Physicochemical and Biochemical Characterization, Total Phenolic and Energy Value from Bulbs of Different Onion (Allium cepa L.) Varieties in Senegal

The purpose of this study is to investigate the physicochemical properties of some local varieties of onion (Allium cepa L.) and compare them with an imported variety, all collected in May 2021. Proteins, reducing sugars, lipids, and polyphenol content were estimated according to the AFNOR standardized methods. The determination of calcium, magnesium, iron, sodium, potassium and phosphorus was performed by atomic absorption spectrophotometer coupled with a CCD detector. The results highlighted an average acidity of 0.377% ± 0.002% lower than the value of the imported variety which is 0.520% ± 0.001%. Local varieties have a pH ranging from 6.35 ± 0.003 to 6.42 ± 0.004, while the variety has a pH of 6.36 ± 0.003. The ash and dry matter contents vary respectively from 4.788% ± 0.004% to 8.253% ± 0.003% and 7.945% ± 0.021% to 11.945% ± 0.007% for the local varieties. Moreover, the imported one has ash and dry matter contents of 5.175% ± 0.007% and 10.035% ± 0.021% respectively. The results show that the protein, reducing sugar and lipid contents in the local onion varieties vary respectively from 2.815 ± 0.000 to 15.634 ± 0.001 g·100 g-1;4.691 ± 0.001 to 12.596 ± 0.002 g·100 g-1 and 0.006 ± 0.001 to 0.050 ± 0.057 g·100 g-1. Furthermore, the imported variety has a protein, reducing sugar and lipid content of 5.649 ± 0.002;8.565 ± 0.002 g·100 g-1 and 0.011 ± 0.010 g·100 g-1 respectively. The maximum levels of total polyphenols are obtained in the imported variety, Bellani and Gandiol, respectively 9.973 ± 0.001, 4.535 ± 0.002, and 3.425 ± 0.006 mg EAG/g of dry matter. The local varieties have a significant calorific intake of between 35.451 ± 0.001 and 112.980 ± 0.003 kcal·100 g-1 compared to the imported one with an energy value of 56.953 ± 0.001 kcal·100 g-1 of dry matter. The bulbs of different onion varieties studied have a fairly high content of mineral elements. The potassium content of local varieties is between 502.16 ± 0.06 mg·100 g-1 and 582.77 ± 0.04 mg·100 g-1 while the imported variety has a content of 536.62 ± 1.30 mg·100 g-1. They note that the local varieties have a better calcium content (249.75 ± 0.07 to 434.20 ± 0.57 mg·100 g-1) and magnesium (142.15 ± 0.07 to 162.60 ± 0.42 mg·100 g-1) than the imported variety (229.58 ± 0.04 mg·100 g-1) except for the varieties White Grano (228.29 ± 0.01 mg·100 g-1) and Rouge Amposta (117.00 ± 0.42 mg·100 g-1) respectively. These results reveal that Gandiol, Dayo and Orient F1 are nutritionally found better due to their higher antioxidant property, proteins, carbohydrates, and reducing sugar and should be included in diets to supplement our daily allowance needed by the body.

The Role of Jasmonates as Antibulbing Substances in the Bulb Formation of Onion

Onion plants form spherical bulbs under long-day conditions.Substances regulating bulb formation remain unknown.In the course of chemical studies on the bulb formation,α-linolenic acid was isolated from onion extracts as an antibulbing substance,the amount of which was synchronized with the bulb formation.Since allene oxide synthase inhibitor canceled the antibulbing activity ofα-linolenic acid,it was disclosed that jasmonic acid concerns this regulation.Structure-activity-relationship study revealed that its(3R,7S)stereochemistry is necessary for showing its antibulbing activity.It is concluded that(3R,7S)-jasmonate derived fromα-linolenic acid actually participates in the regulation of bulb formation.

