PHYSIOLOGICAL AND BIOCHEMICAL BASIS OF CLONAL SECTION IN TEA Conventionally, promising traits were selected on the basis of morphological characters and yield potential of a particular accession which needs man power and has prolonged gestation period. Recently, physiological and biochemical markers have been employed in clonal identification. Based on the data generated, a multiple regression model was formulated and validated to predict the productivity of the seedlings planted in tea gardens. The origin and parentage of these seedling populations was not known. On the basis of green leaf constituents, a regression model was developed to predict the quality constituents of black tea. Similarly, data based on stress related parameters were prepared and correlated individually with yield for screening the productivity under soil moisture stress. Out of 254 mother bushes selected from the estates, 83 were identified as productive plants with good quality and high yielding capacity besides a few accessions performed well during soil moisture stress. Field evaluation of the selectively planted germplasm is in progress.

CATECHIN BIOSYNTHESIS PATHWAY IN TEA Among the tea polyphenols, catechins gained importance in recent years because of their antioxidant potential. In view of importance of catechins, biochemical characterization and influence of environmental, edaphic and agronomic practices in catechin biosynthesis were envisaged. Tea clones were characterized on the basis of catechins and their fractions. According to the principle component analysis, UPASI clones were segregated into five distinct groups. Segregation of these clones was on the basis of ratio between dihydroxylated to trihydroxylated catechins. Substrate specific catechin biosynthesis was confirmed with radio labelled isotopes. Abiotic factors and agronomic practices played an important role in catechin biosynthesis. To generate data on the factors influencing catechin biosynthesis in tea a number of experiments were conducted and the generated results were documented.

GERMPLASM CHARACTERIZATION AND FIELD EVALUATION OF IN VITRO DERIVED TEA PLANTS Under the auspices of DBT funded project, “Improvement of tea through biotechnological tools” complete characterization of existing clones using physiological, biochemical and molecular tools and in vitro propagation and field establishment of superior clones had been studied. So far, one hundred and fifty tea accessions including UPASI released clones and selections from the germplasm collections were used for characterization. Generated data were documented as per the requirement of National Bureau of Plant Genetics Resources (NBPGR), New Delhi. Molecular characterization has been initiated using RAPD and ISSR for the development of molecular markers for desired traits and to assess the genetic diversity among the south Indian germplasm. In vitro derived tea plants were planted in the field.

Clonal propagation of plants in laboratory ( Growth stages )
	ADVANTAGES Propagation of elite cultivars ( Irrespective of origin & age ) Mass multiplication Storage Germplasm collection