Oenothera Biennis Research Articles

Biochemical changes in Oenothera biennis plants infected by ‘Candidatus Phytoplasma solani’

The aim of the present paper was to study the response of Oenothera biennis L. to ‘Candidatus Phytoplasma solani’ (Stolbur) infection by analyzing total sugars, polyphenols, photosynthetic pigments content and the antioxidant capacity in leaves and roots of healthy and infected plants. The infection caused a significant increase in peroxidation of lipids, phenylalanine ammonia-lyase activity, total sugar, polyphenols and anthocyanins content (2.8, 2.6, 1.8, 1.4, 6.8 fold, respectively), as well as a decrease in photosynthetic pigments (2–6 fold) and total flavonoids (1.5 fold) in the leaves of Oe. biennis. Changes in these parameters were insignificant in the roots except for the total polyphenols content that was 2.7 times higher in the infected ones. Reduced gluthatione content in both tested organs was not affected by the infection (3.7 and 1.7 μmol/g fresh weight of leaves and roots, respectively). The elevated content of total sugars, flavonoids and polyphenols, as well as the reduction of photosynthetic pigments and anthocyanins in infected plants are indicative of changes in the metabolism of Oe. biennis affected by the Stolbur phytoplasma. In addition to reduction of chlorophyll and carotenoids, the phytoplasma accelerated leaf senescence. Plants responded to the infection via enhanced superoxide anion scavenging, even though this reaction did not prevent, apparently, membrane damage in analysed leaves. This investigation presents new data on the effect of a phytoplasma infection on its host.

Chemical Constituents From the Roots of Oenothera biennis L.

Oenothera biennis L. (Onagraceae), is a biennial herb, native to eastern and central North America. It is cultivated in temperate regions of the world and in Indian gardens. The plant parts are used to treat gastro-intestinal disorders, eczema, whooping cough, asthma, blood disorders, laziness, obesity, piles and boils. The dried root powder was exhaustively extracted with methanol and the extract concentrated to yield a dark brown viscous mass. It was dissolved in small quantity of methanol and adsorbed onto silica gel (60 - 120 mesh) for preparation of a slurry. The air dried slurry was subjected to chromatography over silica gel column packed in petroleum ether. The column was eluted successively with petroleum ether, chloroform and methanol in order of increasing polarity to isolate the new phytoconstituents characterized as 3,11,15-trimethyl-14β-hydroxy-n-hexadeca-7-en-4,18-olide (phyt-7-enyl-14β-ol 4β,18-olide, 2), 3-methyl-6α,8β-dihydroxy-7-carboxylic acid tetralin-1,9β-olide (3), 3,7-dimethyl-11-hydroxymethylene dodec-3α,6α-diol- 11-enyl 2′,3′,6′-benzene triol (4), 1,9,10-trimethoxy-3,11-dihydroxy-13-(18,19-dihydroxyprenyl)-anthracene (5) and α-D-glucopyranosyl–(4→1′)-α-D-glucopyranosyl -6′-cetoleate (6) along with benzoic acid (1). The structures of all the isolated phytoconstituents have been established on the basis of spectral data analysis and chemical reactions.

Isovaleronitrile co-induced with its precursor, l-leucine, by herbivory in the common evening primrose stimulates foraging behavior of the predatory blue shield bug

Herbivore-induced plant volatiles play important roles in plant-insect and plant-plant interactions. The common evening primrose, Oenothera biennis, is often infested by the flea beetle, Altica oleracea, on which the predatory blue shield bug, Zicrona caerulea, is usually found. This observation suggests that the predatory bug can discriminate infested plants from intact ones to locate its prey. In this study, l-leucine-derived nitrogen-containing compounds [isovaleronitrile (3-methylbutanenitrile), (E/Z)-isovaleraldoxime and 3-methyl-1-nitrobutane] and some terpenes were identified as a characteristic volatile blend from herbivore-infested O. biennis leaves by gas chromatography/mass spectrometry, chemical synthesis, and incorporation assays using deuterium-labeled l-leucine. Volatile emission was also elicited by exogenous methyl jasmonate (MeJA), but not by mechanical damage. l-Leucine accumulated temporarily in O. biennis leaves after MeJA treatment prior to isovaleronitrile emission. Behavioral assays revealed that Z. caerulea showed a strong preference for herbivore-infested leaves, their volatiles, and isovaleronitrile in laboratory conditions.