Effect of onion (<i>Allium cepa</i>L.) as an antibiotic growth promoter substitution on performance, immune responses and serum biochemical parameters in broiler chicks

This experiment was conducted to evaluate the effect of onion (Allium cepa L.) as an antibiotic growth promoter substitute on growth performance, immune responses and serum biochemistry in broilers. A total of 192 one-d-old as hatched broiler chicks (Ross 308) were weighed and randomly allocated to four treatment groups, each with 4 replicate pens of 12 chicks. The dietary treatments consisted of the basal diet (control), antibiotic (15 mg Virginiamycin/kg), and control +10 or 30 g fresh onion bulb/kg diet. Body weights of broilers were determined at d 1, 21 and 42, feed intake was determined at the same periods, and feed conversion ratio was calculated accordingly. At 14th and 21st days blood samples were taken for measuring antibody titers against NDV and at 42nd day for biochemical analysis. At d 42, two birds per replicate were slaughtered for determination of lymphoid organ weights. Dietary supplementation of30 g/kg onion increased final body weight of broilers at 42nd d of age compared to the other treatments (P < 0.05). Birds fed30 gonion/kg in the diet had the highest feed intake than other treatments at different growth periods (P < 0.05). Dietary treatments failed to induce any significant effect on antibody titers against NDV, although the weight of lymphoid organs was significantly (P Broilers receiving30 g/kg onion had a significantly higher HDL and lower triglyceride concentrations compared to control groups (P . Feeding30 g/kg onion resulted in a marked reduction in the concentration of the glucose compared to control groups (P . The results suggested that dietary inclusion of30 g/kg onion can be applied as alternatives to in-feed antibiotics for broiler diets.

Effect of Different Mulching Types on Insect and Disease Infestation and Yield of Onions (Allium cepa L.) in Loamy Sand

This research was carried out to assess the effect of different varieties and mulching types on insect and disease infestation,and the yield of onions.The experiment was conducted in Sangkat TuekVil,KrongSiem Reap,in Cambodia.A 2×4 factorial in RCBD(Randomized Complete Blocks Design)was used to layout the trial,in which two varieties(Texas Early Grano 502 PRR and Earth F1)and four mulch types(non-mulch,rice Straw,silver plastic mulching and black plastic mulching)were used as the treatments.Application of these treatments was to enhance soil temperature,leaf number plant-1,stand count,bulb diameter,single bulb weight,insect incidence,disease incidence and bulb yield are different to all treatments.As the result,the bulb yields of onions among these treatments were found superior in Texas Early Grano 502 PRR combined with Black Plastic mulch followed by Texas Early Grano 502 PRR combined with silver plastic mulch and Texas Early Grano 502 PRR combined rice straw mulch,whereas the lowest was found in Earth F1combined with non-mulch.

洋葱(Alliumcepa L.)RAPD-PCR反应体系及扩增程序的优化

为建立多态性高、稳定性好的洋葱RAPD-PCR反应体系,采用正交设计,研究了Taq酶、Mg2+、引物和dNTP 4种RAPD-PCR反应组分浓度变化对扩增结果的影响,在此基础上对模板DNA用量、扩增程序中退火温度和反应循环次数进行了筛选。试验结果表明,洋葱20μl RAPD-PCR优化反应体系为1×Buffer、2.0 mmo1/L Mg2+、1.0 UTaqDNA聚合酶、200μmo1/L dNTP、0.6μmo1/L引物、2%甘油和15 ng DNA模板;PCR扩增程序为94℃预变性4 m in;94℃变性30 s,35℃退火40 s,72℃延长1.5 m in,45个循环;72℃保温延伸7 m in。

Molecular Cloning and Expression Analysis of AcFT3 in Allium cepa

Onion （Allium cepa L.） was an economic vegetable and a strictly biennial herb, which was widely distributed in the world. In the past, it was a strictly biennial plant, the studies had shown that FT （FLOWERING LOCUS T） gene was involved in the photoperiod pathway to regulate fowering in the model plant. In this study, transcriptome sequencing method was used to obtain cDNA sequence of FT homologous gene in onion, named AcFT3 （KF864665）. AcFT3 had a full-length of 540 bp, encoded 179 amino acids, with 98.31% homology to AfFT （Allium fstulosum）, and 63.0%-84.0% homology to other higher plants. Phylogenetic tree analysis indicated that AcFT3 had the closest relationship with AfFT. The results of quantitative RT-PCR showed the expression pattern of AcFT3 both in vegetative growth of onion and in different organs of bolting and fowering, the expression level of AcFT3 reached the highest in the leaves before bolting and in the fower organs after bolting.

