Sugars,organic acids,and phenolic compounds of ancient grape cultivars (Vitis vinifera L.) from Igdir province of Eastern Turkey

Background

The Eurasian grapevine (Vitis vinifera L.) is the most widely cultivated and economically important horticultural crop in the world. As a one of the origin area, Anatolia played an important role in the diversification and spread of the cultivated form V. vinifera ssp. vinifera cultivars and also the wild form V. vinifera ssp. sylvestris ecotypes. Although several biodiversity studies have been conducted with local cultivars in different regions of Anatolia, no information has been reported so far on the biochemical (organic acids, sugars, phenolic acids, vitamin C) and antioxidant diversity of local historical table V. vinifera cultivars grown in Igdir province. In this work, we studied these traits in nine local table grape cultivars viz. ‘Beyaz Kismis’ (synonym name of Sultanina or Thompson seedless), ‘Askeri’, ‘El Hakki’, ‘Kirmizi Kismis’, ‘Inek Emcegi’, ‘Hacabas’, ‘Kerim Gandi’, ‘Yazen Dayi’, and ‘Miskali’ spread in the Igdir province of Eastern part of Turkey.

Results

Variability of all studied parameters is strongly influenced by cultivars (P < 0.01). Among the cultivars investigated, ‘Miskali’ showed the highest citric acid content (0.959 g/l) while ‘Kirmizi Kismis’ produced predominant contents in tartaric acid (12.71 g/l). The highest glucose (16.47 g/100 g) and fructose (15.55 g/100 g) contents were provided with ‘Beyaz Kismis’. ‘Kirmizi Kismis’ cultivar had also the highest quercetin (0.55 mg/l), o-coumaric acid (1.90 mg/l), and caffeic acid (2.73 mg/l) content. The highest ferulic acid (0.94 mg/l), and syringic acid (2.00 mg/l) contents were observed with ‘Beyaz Kismis’ cultivar. The highest antioxidant capacity was obtained as 9.09 μmol TE g^-1 from ‘Inek Emcegi’ in TEAC (Trolox equivalent Antioxidant Capacity) assay. ‘Hacabas’ cultivar had the highest vitamin C content of 35.74 mg/100 g.

Conclusions

Present results illustrated that the historical table grape cultivars grown in Igdir province of Eastern part of Turkey contained diverse and valuable sugars, organic acids, phenolic acids, Vitamin C values and demonstrated important antioxidant capacity for human health benefits. Further preservation and use of this gene pool will be helpful to avoid genetic erosion and to promote continued agriculture in the region.     

Phenolic compounds and vitamins in wild and cultivated apricot (Prunus armeniaca L.) fruits grown in irrigated and dry farming conditions

Background

Turkey is the main apricot producer in the world and apricots have been produced under both dry and irrigated conditions in the country. In this study, phenolic compounds and vitamins in fruits of one wild (Zerdali) and three main apricot cultivars (‘Cataloglu’, ‘Hacihaliloglu’ and ‘Kabaasi’) grown in both dry and irrigated conditions in Malatya provinces in Turkey were investigated.

Results

The findings indicated that higher content of phenolic compounds and vitamins was found in apricot fruits grown in irrigated conditions. Among the cultivars, ‘Cataloglu’ had the highest rutin contents both in irrigated and dry farming conditions as 2855 μg in irrigated and 6952 μg per 100 g dried weight base in dry conditions and the highest chlorogenic acid content in irrigated and dry farming conditions were measured in fruits of ‘Hacıhaliloglu’ cultivar as 7542 μg and 15251 μg per 100 g dried weight base. Vitamin C contents in homogenates of fruit flesh and skin was found to be higher than β-caroten, retinol, vitamin E and lycopen contents in apricot fruits both in irrigated and dry farming conditions.

Conclusion

The results suggested that apricot fruits grown in both dry and irrigated conditions had high health benefits phytochemicals and phytochemical content varied among cultivars and irrigation conditions as well. However, more detailed biological and pharmacological studies are needed for the demonstration and clarification of health benefits of apricot fruits.     

