Rapistrum Rugosum Research Articles

Study of Chemical Composition, Antibacterial and Antioxidant Activities of Rapistrum rugosum L. Essential Oils from Flowers, Leaves, and Stems

The chemical composition of the essential oils of three organs (flowers, leaves and stems) from Rapistrum rugosum (L.) All., was studied and screened for their possible antibacterial and antioxidant properties. According to the GC and GC/ MS analysis, 28 (represent 92.5 % of the total oil composition), 23 (93.9 %), and 38 compounds (94.3 %) were identified from flowers, leaves and stems, respectively. The major compound in the leaves essential oil was found to be pentadecanal (55.3 %) followed by hexahydrofarnesylacetone (8.4 %) and tetradecanoic acid (5.7%). While hexahydrofarnesylacetone (17.2 %) followed by 1-pentadecanol (8.3 %), tetradecanoic acid (5.9 %), (E)-β-damascenone (5.7 %) were the major compounds of the flowers oil. Tetradecanoic acid (13.1 %), hexahydrofarnesylacetone (10.1 %), dodecanoic acid (10.0 %), isobornyl acetate (7.6 %), 5-methylthiopentyl isothiocyanate (6.7 %) and (E)-β-ionone (6.2 %) were the main constituents for the stem essential oil. The essential oil of flowers exhibited the higher activity in each antioxidant system (ABTS, DPPH and β-Carotene-linoleic acid methods) with an important value for DPPH assay (PI = 69.88 ± 0.02 %). Furthermore, the isolated oils were tested against five Gram-positive and Gram-negative bacteria. It was found that the essential oil of all organs exhibited interesting antibacterial activities against Gram-positive bacteria, comparable to those of Gentamicin, which was used as positive control.

Bastard Cabbage (Rapistrum rugosum L.) Resistance to Tribenuron-Methyl and Iodosulfuron-Methyl-Sodium in Spain and Alternative Herbicides for Its Control

Complaints about the lack of control of Rapistrum rugosum with tribenuron-methyl and iodosulfuron-methyl-sodium in winter cereals in Northeastern Spain motivated this study. During 2015–2018, greenhouse trials were conducted to test the responses of two possibly resistant (R1 and R2) and two susceptible populations to both active ingredients to determine the response of these populations to alternative herbicides. In the first trial that was repeated twice, populations were treated with both active ingredients (three rates, six replicates), and the lack of control confirmed resistance both times. The second trial was conducted on the self-pollinated progeny of the initial populations (13 rates, 6 replicates) to confirm the heritable character of resistance and to determine the resistance factors related to survival and biomass. Resistance factors based on biomass were 188 and 253 for tribenuron-methyl and 42 and 26 for iodosulfuron-methyl-sodium for R1 and R2, respectively, confirming the strong resistance of the progeny. In the third trial, nine active ingredients (a.i.) registered for broadleaved weed control in winter cereals were tested on the four populations (two rates, four replicates). All the alternative herbicides, except florasulam, results in important phytotoxicity to all tested populations, with 100% efficacy for several a.i. This work is the first report of R. rugosum that is resistant to iodosulfuron-methyl-sodium and the first report in Europe of R. rugosum that is resistant to tribenuron-methyl.

Interference of turnipweed (Rapistrum rugosum) and Mexican pricklepoppy (Argemone mexicana) in wheat