不同浓度NaCl胁迫对洋葱种子发芽的影响

为明确不同浓度NaCl胁迫对洋葱种子发芽的影响,本研究采用模拟试验方法,设置5个浓度NaCl溶液处理即0(CK)、50、100、150 mmol/L和200 mmol/L,测定并分析其对洋葱品种‘早黄金’‘天正105’‘火星1号’种子发芽势、发芽率、根长、活力指数、盐害系数等指标的影响,并对各洋葱品种进行耐盐性筛选。结果表明,随着NaCl溶液浓度升高,3个洋葱品种的种子发芽势、发芽率、活力指数都随之降低,根长不同程度缩短,盐害系数增大。NaCl溶液浓度为200 mmol/L时,3个洋葱品种间的种子发芽势和发芽率均差异显著(P<0.05)。综合来看,洋葱种子发芽对中等浓度盐胁迫敏感,对低浓度盐胁迫敏感性低且种子萌发受到的抑制作用不强,高浓度盐胁迫显著抑制种子萌发。3个洋葱品种种子萌发期的耐盐能力表现为‘火星1号’>‘天正105’>‘早黄金’。

Two new furostanol saponins from the seeds of Allium cepa L.

Phytochemical analysis of the n-BuOH extract from the seeds ofAllium cepa L.led to isolation of four furostanol saponins,two of which were new compounds,named ceparoside A（la）and ceparoside B（2a）.The chemical structures of the new compounds were elucidated through a combination of NMR,MS spectral data and chemical analysis.

Assessing the Pathogenic Ability of Six Species of Fusarium Genus on Onion Variety in Burkina Faso

Prema 178 onion variety is widely used in production in Burkina Faso. It is greatly appreciated but susceptible to basal rot. This study aimed to evaluate the pathogenic ability of six strains of Fusarium genus identified in Burkina Faso on onion. Seeds, seedlings and bulbs were used for the test. A conidial suspension of each strain was made in tubes and adjusted to 1 × 106 conidia/ml with distilled water for the different tests. Germination test in the laboratory and greenhouse showed that all treatments with the strains of Fusarium oxysporum f. sp. cepae, F. solani, F. falciforme, F. acutatum, F. proliferatum and F. sp. induced failure to emerge and showed a significant difference with the control. The different strains also induced stunting rates of coleoptile growth. Fusarium oxysporum f. sp. cepae, F. acutatum, F. proliferatum, F. falciforme and F. solani were very aggressive, as they recorded above 50% damping-off rates. The test on the bulbs revealed that the strains were classified into two groups. The first consists of F. oxysporum f. sp. cepae, F. solani, F. falciforme, F. acutatum, which caused rots with respective lengths from 2.06;1.48;1.84;1.46 and 2.12 cm, thus very aggressive according to Ghanbarzadeh scale. The second is formed by F. proliferatum which recorded 0.90 cm of rot length, thus moderately aggressive. It would be appropriate to suggest a sustainable management method for these pathogens in order to improve the yield of onion production.

