Oilseed Rape Plants Research Articles

Physiological mechanisms of enhancing salt tolerance of oilseed rape plants with brassinosteroids

The ability of brassinosteroids, such as 24-epibrassinolide (EBL) to increase the resistance of oilseed rape plants (Brassica napus L.) to salt stress (175 mM NaCl) was investigated along with the possible mechanisms of their protective action. Seedlings were grown for three weeks on the Hoagland-Snyder medium under controlled conditions. The experimental plants were treated with either (1) 175 mM NaCl, or (2) 10−10 M EBL, or (3) 175 mM NaCl plus 10−10 M EBL by adding the corresponding components to the growth medium. The exposure was 7 and 14 days. As compared to the control, salinization inhibited plant height by 33–35%, reduced leaf area by 2.0–2.5 times, reduced 2.5- and 2-fold plant fresh and dry weight, respectively, reduced water content of plant tissues by 26–31% and, twofold, the content of chlorophylls a and b. Plants responded to NaCl by developing oxidative stress conditions, lowering the osmotic potential of the cell contents down to −2 MPa, accumulating proline (by 43–52 times) and low-molecular-weight phenolics (by 1.9–2.7 times). Oilseed rape plants were shown to respond to salinization with an increase of endogenous content of steroid hormones: 24-epibrassinosteroids (24-epibrassinolide and 24-epicastasterone), 24S-methyl-brassinosteroids (brassinolide and castasterone), and 28-homobrassinosteroids (28-homobrassinolide and 28-homocastasterone); such evidence indirectly confirms the involvement of brassinosteroids in the development of salt tolerance. Adding EBL to the nutrient medium under optimal growth conditions did not significantly affect the indices under study. Under salt stress, EBL showed a pronounced protective effect: stem growth was fully restored, plant assimilation area increased by as much as 67–76% as compared to the control index, fresh and dry weight largely recovered (up to 85–92% of the control values), and the inhibitory effect of NaCl on photosynthetic pigments was diminished. Exogenous EBL impeded the development of NaCl-dependent lipid peroxidation and increased the osmotic potential of the leaf cell contents. The protective effect of EBL under salt stress was probably associated with EBL antioxidant effect, rather than the hormone-induced accumulation of proline and of low-molecula-weight phenolics, as well as with the ability to regulate water status by maintaining intracellular ion homeostasis.

Stimulatory Effects of Sublethal Doses of Dimethachlon on Sclerotinia sclerotiorum.

Growth and virulence stimulations of sublethal doses of fungicides on plant-pathogenic fungi and oomycetes have been reported and the stimulatory effects are potentially relevant to plant disease management. Sclerotinia sclerotiorum is one of the most devastating and economically important necrotrophic fungal phytopathogens, capable of infecting more than 400 species of plants worldwide. In order to study stimulatory effects of sublethal doses of fungicides on S. sclerotiorum, 55 dimethachlon-sensitive isolates and 3 dimethachlon-resistant isolates of S. sclerotiorum were assayed to determine effects of sublethal doses of dimethachlon on mycelial growth rate on potato dextrose agar (PDA) media and virulence on oilseed rape plants. Results showed that all 3 dimethachlon-resistant isolates and 13 of the 55 sensitive isolates exhibited stimulatory responses to sublethal doses of dimethachlon. Dimethachlon-resistant isolates grew significantly (P < 0.05) faster on PDA media amended with dimethachlon at 0.5 to 4 μg/ml than on fungicide-free PDA media. As for virulence on detached leaves of oilseed rape plants, lesion diameters of dimethachlon-resistant isolates after growth on PDA media amended with dimethachlon at 0.5 to 2 μg/ml were significantly larger (P < 0.05) than the control. The maximum stimulatory effects were 42.40 to 59.80%. In pot experiments, for both dimethachlon-sensitive and -resistant isolates, significant (P < 0.05) virulence stimulations were observed after spraying with dimethachlon at a concentration of 2 μg/ml. After growing on dimethachlon-amended PDA media, H2O2 sensitivity of S. sclerotiorum decreased significantly (P < 0.05) compared with the nonamended PDA control.