AbstractTurnipweed [Rapistrum rugosum (L.) All.] and Mexican pricklepoppy (Argemone mexicana L.) are increasingly prevalent in the northern cropping regions of Australia. The effect of different densities of these two weeds was examined for their potential to cause yield loss in wheat (Triticum aestivum L.) through field studies in 2016 and 2017. There was 72% to 78% yield reduction in wheat due to competition from R. rugosum. Based on the exponential decay model, 18.2 and 24.3 plants m−2 caused a yield reduction of 50% in 2016 and 2017, respectively. Rapistrum rugosum produced a maximum of 32,042 and 29,761 seeds m−2 in 2016 and 2017, respectively. There was 100% weed seed retention at crop harvest. Competition from A. mexicana resulted in a yield loss of 17% and 22% in 2016 and 2017, respectively; however, plants failed to set seeds due to intense competition from wheat. Among the yield components, panicles per square meter and grains per panicle were affected by weed competition. The studies indicate a superior competitiveness of R. rugosum in wheat and a suppressive effect of wheat on A. mexicana. The results indicate that a wheat crop can be included in crop rotation programs where crop fields are infested with A. mexicana. High seed retention in R. rugosum indicates the possibility to manage this weed through seed catching and harvest weed seed destruction.

Resistance of Rapistrum rugosum to tribenuron and imazamox due to Trp574 or Pro197 substitution in the acetolactate synthase

Ten putative resistant and two susceptible Rapistrum rugosum populations originating from Greece were studied for resistance to acetolactate synthase (ALS)-inhibiting herbicides, using dose–response assays, sequencing of als gene and in vitro ALS activity assays. The dose–response assays showed that one (P1) out of ten putative resistant populations was cross-resistant to tribenuron and imazamox, while another population (P4) was resistant to tribenuron only. All populations were susceptible to MCPA at the recommended rate. Gene sequencing of als revealed that the P4 population had a point mutation at Pro197 by His providing resistance to tribenuron, whereas the P1 had a Trp574 by Leu point mutation conferring cross-resistance to tribenuron and imazamox. The in vitro activity of the ALS enzyme indicated I50 values (tribenuron concentration required for 50% reduction of the ALS activity) ranging from 66.68 to 137.01 μM, whereas the respective value for the S populations ranged from 0.29 to 0.54 μM. These results strongly support that two R. rugosum populations evolved resistance to ALS-inhibiting herbicides due different point mutations in the als gene.

Resistances to downy mildew (Hyaloperonospora brassicae) in diverse Brassicaceae offer new disease management opportunities for oilseed and vegetable crucifer industries

Some 154 Brassicaceae genotypes (78 Brassica napus, 38 B. carinata, 25 B. juncea, three Raphanus sativus, two each of Rapistrum rugosum and B. incana and one each of Crambe abyssinica, B. fruticulosa, Hirschfeldia incana, B. insularis, B. oleracea and Sinapis arvensis), were inoculated with a mixture of seven isolates of Hyaloperonospora brassicae to identify effective host resistances. Many highly resistant genotypes were identified, particularly R. sativus Krasnodar Market B (%Disease index 6.6) and Pegletta (%DI 9.0); B. carinata Tamn Rex-sel Green (%DI 7.6), BRA926/18 (%DI 9.7) and PI360884 (%DI 9.7); and B. juncea, Ringot1 (%DI 9.7). A further 13 B. carinata, seven B. juncea and single R. sativus (Boss) and B. incana (UPM6563) genotypes were also highly resistant (%DI 11.1), as were B. oleracea CPI106844 (%DI 14.6) and Crambe abyssinica (%DI 17.4). Almost all B. carinata and B. juncea genotypes showed high resistance (%DI 7.6–22.2). In contrast, B. napus genotypes showed wide ranging responses, from high resistance in SN-8 (%DI 22.2%) to extreme susceptibility in Hyola 450TT and Thunder TT (%DI 83.7, 95.5, respectively). R. rugosum, B. fruticulosa, H. incana and B. insularis genotypes ranged from moderately to highly susceptible (%DI 55.2–78.8). This study highlights the ready availability of very high levels of pathotype-independent resistance across diverse Brassicaceae to H. brassicae, particularly R. sativus, B. carinata, B. juncea, B. oleracea and C. abyssinica. Resistances identified can be utilized as sources of resistance in oilseed and vegetable Brassicaceae breeding programs and/or directly deployed as new varieties where downy mildew is prevalent.

Germination ecology of turnip weed (Rapistrum rugosum (L.) All.) in the northern regions of Australia.