The Transfer of Cu, Zn, Mn and Fe between Soils and <i>Allium</i>Plants (Garlic and Onion), and Tomato in the Southwest of the Buenos Aires Province, Argentina

Chemical extraction methods are generally used to evaluate trace element concentrations in soils. The adequacy of these soil tests is commonly assessed by comparing the extraction results with the metal contents in the plants. In this study, soil and leaf samples were collected in the southwest area of the Buenos Aires Province, Argentina. Garlic (Allium sativum L.), onion (Allium cepa L.) and tomato (Solanum lycopersicum L.) are species of great regional economic importance. These crops need good mineral nutrition for optimum growth and sustainable production. Cu, Zn, Mn and Fe micronutrient uptake by plants was analyzed together with the trace element contents in the soil in which those plants were grown. A single EDTA-extraction procedure was performed to determine soil micronutrients. The amount of extractable-trace elements increased as the concentration of the chelating agent EDTA increased. The range of total element content in soil was: 15.68-31.5 mg·kg-1 for Cu, 75.0-386.3 mg·kg-1 for Zn, 542.5 -1686 mg·kg-1 for Mn and 28,325-32,675 mg·kg-1 for Fe. Micronutrient contents in mature leaf tissue were determined by the acid digestion method. Total and available micronutrient content in soil as well as total content in leaves were measured by flame atomic absorption spectrometry (FAAS). Total micronutrient content and the available extractable-fraction in soils were below the critical values for plant growth. This was in agreement with the amount of micronutrients present in the leaf tissue. A strong relationship between the extraction data and the soil-plant transfer coefficients suggested an appropriate exchange of trace elements from soils to garlic, onion and tomato plants.

Quantification and analysis of anthocyanin and flavonoids compositions,and antioxidant activities in onions with three different colors

Onion（Allium cepa L.） is a very important vegetable crop widely cultivated throughout the world. In this study, we measured total anthocyanins and flavonols of onions of three colors. The fresh weight（FW） of total anthocyanins were（29.99±1.19）,（9.64±1.30） and（0.75±0.40） mg 100 g^–1 fruit in red, yellow and white onions, respectively. Likewise, the FW of total flavonoids were（111.10±5.98）,（36.64±3.59）, and 0 mg 100 g^–1 in red, yellow and white, respectively. Four types of anthocyanins（delphinidin 3,5-diglycosides, cyanidin 3,5-diglycosides, cyanidin 3-glycosides and cyanidin 3-（6′′-malonyl）-glucopyranoside） and two kinds of flavonoids（quercetin and quercetin 3-glycosides） were identified in two varieties（red and yellow bulb） of onions by HPLC/DAD-ESI/MS. The total polyphenol contents were also measured by means of Folin-Ciocalteu method. Moreover, all the concentrations of anthocyanins, flavonoids and polyphenols showed significantly positive correlations with antioxidant activities measured by DPPH˙, ABTS˙＋ and FRAP assays. This study provided information on anthocyanin and flavonoids compositions that will be useful for onion breeding.

Isolation,purification,structural characteristic and antioxidative property of polysaccharides from A.cepa L.var.agrogatum Don

Allium cepa L.var.agrogatum Don(ALAP)is commonly consumed in China as well as other regions and has various beneficial health effects.A novel acidic polysaccharide(named ALAP-21)was obtained from ALAP by ultrasonic and microwave-assisted extraction and purification using DEAE-52 anion exchange and Sephadex G-100 columns.The monosaccharide composition,structural and antioxidative properties of ALAP-21 were investigated by GC–MS chromatography,FT-IR and NMR spectroscopies and three antioxidative activity tests in vitro.The results showed that ALAP-21 was a heteropolysaccharide composed of glucose,galacturonic acid,mannose,galactose,arabinose,rhamnose,xylose,fructose and glucuronic acid with a relative molar ratio of 26.282:27.546:11.400:4.781:2.467:2.445:3.622:1.106:1.753,owning(1→4)-β-d-Glcp,(1→4)-β-d-GalAp6Me3OA,(1→4)-β-d-Galp6OMe,(1→2)-β-l-Rhap,(1→4)-β-d-Manp glycosidic linkages.(1→4)-β-d-Glcp and(1→4)-β-d-GalAp6Me3OA residues might be the main components of the sugar chain backbone of ALAP-21.Furthermore,ALAP-21 exhibited high potential for DPPH radicals(82.02%),hydroxyl radicals(53.33%)and superoxide anion radicals(50.28%).These results provide a reference for further research and rational development of ALAP polysaccharides.