Outbreak Risk of Club Root Caused by Plasmodiophora brassicae on Oilseed Rape in Chile.

Oilseed rape (Brassica napus L.) plants with typical club root symptoms were detected on two farms in the La Araucanía region (37°35' to 39°37' S), southern Chile. In 2010, affected plants were found in large areas throughout three fields on a single farm and disease incidence ranged from 30 to 100%. In 2013, plants with club root were found in one field on a different farm. Disease incidence in the affected areas was 30%. In both cases, affected plants showed root swellings or distortions, but no aerial symptoms were evident. Cross-sections from symptomatic roots were observed under light and fluorescent microscope and compared to healthy roots. The presence of plasmodia with resting spores in the root tissue pointed to Plasmodiophora brassicae Woronin as the causal agent. Pathogenicity was evaluated in the greenhouse. Inoculum was prepared by grinding 10 g of fresh galled roots in sterile water. The macerated tissue was filtered through sterile cheesecloth and the spore suspensions were adjusted to 1 × 107 spores/ml. Seeds of oilseed rape cv. Imminent were germinated and 5-day-old seedlings were transplanted in 250-ml pots (4 seedlings per pot). The soil surrounding the base of each seedling was inoculated with 1 ml of spore suspension. One pot received no inoculum and was used as a control. Pots were watered regularly. After 45 days, the inoculated plants showed root swelling similar to that observed in the field, whereas no symptoms were observed on the roots of the control plants. Specific PCR detection for P. brassicae was performed with pairs of primers TC1F/TC1R and TC2F/TC2R, according to the protocol described by Cao et al. (1). Total DNA was obtained from old galled roots collected in the field and galled roots from plants of the pathogenicity test, using the E.Z.N.A HP Plant DNA mini kit (Omega Biotek). Amplicon sizes of 548 and 519 bp, respectively, were obtained for each primer set, which is consistent with that reported by Cao et al. (1). Seed contamination with P. brassicae in the same seed lot used to sow the commercial field of 2013 was evaluated using the PCR method described above. Washing protocols to collect resting spores from seed was based on Rennie et al. (2). Total DNA was extracted from the resting spores pellet that had been ground in liquid nitrogen, using E.Z.N.A HP Plant DNA mini kit. PCR was performed on undiluted and diluted (1/10, 1/100, 1/1000, and 1/10000) DNA. Total DNA from a plant with gall roots where plasmodia were observed and a plant with healthy roots were used as positive and negative control, respectively. A 548-bp amplicon was amplified in the 1/10 and 1/100 dilutions with the TC1F/TC1R primers only indicating that the pathogen may have been present in the seed lot. In Chile, club root symptoms on B. napus were described in 2008 (3), though no indication of location or incidence was given. To our knowledge, this is the first confirmed case of club root disease in an oilseed rape field. This finding could prelude new cases and possibly an outbreak of club root disease on oilseed rape, jeopardizing this important crop of southern Chile. Oilseed rape production in Chile relies on imported seed of hybrids and parental materials. Although seed contamination with P. brassicae is thought to play a minor role in the epidemiology of the disease, we cannot ignore the possibility that the occurrence of this disease in 2013 may have been associated with the use of contaminated seed.

Dimethachlon Resistance in Sclerotinia sclerotiorum in China.

