Heterologous nuclear and chloroplast microsatellite amplification and variation in tea,Camellia sinensis

Abstract

The advantage of the cross transferability of heterologous chloroplast and nuclear microsatellite primers was taken to detect polymorphism among 24 tea (Camellia sinensis (L.) O. Kuntze) genotypes, including both the assamica and the sinensis varieties. Primer information was obtained from the closely related Camellia japonica species for four nuclear microsatellites, and from Nicotiana tabaccum for seven universal chloroplast microsatellites. All of the nuclear microsatellite loci tested generated an expected DNA fragment in tea, revealing between three and five alleles per locus. Four out of the seven chloroplast microsatellites primers amplified positively, and of these only one was polymorphic with three alleles, which is in agreement with the conserved nature of chloroplast microsatellites at the intraspecific level. A factorial correspondence analysis carried out on all genotypes and nuclear microsatellite alleles separated the assamica and sinensis genotypes into two groups, thus demonstrating the value of these markers in establishing the genetic relationship between tea varieties. Genetic diversity measured with nuclear microsatellites was higher than that measured with other types of molecular markers, offering prospects for their use in fingerprinting, mapping, and population genetic studies, whereas polymorphisms detected at a cpSSR locus will allow the determination of plastid inheritance in the species. Key words: tea, Camellia sinensis, SSR, microsatellites, genetic diversity.