Effect of Seasonal and Regional Variations on Phenolic Compounds of Deverra scoparia (Flowers/Seeds) Methanolic Extract and the Evaluation of Its in Vitro Antioxidant Activity

The widespread use of Deverra scoparia Coss. & Durieu in Algerian folk‐medicine as a remedy can be relatively attributed to its total phenolic compounds. The current study aimed to provide a scientific basis for optimal collection and usage of Deverra scoparia Coss. & Durieu plant. Hence, 37 samples were gathered from nine sites in Algeria during two seasons 2016 and 2017, then exposed to a green extraction. Total phenolic (TPC), flavonoid (FC) and condensed tannins (CTC) content were estimated spectrophotometrically. The antioxidant activity was measured using five different methods, DPPH^., ABTS^.+, FRAP, CUPRAC and Fe²⁺‐chelating. The results have revealed considerable amounts of TPC varied from 804 to 1544 mg GAE/100 g dry matter, FC started from 187 up to 410 mg QE/100 g dry matter and CTC varied from 111 to 394 mg CE/100 g dry matter. The best IC₅₀ values (μg/mL) of DPPH^., ABTS^?+, FRAP, CUPRAC and Fe²⁺‐chelating tests were 56.62, 5.41, 21.26, 52.93 and 78.10, respectively. Moreover, high correlations were found between CTC and most of the antioxidant tests. Hence, CTC are suggested to be the principal group of antioxidant activity in Deverra scoparia Coss. & Durieu extracts.     

Investigating the Antioxidant and Color Properties of Bee Pollens of Various Plant Sources

In our study, Central and Eastern European bee pollens of different botanical origins were compared, based on their antioxidant and color properties. Total phenolic content (TPC), total flavonoid content (TFC), and in vitro antioxidant capacity (by FRAP, CUPRAC, ABTS⋅⁺ and DPPH⋅ assays) were determined spectrophotometrically. Besides, Relative Antioxidant Capacity Indexes (RACI) were calculated. CIELAB color parameters (L*, a*, b*, chroma) were determined by using a tristimulus-based instrument. Potential correlations between the investigated parameters were also identified. Based on the results of the preliminary study, ethanol:distilled water (60 : 40) was chosen as an extraction solvent. The total phenolic content of our samples ranged between 9.41 and 27.49 mg GAE/g dw. Pollens showed TFC:TPC ratios between 9 and 44 %. RACI values indicate that rapeseed (Brassica napus), traveller's joy (Clematis vitalba) and phacelia (Phacelia tanacetifolia) pollens have relatively high, while pollens of certain plants of the Asteraceae family possess low antioxidant potential. Antioxidant properties correlated significantly in most cases. RACI values showed strong positive correlation with each of the other antioxidant capacity parameters, suggesting that this approach is well applicable for comparing the antioxidant potential of bee pollens. No clear correlation was found between the antioxidant and color parameters.     

Variation in antioxidant activity and phenolic content in different organs of two Tunisian cultivars of Olea europaea L.

This paper reports a comparative study based on the antioxidant compounds, total phenol content and antioxidant activities of leaves, stems and fruits from the main Tunisian cultivars, ‘chetoui’ and ‘chemchali’, grown in two different locations, north and south of Tunisia. The repartition of olive phenolic compounds was organ dependant. Therefore, the HPLC analysis indicated that the olive organs from the northern cultivar had the highest level of hydroxybenzoic acids, hydroxycinnamic acids and flavonoid class; which were less in the southern cultivar. Principal component analysis of the phenolic compounds showed discrimination between methanol extracts of the organs olive. Significant differences (p < 0.05) in the levels of phenols, orthodiphenols and flavonoids were found between cultivars and between organs. Antioxidant activities of the methanolic extract from aerial parts of the two studied cultivars were evaluated using 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) assays. In all tests, methanolic extracts of different olive parts showed higher antioxidant activity. These results can be used to discriminate and to characterize the ‘chetoui’ and ‘chemchali’ aerial parts.     