In Australia, turnip weed has been rapidly emerging as one of the major weeds in conservation agricultural systems. Germination and emergence of turnip weed were examined for two populations collected from Gatton and St George regions of Australia; two locations with high and low rainfall, respectively. The seeds of turnip weed germinated at all the tested temperatures, but germination was the lowest at 15/5°C, intermediate at 20/10°C and highest at 25/15°C and 30/20°C. The results indicated a high adaptability of turnip weed to warm environmental conditions, although it is a major problem in the winter season. Germination was higher in dark than light/dark regimes except at 30/20°C. Three was a concomitant reduction in germination as the osmotic potential values decreased from 0 to -1.0 MPa. There was 2 and 4% germination at -0.8 MPa for Gatton and St George populations, respectively, and no germination occurred at an osmotic potential of -1.0 MPa. There was a reduction in germination when the sodium chloride (NaCl) concentration was increased from 0 to 150 mM, and no germination was observed at 200 and 250 mM of NaCl. Turnip weed germinated over a broad range of pH (4 to 10). Seedling emergence was higher at 1 cm depth compared to 0.5 cm or at the soil surface. There was 28 and 33% emergence at the surface for the Gatton and St George populations, respectively, compared to 48 and 56% emergence from 1 cm depth for the Gatton and St George populations, respectively and no emergence was observed from 6 cm depth. The results indicated that tillage leading to shallow burial would promote the emergence of turnip weed; on the contrary, tillage that could bury seeds deep into the soil profile might minimise the emergence. Under ideal conditions and lack of integrated weed management programmes, this weed will emerge, set seeds and enrich the soil seed bank and thereby continue to be a problem in the northern grain region of Australia.

Diaporthe novem isolated from sunflower (Helianthus annuus) and other crop and weed hosts in Australia

In 2011, patches of lodged plants of Helianthus annuus (commercial sunflower) with stem lesions were observed in a commercial crop at Kingsthorpe, Queensland, Australia. Several species of Diaporthe were consistently isolated from the lesions. Diaporthe novem was identified by DNA sequence analysis. In following surveys, Diaporthe novem was found to be associated with other crop species including Cicer arietinum (chickpea), Glycine max (soybean), Lupinus alba (lupin), Sorghum bicolor (sorghum) Vicia faba (faba bean) and Vigna radiata (mungbean), and with the weed species Datura stramonium (common thornapple), Helianthus annuus (wild-type sunflower), Malva parviflora (small flowered mallow), Rapistrum rugosum (turnip weed), Sambucus gaudichaudiana (wild elderberry), Sisymbrium orientale (indian hedge mustard), Sonchus oleraceus (sowthistle), Verbena sp., Vicia sativa (common vetch), and Xanthium strumarium (noogoora burr). In pathogenicity tests, isolates of D. novem from sunflower were highly virulent when re-inoculated on commercial sunflower varieties. This study has identified D. novem as a frequent cause of stem canker of sunflower in the eastern cropping areas of Australia, and extends the known host range of D. novem.

Natural products to control biofilm on painted surfaces

Purpose This paper aims to study five vegetables extracts as possible additives to control bacterial growth on indoor waterborne paints. The extracts were obtained from the weeds Raphanus sativus, Rapistrum rugosum, Sinapis arvensis, Nicotiana longiflora and Dipsacus fullonum, used in traditional medicine as antimicrobial compounds. Design/methodology/approach Weeds extracts were characterized by Fourier transform infrared spectroscopy and UV–Vis spectrophotometry. Their antibacterial activity against Escherichia coli and Staphylococcus aureus was also determined. Afterward, selected extracts were incorporated in waterborne paint formulations. The paints’ antimicrobial activity was assessed against S. aureus, monitoring biofilm formation by environmental scanning electron microscopy. Findings As a general rule, results showed that tested paints were efficient in inhibiting biofilm formation, especially that formulated with Nicotiana longiflora. Practical implications The tested paints can be used to protect walls from microbial colonization, which shortened coatings’ useful life by discoloration and/or degradation. Concomitantly, indoor microbial colonization by aerosols could be also diminished. This is especially important in places that should have high standards of environmental hygiene, as in the food industry, health-care and sanitary centers. Originality/value The main value of this research was to study the antimicrobial activity of weeds extracts and to incorporate them in waterborne paints to diminish bacterial biofilm formation. This biofilm discolors and degrades the paint, and causes health problems. The use of natural compounds in coatings is increasing because of the convenience of using renewable sources, such as natural antimicrobials, in paint formulations.

