Tea Clones Research Articles

Clonal plain back tea quality parameters responses of hard physical withered leaf to rehydration and fermentation durations

Hard physical withers in tea processing result in reduced plain black tea quality parameters, but improve flavoury black tea quality. Chemical withers with minimal moisture loss improve plain black tea quality parameters. But chemical withered leaf is normally bulky and not flaccid thus reducing maceration rates. Hard physical withers reduce polyphenol oxidase activity, thereby impairing ability of the leaf to produce high amounts of plain black tea quality parameters, especially theaflavins and thearubigins. This study examined if rehydrating hard physical withered leaf could improve its fermentability and influence fermentation duration, and if such changes are cultivar dependent. Rehydrating hard physical withered leaf increased (p≤0.05) total theaflavins, thearubigins, brightness, total colour and sensory evaluation of resultant black teas. The patterns of the responses did not vary with cultivars or fermentation duration. The theaflavins and brightness declined (p≤0.05) while thearubigins and total colour increased (p≤0.05) with long fermentation durations irrespective of withering regime. Results demonstrate that problems of plain black tea quality reduction due to hard physical withers can be partially reversed by rehydration to chemical wither standard, but the withering regime does not influence when maximum plain black tea quality parameters are produced.

Evaluation of tea clones for resistance/tolerance to mites infestations and the influence of environmental factors on mites dynamics in Kenyan tea farms

Mites infestations reduce yields in tea production world wide. However, some tea cultivars are resistant/tolerant to mites attack. The resistance/susceptibility can also be influenced by abiotic factors. This study evaluated some new tea clones for mite resistance/susceptibility and influence of Environmental factors (weather parameters) on dynamics of mite infestations of Kenyan tea at different ecological zones, Kangaita, Kipkebe and Timbilil. Maximum population of mites was reported during March when maximum temperature, average rainfall and relative humidity ranges for the sites were 23.9-28.7°C, 27.7-50.1mm and 38.0-70.4% respectively. There was a sharp decline in mites population in April when average rainfall was high (398.4-514.4mm) which was accompanied by reduction in maximum temperature (18.8-27.5°C) and increase in relative humidity (44.0-82.2%). The minimum population density was found during August which was characterized by low maximum temperature (16.4-26.6°C), low average rainfall (4.8- 190.5mm) and high average relative humidity (46.0-80.9%). The mites infestation levels highly correlated with maximum temperatures in Kangaita (r<sup>2</sup> = 0.801), Kipkebe (r<sup>2</sup> = 0.693) and Timbilil (r<sup>2</sup> = 0.744). There were significant (p≤0.05) monthly variations in clonal mite infestations at all sites. Susceptible clones showed higher monthly mite infestations variations than the resistant/tolerant clones. Of the clones evaluated for the first time, eight new clones were identified as tolerant/resistant while two clones were susceptible to mites attack. Resistant/tolerant clones are recommended for commercial exploitation while mitigation strategies should be put in place in mites prone areas during hot seasons with high monthly temperatures and low humidity

Retraction Note to: Antioxidants and ROS scavenging ability in ten Darjeeling tea clones may serve as markers for selection of potentially adapted clones against abiotic stress.

[This retracts the article DOI: 10.1007/s12298-013-0187-1.].

An assessment of genetic relationship in tea clones based on important chemical compound and yield potential

