An assessment of genetic diversity among Camellia sinensis L. (cultivated tea) and its wild relatives based on randomly amplified polymorphic DNA and organelle-specific STS.

Abstract

Members of the genus Camellia interbreed relatively freely and several natural species hybrids exist. Species introgression into the cultivated germplasm of tea, Camellia sinensis L. (O. Kuntz), from related Camellia species has been postulated, and it is thought that teas currently under cultivation are not archetypal varieties. Randomly amplified polymorphic DNAs (RAPDs) and organelle-specific polymerase chain reactions were used to establish the affinities among cultivated tea and its wild relatives. The measures of similarity obtained indicated that RAPDs were taxonomically informative in Camellia, and the species relationships revealed were generally consistent with those obtained using morphological, compatibility and terpenoid affinities. Species-specific RAPD products and products potentially diagnostic of introgressive hybridization into the cultivated gene pool were identified. The organellar genomes were remarkably conserved, with polymorphism detected in only one of four noncoding regions in the chloroplast and mitochondrial genomes.