Genetic variation in a radish (Raphanus sativus L.) geodiversity collection

Genetic Resources and Crop Evolution - A radish panel of 152 accessions with diverse root shapes was assembled from the National Plant Germplasm System (NPGS) collection based on weighted...     

Antioxidant constituents of radish sprout (Kaiware-daikon), Raphanus sativus L

Methanol extracts of 11 kinds of commonly available vegetables were examined for hydroxyl radical scavenging potency using the bleomycin-Fe method. In this method, the iron ion and bleomycin in water form hydroxyl radicals, and the scavenging activity is monitored by the modified thiobarbituric acid method. All extracts showed scavenging capacity, even though the activity of some of them was lower than that of l-ascorbic acid. Those vegetables were classified into three groups according to their activity, groups showing strong activity, moderate activity, and weak activity, as compared to the activity of l-ascorbic acid at the same concentration. Among them, the methanol extract of radish sprout (Japanese name "kaiware-daikon") exhibited the highest potency (1.8 times as l-ascorbic acid). Then, we investigated the constituents of the methanol extract of radish sprout and the contribution to the overall activity of each compound by examining their activity. As the result, several kinds of sinapinic acid esters and flavonoids were isolated with high radical scavenging potency, which must contribute substantially to the activity.     

二、四倍体萝卜光合特性比较研究

二、四倍体萝卜光合特性比较研究表明:四倍体叶片厚度、叶绿素含量和叶面积明显高于二倍体,且其气孔增大,密度减小.二倍体和四倍体的净光合速率(Pn)和气孔导度(Gs)均随光强增大而增加;而细胞间隙CO2浓度(Ci)随光强增强缓慢下降.二倍体的净光合速率、气孔导度和细胞间隙CO2浓度均高于四倍体.四倍体的光饱和点(LSP)为1 960 μmol · m-2 · s-1,光补偿点(LCP)为59.87 μmol · m-2 · s-1,均高于二倍体.     

Comparison of the glucosinolate-myrosinase systems among daikon (Raphanus sativus, Japanese white radish) varieties

Myrosinase is a cytosolic plant enzyme present in daikon ( Raphanus sativus, Japanese white radish) roots that hydrolyzes 4-methylthio-3-butenyl glucosinolate (MTBGLS) into the natural pungent agent 4-methylthio-3-butenyl isothiocyanate (MTBITC), which possesses antimicrobial, antimutagenic, and anticarcinogenic properties. The concentration of MTBGLS, myrosinase activity, and production of MTBITC in seven daikon varieties (one conventional and six heirlooms) were determined to rank the activity of the glucosinolate-myrosinase system and identify critical factors influencing the production of MTBITC. The six heirloom varieties produced 2.0-11.5 times higher levels of MTBITC as compared to the conventional variety, Aokubi, which is consumed by the present Japanese population. The myrosinase was located exclusively in the outer epidermal layer in Aokubi, and MTBGLS was widely distributed throughout the root tissue. Although the skin is a potentially rich source of myrosinase in Aokubi, the skin is usually peeled off in the current practice of preparing daikon for cooking. New practices are therefore proposed for the preparation of daikon tubers that eliminate the peeling of the skin to avoid removing the enzyme needed to convert MTBGLS to the health-beneficial MTBITC. It is also concluded that the consumption of heirloom daikon varieties in addition to changes in food preparation will optimize the health benefits of daikon.     

LC-PDA-ESI/MS(n) identification of new anthocyanins in purple Bordeaux radish ( Raphanus sativus L. variety)

An LC-PDA-ESI/MS(n) profiling method was used to identify the anthocyanins of purple Bordeaux radish and led to the assignment of 60 anthocyanins: 14 acylated cyanidin 3-(glucosylacyl)acylsophoroside-5-diglucosides, 24 acylated cyanidin 3-sophoroside-5-diglucosides, and 22 acylated cyanidin 3-sophoroside-5-glucosides. The identifications were supported by the presence of 3-sophoroside-5-diglucoside and 3-sophroside-5-glucoside of cyanidin in the alkaline-hydrolyzed extract. A reliable method to identify the anthocyanins containing 3-(glucosylacyl)acylsophorosyl functions is described. The tentative identifications were obtained from tandem mass data analysis and confirmed by high-resolution mass measurements. Further assignments were made for some anthocyanins from a comparison of the mass and UV-vis data and elution order with those of the anthocyanins in the authors' polyphenol database and from consideration of the structural characteristics of the anthocyanins from similar plants and similar anthocyanins in the literature. The presence of 38 acylated cyanidin 3-sophoroside-5-diglucosides and around 10 acylated cyanidin 3-sophoroside-5-malonylglucosides in plants is reported here for the first time.     