Antioxidant properties and phenolic profiling by UPLC-QTOF-MS of Ajwah,Safawy and Sukkari cultivars of date palm

Date palm (P. dactylifera) plays a vital role in ethnomedicinal practices in several parts of the world. There are over 2000 cultivars of date palm that differ in chemical composition and extent of bioactivity. The present study was undertaken to comparatively evaluate the antioxidant potential of three cultivars of date palm (Ajwah, Safawy and Sukkari) from Saudi Arabia and analyze their phenolic constituents in order to draw a rationale for their activity. Antioxidant activities of the date cultivars were evaluated by different quantitative methods including 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical scavenging assay, total antioxidant capacity, reducing power, total phenolic (TPC), flavonoid (TFC) and tannin content (TTC), while qualitative phenolic composition was determined using ultra performance liquid chromatography coupled to quadropole time of flight mass spectrometry (UPLC-QTOF-MS). All the three date extracts showed good DPPH radical scavenging (IC₅₀ 103–177 μg/mL) and hydroxyl radical scavenging (IC₅₀ 1.1–1.55 mg/mL) activity and total antioxidant capacity (IC₅₀ 87–192 μg/mL). The reducing power was also comparable to that of ascorbic acid, used as standard in above experiments. All the three samples contain significant amount of major antioxidant components (phenolic, flavonoid and tannin) that successfully correlates with the results of radical scavenging assays. UPLC-QTOF-MS revealed a total of 22 compounds in these date cultivars classified into common phenolics, flavonoids, sterols and phytoestrogens. Significant variation in the degree of antioxidant activity of these three date cultivars can be attributed to the difference in the content and composition of phenolic compounds.     

Diversity of Selected Lupinus angustifolius L. Genotypes at the Phenotypic and DNA Level with Respect to Microscopic Seed Coat Structure and Thickness

The paper investigates seed coat characteristics (as a percentage of overall seed diameter) in Lupinus angustifolius L., a potential forage crop. In the study ten L. angustifolius genotypes, including three Polish cultivars, two Australian cultivars, three mutants originated from cv. ‘Emir’, and one Belarusian and one Australian breeding line were evaluated. The highest seed coat percentage was recorded in cultivars ‘Sonet’ and ‘Emir’. The lowest seed coat thickness percentage (below 20%) was noted for breeding lines 11257-19, LAG24 and cultivar ‘Zeus’ (17.87%, 18.91% 19.60%, respectively). Despite having low seed weight, the Australian line no. 11257-19 was characterized by a desirable proportion of seed coat to the weight of seeds. In general, estimation of the correlation coefficient indicated a tendency that larger seeds had thinner coats. Scanning Electron Microscopy images showed low variation of seed coat sculpture and the top of seeds covered with a cuticle. Most of the studied genotypes were characterized by a cristatepapillate seed coat surface, formed by elongated polygonal cells. Only breeding line no. 11267-19 had a different shape of the cells building the surface layer of the coat. In order to illustrate genetic diversity among the genotypes tested, 24 ISSR primers were used. They generated a total of 161 polymorphic amplification products in 10 evaluated narrow-leaved lupin genotypes.     

Effects of Infection by Belonolaimus longicaudatus on Rooting Dynamics among St. Augustinegrass and Bermudagrass Genotypes