First Report of Downy Mildew Caused by Peronospora arthurii on Common Evening Primrose (Oenothera biennis) in Italy

First Report of Downy Mildew Caused by <i>Peronospora arthurii</i> on Common Evening Primrose (<i>Oenothera biennis</i>) in Italy

Fitness consequences of occasional outcrossing in a functionally asexual plant (Oenothera biennis).

Many clonal organisms occasionally outcross, but the long-term consequences of such infrequent events are often unknown. During fiveyears, representing three to five plant generations, we followed 16 experimental field populations of the forb, Oenothera biennis, originally planted with the same 18 original genotypes. Oenothera biennis usually self fertilizes, which, due to its genetic system (permanent translocation heterozygosity), results in seeds that are clones of the maternal plant. However, rare outcrossing produces genetically novel offspring (but without recombination or increased heterozygosity). We sought to understand whether novel genotypes produced through natural outcrossing had greater fecundity or different multigenerational dynamics compared to our original genotypes. We further assessed whether any differences in fitness or abundances through time between original and novel genotypes were exaggerated in the presence vs. absence of insect herbivores. Over the course of the experiment, we genotyped >12,500 plants using microsatellite DNA markers to identify and track the frequency of specific genotypes and estimated fecundity on a subset (>3,000) of plants. The effective outcrossing rate was 7.3% in the first year and ultimately 50% of the plants were of outcrossed origin by the final year of the experiment. Lifetime fruit production per plant was on average 32% higher across all novel genotypes produced via outcrossing compared to the original genotypes, and this fecundity advantage was significantly enhanced in populations lacking herbivores. Among 43 novel genotypes that were abundant enough to phenotype with replication, plants produced nearly 30% more fruits than the average of their specific two parental genotypes, and marginally more fruits (8%) than their most fecund parent. Mean per capita fecundity of novel genotypes predicted their relative frequencies at the end of the experiment. Novel genotypes increased more dramatically in herbivore-present compared to suppressed populations (45% vs. 27% of all plants), countering the increased competition from dandelions (Taraxacum officinale) that resulted from herbivore suppression. Increased interspecific competition likely also lead to the lower realized fitness of novel vs. original genotypes in herbivore-suppressed populations. These results demonstrate that rare outcrossing and the generation of novel genotypes can create high-fecundity progeny, with the biotic environment influencing the dynamical outcome of such advantages.

Числа хромосом инвазионных видов во флоре Республики Алтай: сообщение 2

Chromosome numbers (2n) in 16 invasive plant species from the families Amaranthaceae, Asteraceae,&nbsp;Caryophyllaceae, Lamiaceae, Onagraceae and Poaceae are reported on the material from the Altai Republic for the&nbsp;first time. Among them, chromosome complements were first examined in Russia for Chaiturus marrubiastrum (L.)&nbsp;Ehrh. ex Reichenb. (2n = 24) and Oenothera villosa Thunb. (2n = 14). Five species: Amaranthus lividus L. (2n = 34),&nbsp;Elisanthe noctiflora (L.) Rupr. (2n = 24), Galeopsis speciosa Mill. (2n = 16), Oenothera biennis L. (2n = 14) and&nbsp;Bromus japonicus Thunb. (2n = 14), were studied first from Siberia. The most part of the species studied are diploids.&nbsp;The general distribution and the history of floristic findings of these species in the Altai Republic are given. The data&nbsp;on chromosome numbers published earlier on the material from Russia are cited.&nbsp

The influence of range‐wide plant genetic variation on soil invertebrate communities

Plant genetic variation can have far‐reaching effects on associated communities and ecosystems. Heritable variation in ecologically relevant plant traits is often non‐randomly distributed across a species’ range and can exhibit geographic clines. In the event of range expansions and migration, previously unfamiliar genotypes may have large impacts on resident communities and ecosystems due to the introduction of novel and heritable phenotypic variation. Here we test the hypothesis that geographic origin of a focal plant genotype has effects on belowground invertebrate communities using a common garden field experiment. We sampled soil invertebrates from 103 Oenothera biennis genotypes, which were collected from across the species’ range and planted into a common garden field experiment at the northern range limit. We enumerated 24 000 individuals from 190 morphospecies and found that the diversity, abundance, and composition of soil invertebrate communities varied greatly among plant genotypes. Despite strong effects of plant genotype, we found few genetic correlations between plant traits and soil invertebrate community variables. However, herbivore damage was strongly related to variation in the soil invertebrate community. Geographic origin of plant genotypes had at most a weak effect on belowground communities. We speculate that predicting the extended effects of population movement on associated communities will require detailed knowledge of the trait variation occurring within focal species across particular environmental gradients.

