Thlaspi Arvense Research Articles

Extraction, Composition and Functional Properties of Pennycress (Thlaspi arvense L.) Press Cake Protein

AbstractThis study compared two methods for extracting the protein in pennycress (Thlaspi arvense L.) press cake and determined the composition and functional properties of the protein products. Proteins in pennycress press cake were extracted by using the conventional alkali‐solubilization–acid‐precipitation (AP) method or saline‐based (SE) procedure (0.1 M NaCl at 50 °C). The extraction method has a major influence on the purity and functional properties of press cake protein products. AP had a lower protein yield (23 %) but much higher purity (90 % crude protein) compared with SE (45 % yield, 67 % crude protein). AP protein isolate had high foam capacity (120 ml), high foam stability (96 % foam volume retention) and high emulsion stability (24–35 min), and it was resistant to heat denaturation (3 % loss of solubility at pH 2 and pH 10). On the other hand, SE protein concentrate showed remarkably high solubility (>76 %) between pH 2 and 10 and exceptional emulsifying activity (226–412 m2/g protein), but was more susceptible to heat denaturation at pH 7 and pH 10 (65–78 % loss of solubility). These results strongly demonstrate that higher purity pennycress press cake protein can be produced by either saline extraction or acid precipitation and have functional properties that are desirable for non‐food uses.

Impacts of cropping system and management practices on the assembly of weed communities

SummaryUnderstanding how weed communities assemble as a function of biotic and abiotic filters and transform through time has important implications for the sustainable management of agronomic systems. In a three‐year study, we evaluated weed community responses to lucerne (Medicago sativa, perennial) vs. continuous spring wheat (Triticum aestivum, annual, CSW) and weed management practices where weeds in the CSW system were managed with three contrasting approaches (herbicide, tillage or sheep grazing). Our results indicated no differences in weed diversity between the perennial and annual crops or across the different management practices in CSW. However, there were differences in weed community composition. Lucerne, with the exception of the establishing year, impeded the growth and reproduction of several annual weeds, including Amaranthus retroflexus, Thlaspi arvense, Lamium amplexicaule and Chenopodium album, but favoured perennial broad‐leaved weeds such as Taraxacum officinale and Cirsium arvense. The replacement of herbicide treatments in pre‐plant and post‐harvest in CSW with soil tillage or sheep grazing selected for different weed communities beyond the second year of establishment. The weed species driving the differences in CSW systems were Androsace occidentalis, more common in CSW managed chemically; Asperugo procumbens, more common in CSW managed with tillage; and T. officinale and Lactuca serriola, more common in CSW managed with sheep grazing. Understanding how cropping systems modify weed communities is a necessary step to shift from reactive weed control programmes to predictive management strategies.

Fuel property quantification of triglyceride blends with an emphasis on industrial oilseeds camelina, carinata, and pennycress

Industrial oilseeds camelina (Camelina sativa L.), carinata (Brassica carinata), and pennycress (Thlaspi arvense L.) offer great potential as biofuel feedstocks. Their positive agronomic attributes allow for cropping systems and rotations that increase biofuel production on existing lands. The objective of this study was to perform a comprehensive fuel property evaluation of these promising oilseeds and compare them to several traditional oils. Three industrial (camelina, carinata, pennycress) and four conventional (soybean, canola, sunflower, corn) oilseed feedstocks were evaluated and compared. Both crude and refined oils were used in the evaluation to determine refinement’s effect on fuel properties. Straight vegetable oil (SVO), biodiesel (B100), triglyceride blends (TGB), and renewable diesel (R100) fuel pathways were compared to petroleum diesel for the fuel properties that were measured. The paper focuses on TGBs as an on-farm fuel pathway, since the commercial market for these oils is still emerging. The TGB blend percentage of vegetable oil to E10 gasoline was varied to show its effects on fuel properties. For several feedstock and fuel pathway combinations, this paper presents the first published fuel property results. The physical and chemical properties of TGBs were also studied through phase diagrams and NMR spectroscopy. TGBs were found to be both physically and chemically stable over the expected timescale of use. For the TGBs, several fuel properties were improved compared to SVO due to the addition of gasoline, such as viscosity, density, speed of sound, heating value, and cold flow properties. Flash point was reduced due to the volatility of the gasoline component, hence users should treat TGBs with same handling and storage precautions as gasoline. The results were similar for the industrial oils as the traditional oils in the evaluation. The results show TGB may be an ideal fuel pathway for farm-scale fuel production or for other users in remote areas using locally sourced plant oils as feedstock.

