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Background: Camellia sinensis (L.) O. Kuntze (tea) belongs to the family of Theaceae and is one of the most popular beverages. According to traditional Chinese medicine, its phytochemicals have the ability to cure various diseases of the liver, heart, spleen, and lungs. This study was done to explore the phytochemical potentiality of leaf extracts from different tea clones with special emphasis on their antioxidant, total phenol, flavonoid, and antibacterial activity. Methods: The leaves were extracted in methanol for various qualitative, and quantitative tests like antioxidant assay, total phenolic content, flavonoid content etc. Results: The result of this study delivers comparative data about the biochemical properties of various tea clones which will further help in future studies. Leaves extract of tea clones like TV-9, TV-26, CP-1 and Phoobsering-312 showed promising antioxidant activity. Leaves extract of TV-9, TV-23, TV-26 and CP-1 has shown an inhibitory effect on the growth of Gram-negative bacteria Escherichia coli. Among the clones, Phoobsering-312 was found to be the most prominent tea clone as it exhibited total phenolic content, and antioxidant properties along with very significant antibacterial activity against Escherichia coli and Bacillus subtilis. Conclusion: This study showed the Darjeeling Garden clone (Phobsering-312) could be selected as an ideal clone for cultivation in the study area. This is to sustain the phytochemical quality of tea and gain health benefits, as the quality of manufactured tea is reflected in all aspects of the green harvest.

• EGC, caffeine, catechin, EC, EGCG, and ECG were isolated using HPLC at UPASI 3 and UPASI 17. • Phytochemical levels were relatively higher in UPASI 17 than in UPASI 3. • CHS, F3′5′H, ANS, DFR , and LAR expressions were upregulated in UPASI 17 compared with UPASI 3. • UPASI 17 treated cancer cells elevated the activation of caspase 3 enzyme more effectively than UPASI 3 for apoptosis. Genetically superior tea clones United Planters Association of Southern India (UPASI) 3 and UPASI 17 have been identified as prime candidates for chemo-profiling, assessment of antioxidant activity, and evaluation of anticancer properties against the human adenocarcinoma A549 cancer cell line. High-performance liquid chromatography (HPLC) analysis of UPASI 3 and UPASI 17 revealed the presence of caffeine and five catechins, including epicatechin-3-gallate, catechin, epicatechin, epigallocatechin gallate, and epicatechin gallate, with UPASI 17 exhibiting a higher total catechin content than UPASI 3. Comparative assays of antioxidant capacity and tea quality enzymes, such as total polyphenols, polyphenol oxidase (PPO), superoxide dismutase (SOD), catalase (CAT), phenylalanine ammonia-lyase (PAL), and peroxidase (POD), showed higher levels in UPASI 17 than in UPASI 3. Additionally, transcriptional analysis revealed upregulated expression of key flavonoid biosynthesis genes such as chalcone synthase (CHS), flavonoid 3′,5′-hydroxylase (F3′5′H), anthocyanidin synthase (ANS) dihydroflavonol 4-reductase (DFR) and leucoanthocyanidin 4-reductase (LAR) in UPASI 17 compared with UPASI 3. The anticancer potential of the methanolic extracts of these tea clones against the A549 cancer cell line was evaluated using MTT cytotoxicity assays, along with cell cycle, caspase activation, and mitochondrial membrane potential analyses. Notably, UPASI 17 significantly inhibited cancer cell viability at a concentration of 0.5 µg/ml within 36 h, induced cell cycle arrest in the S phase, and more effectively activated the caspase 3 enzyme to promote apoptosis than UPASI 3. Furthermore, exposure to UPASI 3 and UPASI 17 extracts triggered apoptosis in A549 cells through modulation of the PI3K-Akt-mTOR signalling pathway. The enhanced anticancer activity of UPASI 17 was attributed to its high concentration of phytocompounds and its antioxidant activities. These findings underscore the potential for further molecular-level research and animal studies to develop novel anticancer drugs that target lethal diseases. [Display omitted] [ABSTRACT FROM AUTHOR]