Efficacy and Tolerability of Phytomedicines in Multiple Sclerosis Patients: A Review.

Multiple sclerosis (MS) is a chronic inflammatory and demyelinating disorder of the central nervous system (CNS) that can cause cognition, mobility, and sensory impairments. It is considered one of the most common non-traumatic causes of disability in the world. The aim of the present article was to review the clinical evidence related to medicinal plants in the management of MS symptoms. Electronic databases, including the Cochrane Library, Pubmed, and Scopus, were searched for entries from 1966 to February 2017. Only clinical studies were included in this review. Different medicinal plants have positive effects on MS, including Andrographis paniculata, Boswellia papyrifera, Ruta graveolens, Vaccinium spp., Camellia sinensis, Panax ginseng, Aloysia citrodora, Ginkgo biloba, Oenothera biennis, and Cannabis sativa. C. sativa had the highest level of clinical evidence, supporting its efficacy in MS symptoms. Proanthocyanidins, ginkgo flavone glycosides, ginsenosides, epigallocatechin-3-gallate, cannabinoids (including delta-9-tetrahydrocannabinol and cannabidiol), boswellic acid, and andrographolide were presented as the main bioactive components of medicinal plants with therapeutic benefits in MS. The main complications of MS in which natural drugs were effective include spasticity, fatigue, scotoma, incontinence, urinary urgency, nocturia, memory performance, functional performance, and tremor. Herbal medicines were mostly well tolerated, and the adverse effects were limited to mild to moderate. Further well-designed human studies with a large sample size and longer follow-up period are recommended to confirm the role of medicinal plants and their metabolites in the management of MS.

Drug-Herb Interactions in the Elderly Patient with IBD: a Growing Concern.

Inflammatory bowel disease (IBD), which includes conditions such as Crohn's disease and ulcerative colitis, is becoming more prevalent with the elderly being the fastest growing group. Parallel to this, there is an increasing interest in the use of complementary and alternative medicine (CAM). Nearly half of patients with IBD have used CAM at one time. The elderly patients, however, are burdened by comorbid conditions, polypharmacy, and altered functional status. With increasing use of complementary and alternative medicine in our elderly patients with IBD, it is vital for the provider to provide counsel on drug-herb potential interactions. CAM includes herbal products, diet, dietary supplements, acupuncture, and prayer. In this paper, we will review common CAM, specifically herbs, that are used in patients with IBD including the herb background, suggested use, evidence in IBD, and most importantly, potential interactions with IBD medications used in elderly patients. Most important evidence-based adverse events and drug-herb interactions are summarized. The herbs discussed include Triticum aestivum (wheat grass), Andrographis paniculata (chiretta), Boswellia serrata, tormentil, bilberry, curcumin (turmeric), Plantago ovata (blond psyllium), Oenothera biennis (evening primrose oil), germinated barley foodstuff, an herbal preparation of myrrh, chamomile and coffee extract, chios mastic gum, wormwood (absinthe, thujone), Cannabis sativa (marijuana, THC), tripterygium wilfordii (thunder god vine), Ulmus rubra (slippery elm bark), trigonella foenugraecum (fenugreek), Dioscorea mexicana (wild yam), Harpagophytum procumbens (devil's claw), ginger, cinnamon, licorice, and peppermint.

