(International Society of Tea Science (ISTS), 2006) Singh, I.D.; Jain, N.K.
The early efforts by tea breeders in India for selecting candidate tea clones from natural variability existing in seed-grown plantations are reviewed. The procedures and criteria in selecting elite clones are described. The genetical and morphological differences between seed and clonal plantations and their complementarity as planting materials are highlighted. The need to conserve valuable tea germplasm present in existing old seed-grown plantations is suggested. The danger of genetic vulnerability of new clonal plantations using few popular clones which is resulting into narrowing of their genetic base, is highlighted.
(International Society of Tea Science (ISTS), 2006) Mishra, J.; Nandi, S.K.; Palni, L.M.S.; Jain, N.K.
Tea [Camellia sinensis (L) 0. Kuntze] is the oldest non-alcoholic caffeine containing beverage crop, belonging to the genus Camellia (family Theaceae). India is the foremost producer, and after Sri Lanka and China, it is the third largest exporter of commercial tea in the world (Anonymous 2000). The ever-increasing demand for higher productivity and better quality of tea has resulted in the need for mass multiplication of elite clones. Tea is propagated largely through seeds or cuttings, but a major concern associated with seed raised populations has been the occurrence of high genetic variability.
(International Society of Tea Science (ISTS), 2006) Htay, H.H.; Kawai, M.; MacNaughton, L.E.; Katsuda, M.; Juneja, L.R.; Jain, N.K.
Eating habit of fermented wet green tea leaves (Pickled tea) in Myanmar and its culture, history, production, processing and health benefits are reported in this paper, together with drinking green tea and black tea. Types of tea plants found in Myanmar, include the indigenous species Camellia irrawadiensis. The antioxidant effects of Myanmar tea were determined for 3-minutes and 30-minutes infusion. The latter infusion is Myanmar's way of drinking tea and has 3 times higher antioxidant activity than 3-minute infusion. Antioxidant activity of green tea is higher than black tea and pickled tea in both 3 min and 30 min infusions. This is the first report on the antioxidant properties of Myanmar tea, which needs to be studied further.
(International Society of Tea Science (ISTS), 2006) Ghosh, J.J.; George, U.; Barpujari, N.; Jain, N.K.
Available sulphur was determined on 5077 soils from the tea growing areas of Dooars (North Bengal), received for routine soil testing between 2000-2003. Over 43% of the soils had more than the critical limit of 40 ppm available sulphur. A distinct geographical trend in sulphur availability was observed, with the four western sub-districts showing a greater frequency of
high available sulphur than the three eastern sub-districts. As expected, increased organic carbon in the soils could be correlated by a quadratic equation to the available sulphur status. Three sub-districts, Chulsa, Binnaguri and Dalgaon did not show a high correlation between organic carbon and available sulphur. Surprisingly, a negative linear relationship could be observed between soil pH and available sulphur, in all but the Jainti sub-district. This may be compounded by a negative correlation between soil pH and organic carbon status, in all but the Binnaguri, Kalchini and Jainti sub-districts.
(International Society of Tea Science (ISTS), 2006) Choudhury, P.; Dutta, B.K.; Bhattacharjee, P.C.; Jain, N.K.
Mites are serious pests of tea known since the early days in all the tea growing area countries. They damage the green tissues and affect photosynthesis, causing reduction in yield. In the present study, varied severity of damage caused by Red Spider Mite (Oligonychus coffeae, Nietner) was observed in different tea growing sub areas of Barak Valley, south Assam. The pest population was found to be seasonally variable and dependent on the prevailing agroclimatic conditions (viz. temperature, rainfall etc.). Some of the clonal tea varieties were highly susceptible to red spider mite, some were moderate and others were fairly resistant. Amongst the inorganic pesticides, a mixture of Ethion & Sulfex controlled the pest reasonably well. Of the organic pesticides, the neem-based products showed good control of the pest. A
mixture of a neem based product (viz. Neemox) and Ethion gave an excellent control of the mite. Prophylactic sprays with organic and inorganic chemicals during the winter months (December - February) helped to considerably reduce the carried-over population of red spider mite, and consequently reduced the degree of infestation in the subsequent years.
(International Society of Tea Science (ISTS), 2006) Bhattacharya, Amita; Saini, U.; Ahuja, P.S.; Jain, N.K.