Influence of Variety and Maturity Level on Natural Convective Heat Drying of Four Onion Varieties Grown in Senegal

The considerable post-harvest losses (5% to 40% depending on storage time) due to the high water content level of the onion varieties in Senegal are the main cause of the problem of access to local onion all year round. Therefore, drying is one of the techniques that can be used to solve the problem of onion perishability. This study deals with the characterization of naturally convective kinetics drying of four onion varieties in relation to their maturity level. The experiment was carried out using the gravimetric method. The Welch and Turkey statistical tests display a significant difference between the effective diffusivity coefficients depending on the maturity level within each variety and across the four varieties. The effective diffusivity coefficients of the Galmi Violet, Safari, Gandiol F1 and Orient F1varieties range from 2.18 × 10&minus;11 ± 2.69 × 10&minus;12 to 1.32 × 10&minus;10 ± 1.17 × 10&minus;11 m2&sdot;s&minus;1 at a maturity level less than 80%. When the maturity level is greater than 85%, the effective diffusivity coefficients range from 1.30 × 10&minus;11 ± 1.24 × 10&minus;12 to 8.05 × 10&minus;11 ± 8.94 × 10&minus;13 m2&sdot;s&minus;1. As far as the activation energy is concerned, the study only reveals a significant difference between the varieties whatever the maturity level is. The Galmi Violet variety stands out with an average activation energy of 66.71 ± 0.12 KJ&sdot;mol&minus;1 K&minus;1 for the maturity level below 80% and 58.74 ± 0.11 KJ&sdot;mol&minus;1 for the maturity level above 85%. For the three remaining varieties, the average activation energy ranges from 58.15 ± 0.19 to 59.12 ± 0.13 KJ&sdot;mol&minus;1 for a maturity level less than 80% whereas the rates go from 47.63 ± 0.28 to 49.96 ± 0.77 KJ&sdot;mol&minus;1 when the maturity level is greater than 85%. In summary, the higher the maturity level is, the lower the effective diffusivity coefficients will be. The same tendency was observed with the activation energy. The Galmi Violet variety represents the limitative one in case of the drying of the four varieties mix together.

Physiological Changes in Red Onion Bulbs at Different Storage Temperature

Onion bulbs were stored at five different temperatures to know the storage behavior of onion bulbs. Indian red onion bulbs were kept without wrapping at ambient conditions (25℃ ± 3℃ and 75% RH) and within polyethylene pouch at 2.5℃, 6℃, 7℃ and 13℃ for 60 days of storage period. Weight loss, total soluble solids (TSS), number of sprouted and rotten bulbs were measured at an interval of 10 days throughout storage. The greatest decrease (23.25%) in weight was observed throughout storage for onions stored at ambient conditions. TSS was observed to increase in all samples until 40 days of storage and then decreased up to 60 days. Lowest TSS (14.89 ?Bx) was found in onion stored at ambient conditions at the end of storage. Maximum sprouted (67.25%) and rotten (17.78%) onions were observed for onions stored at 13℃, whereas minimum sprouted and rotten onions were found at 2.5℃ at 60 days of storage. Results also recommend lowest temperatures (2.5℃ - 6℃) for prolong storage life of onion with no detrimental effects.

AtWUS过表达诱导分蘖洋葱体细胞胚高频发生

以分蘖洋葱茎尖外植体诱导的愈伤组织为试材,采用农杆菌介导法,将外源基因AtWUS导入分蘖洋葱愈伤组织中,研究AtWUS对分蘖洋葱愈伤组织诱导体细胞胚发生的影响,以期建立分蘖洋葱体细胞胚高频发生体系。结果表明:过表达AtWUS可以显著促进分蘖洋葱愈伤组织的体细胞胚发生率(大约6倍),91%的双极性体细胞胚具有发育形成完整植株能力。RT-PCR分析结果表明,AtWUS在体细胞胚和转基因植株中高丰度表达。