Understanding rooting dynamics using the minirhizotron technique is useful for cultivar selection and to quantify nematode damage to roots. A 2-yr microplot study including five bermudagrass (‘Tifway’, Belonolaimus longicaudatus susceptible; two commercial cultivars [TifSport and Celebration] and two genotypes [‘BA132’ and ‘PI 291590’], which have been reported to be tolerant to B. longicaudatus) and two St. Augustinegrass (‘FX 313’, susceptible, and ‘Floratam’ that was reported as tolerant to B. longicaudatus) genotypes in a 5 x 2 and 2 x 2 factorial design with four replications, respectively, was initiated in 2012. Two treatments included were uninoculated and B. longicaudatus inoculated. In situ root images were captured each month using a minirhizotron camera system from April to September of 2013 and 2014. Mixed models analysis and comparison of least squares means indicated significant differences in root parameters studied across the genotypes and soil depths of both grass species. ‘Celebration’, ‘TifSport’ and ‘PI 291590’ bermudagrass, and ‘Floratam’ St. Augustinegrass had significantly different root parameters compared to the corresponding susceptible genotypes (P ≤ 0.05). Only ‘TifSport’ had no significant root loss when infested with B. longicaudatus compared to non-infested. ‘Celebration’ and ‘PI 291590’ had significant root loss but retained significantly greater root densities than ‘Tifway’ in B. longicaudatus-infested conditions (P ≤ 0.05). Root lengths were greater at the 0 to 5 cm depth followed by 5 to 10 and 10 to 15 cm of vertical soil depth for both grass species (P ≤ 0.05). ‘Celebration’, ‘TifSport’, and ‘PI 291590’ had better root vigor against B. longicaudatus compared to Tifway.     

Differential expression of anthocyanin biosynthetic genes in relation to anthocyanin accumulation in the pericarp of Litchi chinensis Sonn

Litchi has diverse fruit color phenotypes, yet no research reflects the biochemical background of this diversity. In this study, we evaluated 12 litchi cultivars for chromatic parameters and pigments, and investigated the effects of abscisic acid, forchlorofenron (CPPU), bagging and debagging treatments on fruit coloration in cv. Feizixiao, an unevenly red cultivar. Six genes encoding chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), anthocyanidin synthase (ANS) and UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT) were isolated from the pericarp of the fully red litchi cv. Nuomici, and their expression was analyzed in different cultivars and under the above mentioned treatments. Pericarp anthocyanin concentration varied from none to 734 mg m⁻² among the 12 litchi cultivars, which were divided into three coloration types, i.e. non-red (‘Kuixingqingpitian’, ‘Xingqiumili’, ‘Yamulong’and ‘Yongxing No. 2′), unevenly red (‘Feizixiao’ and ‘Sanyuehong’) and fully red (‘Meiguili’, ‘Baila’, Baitangying’ ’Guiwei’, ‘Nuomici’ and ‘Guinuo’). The fully red type cultivars had different levels of anthocyanin but with the same composition. The expression of the six genes, especially LcF3H, LcDFR, LcANS and LcUFGT, in the pericarp of non-red cultivars was much weaker as compared to those red cultivars. Their expression, LcDFR and LcUFGT in particular, was positively correlated with anthocyanin concentrations in the pericarp. These results suggest the late genes in the anthocyanin biosynthetic pathway were coordinately expressed during red coloration of litchi fruits. Low expression of these genes resulted in absence or extremely low anthocyanin accumulation in non-red cultivars. Zero-red pericarp from either immature or CPPU treated fruits appeared to be lacking in anthocyanins due to the absence of UFGT expression. Among these six genes, only the expression of UFGT was found significantly correlated with the pericarp anthocyanin concentration (r = 0.84). These results suggest that UFGT played a predominant role in the anthocyanin accumulation in litchi as well as pericarp coloration of a given cultivar.     

Phytochemical Profiles and Antioxidant Activities in Six Species of Ramie Leaves

Increased consumption of vegetables or plant food has been associated with decreased risk of developing major chronic diseases, such as cancers, diabetes, cardiovascular diseases, and age-related functional decline. Ramie leaves are rich in phenolics and flavonoids, which have been suggested for human health benefits. Phenolic contents, flavonoid contents, phenolic compounds, and anti-cancer properties in six species of ramie leaves were analyzed by Folin-reagent method, sodium borohydride/chloranil-based assay (SBC), HPLC method and antiproliferation, cytoxicity, respectively. Antioxidant activities were measured through peroxyl radical scavenging capacity (PSC) method, oxygen radical absorbance capacity (ORAC) method, and cellular antioxidant activity (CAA). Research indicated that Boehmeria penduliflora contained the highest total phenolic content (2313.7±27.28 mg GAE/100 g FW), and flavonoid content (1682.4±27.70 mg CAE/100 g FW). Boehmeria tricuspis showed the highest PSC value (9574.8±117.63 µM vit. C equiv./100 g FW), while Boehmeria penduliflora indicated the highest ORAC value (330.44±16.88 µmol Trolox equiv./g FW). The antioxidant activities were correlated with phenolic contents and flavonoid contents. Boehmeria tricuspis had the highest antiproliferative capacity with the lowest EC₅₀ (4.11±0.19 mg/mL). The results for the analyzed ramie for CAA were significantly different from each other (p<0.05), Boehmeria tricuspis had the highest CAA value (133.63±7.10 µmol QE/100 g). Benzoic acid, 4-coumaric acid, caffeic acid, and ferulic acid were the dominant phenolic ingredients in the ramie leaves according to HPLC analysis. Our research is the first report to study the phytochemical profiles and antioxidant activities in different species of ramie leaves for their health benefit.     