4-(Methylthio)-3-butenyl isothiocyanate, a principal antimutagen in daikon (Raphanus sativus; Japanese white radish).

The antimutagenic activity of n-hexane extracts from eight strains of daikon (Raphanus sativus; Japanese white radish) have been examined using the UV-induced mutation assay of Escherichia coli B/r WP2. A correlation was found between the potency of antimutagenicity and the amount of 4-(methylthio)-3-butenyl isothiocyanate (MTBITC) in their n-hexane extracts. Because the pure MTBITC also showed antimutagenicity, MTBITC is presumably the active antimutagen principle in n-hexane extracts of daikon. Among the eight strains of daikon studied, Aokubi, the improved common strain in Japan, contained 71.0 micromol of MTBITC in 100 g of fresh daikon. In contrast, Karami and Momoyama, which are original wild strains, contained much more MTBITC (363.5 and 168.0 micromol/100 g, respectively). In addition, phenethyl isothiocyanate was found in a lesser amount (5-33 nmol/100 g) in eight strains of daikon, and allyl isothiocyanate and benzyl isothiocyanate were not detectable in any strains (<3 nmol/100 g). The amount of total isothiocyanate in grated daikon was 7.0 times higher than that in cut daikon measured after 30 min of cooking. Through eating habits, humans might be able to consume substantial amounts of the antimutagen MTBITC from dishes using the grated form of wild strains of daikon. Therefore, it is possible to substantially increase the intake of the antimutagenic ingredient of daikon (i.e., MTBITC) by changing food preferences and preparation procedures (i.e., using the grated form of the wild strains).     

施氮量对白萝卜硝酸盐含量和土壤硝态氮淋溶的影响

在保护地栽培条件下,通过6个施氮水平的田间小区试验,结合土层原位渗滤装置,研究了施用氮肥对白萝卜（Raphanus sativus L.）产量和硝酸盐含量及土壤硝态氮淋溶的影响。结果表明,施氮处理白萝卜产量比不施氮处理仅增加6.04%～10.92%,当尿素氮施用量大于N 100 kg/hm2时,增产幅度开始下降。不同施氮处理白萝卜产量没有显著差异,说明在土壤基础肥力较高的情况下,增施氮肥不能明显提高白萝卜的产量;单施有机肥白萝卜体内硝酸盐含量为 196.86 mg/kg,比不施氮处理降低 5.08%。在此基础上加施尿素后,硝酸盐含量随氮肥施用量的增加显著升高（p0.05）;0—100cm土壤剖面硝态氮累积量随氮肥施用量的增加而增加,且与氮肥施用量显著正相关（r=0.993, r0.01=0.917）;白萝卜生长期间收集到的土壤淋溶液中硝态氮浓度较高,平均为32.88 mg/L,硝态氮的淋失量为 4.42～6.14 kg/hm2,不同施氮量处理之间没有显著差异。     

Variation of glucosinolates in wild radish (Raphanus raphanistrum) accessions

Glucosinolate composition was determined in wild radish accessions from eight states in the northeastern and southern United States to determine the variability of production among accessions. Glucosinolates were evaluated from roots, leaves, flowers, primary, and secondary branches. Seventeen glucosinolates were identified, with glucoerucin, glucoraphenin, glucobrassicin, and gluconasturtiin contributing 90% to 100% of the total glucosinolates. Flowers contained the highest glucosinolate concentrations, 12.07 to 55.36 μmol/g, but flowers contributed only 5.3 to 21.3% to the total glucosinolates. Of the eight accessions, the Mississippi accession produced significantly higher levels of total glucosinolates and glucosinolates which can be degraded to isothiocyanates per plant, totals of 618.97 and 563.53 μmol/plant, respectively. Total plant biomass did not differ between accessions indicating a difference in the ability of the Mississippi accession to produce glucosinolates. Further studies are needed to determine if this accession would consistently produce higher glucosinolate levels under different environmental conditions.     

