Rapeseed Germination Research Articles

Application of the hydrotime model to assess seed priming effects on the germination of rapeseed (Brassica napus L.) in response to water stress

Our aim was to determine whether the parameters of the hydrotime model can be used to compare the effects of seed priming treatments on germination. Seeds of three rapeseed cultivars (‘H61’, ‘H4815’, and ‘DK003’) were exposed to priming treatments and then their germination was tested at different water potentials. Seed priming improved the germination percentage, which was higher in ‘H4815’ than in the other two cultivars, and it increased germination rate (decreased θH) and uniformity (decreased σψb). The increase in germination rate was higher in PEG-osmoprimed than in NaCl-osmoprimed and hydroprimed seeds. The base water potential allowing 50% germination ([Formula: see text]) also was affected by seed priming, but the response of cultivars to different priming treatments varied. Compared with the control seeds, hydropriming of ‘H61’ seeds shifted ψb(50) toward negative values, whereas NaCl-osmopriming of ‘H4815’ seeds shifted ψb(50) toward negative values. On the other hand, priming of ‘DK003’ seeds shifted ψb(50) to more positive values and increased susceptibility to water stress. After dormancy-breaking and dormancy-induction treatments, ψb(50) shifted to more negative or positive values, indicating the release of primary dormancy and induction of dormancy, respectively. Therefore, priming treatments should be selected, depending on the environmental conditions anticipated to prevail during the germination of rapeseed seeds.

Population-based threshold models: A reliable tool for describing aged seeds response of rapeseed under salinity and water stress

Rapeseed (Brassica napus L.; Brassicaceae) is the second largest source of oilseed crop which is used for food and industrial applications globally. The production of this plant will be affected by climate change, increasing heat, salt and water stresses, in the future. Therefore, this study aimed to quantify the seed germination responses of two spring (‘Dalgan’ and ‘Hyola 50′) and one winter (‘Ahmadi’) rapeseed cultivars with a range of seed vigor (artificially aged at 42 °C) under water and salt stresses using hydrotime and halotime models, respectively. Germination time courses were recorded and seed germination characteristics were calculated. Seed moisture content and electrical conductivity were measured and also osmotic adjustment value associated with accumulation of salt ions was estimated. Rapeseed germination was negatively influenced by the accelerated aging period (AAP), water potential (ψ) and salinity (NaCl concentration) in all cultivars (P < 0.01). The hydrotime and halotime models accurately describe rapeseed germination at a range of ψs and NaCls at each AAP, with R2 values of 0.80–0.96. The estimated median threshold water potential (ψb(50)) and salinity (NaClb(50)) were −1.291, −1.170 and −1.104 MPa and 373.3, 326.7 and 304.4 mM for Ahmadi, Dalgan and Hyola 50 cultivars at AAP = 0, respectively. With increasing AAP, the ψb(50) increased (become more positive) and NaClb(50) decreased (linearly in both), reached zero at 130, 85.5 and 77.3 h AAP. The ψb(50) estimated by the hydrotime model was higher after converting the NaCl concentrations to ψ as salt ions absorbed by the seeds in response to salt stress (–1.707, –1.455, –1.361 MPa, respectively). The highest osmotic adjustment value observed in Ahmadi (∼21−54 %, depending on AAP) than those obtained in other cultivars, suggesting that the seed mass/size is an effective factor for improving seed germination of rapeseed under saline conditions (r ≥ 0.86, osmotic adjustment value vs. seed mass). However, this value decreased linearly with AAP in all cultivars, reflecting the cell membrane damage and loss of seed vigor. It was confirmed by the increasing conductivity values at higher AAP. In conclusion, the models used in this study were able to accurately predict the rapeseed germination behavior at different levels of water and saline conditions.

