens, and pharmaceuticals, which can cause adverse effects on crop growth and contaminate the groundwater, soil, and food chain. Scope The aim of this review is to focus on the pote...

Among grain legumes, faba bean is reputed to be relatively sensitive to drought stress. Epicuticular wax (ECW) quantity is considered as an important drought adaptation strategy in plant species. This study aimed to define variation in leaf ECW concentration as a drought-adaptive trait in 197 faba bean accessions under well-watered conditions. The...

Jerusalem artichoke (Helianthus tuberosus L.) produces substantial shoots not used as food. To test its potential as a sustainable bioenergy crop, we studied the effects of synthetic fertilizer and intercropped legumes as nitrogen (N) sources on the growth, aboveground biomass dry matter yield and energy qualities of this crop. Plant height, leaf a...

The biomass potential of eight high yielding maize cultivars was studied in the sub-boreal climate of southern Finland. The effects of harvest date on lignin and sugar production, biomass yield, mineral element composition, bioenergy potential and soil nutrient management were determined in two years. The eight maize cultivars produced 17.6–33.3 t...

Bioenergy cropping, like all agricultural practices, may lead to the release of greenhouse gases. This study was aimed at determining biomass and energy yields of reed canary grass (RCG) (Phalaris arundinacea), galega (Galega orientalis) and a mixture of these, and to relate these to fluxes of nitrous oxide (N2O), a potent greenhouse gas, emitted f...

Introduction: Arbuscular mycorrhizal fungi (AMF) are the most common and widespread symbioses occurring in terrestrial plant (Smith and Smith, 2011). They can improve the nutritional status of the host plant through the uptake of nutrients, particularly P, according to the extensive mycelium in the soil. The mycelium accumulates and translocates di...

We evaluated the weed suppressive abilities of 6-dicotyledonous crops [buckwheat (Fagopyrum esculentum L), caraway (Carum carvi L.), faba bean (Vicia faba L.), oilseed hemp (Cannabis sativa L.), vetch (Vicia sativa L.) and white lupine (Lupinus albus L.)] in glasshouse and field experiments. In glasshouse experiment, incorporation of active charcoa...

Aims and background Acid sulphate (AS) soils require careful management to prevent the environmental hazards that result from the oxidation of sulphide-bearing deep soil layers and the consequent acidification of soil and waters. Management with a high water table precludes many food crops, so their suitability for perennial energy cropping was inv...

Drought is a major constraint to faba bean (Vicia faba L.) production, and there are many mechanisms by which leaves can regulate water loss. Our primary objective was to test if the origin of the faba bean accessions, from drought-prone and non-drought-prone environments, was associated with differences in measurable aspects of stomatal morphology...

Utilization of sludge is an attractive option for fertilizing bioenergy crops, since in addition to its valuable macro- and micro-nutrients, it may also contains some pollutants. Therefore, a three-year field experiment was conducted to investigate the suitability of sewage and digested sludge in comparison to synthetic fertilizer on biomass produc...

Potassium (K) plays a significant role in preventing outbreaks of pathogenic infections and thereby maintains the photosynthetic leaf area which supplies assimilates for grain filling. The aim of this research was to investigate the role of K in barley straw anatomy, plant stand architecture, and yield formation. Growth and yield of barley improved...

Sewage sludge is rich in essential plant nutrients, but its use is restricted for crop production due to the pollutants it contains, such as metalloids and heavy metals. Sludge is also very sticky and compact. Therefore, the objectives of this work were to evaluate (1) the impact of various amounts of sludge on bioenergy crop productivity and quali...

Maaperän saastuminen raskasmetalleilla sekä metalloideilla on kasvava ongelma, joka aiheuttaa uhkia sekä ihmisten että ekosysteemin toiminnalle. Tästä johtuen kiinnostus uusiin ympäristöystävällisempiin sekä taloudellisempiin maaperän puhdistusmenetelmiin on lisääntynyt. Kasvien käyttö saastuneiden alueiden puhdistamisessa eli fytoremediaatio on lu...

Sludge is a good source of plant nutrients, but its use as fertilizer for food or fodder crops is questionable due to its potential content of heavy metals and metalloids. In two pot experiments, germination and growth of maize (Zea mays L., cv. Ronaldino), fiber hemp (Cannabis sativa L., cv. Uso 31) and oilseed rape (Brassica napus L. ssp. oleifer...

Plant tissue cultures are an efficient system to study cell wall biosynthesis in living cells in vivo. Tissue cultures also provide cells and culture medium where enzymes and cell wall polymers can easily be separated for further studies. Tissue cultures with tracheary element differentiation or extracellular lignin formation have provided useful i...

The effect of genotype, the origin of genotype, and germination temperature on Scots pine pollen grain size, hydration rate, germinability, and tube growth was studied in vitro. The mean sizes of dry and germinated pollen grains varied among pollen genotypes in different ways, thus the hydration rate varied among genotypes. Pollen from Scots pine t...