Genotypic differences in Al resistance and the role of cell-wall pectin in Al exclusion from the root apex in Fagopyrum tataricum

Background and Aims

Aluminium (Al) toxicity is one of the factors limiting crop production on acid soils. However, genotypic differences exist among plant species or cultivars in response to Al toxicity. This study aims to investigate genotypic differences among eight cultivars of tatary buckwheat (Fagopyrum tataricum) for Al resistance and explore the possible mechanisms of Al resistance.

Methods

Al resistance was evaluated based on relative root elongation (root elongation with Al/root elongation without Al). Root apex Al content, pectin content and exudation of root organic acids were determined and compared.

Key Results

Genotypic differences among the eight cultivars were correlated with exclusion of Al from the root apex. However, there was a lack of correlation between Al exclusion and Al-induced oxalate secretion. Interestingly, cell-wall pectin content of the root apex was generally lower in Al-resistant cultivars than in Al-sensitive cultivars. Although we were unable to establish a significant correlation between Al exclusion and pectin content among the eight cultivars, a strong correlation could be established among six cultivars, in which the pectin content in the most Al-resistant cultivar ‘Chuan’ was significantly lower than that in the most Al-sensitive cultivar ‘Liuku2’. Furthermore, root apex cell-wall pectin methylesterase activity (PME) was similar in ‘Chuan’ and ‘Liuku2’ in the absence of Al, but Al treatment resulted in increased PME activity in ‘Liuku2’ compared with ‘Chuan’. Immunolocalization of pectins also showed that the two cultivars had similar amounts of either low-methyl-ester pectins or high-methyl-ester pectins in the absence of Al, but Al treatment resulted in a more significant increase of low-methyl-ester pectins and decrease of high-methyl-ester pectins in ‘Liuku2’.

Conclusions

Cell-wall pectin content may contribute, at least in part, to differential Al resistance among tatary buckwheat cultivars.     

Antioxidant Composition of Red and Orange Cultivars of Tomatoes (Solanum lycopersicon L): A Comparative Evaluation

Fourteen commercial cultivars of tomato were analyzed for their antioxidant composition. There was significant difference (p<0.05) in lycopene and phenolic contents between red and yellow cultivars. Red cultivars had higher lycopene content (2.735 to 6.552 mg 100g^?1) than yellow cultivars (0.769 to 1.238 mg 100g^?1). Mean total polyphenolic content and total antioxidant activity in red cultivars was also higher than those in yellow cultivars. Overall cherry tomatoes had highest phenolic content and appeared to be a promising cultivar in terms of their health promoting effects. The results highlight an existing unexploited variability in yellow tomato to improve their antioxidant properties.     

Influence of rootstocks on growth,yield, fruit quality and leaf mineral element contents of pear cv. ‘Santa Maria’ in semi-arid conditions

Background

Rootstocks play an essential role to determining orchard performance of fruit trees. Pyrus communis and Cydonia oblonga are widely used rootstocks for European pear cultivars. The lack of rootstocks adapted to different soil conditions and different grafted cultivars is widely acknowledged in pear culture. Cydonia rootstocks (clonal) and Pyrus rootstocks (seedling or clonal) have their advantages and disadvantages. In each case, site-specific environmental characteristics, specific cultivar response and production objectives must be considered before choosing the best rootstock. In this study, the influence of three Quince (BA 29, Quince A = MA, Quince C = MC) and a local European pear seedling rootstocks on the scion yield, some fruit quality characteristics and leaf macro (N, P, K, Ca and Mg) and micro element (Fe, Zn, Cu, Mn and B) content of ‘Santa Maria’ pear (Pyrus communis L.) were investigated.