Effect of extruded grain feed, with the preliminary germination of rapeseed, on the cicatricial digestion of dairy cows and calves

This article describes the scientific and production experience conducted in the Druzhba LLC, of the Buinsky district of the Republic of Tatarstan. The purpose of the scientific and production experiment is to study the effect of extruded feed, with the preliminary germination of rapeseed in a 0.05 % nicotinic acid solution, on the cicatricial digestion of calves and dairy cows. During the experiment, it is found that feeding calves and dairy cows with extruded feed with preliminary germination of rapeseed in a 0.05 % nicotinic acid solution had a positive effect on cicatricial digestion, contributing to an increase in ammonia to 8.7 and 7.9 %, acetic acid – 12, 6 and 11.5 % and propionic – 13.4 and 12.6 % acids, with a decrease in butyric acid – 12.8 and 10.4 %, an increase in the total microbial number – 8 4.0 and 16.3 %, in including cellulolytic bacteria – 11.6 and 14.3 %, ciliates – 13.4 and 12.9 %, as well as the enzymatic activity of cicatricial microflora, respectively accordingly, in comparison with the control and the group where the grain feed is subjected to only one extrusion. Thus, the use of extruded feed with pre-germinated rapeseed in feeding calves and dairy cows improved the underlying indices of cicatricial digestion compared with the control group of animals fed with non-extruded feed and the group of animals fed with extruded feed.

Integrated pest management of flea beetles (Phyllotreta spp.) in spring oilseed rape (Brassica napus L.)

One of the most dangerous pests of rape is a complex of the undulating flea beetles that can do harm to the plants from the phase of sprouting and until the harvest ripening. According to our research, all six species of the undulating flea beetles are spread in the Eastern Forest–Steppe of Ukraine. The most numerous species are Phyllotreta atra F. (about 71%) and Phyllotreta nigripes F., the latter is less numerous (about 16%). The rest 4 species make up from 0.4 to 8.8% in the population structure. The damage of spring rape sprouts caused by the leaf beetles both against the background with the fertilizers (N30P30K30) and against the background without the fertilizers significantly affects a weight of 1000 seeds. Against the background without the fertilizers it is a little less and R²=0.875 while against the background with the fertilizers R²=0.9986. The yield capacity of spring rape both against the background with the fertilizers (N30P30K30) and against the background without the fertilizers depends on the degree of the sprouts damaged by the leaf–eating pests largely. It is a little higher against the background without the fertilizers and R²=0.9995 while against the background with the fertilizers R²=0.9911. The presowing toxicity of spring rapeseeds with the subsequent spraying of the crops in the phase of sprouting, namely the toxicity of two pairs of true leaves, provides a reduction in the density of the undulating flea beetles population 7.5–10.0 times below the level of the economic threshold of harmfulness. The best field germination of rape seeds both against the background without the fertilizers and against the background with the fertilizers is noted. The applied insecticide and fungicide seed treatment agents have a negative affect on the laboratory germination of spring rape seed material. The worst indices of germination were noted in the variants when applying Royal FLO, 48% of water and suspension concentrate in the dose 5.0 L/t and Royal FLO, 48% of water and suspension concentrate+Taboo, 50% of suspension concentrate in the dose of 5.0+6.0 L/t and on the 9th day these indices were 77.0% and 76.5% respectively.

Seed priming with melatonin coping drought stress in rapeseed by regulating reactive oxygen species detoxification: Antioxidant defense system, osmotic adjustment, stomatal traits and chloroplast ultrastructure perseveration

Water stress encumbers the rapeseed growth and development primarily by oxidative alteration to biological membranes and interrupted tissue water status. Seedling tolerance to water stress is vital for better crop development through the entire period under drought stress condition. The enhancement of plant stress tolerance due to melatonin application is already known; however, the specific underlying mechanisms are still not fully understood. The current study was done to investigate the effect of melatonin-priming on rapeseed germination and subsequent seedling growth under PEG-6000 simulated drought stress. Drought stress significantly inhibited germination and seedling growth, led to oxidative stress from excessive H2O2 generation, and reduced the chlorophyll content. Melatonin-priming alleviated the oxidative damage and the amount of chlorophyll reduction in rapeseed seedlings under the drought stress. The stomatal traits such as number, stomatal length and width were greatly improved in melatonin-primed treatment. Melatonin-priming also preserved the chloroplast structure, maintained cells expansion and strengthened the cell wall in response to drought stress. The results revealed that the ameliorative effects of melatonin-priming may be ascribed to enhancement of antioxidant enzymes activities, increase in the content of non-enzymatic antioxidants, and increase in the amounts of osmo-protectants. The present data suggest that priming seeds with melatonin can be a prime strategy regarding the development of crop drought resistant in crop production.