Genetic variation in radish (Raphanus sativus L.) germplasm from Pakistan using morphological traits and RAPDs

Genetic diversity of 30 radish (Raphanus sativus L.) accessions was investigated at the phenotypic level with morphological characters and at the DNA level using the random amplified polymorphic DNA (RAPD) technique. Thirty-six morpho-physiological traits were recorded from seedling stage to harvest. The 31 primers used generated 202 RAPD bands, of which 158 (78.2%) were polymorphic. Multivariate procedures were used to classify the germplasm on the basis of phenotypic traits and RAPD fragments. Dendrograms were generated for the Euclidean distance from the morphological data and the Nei's genetic distance from the RAPD markers. Phenotypically, all the accessions were classified into four major groups corresponding to the different forms of cultivated radish. The morphological diversity existing within each of these groups suggested that they should be discriminated into the three botanical convarieties, sativusT (large-rooted), caudatus (pod-type) and oleifer (oilseed-type). Clustering of the accessions did not show any pattern of association between the morphological characters and the collection sites. Instead, landrace groups were associated with their morphological similarities and horticultural uses. On the other hand, the intra-specific genetic relationships of several accessions based on RAPD analysis were related primarily to their collection sites rather than to their phenotypic affinities. The level of polymorphism exhibited by the various convarieties could be exploited in genetic mapping populations to tag economically important traits. These genotypes also could serve as a useful germplasm source for root, leaf, pod and seed. This preliminary study of traditional radish landraces from Pakistan provides useful information regarding their horticultural potential.     

Release of carbon and nitrogen from fodder radish (Raphanus sativus) shoots and roots incubated in soils with different management history

Plant roots are generally considered to decompose slower than shoots and contribute more to accumulation of soil organic matter, and management history is expected to shape the structure and function of decomposer communities in soil. Here we study the effect of chemical characteristics of shoots and roots from fodder radish (Raphanus sativus oleiformis L.), a widely used cover crop, on the release of their C and N after addition to soil. Shoots and roots were incubated for 180?d at 20°C using four soils with different management histories (organic versus mineral fertiliser, with and without use of cover crops), and the release of CO₂ and extractable mineral N was determined. More shoot C than root C was mineralised during the first 10?d of incubation. After 180?d, 58% of the C input was mineralised with no difference between shoots and roots. At the end of incubation, shoots had released more N (42% of shoot N) than roots (28% of root N). Moreover, management history did not affect net mineralisation of added plant C. Residues incubated in soil with a management history involving cover crops showed an enhanced net N mineralisation. Therefore, long-term decomposition of C added in radish shoots and roots is unaffected by differences in chemical characteristics or soil management history. However, the net mineralisation of N in shoots is faster than for N in roots, and net N mineralisation of added materials is higher in soil with than without a history of cover crops.

Abbreviations: CC: cover crop; IF: inorganic fertilizer; M: manure     

Metabolic fate of [14C] chlorophenols in radish (Raphanus sativus), lettuce (Lactuca sativa), and spinach (Spinacia oleracea)

Chlorophenols are potentially harmful pollutants that are found in numerous natural and agricultural systems. Plants are a sink for xenobiotics, which occur either intentionally or not, as they are unable to eliminate them although they generally metabolize them into less toxic compounds. The metabolic fate of [ (14)C] 4-chlorophenol (4-CP), [ (14)C] 2,4-dichlorophenol (2,4-DCP), and [ (14)C] 2,4,5-trichlorophenol (2,4,5-TCP) was investigated in lettuce, spinach, and radish to locate putative toxic metabolites that could become bioavailable to food chains. Radish plants were grown on sand for four weeks before roots were dipped in a solution of radiolabeled chlorophenol. The leaves of six-week old lettuce and spinach were treated. Three weeks after treatments, metabolites from edible plant parts were extracted and analyzed by high performance liquid chromatography (HPLC) and characterized by mass spectrometry (MS), and nuclear magnetic resonance spectroscopy (NMR). Characterization of compounds highlighted the presence of complex glycosides. Upon hydrolysis in the digestive tract of animals or humans, these conjugates could return to the toxic parent compound, and this should be kept in mind for registration studies.     

Cadmium uptake in radish (Raphanus sativus L.) and surficial contamination: implications for food safety and local soil management

Journal of Soils and Sediments - Soil management strategies for agricultural lands contaminated with potentially toxic trace elements, especially cadmium (Cd), are still inadequate and require a...     

海藻提取物缓解高温对樱桃萝卜胁迫效应的研究

选取樱桃萝卜(Raphanus sativus L.var.radculus pers)为研究对象,在盆栽试验条件下以清水处理为对照(CK),并以浓度为66.7 mg·L^-1的芸苔素内酯为阳性对照(BHG),通过添加不同浓度(100.0、200.0 mg·L^-1)的海藻提取物处理(SWE-1、SWE-2),探究了在高温胁迫(30℃)条件下海藻提取物对樱桃萝卜产量、果实品质、内源激素水平以及抗氧化酶系统的影响。结果表明,SWE-1、SWE-2均可有效缓解高温对樱桃萝卜生长造成的胁迫效应,以SWE-2处理效果最好。与CK处理相比,SWE-2处理的果实鲜重显著提高180.0%,可溶性蛋白含量显著提高35.2%;其叶片的SPAD值显著提高16.8%,硝酸还原酶活性显著提高57.7%,生长素含量显著提高145.4%,而脱落酸含量显著下降42.0%,丙二醛含量显著下降59.2%,谷胱甘肽还原酶活性提升15.7%,抗坏血酸过氧化物酶活性显著上升9.4%。与BHG处理相比,SWE-2处理的果实鲜重显著提高43.5%;可溶性蛋白含量显著提高49.6%,维生素C...     