The dicarboximide fungicide dimethachlon has been widely used for controlling Sclerotinia sclerotiorum in China for more than a decade. To assess the current status of dimethachlon resistance in S. sclerotiorum in China, 2,424 isolates were collected from disease-infected oilseed rape and soybean plants in five provinces of China in 2011 and 2012, and dimethachlon resistance was monitored by mycelial growth inhibition method on potato dextrose agar (PDA) media. Dimethachlon at 5 μg/ml was used as a discriminatory dose to detect resistance in all isolates, and 50% effective concentration values were determined for all dimethachlon-resistant isolates and some sensitive isolates. No dimethachlon resistance was detected in isolates from Anhui province (eastern China), Gansu province (northwestern China), and Qinghai province (western China). In Hunan province (central China), 3 of 268 (1.12%) isolates collected from oilseed rape plants in 2012 were resistant to dimethachlon, and the resistance ratios for the three resistant isolates were 4.56, 32.70, and 105.53, respectively. In Heilongjiang province (northeastern China), 8 of 243 (3.29%) isolates collected from soybean plants in 2011 were resistant to dimethachlon, with resistance ratios of 5.57 to 94.80; 11 of 409 (2.69%) isolates collected in 2012 were resistant to dimethachlon, with resistance ratios of 3.21 to 9.69. Cross-resistance studies showed that there was positive cross-resistance between dimethachlon and iprodione, procymidone, and the N-phenyl carbamate fungicide diethofencarb. No cross-resistance was found between dimethachlon and carbendazim, tebuconazole, kresoxim-methyl, thiram, and boscalid. Compared with the sensitive isolates of S. sclerotiorum, the field-dimethachlon-resistant isolates were more sensitive to osmotic pressure, grew more slowly on PDA media, and were less pathogenic on leaves of oilseed rape.

Detection of self-incompatible oilseed rape plants (Brassica napus L.) based on molecular markers for identification of the class I S haplotype.

The selection of desirable genotypes with recessive characteristics, such as self-incompatible plants, is often difficult or even impossible and represents a crucial barrier in accelerating the breeding process. Molecular approaches and selection based on molecular markers can allow breeders to overcome this limitation. The use of self-incompatibility is an alternative in hybrid breeding of oilseed rape. Unfortunately, stable self-incompatibility is recessive and phenotype-based selection is very difficult and time-consuming. The development of reliable molecular markers for detecting desirable plants with functional self-incompatible genes is of great importance for breeders and allows selection at early stages of plant growth. Because most of these reliable molecular markers are based on discrimination of class I S-locus genes that are present in self-compatible plants, there is a need to use an internal control in order to detect possible PCR inhibition that gives false results during genotyping. In this study, 269 double haploid F2 oilseed rape plants obtained by microspore embryogenesis were used to verify the applicability of an improved PCR assay based on the detection of the class I SLG gene along with an internal control. Comparative analysis of the PCR genotyping results vs. S phenotype analysis confirmed the applicability of this molecular approach in hybrid breeding programs. This approach allows accurate detection of self-incompatible plants via a different amplification profile.

Impact of fresh root material and mature crop residues of oilseed rape (Brassica napus) on microbial communities associated with subsequent oilseed rape

Glasshouse bioassays were conducted to assess the impact of different inputs of oilseed rape plant material on soil and rhizosphere microbial diversity associated with subsequently grown oilseed rape (Brassica napus) plants. The first bioassay focussed on the effect of oilseed rape rhizodeposits and fresh detached root material on microbial communities, in a rapid-cycling experiment in which oilseed rape plants were grown successively in pots of field soil for 4 weeks at a time, with six cycles of repeated vegetative planting in the same pot. Molecular analyses of the microbial communities after each cycle showed that the obligate parasite Olpidium brassicae infected the roots of oilseed rape within 4 weeks after the first planting (irrespective of the influence of rhizodeposits alone or in the presence of fresh detached root material), and consistently dominated the rhizosphere fungal community, ranging in relative abundance from 43 to 88 % when oilseed rape was grown more than once in the same soil. Fresh detached root material also led to a reduction in diversity within the soil fungal community, due to the increased relative abundance of O. brassicae. In addition, rhizosphere bacterial communities were found to have a reduced diversity over time when fresh root material was retained in the soil. In the second glasshouse experiment, the effect of incorporating mature, field-derived oilseed rape crop residues (shoots and root material) on microbial communities associated with subsequently grown oilseed rape was investigated. As before, molecular analyses revealed that O. brassicae dominated the rhizosphere fungal community, despite not being prevalent in either the residue material or soil fungal communities.

Multilocus sequence analysis of 'Candidatus Phytoplasma asteris' strain and the genome analysis of Turnip mosaic virus co-infecting oilseed rape.