Field Pennycress Production and Weed Control in a Double Crop System with Soybean in Minnesota

Sustainable intensification of agricultural systems has been suggested as a way to increase food, fiber, energy, and feed to meet future demands. Field pennycress (Thlaspi arvense L.) is proposed as a means for temporal intensification of agriculture, increasing profitability through oilseed production while providing needed cover to address soil and water quality issues. Field research was conducted across four environments in Minnesota to (i) evaluate pennycress planting date and seeding rate on pennycress and soybean [Glycine max (L.) Merr.] seed production and (ii) determine the role of pennycress systems as a weed management tool. Pennycress seeding rate had a direct effect on pennycress yield at Rosemount but not at Waseca or Lamberton locations. The use of a companion cover crop along with pennycress further reduced pennycress seed yield at Rosemount, but not Waseca or Lamberton suggesting that water availability is a key driver in pennycress productivity. The effect of pennycress and cover crops on soybean yield was also dependent on location. At Rosemount, soybean yield was reduced when pennycress was planted ahead of soybeans both years of the study while there was no effect of pennycress on soybean yield at Waseca. Although soybean yield was reduced at Rosemount, the combined pennycress and soybean seed yield was greater. This research shows the potential for a double cropping system of pennycress–soybean to increase overall seed yield and reduce early‐season weed pressure.

Archaeobotanical reconstructions of field habitats and crops: the grange in Pomorzany near Kutno, 18th/19th c.

Abstract The paper presents the results of research of plant macrofossils from the grain deposit deriving from the 18th/19th centuries. The analysed material included 24760 diaspores representing 73 taxa. The majority were cultivated cereal crop species, and there was also abundance of accompanying segetal weed species. About 95% of the gathered crop material was Secale cereale. Another important crop was Hordeum vulgare and there were also some remains of Avena sativa, Triticum aestivum, Fagopyrum esculentum. Cannabis sativa and Linum usitatissimum were found as well. Weeds competing with these crops were, among others, the following species: Agrostemma githago, Raphanus raphanistrum, Apera spica-venti, Bromus secalinus, Centaurea cyanus, Spergula arvensis, Thlaspi arvense, Viola arvensis/tricolor, Fallopia convolvulus, Polygonum persicaria, Mentha arvensis, Anthemis arvensis, Papaver rhoeas, Rumex acetosella, Scleranthus annuus, Aphanes arvensis, Setaria pumila, Setaria viridis/verticilata. Extremely large presence of wild plant diaspores in the material allowed conducting economic and environmental interpretations. Reconstruction methods applied, used primarily in the case of macroremains from granaries, were fully applicable to the analysed plant residues. Weed species composition in the analysed material showed that they were mostly typical for the main winter crop. Some amount of species typical for other habitats were also found and they probably came from the near-by rye field. The presence of perennial diaspores indicated that the field was probably set aside

Metabolite fingerprinting of pennycress (Thlaspi arvense L.) embryos to assess active pathways during oil synthesis.

Pennycress (Thlaspi arvense L.), a plant naturalized to North America, accumulates high levels of erucic acid in its seeds, which makes it a promising biodiesel and industrial crop. The main carbon sinks in pennycress embryos were found to be proteins, fatty acids, and cell wall, which respectively represented 38.5, 33.2, and 27.0% of the biomass at 21 days after pollination. Erucic acid reached a maximum of 36% of the total fatty acids. Together these results indicate that total oil and erucic acid contents could be increased to boost the economic competitiveness of this crop. Understanding the biochemical basis of oil synthesis in pennycress embryos is therefore timely and relevant to guide future breeding and/or metabolic engineering efforts. For this purpose, a combination of metabolomics approaches was conducted to assess the active biochemical pathways during oil synthesis. First, gas chromatography-mass spectrometry (GC-MS) profiling of intracellular metabolites highlighted three main families of compounds: organic acids, amino acids, and sugars/sugar alcohols. Secondly, these intermediates were quantified in developing pennycress embryos by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring mode. Finally, partitional clustering analysis grouped the intracellular metabolites that shared a similar pattern of accumulation over time into eight clusters. This study underlined that: (i) sucrose might be stored rather than cleaved into hexoses; (ii) glucose and glutamine would be the main sources of carbon and nitrogen, respectively; and (iii) glycolysis, the oxidative pentose phosphate pathway, the tricarboxylic acid cycle, and the Calvin cycle were active in developing pennycress embryos.