Effectiveness of defatted seed meals from Brassicaceae with or without crude glycerin against black grass (Alopecurus myosuroides Huds.)

Herbicide resistance has become an increasing problem, and at the same time pesticide usage is declining due to stringent EU pesticide legislation which aims to reduce the impact on environment and human health. For these reasons, new alternative integrated weed management approaches are becoming increasingly relevant. Formulations based on Brassica defatted seed meals (DSMs) and glycerin, have previously been shown to be effective in reducing the germination of lettuce seed.In this work five DSMs, formulated with and without crude glycerin, were chosen for in vitro and glasshouse experiments: i) Brassica nigra, ii) Brassica tournefortii, iii) Eruca sativa, iv) Rapistrum rugosum and v) Sinapis alba. Black-grass (Alopecurus myosuroides), a weed demonstrating extensive herbicide resistance, was used as a target, and the germination inhibition caused on this weed by Brassica defatted seed meals was assessed.In both in vitro and in vivo experiments, the most effective DSM for inhibiting germination of both lettuce and black-grass seeds was the sinigrin containing DSM, Brassica nigra.The aim of the manuscript was to suggest a new high value application for Brassicas derived DSM as a co-products from the vegetable oil production chain. The proposed treatments could represent an interesting and 100% novel natural alternative to the conventional herbicides.

Multiple Mechanisms Increase Levels of Resistance in Rapistrum rugosum to ALS Herbicides.

Rapistrum rugosum (turnip weed) is a common weed of wheat fields in Iran, which is most often controlled by tribenuron-methyl (TM), a sulfonylurea (SU) belonging to the acetolactate synthase (ALS) inhibiting herbicides group. Several cases of unexplained control failure of R. rugosum by TM have been seen, especially in Golestan province-Iran. Hence, there is lack of research in evaluation of the level of resistance of the R. rugosum populations to TM, using whole plant dose-response and enzyme assays, then investigating some potential resistance mechanisms Results revealed that the resistance factor (RF) for resistant (R) populations was 2.5–6.6 fold higher than susceptible (S) plant. Neither foliar retention, nor 14C-TM absorption and translocation were the mechanisms responsible for resistance in turnip weed. Metabolism of TM was the second resistant mechanism in two populations (Ag-R5 and G-1), in which three metabolites were found. The concentration of TM for 50% inhibition of ALS enzyme activity in vitro showed a high level of resistance to the herbicide (RFs were from 28 to 38) and cross-resistance to sulfonyl-aminocarbonyl-triazolinone (SCT), pyrimidinyl-thiobenzoate (PTB) and triazolopyrimidine (TP), with no cross-resistance to imidazolinone (IMI). Substitution Pro 197 to Ser 197 provided resistance to four of five ALS-inhibiting herbicides including SU, TP, PTB, and SCT with no resistance to IMI. These results documented the first case of R. rugosum resistant population worldwide and demonstrated that both RST and NRST mechanisms are involved to the resistance level to TM.