Molecular characterization of a pathogenic complex infecting winter oilseed rape (Brassica napus ssp. oleifera (DC.) Metzg.) plants showing typical rape phyllody symptoms along with some atypical changes. Phytoplasma ('Candidatus Phytoplasma') presence was confirmed by PCR-RFLP and 16S rRNA gene sequencing. Phylogenetic analyses of phytoplasma amp, tufB, secY, groEL and ribosomal protein genes confirmed its affiliation to the 'Ca. P. asteris' species. However, in the amp gene encoding a specific protein crucial for insect transmission specificity, significant SNPs were found. Biological and serological tests revealed the co-infection with Turnip mosaic virus (TuMV). The phylogenetic analysis of full TuMV genome sequence, the first reported from the Balkans, classified it into the world-B phylogenetic lineage. A pathogenic complex consisting of 'Ca. P. asteris' and TuMV found to co-infect oilseed rape plants for the first time was molecularly characterized. Rape phyllody is a serious problem in rapeseed production. The molecular information from this first multi-gene analysis of 'Ca. P. asteris' strain associated with rape phyllody as well as the first report of the complete sequence of TuMV isolate from the Balkans is a starting point for understanding the disease complexity and management.

Impact of plant density on the canopy area index and weed infestation depending on different cultivars of winter oilseed rape (Brassica napus L., ssp. oleifera Metzg.)

One way to increase the competitiveness of crop plants against weed infestation is to adjust crop density. Introduction of new (“semi-dwarf”) cultivars of winter oilseed rape triggers a need for research in this field. A two-factor experiment evaluated the effect of plant density and winter oilseed rape (WOSR) cultivars on the canopy architecture and weed infestation of a WOSR crop as well as on the correlation between these traits. During the 2010–2012 study period, the average plant density was 38.0; 29.4; and 22.9 plants m-2 (three row spacings were used: 33, 44, and 55 cm). The oilseed rape cultivars were as follows: conventional, hybrid and “semi-dwarf” hybrid. Experimental factors did not cause significant differences in the number of weeds and their mass. However, there was a clear trend of decreasing total number of weeds in the span of 33 cm spacing than in the 44 and 55 cm. Hybrid cultivar resulted in increasing of total number of weeds in comparison to the conventional one. The differences in the assimilation area of WOSR plants per unit of ground area were significant between row spacings until the end of the flowering stage and between cultivars until the flower bud development stage. During the growth stages from the beginning of flowering until the end of pod development significant negative correlations were found between the assimilation area and the number of weeds, while the correlations between the assimilation area and the weed weight were insignificant. Insignificant correlations also occurred between the number of oilseed rape plants per unit area and the mass of weeds. The results indicate the possibility of reducing the demand for seed sowing, without requiring additional costs for weed control.&#x0D;

Potential for longevity of novel genetically modified herbicide-tolerant traits in the Irish landscape

With the renewed interest in genetically modified crop technology in Ireland, some concern has been raised in relation to the potential impact on biodiversity in the Irish agri-environment. This concern can focus on the potential for a transgenic trait to cross to wild relatives. A novel trait will be judged to have persisted in a wild population via the successful production of seeds, such that these seeds are viable and result in the establishment of a self-sustaining population. In the case of an herbicide-tolerant (HT) trait, feral and volunteer populations can only remain viable if managed with applications of the herbicide that the trait is designed to resist. This surviving population of HT plants would then need to compete successfully with other wild plants in order to prevail in the landscape and persist over time. There are few agricultural crops that can manage this combination, but as oilseed rape plants are often noted along roadsides and hedgerows in Ireland; it is correct to assume that this crop has the ability to be a successful feral survivor. This paper presents the results of a thought experiment, derived exclusively using the academic literature, on the issue of longevity. This is done by taking four hypothetical case scenarios and examining the potential for a combination of events to take place for oilseed rape (Brassica napus); this is selected here because it has a high potential for ‘escaping’ via pollen- and/or seedmediated gene flow. A lack of quantitative data on Irish farmland biodiversity hinders solid conclusions, but when management pressure is eased, biodiversity stress is lessened.

