Genetic variability is one of the key factors for any crop species, which determines the success of its breeding program. Therefore, as a perennial crop, it is important for the tea breeder to estimate the genetic diversity and relationship in a cultivated gene pool to plan future cultivar improvement programs. In the current study, the genetic diversity and relationship of all the recommended tea cultivars of Sri Lanka were analyzed using 20 EST microsatellite or EST simple sequence repeats (EST-SSR) markers. A total of 161 alleles were amplified and the number of alleles per locus varied from 2 to 21 with an average of 8.05. The size of the alleles ranged from 92 to 439 bp. In genetic similarity-based cluster analysis, 64 tea cultivars were grouped into three major clusters, confirming the pedigree or parentage of most cultivars. Most importantly, the outcomes of the present study revealed narrow genetic diversity and the close genetic relationships of recommended tea cultivars, which might threaten the sustainability of the Sri Lankan tea industry. The information generated from this study on the genetic diversity and relationship of recommended tea cultivars in Sri Lanka would be of paramount importance to tea breeders as a platform to direct their breeding strategies towards the further improvement of tea cultivars in a sustainable manner.
Introduction
Materials and Methods