Phytoremediation of lead-contaminated soil by Sinapis arvensis and Rapistrum rugosum

ABSTRACTNowadays, public concern relating to ecological deleterious effects of heavy metals is on the rise. To evaluate the potential of Rapistrum rugosum and Sinapis arvensis in lead- contaminate phytoremediate, a pot culture experiment was conducted. The pots were filled by soil treated with different rates of leadoxide (PbO) including 0 (control), 100, 200, 300, 400, and 500 mg Pb per 1 kg soil. Germinated seeds were sown. Surprisingly, with increasing concentration of Pb, dry weight of R. rugosum and S. arvensis did not decrease significantly. In both of species, the concentration of Pb was higher in roots than shoots. In general, S.arvensis was absorbed more Pb compared to R. rugosum. The results revealed high potential of R. rugosum and S. arvensis in withdrawing Pb from contaminated soil. For both species, a positive linear relation was observed between Pb concentration in soil and roots. However, linear relationship was not observed between Pb concentration in the soil and shoots. Although both species test had low ability in translocation Pb from roots to shoots but they showed high ability in uptake soil Pb by roots. Apparently, these plants are proper species for using in phytoremediation technology.

New sources of resistance to Sclerotinia sclerotiorum for crucifer crops

Current management of Sclerotinia rot (Sclerotinia sclerotiorum) relies heavily upon cultural and chemical control options that provide, at best, only partial, sometimes sporadic control and can be cost prohibitive. Effective host resistance to S. sclerotiorum is urgently needed if Sclerotinia rot is to be successfully managed across diverse oilseed, forage and vegetable crucifer crops worldwide. Differences in resistance across 127 diverse cruciferous genotypes to S. sclerotiorum in one experiment, and a set of 55 Brassica napus lines carrying one or more B. carinata B genome introgressions in a second experiment, were assessed by field-inoculation of stems and natural ascospore infection. Reactions on B. fruticulosa, B. oxyrrhina, B. parachinensis, B. tournefortii, Camelina sativa, Carrichtera annua, Diplotaxis tenuifolia, Eruca vesicaria, Hirschfeldia incana, Raphanus raphanistrum, Raphanus sativus, Rapistrum rugosum, Sinapis arvensis and Sisymbrium irio to this pathogen are reported for the first time. Among these, and across other species previously explored, including B. carinata, B. napus, B. juncea, B. rapa, B. cretica, B. incana, B. insularis, B. nigra, and B. montana, responses ranged from highly resistant (stem lesion length 2mm) to highly susceptible (155mm). Against a highly virulent and prevailing pathogen pathotype, R. raphanistrum RRA 41, B. napus Mystic, B. carinata BRA 926/78, B. carinata 054113, R. sativus Krasnodar. Market B, B. carinata PI 193459 and R. raphanistrum WARR 20 all showed very high-level resistance, with stem lesion length <5mm; with a further 29 genotypes across these species and/or B. incana, B. rapa var. rosularis, B. oleracea vars acephala and italica, and S. arvensis, that showed slightly less but still high resistance (lesions 5–10mm). Natural air-borne ascospore leaf infection occurred in 89% of plots, yet some forage and/or vegetable crucifers, such as B. rapa var. chinensis Ivory and R. sativus Oriental radish, showed high-level resistance to such infections. B. napus with introgression(s) from B. carinata, ranged from highly resistant (lesions <2mm) to very susceptible (>67mm). There appeared to be separate genetic control for stem vs. leaf resistance, crucial to the understanding needed in developing resistant cultivars across different cruciferous crop types. While this study highlighted individual genotypes that offer great potential for improving resistance to Sclerotinia rot in commercial cruciferous crops, it also demonstrated that assessment of the overall value of a species is only possible when a significant number of genotypes within the species are tested. Overall, while genotypes with high-level stem or leaf resistance identified are of particularly significant value for developing new disease-resistant cultivars of oilseed, forage and vegetable crucifers, even genotypes with moderate levels of resistance, if deployed commercially, offer prospects of improving current integrated disease management strategies compared with current reliance upon cultural and/or chemical controls utilized in conjunction with cultivars lacking any effective resistance. As resistance was identified for the first time across many of these diverse cruciferous species, it is likely that some resistances identified constitute new sources and/or types of host resistance not previously identified.