Germination response to phytotoxicity of Impatiens parviflora

Biochemical interactions in ecosystems have revealed the ecophysiological significance of secondary metabolites. Biochemical interaction underlies the novel weapons hypothesis thus presenting one of numerous explanations for the spread of invasive species. The knowledge of how invasive species spread in a new environment might be important for their management control. This study was aimed to determine the total phenolics content in Impatiens parviflora (I parv) and evaluate the germination response of monocot and dicot species to phytotoxicity. Wheat and rapeseed germination response to allelopathic activity of worldwide invasive Impatiens species (Balsaminaceae), namely, I. parviflora (native to Central Asia) was assessed ex situ at Aleksandras Stulginskis University in 2016. Phenolic content ranged between 0.32 and 5.53 mg g–1 in aqueous extracts of donor Impatiens. These allelopathic compounds are phytotoxic and usually reduce the growth of neighbouring plants. The data revealed their inhibition of germination and the seedling growth of both recipient species. However, the germination response was different for each recipient species due to different morphology of the seed coat. Inhibition of Impatiens extracts was recorded stronger for rapeseed (R) germination (mean 51.0%) than that for wheat (W) germination (mean 23.8%), possibly due to different seed coat anatomy and, consequently, its permeability. Therefore the strongest inhibition (93.0%) was recorded for rapeseed germination (4.5%) in 0.2% flower and fruit+seed extract of I. parviflora. Parameters of wheat seedlings also exhibited a weaker response to the extract of I. parviflora than that of rapeseed. The data revealed that Impatiens parviflora might negatively affect the regeneration of neighbouring native species in invaded habitats.

Associating transcriptional regulation for rapid germination of rapeseed (Brassica napus L.) under low temperature stress through weighted gene co-expression network analysis

Slow germination speed caused by low temperature stress intensifies the risk posed by adverse environmental factors, contributing to low germination rate and reduced production of rapeseed. The purpose of this study was to understand the transcriptional regulation mechanism for rapid germination of rapeseed. The results showed that seed components and size do not determine the seed germination speed. Different temporal transcriptomic profiles were generated under normal and low temperature conditions in genotypes with fast and slow germination speeds. Using weight gene co-expression network analysis, 37 823 genes were clustered into 15 modules with different expression patterns. There were 10 233 and 9111 differentially expressed genes found to follow persistent tendency of up- and down-regulation, respectively, which provided the conditions necessary for germination. Hub genes in the continuous up-regulation module were associated with phytohormone regulation, signal transduction, the pentose phosphate pathway, and lipolytic metabolism. Hub genes in the continuous down-regulation module were involved in ubiquitin-mediated proteolysis. Through pairwise comparisons, 1551 specific upregulated DEGs were identified for the fast germination speed genotype under low temperature stress. These DEGs were mainly enriched in RNA synthesis and degradation metabolisms, signal transduction, and defense systems. Transcription factors, including WRKY, bZIP, EFR, MYB, B3, DREB, NAC, and ERF, are associated with low temperature stress in the fast germination genotype. The aquaporin NIP5 and late embryogenesis abundant (LEA) protein genes contributed to the water uptake and transport under low temperature stress during seed germination. The ethylene/H2O2-mediated signal pathway plays an important role in cell wall loosening and embryo extension during germination. The ROS-scavenging system, including catalase, aldehyde dehydrogenase, and glutathione S-transferase, was also upregulated to alleviate ROS toxicity in the fast germinating genotype under low temperature stress. These findings should be useful for molecular assisted screening and breeding of fast germination speed genotypes for rapeseed.