Topworking method of grafting has immense practical applications in reducing the excessive time consumption in conventional breeding programs in tea (Camellia sinensis (L.) O. Kuntze). Hence, the present study was designed to know the influence of grafting time on growth and flowering in topworked scions. Scions from the clone TRF-4 were used for topworking on the field-grown plants of the clone UPASI-9. Topworking was performed during winter (January), pre-monsoon (May), and post-monsoon (September) seasons. The graft success rate was assessed 1 month after grafting. Twelve months after grafting, vigor of the topworked scions was evaluated by measuring length, number, and diameter of branches. Further assessments were carried out on the onset of flowering, length of the flowering period, and the number of flowers per scion during the flowering season. The results showed that the graft success rate, growth, and early onset of flowering were higher when topworking was done in May and September rather than in January. However, the flowering duration and number of flowers were significantly lower in the scions grafted in September. Therefore, topworking of suitable scions in May seems to be appropriate for attaining improved graft survival rate, early flowering onset, a higher number of flowers, and longer flowering duration in tea. [ABSTRACT FROM AUTHOR]

Grafting of fresh cuttings using drought-susceptible and low-yielding clones as scions on drought-tolerant clones as rootstocks offers the possibility of raising composite plants with improved productivity and drought tolerance. Hence, the study was aimed to widen the choice of compatible composites and to delineate the underlying factors responsible for productivity and drought tolerance in grafted plants. One year-old composite plants of TRF-1, TRF-2 and UPASI-28 cleft-grafted on the rootstocks of UPASI-2, UPASI-9, ATK-1 and TRI-2025 were field planted along with their respective controls and evaluated. The results indicated that productivity and drought tolerance of scion clones varied significantly with the rootstocks used. Significant increases in yield and yield components were noted in the following graft combinations compared with their corresponding self-rooted scion clones: TRF-1 grafted on UPASI-9 and ATK-1, TRF-2 grafted on all four rootstocks, and UPASI-28 grafted on UPASI-9, TRI-2025 and UPASI-2. The findings clearly emphasize the scion–rootstock interaction as the critical determinant of productivity in grafted plants compared with vigour, drought tolerance and yield potential of scion and rootstock clones. Further, high-yielding capacity of grafts over the ungrafted scions and rootstocks was largely dependent on the yield potential of the scion clone and the degree of scion–rootstock compatibility. Higher field survival and enhanced yield observed during the drought period in the compatible grafts demonstrated their better drought tolerance compared with their respective self-rooted scions. [ABSTRACT FROM AUTHOR]

To study the impact of the top working method of grafting on flowering behavior in tea clones and its applicability in tea breeding two field experiments were carried out. Field established plants of the clone UPASI-9 was used as the rootstock in both the experiments. Recently released clones TRF-1, TRF-3 and TRF-4 were used as scions to study the influence of top working on flowering. One-year-old rooted plants of the clones used as scions field planted in the same year served as standards for comparison. Precocious flowering was noticed in all the top worked clones by eight months from grafting. In self- rooted plants of the scion clones only sparse flowering was noticed after eighteen/nineteen months. Similarly, the duration of flowering and total number of flowers were significantly higher in top worked plants compared to self-rooted plants. The top worked scions were significantly more vigorous than the corresponding self-rooted plants, except TRF-3. In the second experiment by top working the scions of two different clones on the same rootstock; four sets of combinations were tried. The clone TRF-4 was used as one scion in all the four sets and the clones TRF-1, SA-6, Yabukita and SMP-1 served as the other scions in each set. Early flowering as well as synchronization of flowering was observed in both the scion clones in three of the tested pairs. However, the growth and flowering of the common scion clone TRF-4 varied significantly in each set depending on the other clone used as a scion. [ABSTRACT FROM AUTHOR]