Antioxidant and anti-acetylcholinesterase activities of extracts from Rapistrum rugosum in Tunisia

ObjectiveTo investigate the antioxidant potential and anti-acetylcholinesterase activity of Rapistrum rugosum extracts. MethodsThe crude, ethyl acetate, butanol and water extracts prepared from flowers, roots, stems and leaves of Rapistrum rugosum were tested at 1 mg/mL to determine their total polyphenol content, total flavonoid content and total condensed tannin content. Their antioxidant activity was assessed at different concentrations (0.0312, 0.0625, 0.1250, 0.25, 0.50 and 1.00 mg/mL) by using DPPH, ABTS, reducing power and β-carotene bleAChIng inhibition activity. Anti-acetylcholinesterase activity was also determined. ResultsThe extract of leaves and stems had the highest total phenolic content [(110.45±0.03) mg gallic acid equivalent/g dry weight]. The ethyl acetate extract of flowers had the highest total flavonoid content [(24.62±0.13) mg quercetin equivalent/g dry weight]. The butanolic fraction of flowers had the highest total condensed tannin content [(317.85±0.01) mg catechin equivalent/g dry weight]. The crude extracts of flowers exhibited an interesting antioxidant activity for DPPH assay (93.00±0.01)% at 1 mg/mL. The greatest acetylcholinesterase inhibitory activity (IC50=1.60 mg/mL) was exhibited by the crude extracts from the flowers. ConclusionsThe results demonstrated that Rapistrum rugosum contains active constituents which possess antioxidant and anti-acetylcholinesterase activities.

Genetic differentiation among sexually compatible relatives of Brassica napus L.

Analysis of gene flow between Brassica napus L. and its sexually compatible relatives that could be found in the wild in Slovenia was performed by microsatellite analysis using fifteen selected primer pairs. Genotypes included in the study were obtained from the field survey of sexually compatible relatives of B. napus in natural habitats around Slovenia and from reference collections. Two different wild species of all the presented sexually compatible relatives of B. napus were found in Slovenia, B. rapa and Sinapis arvensis. The reference genotypes included varieties and wild forms from internal collections as marketable seeds or from gene banks. Reference genotypes were represented by the following species and subspecies: B. napus ssp. napobrassica, B. napus ssp. napus, B. nigra, B. oleracea, B. rapa ssp. oleifera, Diplotaxis muralis; D. tenuifolia, Raphanus raphanistrum, R. sativus, R. sativus var. oleiformis, Rapistrum rugosum, S. alba and S. arvensis. Estimation of gene flow described by average number of migrants was 0.72 followed by 0.20 migrants. Due to the observed gene migrations, genetic drift and selection, Hardy-Weinberg equilibrium was not met. The mean number of alleles over all loci was 16.9, the average polymorphic information content was 0.43. We found four highly divergent and polymorphic loci (Na12-C08, Na10-A08, Ni3-G04b and BRMS-050) at statistically significant level (p&lt;0.05) of gene flow detected. Over all gene diversity intra-individual among populations (0.55) was lower than inter-individual among population (0.77). The results of genetic linkages based standard genetic distance and unweighted pair group method with arithmetic mean clustering method, generally divided the genotypes in three divergent groups. Similar results were obtained by principal coordinate analysis where three main groups were constructed according to three factors. A real number of genetic clusters demonstrated a clear separation between populations, where only one was comprised from genotypes from other origins. The 30.7 % out-crossing rate of B. rapa and S. arvensis populations from filed survey represents the potential for spontaneous inter-and intra-specific gene flow under Slovenian production area.