New oilseed rape (Brassica napus L.) varieties – canopy development, yield components, and plant density

Full exploitation of the potential of new varieties requires research, whose aim is to adapt the technology to their needs. A two-factor experiment evaluated the effect of row spacing (33, 44, and 55 cm) of three oilseed rape (OSR) varieties (conventional, hybrid, and “semi-dwarf” hybrid variety) on canopy area index (CAI) and yield components. At higher row spacing, OSR plants were characterized by a strong increase in the CAI at successive growth stages; thereby, the incomplete use of production area was compensated at the pod development stage. The differences in the CAI between row spacings were significant until the end of flowering, whereas differences in the CAI between varieties were significant until the flower bud development stage. In the next development phases, CAI of OSR plants was at a similar level to all plots. However, the statistical analysis showed a declining trend in seed yield and yield biomass (pods and straw weight) with increasing row spacing. A positive aspect of increased row spacing was a decrease in glucosinolates content in seeds. The differences in fat content were statistically insignificant. The hybrid varieties of OSR produced the highest seed yield at a row spacing of 33 cm, while the conventional – at a row spacing of 44 cm. These relationships are confirmed by high positive correlations of seed weight and pod weight per unit area with CAI. The results have important practical aspect, because it shows that it is possible to reduce the number of OSR plants per unit area, thereby reducing demand for expensive certified seeds for sowing but to certain limits. Too small plant density binds to the risk of decreased seed yield. It may be justified, e.g., in extensive or organic farming where wide row creates the possibility of mechanical weed control.

Pollinator sharing between mass-flowering oilseed rape and co-flowering wild plants: implications for wild plant pollination

Pollinating insects are not only important in wild plant pollination, but also in the production of a large number of crops. Oilseed rape production is increasing globally due to demands for biofuels which may have impacts on pollinating insects which visit the crop and on the pollination services delivered to co-flowering wild plants. In this study, we tested (1) the degree of pollinator sharing between oilseed rape and native wild plants in field margins and hedgerows and (2) the effects of oilseed rape on the quality of pollination service delivered to these wild plants. We found large overlap between flower visitors of wild plants and oilseed rape, but the composition of species overlap differed with respect to each wild plant species. Nearly all individual visitors caught on both the crop and foraging on wild species carried crop pollen, but more than half the insects also carried pollen from wild plants. However, very little oilseed rape pollen was deposited on wild plant stigmas. This shows that (1) oilseed rape overlaps in pollinator niche with most co-flowering wild plants, and (2) crop pollen deposition on wild plant stigmas is low which may indicate that it is unlikely to cause reductions in seed set of wild plants, although this was not measured here. Furthermore, wild plants in field margins and hedgerows are important sources of alternative forage for pollinating insects even when a crop is mass flowering, and we suggest maintenance and augmentation of field margins and hedgerows to provide alternative forage for pollinator conservation to continue provision of pollination services to both crops and wild plants.

The possibility of spreading Leptosphaeria maculans and Leptosphaeria biglobosa by rapeseed seed

Stem canker (blackleg) is economically the most important disease of oilseed rape world­wide. This disease is caused by two species of pathogenic fungi of the genus Leptosphaeria: Leptosphaeria maculans (Desm.) ces. and de Not anamorf Phoma lingam (Tode. Fr.) Desmas, that causes stem canker and blackleg root and Leptospaeria biglobosa Shoem and Brun, that causes symptoms such as cancers of the upper part of the stem usually causing less damage, and can cause serious damage in countries with higher summer temperatures. Pathogenic fungi from one area to another are transmitted by ascospores and contaminated (infected) seed. In order to prove the modes of transmission of parasites, the test is done transmitting the parasite by seeds. Disinfected seeds of oilseed rape cultivars Quinta were submerged in the suspension of pycnospores. Submerged seeds were kept at 20 º C ± 1 º C and 12 h photoperiod for 48 h. After planting in plastic containers seeds were kept at 25 º C ± 1 º C and 12h photoperiod. In this experiment the following isolates were used: C-5, L-5, K-7, LJ-3, S-11, St-1, GS-3 and Lm as a reference isolate (L. maculans) fol­lowed by K-113, K-115 and Lb as a reference isolate (L. biglobosa). The symptoms were as­sessed after 7 and 14 days after emergence. Ratings were made with + which meant visible symptoms on cotyledons or hypocotyl and - what referred to healthy plants. After 7 days, the isolates (Lm, C-5, L-5, K-7, LJ-3, S-11, St-1, GS-3) were caused disease symptoms on plants of oilseed rape. This pathogenicity is reflected in the number of seedlings, leaf spots and stalk lodging cotyledons. At izolate Lb (reference isolate L. biglobosa) K-113 and K-115 after 7 and 14 days was not observed pathogenicity on rapeseed plants. The control variety seeds were soaked in distilled water. The trial was set in 6 reps, and pathogenicity of fungal isolates in relation to the control was tested using Dunette's test. After 14 days re-isolation of pathogen was done.