Synthesis and physical properties of pennycress estolides and esters

A new series of pennycress (Thlaspi arvense L.) based free-acid estolides was synthesized by an acid-catalyzed condensation reaction, followed by an esterification reaction to produce the 2-ethylhexyl (2-EH) esters of the initial estolides. The physical properties of the estolides are highly affected by the length and unsaturation level of the capping fatty acid, the base fatty acid unit, and estolide linkage position. Both the free-acid estolides and the estolide 2-EH esters produced proved to have marked viscosity increases over previously synthesized estolides. Kinematic viscosities of the free-acid estolides were higher than the corresponding estolide 2-EH esters, ranging from 494.4cSt to 870.5cSt at 40°C and 53.6 to 75.3cSt at 100°C with viscosity indices (VI) from 134 to 163. Viscosities of the estolide esters ranged from 116.3 to 245.75cSt at 40°C and 18.2 to 33.6cSt at 100°C with viscosity indices (VI) from 169 to 183. The highest viscosity values belonged to the pennycress estolides made with pennycress fatty acids in the reaction acting as the base material, as well as the capping material. The oleic capped pennycress estolide 2-EH esters had the best low-temperature properties with a pour point (PP) of −33°C and cloud point (CP) of −31°C. With the exception of palmitic acid, there was very little variation in the low-temperature properties of the remaining saturate capped estolide 2-EH esters, PP ranging from −18 to −21°C. Pennycress is currently being developed for green diesel applications; the development of other industrial applications is a necessity for the success of an alternative crop. The combination of high viscosity and modest cold temperature properties of these pennycress estolides could fill a specialty niche as a high viscosity industrial lubricant.

A draft genome of field pennycress (Thlaspi arvense) provides tools for the domestication of a new winter biofuel crop

Field pennycress (Thlaspi arvense L.) is being domesticated as a new winter cover crop and biofuel species for the Midwestern United States that can be double-cropped between corn and soybeans. A genome sequence will enable the use of new technologies to make improvements in pennycress. To generate a draft genome, a hybrid sequencing approach was used to generate 47 Gb of DNA sequencing reads from both the Illumina and PacBio platforms. These reads were used to assemble 6,768 genomic scaffolds. The draft genome was annotated using the MAKER pipeline, which identified 27,390 predicted protein-coding genes, with almost all of these predicted peptides having significant sequence similarity to Arabidopsis proteins. A comprehensive analysis of pennycress gene homologues involved in glucosinolate biosynthesis, metabolism, and transport pathways revealed high sequence conservation compared with other Brassicaceae species, and helps validate the assembly of the pennycress gene space in this draft genome. Additional comparative genomic analyses indicate that the knowledge gained from years of basic Brassicaceae research will serve as a powerful tool for identifying gene targets whose manipulation can be predicted to result in improvements for pennycress.

Emergence of field pennycress (Thlaspi arvense L.): Comparison of two accessions and modelling