Hydrocarbon degradation potential and plant growth-promoting activity of culturable endophytic bacteria of Lotus corniculatus and Oenothera biennis from a long-term polluted site

Many endophytic bacteria exert beneficial effects on their host, but still little is known about the bacteria associated with plants growing in areas heavily polluted by hydrocarbons. The aim of the study was characterization of culturable hydrocarbon-degrading endophytic bacteria associated with Lotus corniculatus L. and Oenothera biennis L. collected in long-term petroleum hydrocarbon-polluted site using culture-dependent and molecular approaches. A total of 26 hydrocarbon-degrading endophytes from these plants were isolated. Phylogenetic analyses classified the isolates into the phyla Proteobacteria and Actinobacteria. The majority of strains belonged to the genera Rhizobium, Pseudomonas, Stenotrophomonas, and Rhodococcus. More than 90% of the isolates could grow on medium with diesel oil, approximately 20% could use n-hexadecane as a sole carbon and energy source. PCR analysis revealed that 40% of the isolates possessed the P450 gene encoding for cytochrome P450-type alkane hydroxylase (CYP153). In in vitro tests, all endophytic strains demonstrated a wide range of plant growth-promoting traits such as production of indole-3-acetic acid, hydrogen cyanide, siderophores, and phosphate solubilization. More than 40% of the bacteria carried the gene encoding for the 1-aminocyclopropane-1-carboxylic acid deaminase (acdS). Our study shows that the diversity of endophytic bacterial communities in tested plants was different. The results revealed also that the investigated plants were colonized by endophytic bacteria possessing plant growth-promoting features and a clear potential to degrade hydrocarbons. The properties of isolated endophytes indicate that they have the high potential to improve phytoremediation of petroleum hydrocarbon-polluted soils.

Evening primrose (Oenothera biennis) Δ6 fatty acid desaturase gene family: cloning, characterization, and engineered GLA and SDA production in a staple oil crop

γ-Linolenic acid (GLA), stearidonic acid (SDA), and other polyunsaturated fatty acids (PUFAs) play important roles in human health, and Δ6 fatty acid desaturase (D6D) is a key enzyme for PUFA biosynthesis. Oenothera biennis is a traditional GLA-producing oil crop. Here we report the cloning, characterization, and metabolic engineering of its D6D gene family. The intronless 1922-bp ObD6D1 and 1752-bp ObD6D2 both have alternative transcription start sites, alternative polyadenylation sites, and repeated stop codons. Phylogenetic study revealed five large groups of front-end desaturases which are not simply correlated with desaturase types or organism origins. Any type of front-end enzyme has independently originated for multiple times. “Higher plants,” “higher animals,” and cyanobacteria each has front-end enzymes of single ancient origin, but other taxa are contrary. ObD6D1 and ObD6D2 are most abundantly expressed in bud and root, respectively. In yeast expression, ObD6D1 and ObD6D2 both catalyzed linoleic acid into GLA, and α-linolenic acid into SDA. Based on a newly constructed double-selection vector system, four constructs of ObD6D1 and ObD6D2 both individually driven by double CaMV35S promoter PD35S and seed-specific promoter PNAP were transformed into Brassica napus via Agrobacterium. T1 plants, T2 elite lines, and homozygous T3 elite lines accumulated average GLA + SDA levels of 6.04, 15.77, and 21.56% of seed fatty acids, respectively. ObD6D2 showed higher effect than ObD6D1. PD35S-D6D engineering has little side effect but is weaker than PNAP-D6D engineering in terms of GLA + SDA productivity.

Alien plants in forest communities of the Middle Volga Region: dissemination and degree of naturalization

In forest communities of the Middle Volga forest-steppe zone (within Penza, Samara and Ulyanovsk Regions) there are 60 alien species of vascular plants. 25 species of adventives (42%) have naturalized in forests, 7 species are epecophytes (Cotoneaster lucidus , Oenothera biennis, O. rubricaulis, and O. villosa, Populus suaveolens, Ulmus minor, Xanthoxalis stricta) and 18 species are agriophytes (Acer negundo, Amelanchier spicata, Bidens frondosa, Caragana arborescens, Conyza canadensis, Echinocystis lobata, Heracleum sosnowskyi, Impatiens parviflora, Fraxinus lanceolata, F. pennsylvanica, Lonicera tatarica, Lupinus polyphyllus, Malus domestica, Parthenocissus inserta, Salix euxina, Sambucus racemosa, S. sibirica, Ulmus pumila). Transformer-types are arboreal - Acer negundo, Fraxinus lanceolata, F. pennsylvanica, Parthenocissus inserta, Ulmus pumila, as well as herbaceous plants - Bidens frondosa, Conyza canadensis, Echinocystis lobata, Heracleum sosnowskyi, Impatiens parviflora. The introduction of alien trees and shrubs in the forest can lead to dense thickets, disrupt underbrush resumption and main forest-forming species growth, as well as negatively affect the herbaceous layer. Most vulnerable to the introduction of adventive plants are roadsides and the places where forests are close to human settlements. The introduction of alien plants in forest communities is the result of ornithochory (33; 54%), anemochory (11 species; 18%), anthropochory (8 species; 13%) or a combination of various ways of introduction.