Effects of nutrient levels on growth and quality of radish (Raphanus sativus L.) grown on different substrates

Radish grown in sand or granulated rockwool was irrigated with nutrient solutions of different concentrations. The EC value in the root environment aimed at ranged between 1.0 and 6.0 dS/m at 25°C. Four crops were grown, three crops in the spring‐summer season and one crop in winter. For the spring‐summer grown radish highest plant weights were obtained with EC values in the root environment of about 2 dS/m. In the winter grown crop an EC value between 2 and 4 gave highest plant weights. With too low EC values the yield reduction was more serious in winter than in spring‐summer. High EC values reduced yield especially in the spring‐summer season. In winter, the number of blind plants was strongly affected by the EC value. The bulb/leaf ratio was higher on sand than on rockwool and increased with EC value. Sponginess appeared in the spring‐summer crops and was reduced by increasing EC values. The mineral absorption of the radish was equal for the different crops. The water absorption, however, differed a factor four between winter and spring‐summer. So the nutrient absorption concentration in winter was about four times higher in winter than in spring‐summer.     

Effect of methyl jasmonate on phenolics, isothiocyanate, and metabolic enzymes in radish sprout (Raphanus sativus L.)

The effect of spraying exogenous plant hormone methyl jasmonate (MeJA) upon radish sprout (Raphanus sativus L.) was investigated in aspects of total phenolic content (TPC), isothiocyanate content, antioxidant activity of the radish extract, and enzymatic activities of phenylalanine ammonia lyase (PAL) and myrosinase. The MeJA treatment significantly increased the TPC that resulted in the increased DPPH* (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging capacity. In addition, the PAL activity also increased by 60% at 24 h after MeJA treatment. However, the same treatment decreased the amount of 4-methylthio-3-butenylisothiocyanate (MTBITC), a major isothiocyanate in radish sprout and the activity of myrosinase, an enzyme related to produce isothiocyanates.     

Kaiware Daikon (Raphanus sativus L.) extract: a naturally multipotent chemopreventive agent

Brassica vegetables are attracting major attention as healthy foods because of their content of glucosinolates (GLs) that release the corresponding isothiocyanates (ITCs) upon myrosinase hydrolysis. A number of studies have so far documented the chemopreventive properties of some ITCs. On the other hand, single nutrients detached from the food itself risk being somewhat "reductive", since plants contain several classes of compounds endowed with a polyhedral mechanism of action. Our recent finding that 4-methylthio-3-butenyl isothiocyanate (GRH-ITC) and 4-methylsulfinyl-3-butenyl isothiocyanate (GRE-ITC), released by the GLs purified from Japanese (Kaiware) Daikon (Raphanus sativus L.) seeds and sprouts, had selective cytotoxic/apoptotic activity on three human colon carcinoma cell lines prompted further research on the potential chemopreventive role of a standardized Kaiware Daikon extract (KDE), containing 10.5% w/w GRH and 3.8% w/w GRE, compared to its isolated components. KDE administered in combination with myrosinase at doses corresponding to 50 microM GRH-ITC plus 15 microM GRE-ITC (50 microM KDE-ITC) to three human cancer cell lines (LoVo, HCT-116 and HT-29) significantly reduced cell growth by 94-96% of control in six days (p < 0.05), outperforming pure GRH-ITC or GRE-ITC at the same dose. On the other hand, the same treatment had no significant toxicity on normal human T-lymphocytes. A 50 microM concentration of KDE-ITC had relevant apoptosis induction in all tested cancer cell lines, as confirmed by annexin V assay (e.g., 33% induction in LoVo compared to control, p < 0.05), Bax protein induction (e.g., +20% in HT-29, p < 0.05), and Bcl2 downregulation (e.g.-20% in HT-29, p < 0.05), and induced caspase-1 and PARP-1 activation in all cancer cells as shown by Western blot analysis. Unlike pure GRH or GRH-ITC, KDE also had significant chain-breaking antioxidant activity, retarding the AAPH-initiated autoxidation of methyl linoleate in SDS micelles at concentrations as low as 4.4 ppm (-50% in oxygen consumption rate), as monitored by Clark-type microelectrode oxygen-uptake kinetics, and induced very fast quenching of DPPH. radical in methanol with t(1/2) (s) = (1.47 +/- 0.25) x 10(-2)/[KDE; (g/L)], measured by stopped-flow UV-vis kinetics at 298 K. The potential chemopreventive role of KDE is discussed.     