Many weed species are becoming rare due to intense agricultural management, which leads to a decrease of biodiversity in agroecosystems. Cultivating some of these species for their oilseed content may help preserve them while profiting agronomically. Thlaspi arvense is one of these species with potential as an industrial crop. The aim of this work was to develop a model to describe the emergence of this species, and that can help to make decisions for its management, whether for conservation or production purposes. The emergence of two accessions of T. arvense, one from Spain and the other from USA, sown in Spain (Almenar) and USA (Morris), over two seasons (2011–12 and 2012–13) and in Riga (Latvia) over one season (2012), was followed to compare patterns and extent, as well as to develop emergence prediction models based on hydrothermal time (HTT) and photohydrothermal time (PhHTT). For the USA accession, the percentage of seeds that emerged was significantly higher than that of the Spanish accession. Both accessions presented two emergence peaks (autumn–winter and spring) in both localities, but while these peaks could be considered as two different flushes in Almenar – for both accessions –, they appeared to be a single flush disrupted by low winter temperatures in Morris. An HTT-based model was applicable for both accessions with less precision than the PhHTT-based one, which was more accurate in most cases but failed in certain circumstances for the USA accession. The differences in emergence percentage among accessions suggest that some accessions might be more amenable to being used as a crop. The two models developed in this work predicted the emergence of both accessions of T. arvense quite accurately. The inclusion of photoperiod in the hydrothermal time equation, creating a new unit that we have called photohydrothermal time, offers a possibility to obtain more accurate models.

Registration of Katelyn Thlaspi arvense L. (Pennycress) with Improved Nondormant Traits

Katelyn (Reg. No. GP-35, PI 673443) pennycress (Thlaspi arvense L.) germplasm was publicly released by the USDA–ARS in 2014 as part of a new crop improvement program. Katelyn was developed by two generations of mass selection based on the germination response of freshly harvested pennycress seeds. The original seed source was the wild population Beecher (PI 672505) collected from a winter fallow cornfield 3.2 km north of Hanna City, IL. The germination rate of the original parent seed under conditions of 12-h light/dark cycles at 27.5°C/11.5°C was 0%. Beecher seed kept in the dark under otherwise identical conditions germinated at 7% compared with Katelyn S2 seed, which had an immediate post-harvest germination rate of 91% for seed kept in the dark and 81% under the 12-h light/dark 27.5°C/11.5°C conditions.

Enrichment of erucic acid from pennycress (Thlaspi arvense L.) seed oil

Pennycress (Thlaspi arvense L.) is a winter annual that has a wide geographic distribution and a growth habit that makes it suitable for an off-season rotation between corn and soybeans in much of the Midwestern United States. Pennycress seed contains 36% oil with 36.6% erucic acid content There are a number of markets that pennycress could supply from an enriched erucic fatty acid fraction. Erucic acid was enriched using two independent separation methods; vacuum distillation of fatty acids or methyl esters and fractional crystallization of potassium soaps directly from the triglyceride. Fractional crystallization provided the highest level of purity, yielding an 87% erucic enriched fraction but in low theoretical recovery of 23% when ethanol was used as the crystallization solvent. A higher theoretical erucic recovery (59%) was obtained when methanol was used as a solvent yielding a 71% enriched erucic acid fraction. This method utilized a mixed solvent (90:10 methanol/water) for crystallization with a 5:1 solvent to analyte ratio. In an independent study, molecular distillation of the fatty acid methyl esters at 90°C, 7Pa of pressure enriched the erucic acid content to 67.1% in a single pass and could be further enriched to 71.6% with a second pass with an overall mass balance for this double distilled fraction of 43.2%. Distillation of the fatty acids was similar to the methyl esters yielding a fraction that contained 69.0% erucic with an overall mass balance of this fraction of 38.4% after two distillations. All three enriched fractions (feed, distilled FAME and mother liquor) were suitable for biodiesel; 40°C viscosity range 4.142–5.509, 100°C viscosity range of 1.713–2.095. Pour points were improved from the feed of −18°C to −27°C in the mother liquor fraction and remained the same in the distillate at −18°C. HFRR wear scars ranged from 120 to 177μm across all fractions.

Kształtowanie się zbiorowisk chwastów grochu siewnego (Pisum sativum L.) pod wpływem herbicydu i następstwa roślin

Summary This paper presents the results obtained in the crop rotation experiment carried out in the years 2008–2010. It concerns weed infestation of pea (Venus variety) cultivated in six-field crop rotation: sugar beet – maize – spring barley – pea – winter oilseed rape – winter wheat, and in monoculture since 1993. Two levels of crop protection were compared: level 0 – no chemical protection, and H – with the protection of herbicide (linuron) applied after sowing at 1.5 kg/ha doses. The species composition and the number of weeds were determined at the development stage of 2–4 leaves of pea and prior to the mechanical cultivation using a frame with an area of 0.25 m 2 . On the objects without chemical protection in crop rotation and in monoculture the number of weeds amounted to 237 plants/m 2 and 614 plants/m 2 , respectively. The applied herbicide reduced the number of weeds in the crop rotation by 87.8% and by 82.5% in the monoculture. Regardless of the chosen method of crop protection, the following weed species dominated: Chenopodium album, Thlaspi arvense and Capsella bursa-pastoris. In monocultural cultivation Lycopsis arvensis, Polygonum convolvulus and also perennial weeds occurred as well.