Isozyme systems as markers of genetic deterioration in stored seeds of Brassicaceae species

The main objective of this study was to determine if isozyme systems can be used as markers of genetic deterioration in Brassicaceae seed accessions under different storage conditions. Seed samples of Brassica oleracea, Cardaria draba, Erysimum cheiri, Iberis sempervirens and Rapistrum rugosum were stored for periods of 9 to 30 years at -10°C and 3-4% seed moisture content (long-term or LT conditions) and at 5°C and uncontrolled relative humidity (RH) (short-term or ST conditions). Starch Gel Electrophoresis (SGE) was used to analyse six enzyme systems oriented to determine the genetic deterioration of the accessions studied. The results obtained show that long-term storage conditions (LT) were extremely effective in maintaining the viability of seeds of the five Brassicaceae species studied. The final germination percentages reached by seeds from LT samples ranged from 75 to 100%, while the germination percentages of ST samples (except for B. oleracea) were very low (from 0 to 10%). Similar conclusions were obtained studying the integrity of electrophoretic bands for several isozymes. Two enzyme systems were of special interest: malate dehydrogenase and alcohol dehydrogenase.

Factors Affecting Postdispersal Weed Seed Predation in Barely Fields

Seed predation can be exploited as a mean of natural weed control. Field experiments were conducted in 2007 in four barely fields in Mashhad, NE of Iran to determine the effects of seed covering tissues, seed distribution patterns and interactions between seed density and background seed density on postdispersal seed predation. Five weed species (Avena ludoviciana, Hordeum spontaneum, Sinapis arvensis, Rumex obtusifolius and Rapistrum rugosum), three seed densities (50, 100 and 150 seed dish-1), two background seed densities (with and without), three distribution patterns (random, even, and aggregate), and two level of seed covering tissues (with and without) were arrange in a factorial randomized complete block design. Seed covering tissues had significant negative effect on predation and the most its effect was observed for H. spontaneum. Seed predation was also affected by seed distribution patterns. The highest and lowest seed predations of all species were observed from aggregate and random treatments respectively. The interaction between density and background seed density affected seed predation. Results show that seed predation can play an important role in decreasing the weed seeds on the soil surface and thus, in soil seed bank. Therefore, seed predation could be considered as a control technique in integrated weed management.

Cytotoxic Flavonoid Glycosides from Rapistrum rugosum L.

Five flavonoid glycosides were isolated from the n-butanol soluble fraction of the ethanolic extract of Rapistrum rugosum and their structures were assigned from (1)H- and (13)C-NMR spectra (DEPT) with 2D NMR as quercetin-3-O-α-L-rhamnopyranoside (1), quercetin-3-O- β-D-xyloside (2), quercetin, 3-O-α-L-arabinopyranoside,7-O-α-L-rhamnopyranoside (3), kaempferol 3-O-α-L-arabinopyranoside, 7-O-α-L-rhamnopyranoside (4) and rutin (5). The SRB cytotoxic assay was used to investigate the antitumor activities of n-butanol extract, compound 3 and its hexaacetate 3a, for the first time. Compounds 3 and 3a showed cytotoxic activity against the human cancer cell line, namely, HepG2 (hepatocellular carcinoma cell line) with IC50 (concentration of compound required to reduce cell survival by 50%) 0.86 μg/mL and 3.50 μg/mL, respectively. These results proved that compound 3, the major flavonoid of the n-butanol soluble fraction, has significant cytotoxic activity compared with the standard antitumor drug doxorubicin (0.60 μg/mL).

Effects of Storage and Burial on Germination Responses of Encapsulated and Naked Seeds of Turnipweed (Rapistrum rugosum) to Light

Information on the germination and viability of turnipweed seeds could be helpful in developing appropriate management strategies for this weed. Therefore, experiments were conducted to investigate the effects of light, storage conditions, duration of storage or burial, and seed type (naked, i.e., fruit wall was removed and encapsulated in siliques) on germination and viability of turnipweed. The naked and encapsulated seeds (fruit) were kept under five different storage conditions, including dry storage at 25 ± 2 C and 3 ± 1 C and outdoor environments (soil depths of 10, 20, and 40 cm). All seeds were retrieved every 2 mo and tested for germination in light and darkness. At each exhumation date, nongerminated seeds were treated with triphenyltetrazolium chloride to test their viability. The germination of seeds liberated from siliques (85%) was markedly greater than that of seeds in intact siliques (20%). The germination response of naked and encapsulated seeds to light varied between storage conditions and through time. Under indoor conditions (room and cold), both seed types had greater germination percentages in dark on most occasions than those in light. On the contrary, the germination of siliques buried at soil depths of 20 or 40 cm was considerably stimulated by light. Under indoor conditions, the percent viability of both seed types only declined marginally, whereas seeds buried in soil showed high rates of mortality. Seeds in intact siliques persisted longer under either indoor or outdoor conditions than naked seeds.