Assembling of new excellence high yiel­ding and good quality tea clones was started from identification accession as gene sources, crossing design of parents, selection mother bushes and propagated vegetatively. Crossing beetwen two parent clones which near or remote genetic relationship in tea will failed. Assessment of genetic relationship clone accession was done using secondary datas from description of first and second tea clone gene­ration which cultivated in Indonesia. Data of yield potentials and main chemical com­pound of quality among others catechine, gallat cate­chine, catechine gallo and cafeine were ana­lysed using biplot and cluster analysis. The results showed that no correllation beetwen main chemical compound of quality and yield potentials. Biplot with two dimensions could be explained 92,5% variation of five characters and showed that yield has the highest and catechine the smallest variances. The first gene­ration of tea clones was separated to second at the 46,79% similarity levels. At the 15,60% similarity levels, there were six clusters. GMB 1, GMB 2, GMB 6, GMB 9, and GMB 10 clones were in one cluster was caused of they had high of yield and catechine. GMB 4 and GMB 5 had similarity on medium yields, GMB 7 and GMB 11 had similarity on medium catechine and the highest yield, and GMB 3 and GMB 8 had similarity on low catechine. PS 1 with the lowest catechine gallo was separated to the others. The sixth cluster were SA 40, Kiara 8, SA 35, RB 3, and Cin 143 were characterized by low catechine and yields.Â

Effect of the number of physiologically mature maintenance leaves and the frequency of foliar fertilizer application on the growth of Empoasca, weeds, and the yield of clone GMB 7 tea crop (Camellia sinensis (L.) O. Kuntze)

The objective of this research was to study the interaction effect between the number of physiologically mature maintenance leaves on tipping and the frequency of application foliar fertilizer application on the development of the main pest Empoasca, weeds and the yield of GMB 7 tea clone. The experiment was con­ducted at Gambung Estate, block A4, Re­search Institute Tea and Cinchona, Mekarsari Village, Pasirjambu Subdistrict, Bandung Regency, with altitude about 1.300 m above sea level. The average rainfall was 3.035 mm/year and the type of rainfall is B according to Schmidt and Fergusson (1951). The soil type is Andisol with pH 5,9. The experiment was done from Decem­ber 2011 until July 2012. The experiment has factorial Randomized Block Design (RBD) with three replications. The first factor is physio­logically mature maintenance leaves on tipping (A) with 3 treatments: a0 = 3 leaves, a1 = 5 leaves and a2 = 7 leaves. The second factor is the application of follar fertilizer (B) with three treatments: b0 = without application, b1 = one application and b2 = two applications. The result showed that no interaction between the number of physiologically mature maintenance leaves and the frequency of foliar fertilizer application on the attack intensity of Empoasca. The interaction between five physiologically mature maintenance leaves and one application of folliar fertilizer treatment were effective to control pest and weeds. The interaction hap­pened between the number of physiologically mature maintenance leaves on tipping and the frequency application of foliar fertilizer on yield at 10 and 12 weeks after determined the physiologically mature maintenance leaves. The average of LAI on five physiologically mature maintenance leaves and one application of folliar fertilizer treatment were 3,0087 with regression Ŷ-a1b1 = -0,1923 + 0,0237 X; R^2 = 0,8979 were effective to control Empoasca, weeds and to increase the yield.

The effect of NPK compound fertilizer (27%:6%:10%) compared to conventional fertilizers on productive tea plants of GMB 7 clone in the Andisols soil type

The effectiveness application of compound fertilizer NPK (27%:6%:10%) to increase  tea shoots had been tested in Experimental Garden of Research Institute for Tea and Cinchona Gambung, Bandung, West Java, from January 2006 to March 2007. Experi­mental design used was randomized block design with 6 treatments with five replication. The plot sizes were 20 x 20 m = 400 m2/plot. The tea clone tes­ted was GMB 7. The appli­cation of compound fertilizer NPK (27%:6%:10%) were twice a year (50%-50%) and conventional fertlization were 4 times a year (20%-30%-20%-30%). The composition of treatment was as follows: (A) 500 kg, (B) 600 kg, (C) 700 kg, (D) 800 kg/ha/year, and (E) conventional fertilizer recommended dosage of the Research Institute for Tea and Cinchona Gambung (480 kg urea + 357 kg ZA + 260 kg SP 36 + 300 kg KCl + 278 kg kieserit/ha/year), and (F) control (no fertilizer treatment). Parameters observed were: 1. soil and leaf analysis at before and after treatment, 2. weighting the potential and the yield components each time of plucking, and 3. technoeconomic analysis. The results showed that: statistical analysis of the components as well as potential yield, and nutrient analysis (N, P, K, Mg and Zn) of the mother leaves of GMB 7 clones and the soil demon­strated the significantly differences among the treatments of all the various doses of compound fertilizer NPK and conventional fertilizer application to control (no fertilizer treatment). Meanwhile, there were no significantly differences among the result of  the doses of compound fertilizer NPK, to the conventional fertilizer applications. Further­more, dose of compound fertilizer NPK (27%:6%:10%) for produc­tive tea plant was recommendated at 700 kg/ha rate and was equivalent to 189 kg N/ha/year or 63% of the dose of conventional fertilizer, but could provide equivalent result to conventional fertilizer application, and not only could save the buying cost of conventional fertilizer (urea, ZA, TSP/SP-36, KCl / MOP and kieserit) but also the cost of application cost in the field.