Evaluation of Weed Species from the Northern Great Plains as Hosts of Soybean Cyst Nematode

Weeds can be alternate hosts of soybean cyst nematode (SCN), a major pathogen of soybean in the United States. Weed species from the northern soybean production area of North Dakota-northern Minnesota have not been evaluated for host suitability. Fifty-one weed species with multiple collections from different locations, representing 13 families were evaluated as hosts of SCN. Weeds were inoculated with SCN HG type 0 and a female index (FI) was calculated by comparing reproduction to that on Barnes, a susceptible soybean cultivar. Thirty-three weed species had not previously been tested. For 20 weed species, no reproduction on roots was observed on any collection. For 31 weed species, SCN females developed on roots of one or more collection, but only two weeds, henbit and field pennycress, allowed substantial reproduction with average FI's of 30.5 to 38, respectively; the other 29 species had average FI's of less than 10 and thus were defined as poor hosts. Twenty-six of the weed species from 11 plant families were newly identified hosts of SCN. Collections of species varied in host suitability. Although most weeds were non-hosts or poor hosts, the number of weeds that supported limited SCN reproduction indicates that weed hosts could influence SCN survival and reproduction in the upper Great Plains. Few weed species, however, are major hosts of SCN in this region. Accepted 10 December 2014. Published 28 January 2015.

Evaluation of biochar-anaerobic potato digestate mixtures as renewable components of horticultural potting media

Various formulations are used in horticultural potting media, with sphagnum peat moss, vermiculite and perlite currently among the most common components. We are examining a dried anaerobic digestate remaining after the fermentation of potato processing wastes to replace organic components such as peat moss, and biochars produced from several feedstocks as replacements for inorganic media components such as vermiculite and perlite. Biochars were prepared using a top-lit updraft pyrolytic stove from wood pellets, pelletized wheat straw and field pennycress presscake. Biochar yields and heats of combustion were highest with the field pennycress presscake and lowest with the wood pellets. Because all three biochars had basic pHs, they were treated with citric acid solutions to lower pH values to 6.0 before being used in plant experiments. All three acidified biochars were combined in 1:1 ratios with the digestate and compared against a 1:1 sphagnum peat moss:vermiculite control substrate containing slow-release chemical fertilizers. All digestate:biochar substrates had higher bulk densities and levels of soluble salts than the control. Greenhouse experiments were conducted using tomato (Solanum lycopersicum L.) and marigold (Tagetes erecta L.) plants grown in 2.5-L pots. Combining potato anaerobic digestate with acidified wood pellet biochar resulted in increased growth of tomato plants as compared to the peat:vermiculite control, while the digestate:acidified wheat straw pellet biochar substrate was equal to the control for marigold growth. Plants of both species grown in the digestate:pennycress presscake biochar substrate had less growth than the control. From these results it appears that both the digestate:acidified wood pellet biochar and the digestate:acidified straw pellet biochar would likely be acceptable alternatives to peat:vermiculite substrates, and would also be an option for certified organic producers.

Accumulation and distribution of zinc in the leaves and roots of the hyperaccumulator Noccaea caerulescens