Like most of the important crop plants of the world, transgenic technology has also been extended to tea. Both biolistic and Agrobacterium mediated transformation methods have been employed to transform explants like leaves and somatic embryos. While gusand nptil genes were used to optimize parameters and develop protocols for transgenic production, plants expressing stress tolerance genes (osmotin) have also been produced. These methods have opened a whole new era for developing tea plants akin to the 'golden clone' of tea where yield and quality parameters can be combined to conform to the requirements of the tea industry.
(International Society of Tea Science (ISTS), 2006) Nyirenda, H.E.; Mpangwe, N.I.K.; Jain, N.K.; Apostolides, Zeno
Historically tea seeds were imported into Southern Africa that belonged to either the sinensis or assamica varieties. Later on vegetatively propagated hybrid cultivars selected from F, progeny raised from a deliberate hybridization programme between selected parents with desirable characteristics on the basis of quality and yield related parameters have been used in establishing tea plantations. New high throughput screening methods including biochemical and molecular markers are being investigated to improve the selection process and eliminate genotypes with poor quality potential before the expensive mini manufacture stage. A call is made for the establishment of a Global Tea Research Project to address common problems.
(International Society of Tea Science (ISTS), 2006) Sharma, S.; Raina, S.N.; Jain, N.K.
Resultant of large-scale spontaneous hybridization between Camellia taxa, the present day commercial tea clones are highly variable and heterozygous. It is in this context that thirty two UPASl and other tea clones were investigated with regard to comparative karyomorphology and meiotic pairing properties so as to ascertain the nature and extent of intra - and interclonal differentiation. Barring one clone (UPASI 3), all other investigated clones were diploid (2n = 2x = 30) in constitution. UPASl3 was triploid (2n = 3x = 45) in constitution. The chromosome complements in the diploid tea clones, wherever investigated, resolved into 15 median and submedian homomorphic pairs. Between clones, minor variation in the proportion of median and submedian chromosomes and (or) number and location of secondary constrictions was observed. lnspite of the fact that tea clones are considered to be highly heterozygous, the male meiosis in the diploid clones was perfectly normal resulting in regular 15 bivalents at diakinesislmetaphase I, and equal (1 5:15) distribution of chromosomes at anaphase I. The only feature which could indicate degree of cryptic hybridity was the occurrence of bivalents with localized chiasmata. The predominant occurrence of trivalents in the triploid UPASI 3 indicated either autopolyploid or segmental allopolyploid origin. The genomic constitution of tea clones is discussed in the light of present results.
(International Society of Tea Science (ISTS), 2006) Yong-Xing, Z.H.U.
Tea was first used as medicine during the reign of "Emperor Shengnong" in ancient China. The period of more than 4000 years' of Chinese tea medication can be divided in 3 stages of development. In this paper we briefly discuss the history of medicinal uses of tea in China, review the stages of development, and focus upon the modern achievements. The trend and future direction in tea medical study in China are also briefly discussed.
(International Society of Tea Science (ISTS), 2006) Bag, N.; Palni, L.M.S.; Nandi, S.K.; Jain, N.K.
The application of tissue culture techniques for rapid and clonal mass propagation and improvement of tea is well known. While several laboratories have successfully developed in vitro propagation protocols, the use of this technology for mass multiplication of tea at commercial level is still limited largely due to difficulty in the quality of rooting of microshoots, and problems associated with subsequent hardening and field establishment. The present study reports a reproducible protocol for 100% rooting of in vitro propagated tea microshoots using a two-step method. This involves culture of microshoots on IBA (indole-3-butyric acid; 175.0 pM) containing Murashige and Skoog (1962; MS) medium for 10 days followed by transfer to 113 strength MS medium without any plant growth regulator. Besides the concentration of IBA, the period of exposure of microshoots to IBA containing medium (prior to transfer to PGR-free medium) also played a significant role in rooting. In addition, the culture temperature was found to be quite important; for maximum rooting response the optimum temperature range was 25-30°C.
(International Society of Tea Science (ISTS), 2006) Tripathi, S.B.; Negi, M.S.; Jain, N.K.
Tea (Camellia sinensis [L.] 0. Kuntze) is one of the
most common non-alcoholic beverages of the world used since ancient times. lndia is the largest producer and exporter of processed tea with over 30% share in global tea production. Thus, tea holds a key position in Indian economy generating over
660 million US dollars of foreign exchange annually.