Phytotoxicity and allelopathic impact of Impatiens glandulifera

The knowledge of how invasive species spread in a new environment might be important for their management control. Moreover, biochemical interaction underlies the novel weapon hypothesis thus presenting one of numerous explanations for species invasiveness. This study aimed to determine the total phenolics content in various parts of I. glandulifera and evaluate their phytotoxicity on the germination of monocot and dicot species. Phytotoxicity and allelopathic activity of worldwide invasive Impatiens species (Balsaminaceae) I. glandulifera (originated in the Himalayas) on wheat and rapeseed germination and seedling growth was assessed ex situ at Aleksandras Stulginskis University in 2016. The phenolic content ranged between 0.615 and 7.566 mg g–1 in Impatiens extracts, however, it significantly inhibited germination and seedling growth of the recipient species. Seed germination and seedling emergence are the outcomes of a sequence of biological events initiated by water imbibition followed by enzymatic metabolism of storage nutrients. The recorded germination rate was different for each recipient species. Inhibition of Impatiens extracts was recorded stronger for rapeseed germination (11.5– 81%) than that for wheat germination (71–86.5%), possibly due to different seed coat anatomy and thus its permeability. Therefore the strongest inhibition (86.5%) was recorded for rapeseed germination (11.5%) in 0.2% fruit + seed extract of I. glandulifera. Mean length of wheat hypocotyl (14.2 mm) and radicle (4.4 mm) exhibited a weaker response to the extract of I. glandulifera than rapeseed (4.4 mm and 1.4 mm, respectively). Consequently, recruitment and regeneration of native species might be negatively affected by the invasive Impatiens species in invaded habitats.

Influence of pre-sowing UV-radiation on the energy of germination capacity and germination ability of rapeseed

The object of research is the rapeseed, which is the first among oilseeds by the volume of sowing. One of the most problematic places of the agricultural complex is an increase in the quantity and quality of the seed material. To solve this problem, scientists and agricultural specialists use various methods, preferring optical radiation – pre-sowing UV-seed treatment. Selection of treatment regimes requires detailed studies and a differentiated approach for each crop separately.In the work pre-sowing influence of ultraviolet UV-irradiation of rapeseeds on biological processes (germination energy, germination and growth) is investigated. 20 W low-pressure ultraviolet lamps of the type ZW20D15W (China) emitting in the C region are used. The radiation dose is measured according to standard methods using a Tenzor-31 radiometer (Ukraine).Samples of rapeseeds, in addition to control, are irradiated with ultraviolet radiation in the C region with doses of 10 J/m2, 20 J/m2, 50 J/m2, 80 J/m2, 100 J/m2, 120 J/m2and 200 J/m2. Irradiated and control samples of seeds are germinated in Petri dishes at an air temperature of 24±2 ° C. The number of seedlings is counted after 3 days – the germination energy, and after 7 days – germination ability.Due to the use of UV irradiation at doses of 80-120 J/m2, the following results are obtained in comparison with the control sample: the germination energy of rapeseeds is increased by 20-26 %; germination ability increases by 16%. At the same time, the average biomass of plants from irradiated seeds increases by 18.3 % in comparison with the control samples for 10 days of growth.In field studies, the germination of rapeseeds after irradiation with a UV-C dose of 120 J/m2 compared to the control sample increased by 16% and becomes 89 %.

Produced water reuse for irrigation of non-food biofuel crops: Effects on switchgrass and rapeseed germination, physiology and biomass yield

High volumes of flowback and produced water are generated everyday as a byproduct of hydraulic fracturing operations and shale gas developments across the United States. Since most shale gas developments are located in semi-arid to arid U.S. regions close to agricultural production, there are many opportunities for reusing these waters as potential alternatives or supplements to fresh water resources for irrigation activities. However, the impacts of high salinity and total organic content of these types of water on crop physiological parameters and plant growth needs to be investigated to determine their utility and feasibility. The aim of the present study was to evaluate the response of switchgrass and rapeseed to treated produced water as an irrigation water source. In this greenhouse study, the influence of produced water at four total organic carbon (TOC) concentrations [1.22, 38.3, 232.2 and 1352.4mg/l] and three total dissolved solids (TDS) levels [400,3,500, and 21,000mg/l] on rapeseed (Brassica napus L.) and switchgrass (Panicum virgatum L.), two relatively salt-tolerant, non-food, biofuel crops, was studied. Seedling emergence, biomass yield, plant height, leaf electrolyte leakage, and plant uptake were evaluated. Irrigation water with the highest salinity and TOC concentration resulted in significantly lower growth health and physiological characteristics of both crop species. The organic content of the produced water had a negative impact on biomass yield and physiological parameters of both species. The results of this study could be valuable for regulators and stakeholders in development of treatment standards in which organic matter should be removed to less than 50mg/l to keep leaf EL (cell damage) to less than 50% and a TOC concentration of less than 5mg/l required to keep a sustainable biomass production rate.