Results

Trees on seedling rootstock had the highest annual yield, highest cumulative yield (kg tree⁻¹), largest trunk cross-sectional area (TCSA), lowest yield efficiency and lowest cumulative yield (ton ha⁻¹) in the 10^th year after planting. The rootstocks had no significant effect on average fruit weight and fruit volume. Significantly higher fruit firmness was obtained on BA 29 and Quince A. The effect of rootstocks on the mineral element accumulation (N, K, Ca, Mg, Fe, Zn, Cu, Mn and B) was significant. Leaf analysis showed that rootstocks used had different mineral uptake efficiencies throughout the early season.

Conclusion

The results showed that the rootstocks strongly affected fruit yield, fruit quality and leaf mineral element uptake of ‘Santa Maria’ pear cultivar. Pear seedling and BA 29 rootstock found to be more prominent in terms of several characteristics for ‘Santa Maria’ pear cultivar that is grown in highly calcareous soil in semi-arid climate conditions. We determined the highest N, P (although insignificant), K, Ca, Mg, Fe and Cu mineral element concentrations on the pear seedling and BA 29 rootstocks. According to the results, we recommend the seedling rootstock for normal density plantings (400 trees ha⁻¹) and BA 29 rootstock for high-density plantings (800 trees ha⁻¹) for ‘Santa Maria’ pear cultivar in semi-arid conditions.     

Total phenolics, flavonoids and antioxidant activity of Saptarangi (Salacia chinensis L.) fruit pulp

Salacia chinensis L. has various beneficial properties including antidiabetic and antioxidant activity. The S. chinensis fruit pulp (SCFP) was extracted with four different solvents (Methanol, ethanol, acetone and water) and was screened for total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity (AOA). The AOA was assessed by evaluating the 1, 1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and metal chelating assay. Methanolic SCFP extract exhibited the highest phenolic content (3.20?±?0.12 mg GAE/g FW) whereas, ethanolic extract showed highest flavonoid content (0.31?±?0.68 mg RE/g FW). The methanolic extract possesses highest antioxidant activity towards DPPH (92.44 %), FRAP (1.939 O.D) and metal chelating activity (74.16 %). AOA (DPPH and FRAP) was significantly correlated with TPC. The results indicated that SCFP is a good natural source of antioxidant compounds for use in food and pharmaceutical industry.     

The effects of exogenous ABA applied to maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.) roots on plant responses to chilling stress

This work aimed to discuss the effects of exogenous abscisic acid (ABA) on the root growth regulation of maize seedlings under chilling stress. The roots of the maize cultivar Zhengdan 958 were irrigated with ABA (10^?7, 10^?6, 10^?5 and 10^?4 M) at the third true leaf stage under chilling duration (0, 2, 4, 6, and 8 days). The biomass, the phenylalanine ammonia lyase (PAL), and polyphenol oxidase (PPO) enzyme activities, total phenolic and flavonoid contents, the ferric reducing ability of plasma (FRAP) antioxidant capacity, and 2,2-azinobis (3-ethlbenzothiazo-line-6-sulfonic acid) diammonium salt radical (ABTS^·+) scavenging capacity of the roots of maize seedlings were measured after the treatment. The results showed that appropriate concentrations of exogenous ABA effectively enhanced root biomass, increased PAL and PPO enzyme activities, and significantly increased total phenolic contents and flavonoid contents. Moreover, the ABA markedly improved the FRAP antioxidant capacity and ABTS^·+ scavenging capacity under low-temperature stress. These results indicate that ABA-treated maize seedlings are resistant to chilling stress and that the optimum concentration of ABA is 10^?5 M. Exogenous applications of ABA have a concentration effect in alleviating chilling stress, in which low concentrations have a promoting effect and high concentrations have an inhibiting effect.     