Winter turnip rape (Brassica rapa spp. oleifera) is an underutilized crop that deserves to be revitalized for use in high-latitude agriculture. Many crop rotations around the world are dependent on the small-grain cereals, and turnip rape as a break crop, with its range of secondary chemicals, helps to suppress weeds, nematodes and pathogenic fungi...

Timothy is a long-day grass species well adapted for cultivation in northern latitudes. It produces elongating tillers not only in spring growth but also later in summer. As the quantity and quality of harvested biomass is dictated by canopy architecture and the proportion of stem-forming flowering tillers, the regulation of flowering is of great i...

Sewage sludge is rich in organic matter, and plant nutrients such as nitrogen, phosphorus andpotassium. Nevertheless, using sludge as fertilizer for crops to produce food or feed is limited due to thepresence of trace contaminants such as heavy metals. Therefore, the aim of this study was to investigatethe use of sewage sludge as a nutrient source...

Eri bioenergiantuottotavat asettavat kasvibiomassalle erilaisia vaatimuksia. Biologiset, käymiseen perustuvat menetelmät käyttävät liukoisia sokereita ja tärkkelystä lähteinään. Näissä menetelmissä biomassan epäorgaanisia yhdisteitä sisältävä jäänne voidaan hyödyntää rehuna ja lannoitteina, ja biomassan kosteuspitoisuus aiheuttaa ongelmia vain sato...

Maaperän saastuminen on maailmanlaajuinen ympäristöongelma. Ihmisen toiminnan tuloksenaesimerkiksi raskasmetalleilla pilaantuneita maa-alueita on runsaasti. CCA (chromated copper arsenate)on maailmalla laajasti käytetty puun kyllästysaine, joka on saastuttanut laajoja maa-alueita mm.sahalaitoksilla, tehdasalueilla ja kaatopaikoilla. Kuparin, kromin...

Kasvuston rakenne määrää suurelta osin nurmikasvien sadon määrän. Tämä havaitaan selvimmin vertailtaessa timotein kevät- ja syyskasvustojen rakennetta ja sadon määrää; kevätsadossa esiintyy runsaasti korrellisia, kukintoja muodostavia versoja, kun taas syksyllä kasvusto on matalaa ja lehtevää, ja kortta muodostavien versojen määrä on alhainen. Kevä...

Drought is one of the most important abiotic stresses that causes significant reductions in crop yield, and thushinders the food security of the growing world population. In consequence, it is urgent to select crops able toresist drought, maintain high yield and have a good nutritive content. The purpose of this project was toevaluate the responses...

Pre-zygotic pollen competition is believed to play an important role in nonrandom mating, i.e., the unequal success of different pollen donors. We studied pollen–pollen interactions of Scots pine in vitro using multiwell plates with freely permeable inserts. Six genotypes were included in our experiments: three from northern Finland and three from...

Timing of pollen arrival may affect the level of seeds fertilized by pollen from outside seed orchards, especially in seed orchards of Scots pine (Pinus sylvestris L.) established in southern Finland with stock from northern populations. We performed sequential pollination experiments with Scots pine pollen collected from seed orchard clones origin...

The fluctuations of free and bound polyamines (PAs) were studied in vegetative buds and underlying twigs of linden (Tilia cordata L.) from August to May, to assess the connection between PA levels and seasonal cycles of growth and dormancy. Outer and inner bud scales and shoot tips (short shoot tips with leaf initials in contiguous short internodes...

The oxidation of putrescine and spermidine were studied in embryogenic and nonembryogenic cell cultures of Picea abies (L.) Karst., with [1,4-14C]-putrescine and [1,4-14C]-spermidine as substrates. Activities of putrescine and spermidine oxidation varied at every developmental stage in both cultures. Putrescine was oxidized ca 5 times as fast both...

New macro and microelement solutions were formulated for stimulation of growth and embryogenesis in white and chlorophyllous megagametophyte and embryo callus lines of Picea abies (L.) Karst. Macroelement media with different NH4+ and NO3− ratios (1:2 and 1:4), the increased level of several microelements and the effect of organic nitrogen (100 mg...

The effect of different concentrations of sucrose (0-4%) and of two growth regulators (0–50 μM 2,4-D and 0–25 μM kinetin) was tested on growth and chlorophyll content of suspension cultures of Picea abies (L.) Karst. originating from chlorophyllous embryo callus in an elevated CO2 (2%) atmosphere. A continuous chlorophyllous suspension culture was...

The concentrations of free, conjugated and bound polyamines (putrescine and spermidine) and the activity of a key enzyme, [S-adenosylmethionine decarboxylase (SAMdc)], which participates in the biosynthesis of spermidine, were studied in embryogenic and non-embryogenic callus cultures of Picea abies (L.) Karst. When the calli were transferred on AB...