Analysis of leaves morphology similarity of several first generation tea clones

As an effort to conserve tea clone accessions of first generation from genetic erosion, arrangement germplasm in one particular block/area to be easily monitored and managed, is needed. Ideally, tea germplasm collection should consist of a few clone accession number but high genetic variability. To select representative clones that will be conserved in new germplasm collection, leaves morphology similarity has been analysed by cluster analysis using average method. The results showed that by using leaves morphology parameter, from 50 tea clone accession of first generation coming from several tea plantations, it could be reduced into 25 clone accessions from seven clusters, which each has high similarity. The first cluster with 60% similarity could reduced accession from 15 to 6 clone. The second with 74,8% similarity from 25 to 13 clones. The third with 74,8% similarity, from 4 to 2 clones. The fourth with 61,3% similarity, and seventh with 82,1% similarity, both could reduce from 2 clones to 1 clone. To design a tea germplasm collection with 50 accessions of genetic variability, it could represented by 25 clones with low similarity, i.e PG 3, KP 1, Skm 18, Cin 69, Cin 67 dan Cin 58 as the first cluster representatives, Mel 101, PG 4, Pam 15, PG 5, PG 11, GP 2, BD 13, SA 49, Cin 66, Mal 16, Bks 6 and Sin 5 the second cluster representatives;  Mel 108 and Cin 13 as the third cluster representatives; and Cin 15, Cip 37, GH 5, as well as GP 4 as the fourth, the fifth, and the sixth representatives, respectively.

Selection of superior assamica tea clones with high yield potential and high catechine contents

Selection of superior assamica tea clones with high yielding potential and high catechine contents, was conducted using plant materials of selected mothers bushes from F1 polyclonal seed field with a clone composition of Kiara 8, TRI 777, TRI 2024, TRI 2025, and PS 1. The selected bushes had a minimum 100 g per bush. This research was conducted in Pasir Sarongge Experimental Garden, representing medium elevation and Gambung Experimental Garden, representing high elevation. Experimental design in each location was a randomized complete block design with three replications. Twenty five selected clones were used in this research with one high yielding GMB 7 as a check. Plot contained 15 bushes with plant distant of 120 x 80 cm. Shoot yield were observed in September to November 2010 on six years old plant of third prunning stages with plucking cycle seven days. Catechine content of clone were observed by extracting dry tea shoot in boilling water, followed by deluting in ethyl acetate and HPLC readings. The results showed that in medium elevation clone number of II.32.15 had similar yielding potential with GMB 7 clone with catechine content 16,44%, and at high elevation clones number of II.6.10, III.28.4, III.35.3, and III.36.15 had high yielding potential and catechine content of 15,35%; 16,13%; 16,03%; and 13,14% respectively

Effect of Plant Density and Nitrogen Fertilizer Application Rates on Nutrient Content of Clonal Tea Leaf

Effect of Plant Density and Nitrogen Fertilizer Application Rates on Nutrient Content of Clonal Tea Leaf