Aqueous extract from Spanish black radish (Raphanus sativus L. Var. niger) induces detoxification enzymes in the HepG2 human hepatoma cell line

Spanish black radish (Raphanus sativus L. var. niger) is a member of the Cruciferae family that also contains broccoli and Brussels sprouts, well-known to contain health-promoting constituents. Spanish black radishes (SBR) contain high concentrations of a glucosinolate unique to the radish family, glucoraphasatin, which represents >65% of the total glucosinolates present in SBR. The metabolites of glucosinolates, such as isothiocyanates, are implicated in health promotion, although it is unclear whether glucosinolates themselves elicit a similar response. The crude aqueous extract from 0.3 to 3 mg of dry SBR material increased the activity of the phase II detoxification enzyme quinone reductase in the human hepatoma HepG2 cell line with a maximal effect at a concentration of 1 mg/mL. Treatment of HepG2 cells with the crude aqueous extract of 1 mg of SBR per mL also significantly induced the expression of mRNA corresponding to the phase I detoxification enzymes: cytochrome P450 (CYP) 1A1, CYP1A2, and CYP1B1 as well as the phase II detoxification enzymes: quinone reductase, heme oxygenase 1, and thioredoxin reductase 1. Previous studies have shown that the myrosinase metabolites of different glucosinolates vary in their ability to induce detoxification enzymes. Here, we show that while glucoraphasatin addition was ineffective, the isothiocyanate metabolite of glucoraphasatin, 4-methylthio-3-butenyl isothiocyanate (MIBITC), significantly induced phase II detoxification enzymes at a concentration of 10 microM. These data demonstrate that the crude aqueous extract of SBR and the isothiocyanate metabolite of glucoraphasatin, MIBITC, are potent inducers of detoxification enzymes in the HepG2 cell line.     

Selenium accumulation in beef: effect of dietary selenium and geographical area of animal origin

Selenium (Se) is an essential nutrient with multiple human health benefits; the single most important dietary source of Se is beef. The Se content of beef varies, and cattle fed a high selenium diet may have Se concentrations in beef that are well above average. Such beef is potentially a unique supplemental source of dietary Se. To examine factors affecting Se accumulation in beef, 16 steers (initial wt 374.4 +/- 33.7 kg) were taken from seleniferous or nonseleniferous areas and fed in a 2 x 2 factorial design with diets high or moderate in Se (11.9 or 0.62 mg Se/kg diet). Diets contained 50% alfalfa, 25% wheat, and 25% corn on a dry matter basis. All dietary Se was from agricultural products, and Se in the high Se diet was primarily from high Se wheat and alfalfa hay. A loin muscle biopsy was taken at the start of the trial to determine initial Se content of beef. Steers were slaughtered after 14 weeks of the trial, and edible carcass (round, sirloin, shoulder clod, and ribeye) and organ samples were collected. Diets did not affect growth or feed intake (P > 0.05), and Se toxicity signs were not observed. Different cuts of meat had similar Se concentrations, and the Se content of all cuts was increased by both high dietary Se and high Se background. Except for liver and kidney, Se in tissues was increased by seleniferous background (P < 0.02) and high dietary Se (P < 0.001). Kidney Se concentrations of animals fed the high Se diet were lowest in animals from seleniferous areas (P = 0.04), suggesting a possible adaptation to the high Se diet. These results demonstrate that cattle fed diets high in Se from agricultural products will accumulate substantial amounts of Se in the beef without developing signs of Se toxicity and that prior Se status regulates Se accumulation in some organs. They further demonstrate that management practices may be altered so as to make beef a significant source of dietary Se.     

Effect of earthworm casts on protein synthesis in radish (Raphanus sativum) and lettuce (Lactuga sativa) seedlings

Summary The protein-synthesizing capacity of 3-day-old seedlings of radish and lettuce grown in the presence of earthworm casts was investigated using L-¹⁴-C-leucine incorporation. The results showed that earthworm casts increased protein synthesis by 24% for lettuce and 32% for radish, althought no significant differences in protein content were evident.