Cultivation, varietal structure and possibilities for cross-pollination of Brassica napus L. in Slovenia

Oilseed rape, Brassica napus L., is one of the most important oil plants of the moderate climatic zone and a typical industrial plant. In the past, dynamics of oilseed rape production in Slovenia was reflected in flexible agricultural market situation because of introduction of new crops into rotation and due to financial supports from European Union. In 2010, it was cultivated on 5351ha, accounting for about 1.1% of the total production areas in Slovenia. It is mainly grown in the eastern part of Slovenia (Pomurje, Podravje) and in the Spodnje-Posavska region. From 1984 until 2010, 58 different genotypes of oilseed and fodder rape were grown in Slovenia, of which a total of 28 were registered in the National List of Varieties in each year. Average yield of oilseed rape was ranged between 1.8 and 2.9 t/ha. Under Slovenian fragmented property structure the cross-pollination between B. napus and volunteer or feral populations (within and outside the production area) can occur. In addition to that, the presence of some sexually compatible relatives which have a high affinity to cross-pollination with B. napus are found (B. rapa, B. oleracea, B. nigra, Hirchfeldia incana, Raphanus raphanistrum, Sinapis arvensis, Diplotaxis erucoides, D. tenuifolia, D. muralis, S. alba, R. sativus and Rapistrum rugosum). Uncontrolled gene flow between different forms of B. napus or sexually compatible wild relatives in the case of coexistence of different production systems has a direct impact on the varietal purity of seeds and on crop quality.

Seeds of Brassicaceae weeds have an inherent or inducible response to the germination stimulant karrikinolide

Karrikinolide (KAR(1)) is a smoke-derived chemical that can trigger seeds to germinate. A potential application for KAR(1) is for synchronizing the germination of weed seeds, thereby enhancing the efficiency of weed control efforts. Yet not all species germinate readily with KAR(1), and it is not known whether seemingly non-responsive species can be induced to respond. Here a major agronomic weed family, the Brassicaceae, is used to test the hypothesis that a stimulatory response to KAR(1) may be present in physiologically dormant seeds but may not be expressed under all circumstances. Seeds of eight Brassicaceae weed species (Brassica tournefortii, Raphanus raphanistrum, Sisymbrium orientale, S. erysimoides, Rapistrum rugosum, Lepidium africanum, Heliophila pusilla and Carrichtera annua) were tested for their response to 1 µm KAR(1) when freshly collected and following simulated and natural dormancy alleviation, which included wet-dry cycling, dry after-ripening, cold and warm stratification and a 2 year seed burial trial. Seven of the eight Brassicaceae species tested were stimulated to germinate with KAR(1) when the seeds were fresh, and the remaining species became responsive to KAR(1) following wet-dry cycling and dry after-ripening. Light influenced the germination response of seeds to KAR(1), with the majority of species germinating better in darkness. Germination with and without KAR(1) fluctuated seasonally throughout the seed burial trial. KAR(1) responses are more complex than simply stating whether a species is responsive or non-responsive; light and temperature conditions, dormancy state and seed lot all influence the sensitivity of seeds to KAR(1), and a response to KAR(1) can be induced. Three response types for generalizing KAR(1) responses are proposed, namely inherent, inducible and undetected. Given that responses to KAR(1) were either inherent or inducible in all 15 seed lots included in this study, the Brassicaceae may be an ideal target for future application of KAR(1) in weed management.