Effect of Plant Density, Nitrogen Fertilizer Application Rates and Soil Depth on Clonal Tea Soil Nutrient Content

Trial on plant density which started in 1990 has revealed that in clonal tea, yield significantly increased with decrease in plant population density (ppd), with the highest ppd showing significantly lower yield than all the other ppd. However, this effect was opposite when the tea was young. It is not therefore known whether the same effect applies to nutrients content. This study was carried out to determine the effect of plant density of AHP S15/10 clonal tea plants and rates of nitrogenous fertilizer applied on soil content in Kericho, Kenya. Soil samples were collected from all the experimental plots. The samples were analyzed for their contents of macro and micro elements by ICPE spectroscopy. The results showed that plant density had no significant effect on the soil nutrients content. Nitrogen fertilizer application rates and depths of soil showed significant effects. Every element in the soils showed similar nutritional pattern for different nitrogen application rates across the four depths of the profile. However, the pattern was different for different plant density. Phosphorus content was least in the highest ppd.

Development of CAPS markers to identify Indian tea (Camellia sinensis) clones with high catechin content

Tea leaves are rich in plant secondary phenolics, especially flavonoids. Catechins are considered to be the most valuable flavonoids, and the catechin content in tea is an important trait for determining its quality. We have developed cleaved amplified polymorphic sequence (CAPS)-based markers for evaluating total catechin content that target two important secondary metabolite pathway genes, PAL (phenylalanine ammonia-lyase) and CHS (chalcone synthase). Catechin content levels in the tea samples tested ranged from 9 to 33 mg/mg. The CAPS technique identified clones with the homozygous profile PRc1, which has relatively lower catechin content than clones with the heterozygous profile PRc2. A significant difference (t = 16.85) in the level of catechin content was also detected between heterozygotes and homozygotes in the tea seed stock TS379. We found a polynomial relationship between the marker developed for CHS2 and catechin content in these tea samples with R2 = 0.9788. Moreover, PAL has less of a relationship with catechin content. Therefore, we recommend tea clones with heterozygous CAPS profiles for the gene CHS2+RcaI for the further improvement in these clones.

Genotype and Environment Interactions of Yields and Yield Components of Tea (<i>Camellia sinensis</i>) Cultivars in Kenya

The tea crop provides income and employment to rural populations in many countries. In Kenya, tea, which is the leading export commodity crop, is grown in highlands east and west of the Rift Valley at altitudes ranging from 1300 m to 2700 m above mean sea level. Variable responses of tea genotypes to different environments have been demonstrated. This affects the growth, productivity, and quality of tea. However, most tea husbandry practices are uniform across tea growing regions leading to variations in yields and quality in the different environments. Understanding causes of variations in tea growth parameters and yields to varying environments is vital to optimizing husbandry practices for maximization of productivity. The responses in growth and yield parameters of clonal tea to locations of production and their contribution to yields were compared. A genotype × environment trial was conducted in three sites (Kangaita, Timbilil and Kipkebe). At each site, a trial comprising 20 cultivars was laid in a randomized complete design replicated 3 times. Yields, yield components and climatic data were collected then subjected to analysis of variance and regression analysis. There were significant (p ≤ 0.05) yield variations between clones and locations. Yields ranged from 5162 kg mt/ha on clone TRFK 303/577 at Kipkebe to 935 kg mt/ha/year on clone TRFK 7/3 in Kangaita, surpassing the maximum variation possible postulated in earlier studies. The responses of the tea yield components to weather parameters varied with genotypes and environments. Shoot growth rates in Timbilil (r = 0.476)) and shoot density (Kangaita (r = 0.652) significantly (p ≤ 0.05)) correlated with yields. Yield components and weather parameters contribution to the total yield also varied with locations. The variations demonstrated that not all yield components can be used universally as yield indicators for clonal selection in different locations. For optimal production, selected tea clones should therefore be tested before adoption for commercial planting in other locations.