Loop-mediated isothermal amplification as a good tool to study changing Leptosphaeria populations in oilseed rape plants and air samples

LAMP is an innovative, simple, rapid, specific and cost-effective nucleic acid amplification method. Due to the use of a special enzyme – GspSSD polymerase, the reaction takes a short time and can be performed at isothermal conditions. The sensitivity and specificity of LAMP technique is significantly higher, than standard PCR techniques, as two or three specific primer pairs are used. The technique is regarded as a useful tool for the detection and identification of plant pathogens. In this work, LAMP was used to study the composition of the population of fungi of the genus &lt;em&gt;Leptosphaeria&lt;/em&gt;, causing a damaging disease of oilseed rape, called blackleg or stem canker. The detection concerned DNA present in fungal spores contained in air samples obtained using Hirst-type volumetric trap, in Pomerania (north Poland) in 2010. The results achieved using the LAMP technique were similar to these obtained with previously used, highly specific method of Real-time PCR. Conducting LAMP reaction was much easier and less time-and cost-consuming, due to a simplified method of DNA isolation of pathogens from plant tissues. Then, the LAMP technique was used to assess the composition of the population of &lt;em&gt;Leptosphaeria &lt;/em&gt;spp. in plants of oil- seed rape collected from the field in the Opole region (south-we- stern part of Poland) in 2013. In contrast to studies conducted in 2002–2003, the analysis of leaf symptoms showed a higher pro- portion of &lt;em&gt;L. maculans &lt;/em&gt;compared to &lt;em&gt;L. biglobosa&lt;/em&gt;, what reflects changes in the composition of pathogen population of fungi causing blackleg on oilseed rape in this part of Poland.

Cytoplasmic male sterility and inter and intra subgenomic heterosis studies in Brassica species: A review

Plants of the genus Brassica comprise a remarkably diverse group of crops and encompass varieties that are grown as oilseeds, vegetables, condiment mustards and forages. One of the basic requirements for developing hybrid varieties in oilseed Brassica is the availability of proven heterosis. The development of hybrid cultivars has been successful in many Brassica spp. Midparent heterosis and high-parent heterosis (heterobeltiosis) have extensively been explored and utilized for boosting various quantity and quality traits in rapeseed. Heterosis is commercially exploited in rapeseed and its potential use has been demonstrated in turnip rape (B. rapa L.) and Indian mustard (B. juncea L.) for seed yield and most of the agronomic traits. The oilseed rape plant, B. napus, possesses two endogenous male sterile cytoplasms, nap and pol. Ogura type of cytoplasmic male sterility was first discovered in Japanese wild radish and other male-sterile Brassicas (Ogura bearing cytoplasm) derived from interspecific crosses. Information concerning the allelic frequencies of restorers can be useful in trying to understand their evolutionary origins. The ogu, pol and nap cytoplasms of B. napus induce sterility in all, some, and only a few cultivars, respectively. In this study, different kinds of male sterility, combining ability and heterosis of qualitative and quantitative traits in different Brassica species will be revi?wed.