采收期对代料栽培桑黄子实体活性成分含量和抗氧化活性的影响

桑黄孔菌属Sanghuangporus 是一类具有重要药用价值的大型真菌,目前被国际公认为抗肿瘤效果最好的真菌之一。本研究以桑黄孔菌属中的杨树桑黄Sanghuangporus vaninii、鲍姆桑黄S. baumii为研究对象,通过测定代料栽培原基形成后第30、45、60、75、90天子实体多糖、三萜、总黄酮、总酚含量和抗氧化活性（ABTS和FRAP）,探究采收期对桑黄子实体活性成分含量和抗氧化活性的影响。结果表明,除杨树桑黄三萜含量外,采收期对上述6个指标均产生了极显著的影响。在多糖含量上,鲍姆桑黄在原基形成后75d时急剧升至最大,在原基形成后90d时有所下降;而杨树桑黄在原基形成后45、60、75d均维持较高水平。在三萜含量上,鲍姆桑黄在原基形成后30d时即达最大值,此后缓慢下降,而杨树桑黄则不同采收期差异不显著。关于总黄酮含量、总酚含量和抗氧化活性（ABTS、FRAP）,鲍姆桑黄和杨树桑黄均在原基形成后30、45、60d维持较高水平,在原基形成后75、90d急剧下降。相关性分析结果表明,总黄酮含量、总酚含量、抗氧化活性（ABTS、FRAP）两两极显著正相关。鲍姆桑黄多糖含量与其上述4指标呈显著或极显著负相关,与三萜相关不显著。杨树桑黄多糖含量与其上述4指标相关不显著,与三萜含量呈显著负相关。主成分分析与聚类分析结果一致,表现为原基形成后30、45、60d的子实体聚为一类,原基形成后75、90d的子实体聚为另一类。适时采收,有利于桑黄活性成分含量和抗氧化活性的提升。研究结果为桑黄代料栽培适时采收、质量控制、药材质量综合评价提供了科学参考。     

Mapping the genetic and tissular diversity of 64 phenolic compounds in Citrus species using a UPLC–MS approach

Background and Aims Phenolic compounds contribute to food quality and have potential health benefits. Consequently, they are an important target of selection for Citrus species. Numerous studies on this subject have revealed new molecules, potential biosynthetic pathways and linkage between species. Although polyphenol profiles are correlated with gene expression, which is responsive to developmental and environmental cues, these factors are not monitored in most studies. A better understanding of the biosynthetic pathway and its regulation requires more information about environmental conditions, tissue specificity and connections between competing sub-pathways. This study proposes a rapid method, from sampling to analysis, that allows the quantitation of multiclass phenolic compounds across contrasting tissues and cultivars.Methods Leaves and fruits of 11 cultivated citrus of commercial interest were collected from adult trees grown in an experimental orchard. Sixty-four phenolic compounds were simultaneously quantified by ultra-high-performance liquid chromatography coupled with mass spectrometry.Key Results Combining data from vegetative tissues with data from fruit tissues improved cultivar classification based on polyphenols. The analysis of metabolite distribution highlighted the massive accumulation of specific phenolic compounds in leaves and the external part of the fruit pericarp, which reflects their involvement in plant defence. The overview of the biosynthetic pathway obtained confirmed some regulatory steps, for example those catalysed by rhamnosyltransferases. The results suggest that three other steps are responsible for the different metabolite profiles in ‘Clementine’ and ‘Star Ruby’ grapefruit.Conclusions The method described provides a high-throughput method to study the distribution of phenolic compounds across contrasting tissues and cultivars in Citrus, and offers the opportunity to investigate their regulation and physiological roles. The method was validated in four different tissues and allowed the identification and quantitation of 64 phenolic compounds in 20 min, which represents an improvement over existing methods of analysing multiclass polyphenols.