Evaluation of genetic diversity of cultivated tea clones (Camellia sinensis (L.) Kuntze) in the eastern black sea coast by inter-simple sequence repeats (ISSRS)

Tea is the most globally consumed drink after spring water and an important breeding plant with high economical value in Turkey. In half a century, various kinds of tea cultivars have been bred in Turkey to improve the quality and yield of tea plants. Since tea reproduces sexually, tea fields vary in quality. Thus, determining the genetic diversity and relationship of the plants to support breeding and cultivation is important. In this study we aimed to determine the genetic diversity of tea cultivars breeding in the Eastern Black Sea coast of Turkey and the genetic relationship between them, to verify whether the qualitative morphological designations of the clones are genetically true by the ISSR markers. Herein, the genetic diversity and relationships of 18 Turkish tea cultivars were determined using 15 ISSR markers with sizes ranging from 250 to 3000 base pairs. The similarity indices among these cultivars were between 0.456 and 0.743. Based on cluster analysis using UPGMA, some of tea cultivars originating from the same geographical position were found to be clustered closely. Our data provide valuable information and a useful basis to assist selection and cloning experiments of tea cultivars and also help farmers to find elite parental clones for tea breeding in the Eastern Black Sea coast of Turkey.

Catechins Green Tea Clones GMB4 Inhibit Inflammation Process of Atherosclerosis Through Decreasing TNF-Α Levels

<p>Catechins Green tea clones GMB4 are potential natural subtances to inhibit inflammation process in atherosclerosis. The purpose of this research to determine activity of Catechins Green tea clones GMB4 to decrease TNF-α levels, as well as to determine optimal dose of Catechins. This research was conducted at the Laboratory of Physiology of the University of Brawijaya. The method used in this research is completely randomized design with five treatments: (1) Mice with standard feed (2) mice with high-fat diet (3) mice with high-fat diet + catechins 3mg / day (4) mice with a diet high fat + catechin 6mg / day (5) mice with high-fat diet + catechin 24mg / day. The treatment was done for 60 days and measured levels of TNF-α at the end of the research. The results showed that Catechins green tea clones GMB4 can inhibit the inflammatory process in atherosclerosis through decreasing levels of TNF-α at doses of 3mg / day. The conclusion of this research is catechins at a dose of 3 mg / day can inhibit inflammation in atherosclerosis significantly.</p><p> </p><strong>Keywords</strong> : GMB 4 green tea clones, Catechins, inflammation, TNF-α

Screening of Adoptive Elite Tea (Camellia sinensis) Clones

The research screening of adoptive elite tea clones was conducted at NTRI, Mansehra during 2011-2012. Nine clones 101Aa, 105aa, 108aa, 561aa, 117aa, 219ab, 470bb and 180bd were evaluated for seedling performance. Randomized complete block design was used with three replications. Data was recorded on various morphological characters after 8 months. The results showed that high survival percentage, shoot length, number of roots plant−1, number of leaves plant−1 and root length were observed in clone 105aa. While the highest fresh weight and dry weight of leaves were observed in clones 117aa and 105aa. The clone 105aa was drought resistant, high survival percentage and root growth. On the basis of the results, clone 105aa was recommended for cultivation through cuttings in the hilly areas of Pakistan where unequal rainfall distribution was a major hitch.