Antiproliferative and antimicrobial efficacy of the compounds isolated from the roots of Oenothera biennis L.

Oenothera biennis L., commonly known as evening primrose, harbours the flavonoids, steroids, tannins, fatty acids and terpenoids responsible for a diverse range of biological activity, such as antitumour, anti-arthritic and anti-inflammatory effects. In addition to the previous reports from aerial parts of this plant, studies related to antiproliferative or antimicrobial activity from the roots are warranted. To investigate antiproliferative and antimicrobial activity of compounds/mixture (1-8) isolated and characterized from the roots of O.biennis L. A possible mechanism of antiproliferative activity was also studied by targeting ornithine decarboxylase (ODC) and cathepsin D (CATD). Antiproliferative efficacy of the compounds/mixture was examined in selected cancer cell lines along with their probable mechanism of action. The antimicrobial activity was also studied against selected microbes (bacteria and fungi). Antiproliferative potential was evaluated by MTT assay against selected cell lines. The mechanism of action was studied spectrophotometrically by targeting ODC and CATD using both an in-vitro and an in-silico approach. The antimicrobial efficiency was analysed using the disc diffusion and broth dilution methods. Oenotheralanosterol B (3) and the mixture of oenotheralanosterol A and oenotheralanosterol B (4) exhibited antiproliferative activity against breast, hepatic, prostate and leukaemia cancer cell lines as well as in mouse macrophages (IC50 8.35-49.69μg/ml). Oenotheralanosterol B (3) and the mixture of oenotheralanosterol A and oenotheralanosterol B (4) displayed a strong molecular interaction with succinate dehydrogenase (binding energy -6.23 and -6.84kcal/mol and Ki 27.03 and 9.6μm, respectively). Oenotheralanosterol A (1), oenotheralanosterol B (3) and mixture of oenotheralanosterol A and oenotheralanosterol B (4) potently inhibited the ODC activity with IC50 ranging from 4.65±0.35 to 19.06±4.16μg/ml and also showed a strong interaction with ODC (BE -4.17 to -4.46kcal/mol). Oenotheralanosterol A (1), cetoleilyl diglucoside (2), oenotheralanosterol B (3), dihydroxyprenylxanthone acetylated (6) and dihydroxyprenylxanthone (7) inhibited CATD activity (IC50 3.95±0.49 to 24.35±2.89μg/ml). The in-silico molecular interaction analysis of compounds with CATD revealed the non-specific interaction. A moderate antimicrobial activity was observed against selected microbes with a growth inhibition ranging from 6 to 14mm and minimum inhibitory concentration between 125 and 500μg/ml. Oenotheralanosterol B (3) and dihydroxyprenylxanthone acetylated (6) exhibited better antimicrobial activity with an MIC range from 62.50 to 500μg/ml. Oenotheralanosterol B (3) exhibited stronger antiproliferative and antimicrobial potential with respect to the other compounds tested, whereas oenotheralanosterol A (1) was a potent inhibitor of ODC and CATD. Hence, it is suggested that these in-vitro findings could be studied further invivo for biological activity, safety evaluation and derivatization to enhance potency and efficacy.

Responses of plant phenology, growth, defense, and reproduction to interactive effects of warming and insect herbivory.