荷叶离褶伞发酵液对NaCl胁迫下洋葱根尖细胞有丝分裂的影响

研究了荷叶离褶伞发酵液对NaCl胁迫下洋葱根尖细胞有丝分裂的影响。结果表明:低浓度NaCl(0.05 mol/L)对洋葱根的生长有促进作用,高浓度NaCl(≥0.10 mol/L)对洋葱根的生长有抑制作用,根尖细胞有丝分裂出现异常,且随着NaCl浓度增高和NaCl处理时间延长抑制作用越明显。荷叶离褶伞发酵液对低浓度NaCl(≤0.10 mol/L)短时间处理(24 h)导致的洋葱根尖细胞遗传损伤有一定的修复作用。

人工气候室控制条件下青葱对LED光质的响应特性

【目的】研究人工气候室控制条件下青葱生长、产品品质及光合特性对不同光质的响应特性,优化青葱工厂化生产光环境调控参数,提高以鲜嫩绿叶为产品的青葱生产效率。【方法】在人工气候室LED控制光源条件下,以‘章丘’和‘天光’2个不同品种大葱为试验材料,将苗高15 cm左右、具2—3片真叶的穴盘中大葱幼苗,分别置于蓝光(B)、红光(R)、绿光(G)、黄光(Y)、白光(W)等5种不同光质条件下进行培养,光照强度均控制在(301.6±12.7)μmol·m^-2·s^-1,光照时间为12 h/d,昼/夜温度分别控制在25℃/18℃。分别在试验处理0、10、20、30和40 d时取样,测定不同光质处理的青葱叶片光合作用参数,以及培养40 d时青葱的生长量和产品品质。【结果】青葱的生长量、产品品质、叶片色素含量、净光合速率(Pn)、表观量子效率(AQY)和RuBP最大再生速率均以白光显著优于各单色光处理。培养40 d时,白光处理青葱单株鲜重为25.21 g,分别比蓝光、红光、绿光、黄光处理增加了7.83%、20.28%、35.68%和60.78%;其叶片Pn为7.63μmol·m^-2·s^-1,分别比蓝光、红光、绿光和黄光处理提高了11.39%、24.07%和39.23%和59.62%;叶片光饱和光合速率(Pmax)达13.29μmol·m^-2·s^-1,分别较蓝光、红光、绿光和黄光处理增加了5.39%、9.47%、15.57%和21.48%;光饱和点(LSP)除白光处理较高外,其他单色光处理间无显著差异;而光补偿点(LCP)则以黄光较高,绿光、红光次之,蓝光、白光较低。不同单色光处理间也存在显著差异,以蓝光处理青葱单株鲜重较高,黄光处理较低,分别达24.22和16.52 g,绿光、红光居中;蓝光处理青葱叶片Pn、AQY、光饱和光合速率(Pmax)、羧化效率(CE)以及RuBP最大再生速率也显著高于其他单色光处理。青葱假茎可溶性糖、粗纤维、丙酮酸、可溶性蛋白、游离氨基酸和干物质含量等品质指标均以白光处理显著高于各单色光处理,但各单色光处理之间则以蓝光处理较高,其他依次为红光、绿光、黄光。【结论】全光谱的白光处理最有利于青葱生长,表现为叶片光合效率较高,产品品质较优;各单色光处理则以蓝光效应较高,红光次之,黄光、绿光较差,反映青葱对白光、蓝光光能利用能力较强。

Allelopathic Effects of Adonis vernalis L.: Root Growth Inhibition and Cytogenetic Alterations