Assessment of Culturable Tea Rhizobacteria Isolated from Tea Estates of Assam, India for Growth Promotion in Commercial Tea Cultivars

In the present study, 217 rhizobacterial isolates were obtained from six different tea estates of Assam, India and subjected to preliminary in vitro plant growth promotion (PGP) screening for indole acetic acid (IAA) production, phosphate solubilization, siderophore production and ammonia production. Fifty isolates showed all the PGP traits and five isolates did not exhibit any PGP traits. These 50 potential isolates were further analyzed for quantitative estimation of the PGP traits along with the aminocyclopropane-1-carboxylate (ACC) deaminase, protease and cellulose production. After several rounds of screening, four rhizobacteria were selected based on their maximum ability to produce in vitro PGP traits and their partial 16S rRNA gene sequence analysis revealed that they belong to Enterobacter lignolyticus strain TG1, Burkholderia sp. stain TT6, Bacillus pseudomycoides strain SN29 and Pseudomonas aeruginosa strain KH45. To evaluate the efficacy of these four rhizobacteria as plant growth promoters, three different commercially important tea clones TV1, TV19, and TV20 plants were inoculated with these rhizobacteria in greenhouse condition and compared to the uninoculated control plants. Though, all the rhizobacterial treatments showed an increase in plant growth compared to control but the multivariate PCA analysis confirmed more growth promotion by TG1 and SN29 strains than the other treatments in all three clones. To validate this result, the fold change analysis was performed and it revealed that the tea clone TV19 plants inoculated with the E. lignolyticus strain TG1 showed maximum root biomass production with an increase in 4.3-fold, shoot biomass with increase in 3.1-fold, root length by 2.2-fold and shoot length by 1.6-fold. Moreover, two way ANOVA analysis also revealed that rhizobacterial treatment in different tea clones showed the significant increase (P < 0.05) in growth promotion compared to the control. Thus, this study indicates that the potential of these indigenous plant growth promoting rhizobacteria isolates to use as microbial inoculation or biofertilizer for growth promotion of tea crops.

Phytoconstituents and antioxidant properties among commercial tea (Camellia sinensis L.) clones of Iran

article i nfo Camellia sinensis DPPH assay Methanolic extract Total flavonoid content Total phenolic content Background: Tea (Camellia sinensis), a well-known beverage is consumed frequently worldwide due to its high antioxidant properties. The present study determines the amount of phytochemicals and antioxidant activities among 12 high yielding tea clones cultivated in Iran. Results: Among the 12 clones studied, tea clone Iran 100 had the highest total phenolic content and total flavonoid content with values of 8.44 ± 1.03 mg gallic acid equivalents per gram dry weight and 4.50 ± 0.16 mg rutin equivalents per gram dry weight respectively. High performance Liquid Chromatography (HPLC) analysis of phenolics and flavonoids in 12 clones revealed the presence of (+)-catechin, (−)-epicatechin, (−)-epigallocatechin, (−)-epigallocatechin-gallate, (−)-epicatechingallate, gallic acid and caffeine. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay showed the existence of variation in the antioxidant activity ranging from 22.67 to 65.36%. The highest antioxidant activity with IC50 value of 218.24 μg/mL was observed in the leaf extract of the clone Iran 100, while the lowest was found in the clone Iran 482 with IC50 value of 234.44 μg/mL. The antioxidant activity had a positive correlation with total phenolic content, total flavonoid content, (−)-epigallocatechin-gallate, (−)-epicatechingallate and caffeine (0.59 ≤ r ≤ 0.97, P b 0.05). Conclusion: From the study it can be concluded that the clone Iran 100 has a superior quality compared to any other clones studied due to occurrence of more phenolic compounds and a greater antioxidant activity. Hence, we recommend the use of tea clone Iran 100 for commercial planting.

Yield decline in mechanically harvested clonal tea (Camellia sinensis (L) O. Kuntze) as influenced by changes in source/sink and radiation interception dynamics in the canopy