Climate warming can modify plant reproductive fitness through direct and indirect pathways. Direct effects include temperature-driven impacts on growth, reproduction, and secondary metabolites. Indirect effects may manifest through altered species interactions, including herbivory, although studies comparing the interactive effects of warming and herbivory are few. We used experimental warming combined with herbivore exclusion cages to assess the interactive effects of climate warming and herbivory by Popillia japonica, the Japanese beetle, on flowering phenology, growth, defense, and lifetime reproduction of a biennial herb, Oenothera biennis. Regardless of temperature, herbivory delayed flowering phenology and, surprisingly, led to decreased levels of foliar defenses. At ambient temperatures, plants were able to compensate for herbivory by producing smaller seeds and increasing total seed production, leading to similar investment in seed biomass for plants exposed to and protected from herbivores. At elevated temperatures, plants had elevated total seed production, but herbivory had negligible impacts on flower and fruit production, and total lifetime seed biomass was highest in plants exposed to herbivores in warmed conditions. We speculate that warming induced a stress response in O.biennis resulting from low soil moisture, which in turn led to an increase in seed number at the expense of maternal investment in each seed. Plant-insect interactions might therefore shift appreciably under future climates, and ecologists must consider both temperature and herbivory when attempting to assess the ramifications of climate warming on plant populations.

Study Effect of Evening Primrose Oil Supplement on Type 2 Diabetes Mellitus - Associated Metabolic Parameters

Natural products are reported to be useful for controlling or preventing T2DM as an anti-inflammatory, AMPK activators, insulin secretion stimulators, alpha-glucosidase / disaccharidase or amylase inhibitors. Evening primrose oil (Oenothera biennis) is a substantial source of omega-6 essential fatty acids, mostly gamma-linolenic acid (GLA). The activity of Δ-6-desaturase enzyme responsible to convert linolenic acid (LA) to forms GLA is compromised in patients with type 2 diabetes. Accordingly, this study aimed to evaluate the effect of evening primrose oil in amelioration metabolic parameters of type 2 diabetes mellitus. Twenty six overweight or obese patients newly diagnosed with type 2 diabetes were enrolled. Thirteen patients received metformin 500 mg tablets twice daily alone (as a conventional therapy) for 3 month therapy, and 13 patients received metformin 500 mg plus evening primrose oil 2 gm capsule twice daily. Serum fasting glucose, total cholesterol, triglycerides, high density lipoprotein-cholesterol (HDL-C), low density lipoprotein cholesterol, very low density lipoprotein cholesterol, fasting serum insulin (FSI) was measured. Insulin resistance and β-cell function was determined by using homeostatic model assessment (HOMA). There was statistically significant elevation in baseline level of fasting serum glucose, glycated hemoglobin (HbA1c), total cholesterol, low density lipoprotein-cholesterol (LDL-C), fasting serum insulin, insulin resistance (HOMA- IR), and in both patient groups 1 and 2 compared to control subjects, (P&lt; 0.001). High reduction in these parameters post treatment was found in both patient groups compared to pre treatment level, significantly with fasting serum insulin in group 2 patients (P&lt; 0.001). Inversely, lower levels were seen in HDL-C, HOMA-B, significantly elevated post treatment in both groups. No difference was found in triglyceride and VLDL-C in both patient groups compared to control subjects, but significantly reduced post treatment. In conclusion, early intervention with natural oil rich in gamma linolenic acid with traditional hypoglycemic drugs can improve therapeutic outcome and represent a promising strategy to slow the progression of diabetes complications.

Comparative Study on the Influence of Organic Fertilizer and Soil Amendments on Evening Primrose (Oenothera biennis L.)

Comparative Study on the Influence of Organic Fertilizer and Soil Amendments on Evening Primrose (Oenothera biennis L.)

Nomenclatural notes and neotypification of Oenothera biennis var. sulphurea (Onagraceae)

The taxonomy of individuals of Oenothera biennis (Onagraceae) with sulphur-yellow flowers is discussed. Due to the lack of original material, the modern specimen collected from the classic stand, stored in National Herbarium of the Netherlands in Leiden is designated to serve as neotype.

Effects of some Ggronomic Techniques on Oil Yield and Composition of Oenothera biennis L.