There are many clones grown in Indonesia tea plantations. The latest clones were released around 1990. The new promising clones have been bred through crossing among selected clones in Pagilaran tea plantation. The experiment aimed to select high yield and stable clone. Nine clones were grown in Kayulandak (1300 m asl) and Andongsili (1100 m asl) in Randomized Completely Block Design with three replications. The data of fresh weight per plot in 2007, 2008, 2009, 2011, 2012 were recorded. Eberhart & Russell (1966) and GGE Biplot analysis method was applied for data analyzing. The result showed that all of clones were stable over years in each location except for PGL1 and PGL3 in Andongsili and PGL15 in Kayulandak based on Eberhart & Russell analysis. Significant regression coefficient (1.18) of PGL3 implied that PGL3 was high in yield and responsive. GGE biplot analysis indicated no ideal genotype for each location. PGL10, PGL3, PGL4 and PGL 12 were recommended for Kayulandak, while PGL3 and PGL12 clones were suitable for Andongsili. Both analysis of Eberhart & Russell and GGE biplot showed PGL3 and PGL12 as ideal clone, while PGL10, PGL4, and PGL 15 clone were desireable clones.

This experiment was carried out to diagnose the qualities of green tea from Nigeria using some quality markers like crude fibre, water extracts, total ash, caffeine and moisture contents respectively. Green Tea was processed from seven different tea clones from Mambilla Highland located on 1840m above mean sea level. The clonal materials used were processed into green tea using chinese methods viz: Plucking, Fixing (Pan firing), Rolling and Drying. The green tea produced were analyzed for moisture contents, (MC); crude Fibre, (CF).; Water Extract, (WE).; Total Ash, (TA).; Water Soluble Ash, (WSA).; Alkaline Insoluble Ash, (ALIA) and Acid Insoluble Ash, (AIA). The quality of the green tea produced was compared to the recommended ISO standard for Tea. Our findings showed that there were significant differences (p<0.05) in the chemical components studied as a result of clonal variations which made the quality characteristics of the green tea to vary accordingly. The WE, of all the green tea examined except sample made from clone 236 were within values recommended for good quality green tea as speculated by ISO 3720, % MC was between 4.11-12.5% with average value being 10.2%. The High MC recorded was due to the high humidity of the processing environment where sunlight was inadequate The percentage CF ranged between 4.37-20.8%, the ALIA, 0.90-1.30, TA, 4.2-6.5%, WSA, 50-67% and WE 21.743.6% and the caffeine contents were within 1.29-2.56%. In conclusion, quality of green tea produced in Nigeria has comparable quality characteristics with other tea producing countries of the world and conformed to international standard for green tea. [ABSTRACT FROM AUTHOR]

Abstract: The effects of drip irrigation on the yield and crop water productivity responses of four tea (Camellia sinensis (L.) O. Kuntze) clones were studied four consecutive years (2003/2004–2006/2007), in a large (9ha) field experiment comprising of six drip irrigation treatments (labelled: I 1–I 6) and four clones (TRFCA PC81, AHP S15/10, BBK35 and BBT207) planted at a spacing of 1.20m×0.60m at Kibena Tea Limited (KTL), Njombe in the Southern Tanzania in a situation of limited water availability. Each clone×drip irrigation treatment combination was replicated six times in a completely randomized design with 144 net plots each with an area of 72m2. Clone TRFCA PC81 gave the highest yields (range: 5920–6850kg dried tea ha−1) followed by clones BBT207 (5010–5940kg dried tea ha−1), AHP S15/10 (4230–5450kg dried tea ha−1) and BBK35 (3410–4390kg dried tea ha−1) and drip irrigation treatment I 2 gave the highest yields, ranging from 4954 to 6072kg dried tea ha−1) compared with those from other treatments (4113–5868kg dried tea ha−1). Most of these yields exceeded those (4200kg dried tea ha−1) obtained from overhead sprinkler irrigation system in Mufindi also Southern Tanzania, and Kibena Estate itself. Results showed that drip irrigation of tea not only increased yields but also gave water saving benefits of up to 50% from application of 50% less water to remove the cumulative soil water deficit (treatment I 2), and with labour saving of 85% for irrigation. The yield of dried tea per mm depth of water applied, i.e., “the crop water productivity” for drip irrigation of clones TRFCA PC81, BBT207 and BBK35, in 2003/2004 for instance, were 9.3, 8.5 and 7.1kg dried tea [hamm]−1, respectively. The corresponding values in 2004/2005 were 2.7, 4.5 and 2.0kg dried tea [ha mm]−1 while the yield responses from clone AHP S15/10 were linear decreasing by 1 and 1.6kg dried tea [hamm]−1 in 2003/2004 and 2004/2005, respectively. In 2005/2006 the crop water productivity from clones TRFCA PC81, AHP S15/10, BBK35 and BBT207 were 4.5, 0.4, 5.2 and 6.9kg dried tea [hamm]−1, respectively with quadratic yield response functions to drip irrigation depth of water application. The results are presented and recommendations and implications made for technology-transfer scaling-up for increased use by large and smallholder tea growers. [Copyright &y& Elsevier]