A possible alternative to synthetic agricultural chemicals is through the use of allelopathy. Adonis species are rich sources of secondary metabolites. Such allelochemicals offer potential for the development of future pesticides. Allelochemicals influence plant growth and cause morphological alterations. This visible effect could be due to primary effects at cellular or molecular level. Changes in the mitotic activity and disturbances in different phases of mitotic division are accepted as indicators of cytotoxic influence. Mitotic abnormalities and induction of micronuclei in interphase cells are parameters used to determine genotoxicity. The purpose of the current study was to establish the possible allelopathic effect of Adonis vernalis L. water extracts through evaluation of root growth inhibition effect and cytogenetic alterations. Adonis vernalis L. growing wild in Bulgaria was used in the present study. Two types of water extracts were prepared: Hot and Cold Water Extract of A. vernalis (HWЕА and СWЕА). A 72-h root growth inhibition test was provided in order to determine the toxicity level of extracts. EC50 values were determined. For toxicity test, seeds of Triticum aestivum L. cv. GTW were used. Cytotoxic and genotoxic potential of water extracts (EC50) were evaluated using Allium cepa L.-test. The EC50 for HWEA and CWEA was determined 1.83 g/l and 0.78 g/l respectively. Significant influence on mitotic activity values and a marked decrease in percentage of telophase cells were observed after treatment with both extracts. Adonis extracts also induced different mitotic abnormalities in root-tip cells of Allium cepa L. The percent of interphase cells with micronuclei increased significantly only after treatment with HWEA. The results indicated growth inhibitory, cytotoxic and genotoxic effects of crude water extracts of A. vernalis L. These effects demonstrated the presence of water soluble allelochemicals in Adonis aerial parts.

洋葱种子消毒和无菌苗培养新方法

为了获得简便、高效、低污染的洋葱种子消毒及无菌苗培养方法,通过控制植物组培抗菌剂(PPM)的pH值、消毒浸泡时间及培养浓度,对洋葱种子消毒及无菌苗培养进行研究。结果表明,PPM(20 mL/L,pH 2)浸种24-48 h消毒效果可以达到10%NaClO消毒10 min水平,且不影响种子发芽,8 d发芽势超过90%。污染微生物分析鉴定了4种真菌(Alternaria alternata、Fusarium proliferatum、Fusarium oxysporum、Stemphylium vesicarium)和2种细菌(Phytobacter diazotrophicus、Atlantibacter hermannii)可以通过洋葱种子进行传播,抑菌试验明确了PPM可有效的抑制污染微生物的生长。培养基中添加PPM可以有效的降低污染率,高浓度PPM(1-9 mL/L)可以抑制洋葱幼苗的生长,而低浓度PPM(0-0.5 mL/L)对洋葱幼苗生长无明显抑制作用。探索开发了一套操作简便无需繁琐冲洗的洋葱种子消毒以及高发芽率、低污染率无菌苗培养方法。

Allelopathy of Cold Water Extracts from Origanum vulgare ssp. vulgare L.

Secondary metabolites in medicinal plants could lead to discovery of new classes of herbicides. Recently aromatic plants have gained interest as a source of allelopathic secondary metabolites. Origanum vulgare ssp. vulgare L. infusions in hot water are used in folk medicine and possess proved beneficial biological activity. Plant-to-plant variability of metabolites due to genetic heterogeneity is established in Lamiaceae family. From this point of view, studies on plants from different geographic regions might reveal important sources of variability. The objective of this study was to evaluate allelopathic activity of cold water extracts made from the aerial parts of O. vulgare ssp. vulgare growing wild in Northeast Bulgaria in laboratory conditions. The allelopathic effect was evaluated using root elongation test and Allium cepa-test. Oregano extracts (17.5 g/l, 52.5 g/l) significantly decreased root length of Triticum aestivum L. (P ≤ 0.001). The root growth reduction could serve as a sign for presence of water soluble allelopathic secondary metabolites in the plant tested. Oregano (3.5 g/l) inhibited cell division in Allium root meristematic cells. The decline of the mitotic index indicates the occurrence of a cytotoxic effect. Oregano induced abnormalities in mitotic and interphase cells, so can be also considered as genotoxic. The observed macroscopic and microscopic effects of tested extracts indicated presence of water soluble allelochemicals in O. vulgare ssp. vulgare. This characteristic could be further studied as a possibility to be used in weed management programs.