High labour costs and shortages and the cost of production has resulted in tea (Camellia sinensis (L) O. Kuntze) industries in central and southern Africa becoming unprofitable. This has led to the full mechanization of shoot harvesting, however, a reduction in yield has been observed with mechanical harvesting. It was hypothesized that the decline in yield as a result of mechanical harvesting is a result of the indiscriminate harvesting of shoots which leads to a change in sink/source and radiation interception dynamics within the canopy. As a result whole plant photosynthesis is impacted; which ultimately impacts tea bush productivity. Studies conducted at Tingamira estate, Chipinge, Zimbabwe showed significant yield differences between hand plucking and machine harvesting treatments, with higher yields under hand plucking across all seasons (43945kggreen leafha−1) as compared to hand-held (35114kggreen leafha−1) and ride-on machines (36268kg green leafha−1) (p<0.05). This reduction in yield was associated with a decrease in both the number and mass of desirable shoots over each season. The cause of this change was largely attributed to the indiscriminate removal of foliage by the machines which resulted in the proliferation of immature shoots, with an associated increase in sink strength and competition for available photo-assimilates. In addition, the depletion of the maintenance layer in mechanically harvested bushes, as indicated by reduced fractional interception of photosynthetically active radiation in the top 10cm in these bushes and reduced photosynthetic rates in these bushes, suggests that these bushes were also source limited, as compared to hand plucked bushes. Therefore the changes in tea bush architecture, as a result of mechanical harvesting, resulted in changes in sink/source dynamics which led to a proliferation of immature shoots which competed for limited photo-assimilates.

Fingerprinting 128 Chinese clonal tea cultivars using SSR markers provides new insights into their pedigree relationships

The improved clonal tea cultivars play a crucial role in the modern tea industry. In present study, we analyzed 128 elite clonal tea cultivars in China with 30 well-chosen simple sequence repeat (SSR) markers, aiming at (1) characterizing a set of DNA markers for unambiguously fingerprinting clonal tea cultivars and (2) confirming or identifying the parent-offspring (PO) relationships among them. The results showed that the markers are highly polymorphic among the tested cultivars with an average allele number of 10.4 per locus and an average polymorphic information content of 0.704. Robust fingerprinting power was demonstrated: It was possible to fully discriminate all 128 cultivars by a combination of four markers, and the overall possibility of finding two random individuals having the same genotypes across the 30 loci was estimated to be 4.8 × 10−33. Eight SSR loci were further recommended as a core marker set for fingerprinting the tea plant. Meanwhile, parentage analysis based on the fingerprint data revealed 47 pairs of putative PO relationships, among which 33 were in agreement with the known pedigree information, whereas the other 14 were newly identified in this study. The SSR markers and pedigree relationships reported here are valuable for tea cultivar identification and new breeding programs.

P.1.i.021 Improvement of well-being measures after regular physical exercise correlates with resting state connectivity in attentional and default mode networks

Tea (Camellia sinensis), a well-known beverage is consumed frequently worldwide due to its high antioxidant properties. The present study determines the amount of phytochemicals and antioxidant activities among 12 high yielding tea clones cultivated in Iran.Among the 12 clones studied, tea clone Iran 100 had the highest total phenolic content and total flavonoid content with values of 8.44 ± 1.03 mg gallic acid equivalents per gram dry weight and 4.50 ± 0.16 mg rutin equivalents per gram dry weight respectively. High performance Liquid Chromatography (HPLC) analysis of phenolics and flavonoids in 12 clones revealed the presence of (+)-catechin, (−)-epicatechin, (−)-epigallocatechin, (−)-epigallocatechin-gallate, (−)-epicatechingallate, gallic acid and caffeine. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay showed the existence of variation in the antioxidant activity ranging from 22.67 to 65.36%. The highest antioxidant activity with IC50 value of 218.24 μg/mL was observed in the leaf extract of the clone Iran 100, while the lowest was found in the clone Iran 482 with IC50 value of 234.44 μg/mL. The antioxidant activity had a positive correlation with total phenolic content, total flavonoid content, (−)-epigallocatechin-gallate, (−)-epicatechingallate and caffeine (0.59 ≤ r ≤ 0.97, P < 0.05).From the study it can be concluded that the clone Iran 100 has a superior quality compared to any other clones studied due to occurrence of more phenolic compounds and a greater antioxidant activity. Hence, we recommend the use of tea clone Iran 100 for commercial planting.