The effect of water and salt stresses on the phosphorus content and acid phosphatase activity in oilseed rape

Oilseed rape plants responded to water and salt stresses (-0.5 MPa, PEG 6000 and NaCI) by reduction of the fresh and dry weights of shoots and roots. When PEG was used, the ratio of dry weights of roots:shoots surpassed that of controls. The leaf protein content increased considerably. The phosphorus content decreased only in the roots, most significantly after three days of stress. Immediately after the stresses were induced, an increase in the acid phosphatase (AP) activity was noted. Water and salt stresses caused four- and two-fold increases in AP activity in leaves, respectively. Changes in the enzyme activity were negligible in stems and roots. There are nine forms of AP in young leaves of oilseed rape. In the stressed plants, from No. 5 revealed lower activity and forms Nos 8 and 9, higher activities than in the control. The increase in AP activity was directly accompanied by the decrease in the water potential of the tissues. Oilseed rape is considerably less sensitive to salt stress than to water stress, which is manifested as the lower inhibition of plant growth and also by a smaller increase in acid phosphatase activity.

Morphometric Parameters and Biochemical Status of Oilseed Rape Exposed to Fine-Dispersed Metallurgical Sludge, PHMB-Stabilized Silver Nanoparticles and Multi-Wall Carbon Nanotubes

Thepaper Presents Biological Properties of Threefine-Dispersed Materials, Namely Metallurgical Sludge, Colloidal Silver Andmulti-Wall Carbon Nanotubes (MWCNT) Exposing Oilseed Rape Plants. the Stimulationof Plant’s Growth by Silver Nanoparticles and the Intensification of Plantpigments Synthesis by MWCNT have been Experimentally Demonstrated. A Small Decreasein Energy and Germination Capacity were Noticed Whereby Colloidal Silver Hadthe Lowest Suppressive Effect, MWCN Tubes had the Highest Effect, and Sludge Wasfound in between Two above-Mentioned Materials. According to the Research, the Usageof Sludge is the most Effective at the Concentration of 10 and 100 g/l,colloidal Silver – 10 g/l and 300 g/l, MWCNT – 0,001 g/l and 1 g/l.

바이오에너지 개발용 스위치그라스의 조직배양 및 형질전환 최근 연구동향

Over the past decades, carbon dioxide concentration of the atmosphere of the world has increased significantly, and thereby the greenhouse effect has become a social issue. To solve this problem, new renewable energy sources including solar, hydrogen, geothermal, wind and bio-energy are suggested as alternatives. Among these new energy sources, bio-energy crops are widely introduced and under rapid progress. For example, corn and oilseed rape plants are used for the production of bio-ethanol and bio-diesel, respectively. However, grain prices has increased severely because of the use of corn for bio-ethanol production. Therefore, non-edible switchgrass draws attention as an alternative source for bio-ethanol production in USA. This review describes the shortage of fossil energy and an importance of switchgrass as a bio-energy crop. Also, some characteristics of its major cultivars are introduced including growth habit, total output of biomass yields. Furthermore, biotechnological approaches have been conducted to improve the productivity of switchgrass using tissue culture and genetic transformation.

QuEChERS and solid phase extraction methods for the determination of energy crop pesticides in soil, plant and runoff water matrices

QuEChERS and solid phase extraction (SPE) methods were applied for determining four herbicides (metazachlor, oxyfluorfen, quizalofop-p-ethyl, quinmerac) and one insecticide (α(±)-cypermethrin) in runoff water, soil, sunflower and oilseed rape plant matrices. Determination was performed using gas chromatography mass spectrometry (GC-MS), whereas high-pressure liquid chromatography mass spectrometry (HPLC-MS) was used for quinmerac. In all substrates linearity was evaluated using matrix-matched calibration samples at five concentration levels (50–1000 ng L−1 for water, 5–500 μg kg−1 for soil and 2.5–500 μg kg−1 for sunflower or oilseed rape plant). Correlation coefficient was higher than 0.992 for all pesticides in all substrates. Acceptable mean recovery values were obtained for all pesticides in water (65.4–108.8%), soil (70.0–110.0%) and plant (66.1–118.6%), with intra- and inter-day RSD% below 20%. LODs were in the range of 0.250–26.6 ng L−1 for water, 0.10–1.8 μg kg−1 for soil and 0.15–2.0 μg kg−1 for plants. The methods can be efficiently applied for field dissipation studies of the pesticides in energy crop cultivations.