Abstract: Five tea clones of the Camellia assamica variety grown in Wushwush tea plantation farms, Ethiopia, were analyzed for their contents of essential, non-essential and toxic metals (K, Ca, Mg, Fe, Mn, Cu, Zn, Na, Cd and Pb) by atomic absorption flame emission spectroscopy. Both the tea leaves and the soils of the study farms showed similar accumulation patterns in their contents of the studied macronutrients. Among the macronutrient metals, K was the most abundant element in the tea leaves (17.7–24.8mg/g) and the soils (7.14–9.73mg/g). Mn was the predominant micronutrient heavy metal in the tea leaf tissues ranging between 501 and 1281mg/kg. Level of Fe (29.6–100mg/kg) in the leaf tissue was found to be the second most abundant micronutrient next to Mn whereas concentrations of Cu and Co were relatively lower both in the soil and tea samples. The toxic heavy metals Pb and Cd in the leaf tissues were present at levels too low to be detected by the analytical technique used in this study. The soils were found to be acidic (pH 5.04–5.49) with high organic matter (5.48–6.02%). Fe was the most abundant metal followed by Mn, Na and Zn in the soils. Unlike the tea leaves, the soils were found to contain traces of the toxic metal, Cd (0.02–1.10mg/kg). The levels of most of the metals determined in this study compared well with those reported for tea leaves from some other parts of the world. [Copyright &y& Elsevier]

Abstract: Tea is an important cash crop in Tanzania, contributing over US$45million of annual exports and grown by over 30000 smallholder households, and a further 10000 people are employed by large estate producers. Over 70% of the national tea production comes from the Southern Highlands of Tanzania where expansion of tea estates under limited suitable land for tea is expected for the next two decades. Thus a client-demand driven field experiment was established in January 1993 to study and advice tea growers on the effects of plant density on the productivity and water use of young tea. The experiment comprised of two types of vegetative propagated tea plants (known as “clones”) of contrasting growth behaviour (AHP S15/10: spreading type and BBK35: erect), six plant densities (labelled D 1: 8300plantsha−1 to D 6: 83300plantsha−1) and seven irrigation or drought levels (labelled I 0: un irrigated, to I 6: well irrigated condition) as the treatments. Clone AHP S15/10, with larger crop cover than clone BBK35, consistently out-yielded clone BBK35 at all densities and under both well watered and drought stressed conditions. The corresponding yields from clone BBK35 were 2620 and 5960kgha−1. Reciprocal of yield per plant- and asymptotic yield–density relationships were used to explain these responses to density. Yields from clone AHP S15/10 during the period of drought treatments decreased as the maximum soil water deficit increased at all densities, but there were no yield responses to drought from clone BBK35 at the low densities. The study recommends planting densities of 20000 and 40000plantsha−1 for clones AHP S15/10, respectively for well irrigated conditions and a density of 20000plantsha−1 for both clones under un-irrigated environments. [Copyright &y& Elsevier]