Understanding the uptake mechanisms of heavy metals by hyperaccumulators is necessary for improving phytoextraction options to reduce metal toxicities in contaminated soils. In this study, the capacity of Zn uptake by the hyperaccumulator Noccaea caerulescens was investigated and compared to the non-hyperaccumulator Thlaspi arvense. The plants were grown under hydroponic conditions in a glasshouse. The distribution of Zn in the roots and leaves of these species was investigated by scanning electron microscopy with energy-dispersive X-ray analysis. Compared with the control with no Zn added, it was shown that prolonged Zn treatments decreased the biomass of both N. caerulescens and T. arvense. Since N. caerulescens requires Zn for growth, no Zn toxicity symptoms were observed, even when the Zn concentration in shoots reached 2.5% dry mass. T. arvense showed serious Zn toxicity only after two weeks of Zn treatment. Zn uptake by N. caerulescens was mainly translocated to the leaves while almost all of the Zn taken-up by T. arvense was retained in the roots. In N. caerulescens, increasing concentration of Zn in the supply decreased Ca and P concentrations in the shoots by up to 50 and 35%, respectively. Zn-containing crystals were abundant in both the upper and lower epidermal cells of the leaves and in the cortex of the roots during the later growth phase. Co-localization of Ca and Zn, P and S were found in leaf and root tissues. The results suggest that Zn-rich crystals with an abundance of the Zn ligand in the roots and shoots, and co-localization and interaction between Zn and other ions, may have functional significance with respect to conferring particular attributes to N. caerulescens that are not present in the non-hyperaccumulator counterpart. An understanding of these species-specific differences has relevance from the perspective of offering some insight into how particular species could contribute to a strategy for the detoxification of Zn-contaminated sites.

Aerobic methane emissions from stinkweed (Thlaspi arvense) capsules

Aerobic methane (CH4) emission from plant vegetative parts has been confirmed by many studies. However, the origin of aerobic CH4 from plants and its emission from reproductive parts have not been well documented. We determined the effects of developmental stages (early, mid, late) and incubation conditions (darkness, dim light, bright light) on CH4 emissions from stinkweed (Thlaspi arvense) capsules. We found that CH4 emissions from capsules varied with developmental stage and incubation light. Methane emission was highest for the late harvested capsules and for those incubated under lower (dim) light condition. Our results also showed a significant negative correlation between CH4 emission and capsule moisture content. We conclude that CH4 emissions vary with capsule age and diurnal light environment.

Potential of industrial hemp (Cannabis sativa L.) genotypes to suppress weeds

Field experiments designed to explore weediness of hemp crops of industrial varieties were carried out at the Upytė Experimental Station of the Lithuanian Research Centre for Agriculture and Forestry in 2010–2012. Eight monoecious industrial hemp varieties from France (5), Poland (2) and Ukraine (1) were grown in a conventional crop rotation after winter wheat. Hemp was sown at a seed rate of 50 kg ha -1 with 10 cm interrows at the beginning of May and harvested when the first matured seeds appeared. No mechanical or chemical weed control was applied during hemp growth period. Density of weeds at full hemp emergence was relatively high, with the highest average value of 202 plants m -2 in 2011, the year with relatively high air temperatures at the end of May – beginning of June and adequate rainfall. At hemp harvesting, the highest weed density and above-ground biomass was found in 2010, the year characterised by high temperatures in July and August, in the plots of the USO 31, the variety with the shortest growth period and the lowest plant height. A total of 31 weed species were identified in hemp experiments – 26 species of broad-leaf and grass weeds and 5 species of perennial weeds. At full hemp emergence, weeds typical of spring crops of the region were most abundant: Chenopodium album L. dominated in 2010, Veronica arvensis L. in 2011, while in 2012 the domination was shared by the four weed species Lamium purpureum L., Thlaspi arvense L., V. arvensis and Poa annua L. At harvest, in total 8 weed species were found; however, only C. album and partly Polygonum aviculare L. were relatively abundant in all years.

Nickel and zinc isotope fractionation in hyperaccumulating and nonaccumulating plants.