The Cpc1 Regulator of the Cross-Pathway Control of Amino Acid Biosynthesis Is Required for Pathogenicity of the Vascular Pathogen Verticillium longisporum

The plant-pathogenic fungus Verticillium longisporum is a causal agent of early senescence and ripening in cruciferous crops like Brassica napus. Verticillium wilts have become serious agricultural threats in recent decades. Verticillium species infect host plants through the roots and colonize xylem vessels of the host plant. The xylem fluid provides an environment with limited carbon sources and unbalanced amino acid supply, which requires V. longisporum to induce the cross-pathway control of amino acid biosynthesis. RNA-mediated gene silencing reduced the expression of the two CPC1 isogenes (VlCPC1-1 and VlCPC1-2) of the allodiploid V. longisporum up to 85%. VlCPC1 encodes the conserved transcription factor of the cross-pathway control. The silenced mutants were highly sensitive to amino-acid starvation, and the infected plants showed significantly fewer symptoms such as stunting or early senescence in oilseed rape plant infection assays. Consistently, deletion of single CPC1 of the haploid V. dahliae resulted in strains that are sensitive to amino-acid starvation and cause strongly reduced symptoms in the plant-host tomato (Solanum lycopersicum). The allodiploid V. longisporum and the haploid V. dahliae are the first phytopathogenic fungi that were shown to require CPC1 for infection and colonization of their respective host plants, oilseed rape and tomato.

Geny awirulencji i typy kojarzeniowe w populacjach Leptosphaeria maculans zebranych z porażonych roślin rzepaku w Polsce jesienią 2010 roku

The fungi Leptosphaeria maculans and L. biglobosa cause stem canker – one of the most damaging diseases of oilseed rape in Poland and worldwide. The aim of this study was to characterize the composition of avirulence genes and mating types present in current populations of L. maculans in Poland. The study was done in autumn 2010. The isolates of L. maculans (254) were obtained from infected winter rapeseed leaves collected at six locations. DNA (deoxyribonucleic acid) of each isolate was extracted using a CTAB (cetyltrimethyl ammonium bromide) method. The taxonomic identity of isolates was checked by RAPD (random amplification of polymorphic DNA) using OPJ-10 primer and compared with specific banding patterns characteristic for the representatives of L. maculans and L. biglobosa. Isolates of L. maculans were studied to identify a mating type and avirulence alleles AvrLm1 and AvrLm6. Mating types MAT1.1 and MAT1.2 were found in similar frequencies at all sites, what suggests that both types are well adapted to environment. The AvrLm1 avirulence allele was observed only in isolates obtained at one collection site. For the first time in Poland the avrLm6 virulence allele has been found. Grzyby Leptosphaeria maculans i L. biglobosa powodują suchą zgniliznę kapustnych – jedną z najgroźniejszych chorób rzepaku w Polsce i na świecie. Celem tych badań było określenie składu genów awirulencji i typów kojarzeniowych w populacjach L. maculans aktualnie występujących w Polsce. Badania prowadzono jesienią 2010 roku. Z porażonych liści rzepaku ozimego pobranych w sześciu miejscach uzyskano 254 izolaty L. maculans. DNA (deoxyribonucleic acid – kwas deoksyrybonukleinowy) izolatów ekstrahowano przy zastosowaniu metody CTAB (cetyltrimethyl ammonium bromide – bromek heksadecylotrimetyloamoniowy). Przynależność taksonomiczną sprawdzano przy zastosowaniu metody RAPD (random amplification of polymorphic DNA – metoda losowej amplifikacji polimorficznych fragmentów DNA) z użyciem startera OPJ-10 i porównywano z wzorem produktów PCR (polymerase chain reaction – reakcja łańcuchowa polimerazy), charakterystycznych dla izolatów wzorcowych dla L. maculans i L. biglobosa. Izolaty L. maculans oznaczano pod względem przynależności do typu kojarzeniowego i określano ich allele awirulencji AvrLm1 i AvrLm6. Typy kojarzeniowe MAT1.1 i MAT1.2 występowały w podobnych proporcjach we wszystkich populacjach, co sugeruje, że oba są dobrze przystosowane do środowiska. Allel awirulencji AvrLm1 obserwowano tylko u izolatów zebranych w jednej lokalizacji. Po raz pierwszy w Polsce stwierdzono allel wirulencji avrLm6.