Influence of hydroxyurea on the course of germination and growth of rape (Brasica napus L.) seedlings

The effects of continuous incubation in hydroxyurea (HU) solutions (0.2, 0.4, 0.8 mg/ml) on germination of rape seeds and growth of young seedling axes were studied during 132 hours from initial soaking. Germination turned out to be unaffected by the treatment. Root growth was first increasingly inhibited by the HU concentration tested, but after prolonged incubation a complete arrest of the root growth was noted at all HU concentrations. The elongation growth of hypocotyls was found to be stimulated by a HU 0.2 mg/ml concentration while it was markedly suppressed by 0.4 mg/ml, and completely arrested by 0.8 mg/ml Inhibition of growth of the upright hypocotyl part at higher HU concentration was found to be accompanied by the unbending of the hooked under-cotyledonary part. It is suggested that inhibition of nuclear endomitotic DNA synthesis In elongating hypocotyl cells, suppresses only partially their growth, whereas a complete inhibition of the hypocotyl growth results from arrest of the mitochondrial DNA synthesis.

Cluster analysis for different rapeseed varieties on seed germination and seedling growth under low temperature stress

In this study, the authors systematically evaluated the effect of low temperature stress on the germination of rapeseeds for 39 oilseed rape (Brassica napus L.) varieties. The results indicated a significant variation in the low temperature resistance of the seeds for different rape varieties. Using clustering method, various varieties were divided into different types, among which Huayouza No. 13, Fengyou 5103, Huayouza 95, Huayouza 62 and Fengyou 701 germinated well at low temperatures, while Zhongshuang No. 8 and Zhongshuang No. 11 showed poor germination. Correlation analysis was performed for 18 indices of seed germination, of which any two of germination percentage (GP), emergence percentage (EP), germination index (GI) and seedling vigour index (SVI) had high significant positive correlation, and they were all high significantly negatively correlated to the mean germination time (MGT). The GP was significantly negatively correlated with dry weight (DW). The MGT also showed a negative correlation with the root length (RL) and the total length (TL). The MGT had a statistically significant positive correlation with DW, and a negative correlation with shoot length (SL). Both the GI and SVI were significantly negatively correlated with DW. No correlation was observed between root to shoot length ratio (RL/SL) and any other index.

Research on the Effect of Rape Seed Germination Based on Environment Friendly Seed Coating Mixing Different Potassium Fertilizers

Studying on the effect of different potassium fertilizers (KCl, KNO3, KH2PO4, K2SO4) based on pre-development environment friendly seed coating, which using chitosan as the main material. The results indicated that: 1) the best ratios of 4 potassium fertilizers in environment friendly seed coating , which was KCl, KNO3, KH2PO4, K2SO4, were from 0.025% to 0.05%, from 0.025% to 0.05%, from 0.025% to 0.075%, 0.025% respectively. And the high-to-low effect of coating rape seeds, based on environment friendly seed coating mixed different potassium fertilizers, was KNO3 &gt; KH2PO4 &gt; K2SO4 &gt; KCl; 2) when mixed with environment friendly seed coating and used to coat rape seed, the synergistic effect between K and N in KNO3 was better than K and P in KH2PO4, and the above-mentioned two synergistic effects were better than K and S in K2SO4; 3) when the percent range of total weight of three elements (N, P, K) in environment friendly seed coating from 0.01% to 0.03%, the effect of rape seed germination was improved remarkable.

Effects of Plant Residue, Root Exudate and Juvenile Plants of Rapeseed (Brassica napus L.) on the Germination, Growth, Yield, and Quality of Subsequent Crops in Successive and Rotational Cropping Systems