Until now, there has been little data on the isotope fractionation of nickel (Ni) in higher plants and how this can be affected by plant Ni and zinc (Zn) homeostasis. A hydroponic cultivation was conducted to investigate the isotope fractionation of Ni and Zn during plant uptake and translocation processes. The nonaccumulator Thlaspi arvense, the Ni hyperaccumulator Alyssum murale and the Ni and Zn hyperaccumulator Noccaea caerulescens were grown in low (2 μM) and high (50 μM) Ni and Zn solutions. Results showed that plants were inclined to absorb light Ni isotopes, presumably due to the functioning of low-affinity transport systems across root cell membrane. The Ni isotope fractionation between plant and solution was greater in the hyperaccumulators grown in low Zn treatments (Δ(60)Ni(plant-solution) = -0.90 to -0.63‰) than that in the nonaccumulator T. arvense (Δ(60)Ni(plant-solution) = -0.21‰), thus indicating a greater permeability of the low-affinity transport system in hyperaccumulators. Light isotope enrichment of Zn was observed in most of the plants (Δ(66)Zn(plant-solution) = -0.23 to -0.10‰), but to a lesser extent than for Ni. The rapid uptake of Zn on the root surfaces caused concentration gradients, which induced ion diffusion in the rhizosphere and could result in light Zn isotope enrichment in the hyperaccumulator N. caerulescens. In high Zn treatment, Zn could compete with Ni during the uptake process, which reduced Ni concentration in plants and decreased the extent of Ni isotope fractionation (Δ(60)Ni(plant-solution) = -0.11 to -0.07‰), indicating that plants might take up Ni through a low-affinity transport system of Zn. We propose that isotope composition analysis for transition elements could become an empirical tool to study plant physiological processes.

Dynamics and Structure of a Native Pieris Population in the Presence of a Non-Native, Toxic Larval Host Plant

ABSTRACT. There have been reports of butterflies that oviposit on non-native plants that do not support the development of the larvae, and the fitness cost of this behavior has been estimated in one such case. However, the long-term consequences of this fitness cost for the population dynamics of such butterflies have not been studied. Here we report changes over 40 years in a population of Pieris macdunnoughii (Lepidoptera, Pieridae; formerly Pieris napi macdunnoughii Remington), which oviposits on a lethal, non-native plant, Thlaspi arvense (Brassicaceae), as well as on suitable native hosts. Mark-release-recapture (MRR) studies conducted at four intervals over 40 years showed no significant trends across years in population structure or dynamics, including estimated population density and temporal changes in the number of newly emerged individuals within a year. The estimated daily residence rate differed between the sexes. However, male estimated daily residence rate showed no significant change acros...

Compression ignition engine performance and emission evaluation of industrial oilseed biofuel feedstocks camelina, carinata, and pennycress across three fuel pathways

Industrial oilseeds camelina (Camelina sativa L.), carinata (Brassica carinata), and pennycress (Thlaspi arvense L.) offer great potential as biofuel feedstocks due to their non-food nature and positive agronomic attributes. This research focused on compression ignition (CI) engine performance and emissions of these industrial oilseeds as compared to both traditional feedstocks and petroleum diesel. A John Deere 4.5L test engine was used to evaluate these oils using three fuel pathways (triglyceride blends, biodiesel, and renewable diesel). This engine research represents the first direct comparison of these new biofuel feedstocks to each other and to conventional sources. For some industrial oilseed feedstock and fuel pathway combinations, this study also represents the first engine performance data available. The results were promising, with camelina, carinata, and pennycress engine performance very similar to the traditional oils for each fuel pathway. Fuel consumption, thermal efficiency, and emissions were all were typical as compared to traditional oilseed feedstocks. Average brake specific fuel consumption (bsfc) for the industrial oilseed biofuels was within ±1.3% of the conventional oilseed biofuels for each fuel type. Initial research with triglyceride blends (TGB), formed by blending straight vegetable oil with gasoline, indicate it may be an ideal fuel pathway for farm-scale fuel production, and was compatible with a direct injection CI engine without modification. TGB had lower fuel consumption and a higher thermal efficiency than biodiesel for each feedstock tested. For several categories, TGB performed similar to petroleum diesel. TGB volumetric bsfc was only 1.9% higher than the petroleum runs. TGB combustion characteristics were similar to biodiesel. Biodiesel runs had several emission benefits such as reductions in carbon monoxide (CO), non-methane hydrocarbons (NMHC), volatile organic compounds (VOCs), and formaldehyde (CH20) emissions as compared to TGB runs. The renewable diesels had petroleum-like engine performance and combustion characteristics, while still maintaining some of the benefits of biodiesel such as reduced CO emissions. Nitrogen oxides (NOx) emissions were also 6% lower for renewable diesel runs than petroleum. Both crude and refined oil was used as feedstock, and did not significantly affect engine performance or emissions in a modern CI engine.