Abstract:
Characterization of germplasm is an important initial step towards proper utilization of
genetic resources in plant breeding programs. Tea germplasm accessions, especially the
“estate selections”, which originating; from old seedling tea populations in various tea
estates have not been adequately studied to maximize its utilization in tea breeding
programs. Hence, present study aimed at assessing the phenotypic variation of
germplasm originating from old seedling tea populations adapted in various agro ecological regions in Sri Lanka through a multivariate statistical analysis. A
representative sample of 62 “estate selections” originating from 9 agro ecological
regions of the country were scored using six highly discriminating morphological
descriptors identified in a previous study. Principle Component Analysis (PCA) and
cluster analysis based on first 4 principle component (PCs), which accounted for about
83% of the total phenotypic variation, delineate 62 estate selections accessions into 6
major groups. However, the phenotypic diversity among the members between groups
were revealed as marginal and hence', the agro-ecological isolation of the seedling tea
populations on various tea plantations did not contribute to the phenotypic variation
among the old seedling tea populations in the country. The study also enabled
identification of useful morphological traits that are decisive in distinguishes estates
selections that fall into individual groups. The exceptional morphological descriptors
identified in this study would facilitate cultivar identification, which has become one of
most demanding needs among tea growers. The results generated also lay a proper base
for more advanced characterization studies using molecular makers in order to
assemble a core collection in tea to facilitate utilization and managerial aspects of tea
germplasm.