Double-low rapeseed cultivars that produce no erucic acid and have only a small amount of glucosinolates are widely used. However, the roots in mature plant residue and leaves and roots of these seedlings still contain a large amount of biologically active glucosinolates, and it is important to clarify the effect of rapeseed cultivation on the subsequent crops. We analyzed the biological activities of the tissues of double-low cultivar at harvest. The laboratory bioassays revealed that the seeds and roots of mature rapeseed plants contained some autotoxic components that were volatile and water-soluble. We also analyzed the effects of root exudates from growing rapeseed plants on rapeseed germination and growth using the stair-step method and found that the root exudates were autotoxic. In the field, we investigated the allelopathic effects of rapeseed plants on the growth, yield, and quality of the subsequent sunflower plant in the same field. The growth, yield and thousand kernel weight of sunflower were reduced by the preceding cultivation of rapeseed. There were many spontaneously germinated juvenile rapeseed plants in the sunflower field preceded by rapeseed cultivation. Analysis of the plant and soil nitrogen (N) indicated that the growth reduction of sunflower was not caused by the competition for N with the spontaneously germinated juvenile rapeseed plants. The main factors responsible for poor sunflower growth under field after the cultivation of rapeseed were suggested to be some non-volatile, water-soluble components produced by the roots of the spontaneously germinated juvenile rapeseed.

Expression Patterns of PR proteins with Different Extract Methods during Germination of Rape Seed (Brassica napus L.)

This study was conducted to investigate the expression patterns of pathogenesis-related proteins (chitinase, β-1,3-glucanase and peroxidase) using activity staining of native-polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate (SDS)-PAGE during germination of rape seed (Brassica napus L. cv. Saturnin). The crude enzymes were extracted by distilled water (DW, pH 6.0) and 100 mM K-PO4 buffer (pH 7.0). The expression patterns of chitinase isozymes changed clearly on 10% native-PAGE gel with DW and K-PO4 buffer extract and on 12% SDS-PAGE gel with K-PO4 buffer extract, except for 12% SDS-PAGE conducted using DW during germination. The active bands of the chitinase isozymes were observed as four major bands (ch1, ch2, 86, and 78 kDa) and three minor bands (71, 60, and 54 kDa) on 10% native-PAGE gel conducted using DW and K-PO4 buffer extract. The two active bands on the 12% (w/v) SDS-PAGE gel presented as 34 and 29 kDa with DW extract, whereas one active band of 34 kDa was observed when the K-PO4 buffer extract was used. Active bands of β-1,3-glucanase isozymes changed slightly on 10% native-PAGE gel with DW and K-PO4 buffer extract during germination. The active band of β-1,3-glucanase isozymes were shown to have a high molecular weight (G1 and G2) on native-PAGE gel with DW extract at 0, 1, 2, and 3 days after germination, but not at 4 and 5 days. One active band of β-1,3-glucanase presented as G1 in the K-PO4 buffer extract. Active staining of peroxidase was stronger earlier in the DW extract than K-PO4 buffer extract at 2 days. The active bands showed as P1 and P2 in both DW and K-PO4 buffer extract at 5 days after germination.

Isolation and Expression Analysis of a GDSL-like Lipase Gene from Brassica napus L.

As lipolytic enzymes, GDSL lipases play an important role in plant growth and development. In order to identify their functions and roles, the full-length cDNA of a GDSL lipase gene, designated BnLIP2, was isolated from Brassica napus L. BnLIP2 was 1,300 bp long, with 1,122 bp open reading frame (ORF) encoding 373 amino acid residues. Sequence analysis indicated that BnLIP2 belonged to GDSL family. Southern blot analysis indicated that BnLIP2 belonged to a small gene family in rapeseed genome. RT-PCR analysis revealed that BnLIP2 was a tissue-specific expressing gene during reproductive growth and strongly expressed during seed germination. BnLIP2 expression could not be detected until three days after germination, and it subsequently became stronger. The transcript of this gene was deficient in root of seedlings growing at different stages. When juvenile seedlings were treated by methyl jasmonate (MeJ), salicylic acid (SA) and naphthalene acetic acid (NAA), BnLIP2 expression could not be induced in root. Our study implicates that BnLIP2 probably plays an important role in rapeseed germination, morphogenesis, flowering, but independent of root growth and development.