Evening Primrose oil (Oenothera biennis L.) is a rich source of Gamma linolenic acid (GLA) and other useful unsaturated fatty acids. Despite the diversity of sources of GLA, due to better absorption in the human body, evening primrose oil is the main source of GLA. In this study, the effects of pollination, harvesting method and application of salicylic acid on yield, yield components, and quality of evening primrose oil were studied. A factorial experiment as a randomized complete block design with three treatments including pollination (pollination by bees, no pollinators and free pollinators), salicylic acid (0 and 200 ppm) and harvest method (normal harvest, pre harvest by flame) and four replications was performed. The effect of treatments on the oil yield, oil content, fatty acids composition and the content of free fatty acids of oil were studied. Results showed that the oil yield and oil percentage of plants which visited by bees were at the highest amount (1.87 gr/ plant and 33.6%, respectively). Compared to the control, the oil yield of plants which treated with salicylic acid significantly increased. Between two different harvest methods, the highest oil percent (31.6 %) was observed in plants treated with flame. Under the interaction effect of treatments, the highest oil yield (2.24 g/plant) was observed in combination of bee and salicylic acid 200 ppm and the highest free fatty acids (2.19%) accumulation was recorded in the open cage with 200 ppm salicylic acid. Since pollination increases the number of formed seeds per capsules, therefore, it is expected that simultaneous application of pollinator and pre-harvest treatment by flame increases seed yield, oil yield and quality which is partly shown in the obtained results of present study.

Genotypic diversity mitigates negative effects of density on plant performance: a field experiment and life cycle analysis of common evening primrose Oenothera biennis

Summary Genotypic diversity in plant populations is known to enhance plant performance and ecosystem function. Nonetheless, the effect of genotypic diversity has rarely been examined across a population's lifecycle despite the expectation that changing conditions, such as population density, will alter the benefits of diversity. We simultaneously manipulated a component of genotypic diversity (richness, the number of genotypes) and density of common evening primrose Oenothera biennis to address the consequences for herbivory and lifetime fitness in a 2‐year field experiment that spanned seed germination to lifetime fruit production. We genotyped &gt;1100 seedlings with microsatellite DNA markers to determine realized diversity and density in plots sown with O. biennis seeds. Our design achieved quantitative variation in plant density and diversity, with one to 44 individuals established in field plots and two to eight genotypes per polyculture plot (based on microsatellite analysis of reproductive plants). We found a strong interaction between seed density and genetic diversity, with germination and establishment being 24% higher in genetic polycultures than monocultures, but only at low seed density. At high seed density, the opposite pattern emerged, with polycultures having 12% fewer individuals established than monocultures. Initial effects of emergence on plot density persisted through to the fruiting stage. Higher plant densities resulted in increased mortality, decreased probability of reproduction, decreased plant height and lower levels of lifetime fruit production per plant. Increasing genotypic diversity increased the probability of reproduction overall and showed a significant interaction with plant density mitigating the negative effects of high density on individual height and lifetime fruit production. Synthesis. Plant density and genotypic diversity interacted from the very early stages of seed germination and establishment of Oenothera biennis. This effect persisted over the 2‐year life cycle of plants, and genotypic diversity buffered against the negative fitness consequences of high plant density. These results imply a dynamic interplay between the long‐held paradigm of density effects in plant ecology and the genetic structure of populations.

Seed oil quality of GA3 induced flowering evening primrose (Oenothera biennis L.).

Gamma-linoleic acid in the seed oil of evening primrose makes it nutritionally and pharmaceutically valuable. If evening primrose wants to be cultivated as an annual plant, sowing time is important. By the late sowing and depends to time most plants do not produce flower stem and stay in rosette stage until next spring. To solve this problem, the present study was performed. Seedling were transplanted to 4 kg plastic pots containing a mixture of leaf compost: local soil: perlite (1:2:1 ratio) and placed in outdoor conditions. Non-vernalized plants were then selected and treated with different temperature regimes (1, 2 and 3 weeks in 4-6oC) and gibberellic acid (GA3) application in different concentrations of 0, 500, 1000, 2000 ppm, separately. The results showed that although some physiological parameters were affected by low temperature, no flower stem was produced. In contrast, plants that were treated with GA3 produced flower stem. Time of flowering and the number of flowers were significantly affected by the concentrations of applied GA3. Although yield components of GA3 induced plants were higher than that of normal growth plant, the seed yield of them was low. Surprisingly, the gamma linolenic acid (GLA) percentage of seed oil of plants treated with 2000 ppm GA3 was significantly higher than that of non- treated plants. Finally, it can be concluded that, although the application of GA3 guarantees delayed sowing evening primrose flowering and better GLA production, but low seed yield is a subject that cannot be easily ignored in production.