The effect of germination process on the superoxide dismutase-like activity and thiamine, riboflavin and mineral contents of rapeseeds

Seeds of double low oilseed rape variety Mango ( Brassica napus, var. oleifera) were subjected to a 7-day germination at 25 °C and 95% moisture content in darkness in a conditioning cabinet. The effects of the germination process on the superoxide dismutase-like activity (SOD-like activity), thiamine (vitamin B 1) and riboflavin (vitamin B 2) and minerals, such as Ca, Mg, Cu, Fe and Mn, were studied. Correlations between individual mineral contents, vitamin B 1 and B 2 contents, and the ability of phosphate buffered saline (PBS) extracts from germinated rapeseed to scavenge superoxide anion radicals in vitro were also investigated. SOD-like activity showed a gradual increase after the second day of germination, reaching a maximum level on the sixth day, and remained almost constant up to the end of the germination period. During germination, thiamine underwent a progressive decrease up to the sixth day, reaching a constant level between the sixth and the seventh day. In contrast, riboflavin content increased throughout the germination period up to the fifth day, and after that a constant level was observed. Levels of Ca and Mg were almost constant up to the fourth day and after that an increase of these minerals was observed. Cu and Mn increased during the germination process, and retentions of 33% and 22%, respectively, were observed at the end of germination. Fe content dropped after 1 day of germination and from there onward it started to increase gradually and an 18% retention was observed in 7-day germinated seeds. Positive correlations between SOD-like activity and riboflavin ( r = 0.87), Cu ( r = 0.74) and Mn ( r = 0.87) were found during rapeseed germination.

Effects of sewage sludge compost application on crops and cropland in a 3-year field study

Composted sewage sludge can be applied to cropland to supply nutrients and improve soil physical properties. However, farmers are much concerned about heavy metal accumulation in cropland and heavy metal availability for crops. A 3-year field study was carried out in this study to investigate the effects of sewage sludge compost (SSC) application on the heavy metal accumulation in cropland soil, rapeseed germination and plumelet development, and yields of barley and Chinese cabbage, compared with conventional mineral fertilization. In addition, the availability of heavy metals for barley and Chinese cabbage was examined. Experimental results showed that SSC application produced little effects on rapeseed germination and stimulated the rape plumelet development at lower application rates (<150 ton ha −1). Heavy metals (Cu and Zn) were accumulated in the topsoil (0–20 cm), the barley grains and the cabbage leaves. The yields of barley and Chinese cabbage generated positive response to the SSC application. Addition of mineral N–P–K fertilizers into SSC could further increase the crop yield. Considering the heavy metals accumulation in cropland soil and their availability for crops, SSC should be applied to cropland at a limited application rate (<150 ton ha −1).

Rapid and efficient screening of phosphinothricin tolerant oilseed rape (Brassica napus) with a novel germination test

A novel screening test is described for the discrimination of transgenic phosphinothricin tolerant oilseed rape from non transgenic rape seedlings. The method is based on the germination of rape seeds on filter paper soaked with a 0.005% phosphinothricin solution. Under these conditions inhibition of seedling development by the herbicide can be observed after 10 days. The germination test gains an advantage over the routinely used herbicide spraying, because it is rapid, needs little space and allows efficient screening of huge numbers of seeds. The assay has been successfully applied to the screening of different transgenic and non transgenic rapeseed varieties/lines and has been compared to other methods such asBasta® spray test, drop test, ELISA-technique and PCR-amplification of the pat gene. This test allows on one hand large screening programmes to monitor the foreign gene in the environment and on the other quality control of seedlots before market introduction of herbicide tolerant oilseed rape.

Thin layer Drying Rate and Loss of Viability Modelling for Rapeseed (Canola)

For the drying process and safe storage of rapeseed, the experimental equilibrium moisture content and the thin layer drying curves for rapeseed (Brassica napus L.), variety Hyola-401, were determined; and the effect of drying air temperature and relative humidity on seed quality was evaluated. The equilibrium moisture content curves were obtained, both experimentally and by fitting the modified Henderson equation to the experimental data, using non-linear regression. The same procedure was used to fit the Page thin layer drying equation to the thin layer drying experimental data. The results showed that both, the modified Henderson and the Page equations describe adequately the variation of equilibrium moisture content and thin layer drying rates, respectively, as a function of drying air temperature and relative humidity. It was also observed that the drying air temperature and relative humidity affect significantly the vigour and germination of rapeseed, showing that the drying conditions is a crucial factor for maintaining the physiological quality of the seeds.